WO2017073476A1

WO2017073476A1 - Milk-containing beverage production method

Info

Publication number: WO2017073476A1
Application number: PCT/JP2016/081252
Authority: WO
Inventors: 尭長田; 淳平斎藤
Original assignee: 株式会社明治
Priority date: 2015-10-26
Filing date: 2016-10-21
Publication date: 2017-05-04
Also published as: JP2017118886A; SG11201803326WA; JP6129463B1; CN108135221A; JPWO2017073476A1; HK1248471A1; JP6892310B2

Abstract

A method of producing a milk-containing beverage is provided which can effectively suppress foaming in the raw milk occurring in the production process while greatly reducing the dissolved oxygen concentration of the milk-containing beverage. This milk-containing beverage production method involves: (A) a first oxygen concentration reduction step in which the supply method and supply conditions in an inert gas treatment are controlled, the raw milk is subjected to the inert gas treatment such that the foam ratio of the raw milk is less than or equal to 10%, and thereafter, the raw milk is discharged to obtain raw milk with a reduced dissolved oxygen concentration; (B) a second oxygen concentration reduction step in which the supply method and supply conditions in an inert gas treatment are controlled, the raw milk obtained in step (A) is subjected to inert gas treatment such that the foam ratio of the raw milk is less than or equal to 10% to obtain raw milk with reduced dissolved oxygen concentration; and (C) a heating sterilization step for heat-sterilizing the raw milk obtained in the step (B).

Description

Method for producing milk-containing beverage

The present invention relates to a method for producing a milk-containing beverage.

As a conventional technique, a method for improving the flavor and quality of milk by reducing the dissolved oxygen concentration is known. For example, in Patent Document 1, milk or an unheated liquid containing milk is replaced with an inert gas such as nitrogen gas before heat treatment, and heat treatment is performed in a state where dissolved oxygen in the liquid is reduced to 5 ppm or less. A method for producing a beverage having a flavor similar to raw milk or unheated liquid that suppresses generation of dimethyl disulfide due to heating is described.

Patent Document 2 describes a means for directly mixing and dispersing nitrogen gas in milk and the like, and milk and the like in which nitrogen gas is not mixed and dispersed, and nitrogen gas stored in a nitrogen gas replacement tank in a nitrogen gas atmosphere. In combination with a means of spraying with a nozzle from above, the amount of dissolved oxygen such as milk is reduced by substitution with dissolved oxygen and nitrogen gas, and then sterilized, such as milk A method of disinfecting dissolved oxygen with nitrogen gas is described. Further, in Patent Document 2, a nitrogen gas replacement tank connected to a raw material tank and a liquid supply pipe is provided, a nitrogen gas supply means is connected to the raw material tank side of the liquid supply pipe, and nitrogen gas replacement of the liquid supply pipe is performed. A nitrogen gas mixing / dispersing machine is installed on the tank side, a branch liquid feeding pipe leading from the raw material tank side into the nitrogen gas replacement tank is installed on the branch gas feeding means rather than the nitrogen gas supply means connected to the liquid feeding pipe. Milk or the like, characterized in that a spray nozzle is connected to the tip of the liquid pipe in the nitrogen gas replacement tank, and each liquid feed pipe, nitrogen gas supply means, and branch liquid feed pipe are provided with a flow rate control device. An apparatus for replacing the dissolved oxygen with nitrogen gas is described.

Patent Document 3 describes a method for maintaining freshness of stored raw milk, wherein nitrogen gas is passed through the stored raw milk and the raw milk is agitated. Specifically, in the case of a storage tank with a scale of 100 tons, nitrogen gas is aerated at a rate of 100 to 300 liters per minute at a pressure of about 2 to 3 kg / cm ² and stored in a standard state for stored raw milk. Of raw milk is described.

JP-A-10-295341 JP 2001-078665 A JP 05-049395 A

When producing a milk-containing beverage having a fresh flavor, in order to greatly reduce the dissolved oxygen concentration of the milk-containing beverage, for example, the supply amount of an inert gas such as nitrogen gas mixed with the milk-containing beverage is increased. It is necessary to replace the dissolved oxygen in the contained beverage with a large amount of inert gas. However, at this time, a large amount of inert gas that is a gas is brought into contact with the milk-containing beverage that is a liquid, and thus excessive foaming is likely to occur in the milk-containing beverage. Moreover, when the milk-containing drink in which excessive foaming generate | occur | produced is indirectly heat-sterilized with a plate-type heat sterilizer etc., it will become easy to generate | occur | produce the burning derived from foaming in the inner surface of a plate. This scoring causes a decrease in the thermal conductivity during heating, and therefore the heating medium temperature must be raised to normal to heat it to a constant temperature, and the plate is washed or replaced more frequently than usual. However, there are problems such as a decrease in overall production efficiency and an increase in manufacturing costs due to equipment renewal.

The object of the present invention is to produce a milk-containing beverage having a fresh flavor, while effectively reducing the dissolved oxygen concentration of the milk-containing beverage and effectively suppressing the foaming of the milk-containing beverage generated during the production process. And it is providing the manufacturing method of a milk-containing drink whose production efficiency does not fall.

As a result of intensive studies to solve the above problems, the present inventors have
(A) Inert gas processing supply method (for example, processing using a proportional mixing device) and supply conditions (for example, the supply speed of raw milk and the supply amount of inert gas) are controlled, After the inert gas treatment is performed on the raw milk so that the bubble rate of the raw milk becomes a specific numerical value or less at the time of storage, the raw milk is discharged to reduce the dissolved oxygen concentration. A first oxygen concentration reduction step for obtaining milk;
(B) First oxygen concentration reduction by controlling the supply method (for example, processing using a proportional mixing device) and supply conditions (for example, the supply speed of raw milk and the supply amount of inert gas) of the inert gas treatment The raw material milk is treated with an inert gas so that the bubble rate of the raw material milk obtained in the process (that is, the raw material milk sent after finishing the first oxygen concentration reduction step) becomes a specific numerical value or less. A second oxygen concentration reduction step;
(C) a heat sterilization step for heat sterilizing the raw material milk obtained in the second oxygen concentration reduction step,
The present invention has been completed by finding that the above-described problems can be solved by the method for producing a milk-containing beverage containing

The present invention provides the following [1] to [5].
[1] (A) After controlling the supply method and supply conditions of the inert gas treatment, and performing the inert gas treatment on the raw milk so that the bubble rate of the raw milk is 10% or less, the above A first oxygen concentration reduction step for discharging raw milk and obtaining raw milk with reduced dissolved oxygen concentration;
(B) The inert gas treatment is performed on the raw milk so that the supply method and supply conditions of the inert gas treatment are controlled and the bubble rate of the raw milk obtained in the first oxygen concentration reduction step is 10% or less. And a second oxygen concentration reduction step for obtaining raw milk with reduced dissolved oxygen concentration,
(C) a heat sterilization step for heat sterilizing the raw material milk obtained in the second oxygen concentration reduction step,
A method for producing a milk-containing beverage comprising
[2] The method for producing a milk-containing beverage according to [1] above, wherein raw milk of 8 ppm or less is obtained in the first oxygen concentration reduction step.
[3] The method for producing a milk-containing beverage according to the above [1] or [2], wherein raw milk of 1 ppm or less is obtained in the second oxygen concentration reduction step.
[4] A supply method of the inert gas treatment in each of the first oxygen concentration reduction step and the second oxygen concentration reduction step is as follows:
(A) mixing raw milk and inert gas using a proportional mixing device;
(B) spraying raw milk into a device (for example, a tank) having a space filled with an inert gas;
(C) Mixing raw milk and inert gas using a centrifuge (separator type centrifuge),
(D) mixing raw milk and inert gas using a pump;
(E) Blowing inert gas into the raw milk contained in the apparatus (for example, tank) (bubbling),
The method for producing a milk-containing beverage according to any one of [1] to [3], wherein the method is performed by one or a combination of two or more selected from among the above.
[5] In at least one of the first oxygen concentration reduction step and the second oxygen concentration reduction step, the supply method of the inert gas treatment is (a) raw milk and inert gas using a proportional mixing device, Mixing,
In mixing raw material milk and inert gas using the proportional mixing device of (a), the supply rate of inert gas relative to the supply rate of supply of raw material milk (supply amount per unit time) (supply amount per unit time) ) Volume ratio (inert gas supply amount (volume) / raw milk supply amount (volume) × 100) is 5 to 70%, the method for producing a milk-containing beverage according to the above [4].

According to the present invention, a milk-containing beverage having a fresh flavor with a greatly reduced dissolved oxygen concentration can be obtained. In addition, according to the present invention, while greatly reducing the dissolved oxygen concentration of the milk-containing beverage, the foaming of the milk-containing beverage that occurs during the production process is effectively suppressed, and the defoaming process during or after production Thus, it is possible to suppress or prevent a decrease in the production efficiency by eliminating the process.

The present invention
(A) The supply method and supply conditions of the inert gas treatment are controlled, and the raw material milk is inert so that the foam rate of the raw material milk is 10% or less before and / or during the storage of the raw material milk. After performing the gas treatment, a first oxygen concentration reduction step (hereinafter referred to as “step (A)”) for discharging the raw milk and obtaining raw milk with a reduced dissolved oxygen concentration;
(B) The inert gas treatment is performed on the raw milk so that the supply method and supply conditions of the inert gas treatment are controlled and the bubble rate of the raw milk obtained in the first oxygen concentration reduction step is 10% or less. A second oxygen concentration reduction step (hereinafter referred to as “step (B)”) to obtain raw milk with reduced dissolved oxygen concentration,
(C) a heat sterilization step (hereinafter referred to as “step (C)”) for heat sterilizing the raw material milk obtained in the second oxygen concentration reduction step;
It is a manufacturing method of the milk-containing drink containing this.

Hereinafter, each process will be described in detail.

[Step (A): First oxygen concentration reduction step]
Step (A) controls the supply method (for example, processing using a proportional mixing device) and supply conditions (for example, the supply speed of raw milk and the supply amount of inert gas) of the inert gas treatment, Before the storage and / or during storage, the raw milk is treated with an inert gas so that the bubble rate of the raw milk is 10% or less, and then the raw milk is discharged to reduce the dissolved oxygen concentration. This is a first oxygen concentration reduction step for obtaining raw milk.

The raw milk of the present invention refers to a milk-containing beverage before heat treatment such as unheated raw milk. At this time, the raw material milk of the present invention may be in a liquid form that can be treated with an inert gas. For example, animal milk such as cow, goat, sheep milk (sheep milk), etc. ), Processed milk products (for example, skim milk, partially skim milk, skim concentrated milk, partially skim concentrated milk, ingredient-adjusted milk, cream, butter milk, etc., liquid skim milk, skim milk powder, partially skimmed milk powder, butter , Fermented milk, processed milk products reduced to cheese, etc.), plant milk such as soy milk, coconut milk, processed milk products (processed milk products reduced to liquid), artificial milk (edible oils, water, emulsifiers Etc. are mixed to obtain an oil-in-water emulsion, and a liquid milk processed product). The raw milk of the present invention may contain raw materials other than milk, for example, coffee, tea, green tea, matcha tea, mate tea, fruit juice, vegetable juice, sweetener, sour agent, vitamin, mineral, function Any liquid form may be used as long as the material is added. Examples of the inert gas of the present invention include nitrogen gas, argon gas, helium gas, and the like.

The dissolved oxygen concentration (upper limit value) of the raw material milk obtained in the first oxygen concentration reduction step of step (A) is preferably 8 ppm or less, more preferably 6 ppm or less, further preferably 4 ppm or less, more preferably 3 ppm or less. More preferably, it is 2 ppm or less. If the dissolved oxygen concentration of the raw milk obtained in the first oxygen concentration reduction step of step (A) is 8 ppm or less, the dissolved oxygen concentration of the milk-containing beverage in the second oxygen concentration reduction step of step (B) It is preferable in that the foaming of the milk-containing beverage generated during the production process can be effectively suppressed and the present invention can be easily implemented.

The lower limit value of the dissolved oxygen concentration of the raw material milk obtained in the first oxygen concentration reduction step of the step (A) is not particularly limited, but is preferably 0.1 ppm, more preferably 0.5 ppm, still more preferably 1. 0 ppm, more preferably 1.5 ppm. When the dissolved oxygen concentration of the raw material milk is 0.1 ppm or more, the dissolved oxygen concentration of the milk-containing beverage can be greatly reduced and foaming of the milk-containing beverage generated in the production process can be effectively suppressed. This is preferable because the invention can be easily implemented. In addition, when the dissolved oxygen concentration of the raw material milk obtained in the first oxygen concentration reduction step of step (A) is significantly lower than 0.1 ppm, depending on the method of the inert gas treatment, the step of (A) A considerable amount of inert gas remains in the raw milk obtained in the first oxygen concentration reduction step, and foaming of the raw milk cannot be effectively suppressed due to the residual inert gas.

The inert gas treatment in the step (A) is not particularly limited as long as it is a method capable of obtaining a milk-containing beverage having a fresh flavor with a greatly reduced dissolved oxygen concentration, which is a feature of the present invention. For example,
(A) mixing raw milk and inert gas using a proportional mixing device;
(B) spraying raw milk into a device having a space filled with an inert gas;
(C) mixing raw milk and inert gas using a centrifuge,
(D) mixing raw milk and inert gas using a pump;
(E) Blowing inert gas into raw milk contained in the device,
It can carry out by the 1 type selected from these, or the combination of 2 or more types. In the step (A), one kind of method selected from (a) to (e) (for example, the method (a)) can be performed once or twice or more.

The proportional mixing device for mixing the raw material milk and the inert gas in the above (a) is, for example, supplying the inert gas to a specific ratio (inert gas) to the raw material milk continuously supplied into the proportional mixing device. Gas supply amount / raw milk supply amount), so that the raw milk and the inert gas are distributed so that the distribution of the inert gas is uniform in the raw milk treated with the inert gas. Examples thereof include an apparatus configured to stir in-line (continuously in the pipe) (for example, a shearing apparatus such as a static mixer). In addition, the proportional mixing device controls the supply conditions of the inert gas (feed amount of raw material milk and / or supply amount of inert gas) at the supply portion (inlet portion) of the proportional mixing device as necessary. it can. Further, the mixing ratio of the raw material milk and the inert gas is detected in the supply part (inlet part) and / or the discharge part (outlet part) of the proportional mixing device, and the supply part of the proportional mixing device is detected based on the detection result. , The supply conditions of the raw milk and the inert gas (the raw milk supply and / or the inert gas supply) can be controlled.

The apparatus for spraying raw material milk into the apparatus having the space filled with the inert gas (b) is located, for example, in the tank filled with the inert gas and at the upper part of the tank. Examples include a device configured to inject and / or spray raw milk through the supply portion. Here, injection | pouring of raw material milk is not specifically limited, For example, it can carry out through well-known piping etc. Moreover, spraying of raw material milk is not specifically limited, For example, it can carry out through a well-known spray nozzle, a shower ball, etc. In addition, the direction of injection | pouring of raw material milk and the direction of spraying of raw material milk are not specifically limited, For example, a horizontal direction, an upward direction, a downward direction, etc. are mentioned. Moreover, the arrangement | positioning of the supply part located in the upper part etc. of this tank is one place or two places or more.

The centrifuge for mixing the raw material milk and the inert gas of the above (c) is, for example, using centrifugal force, fine dust and / or components derived from animals such as dairy cows (for example, cytoplasm, For the purpose of separating skim milk and cream from raw milk, clarifier aiming to separate and remove leukocytes, etc., bactofuge aiming to separate and remove microorganisms using centrifugal force And a separator type centrifuge such as a cream separator. In addition, the raw material milk and the inert gas are continuously supplied into the rotating storage container installed inside the centrifuge and the inert gas treatment is performed by mixing them. Can do. In general, when bubbles such as gas remain in raw milk during processing with a centrifugal separator, it is known that the processing efficiency of raw milk decreases. That is, conventionally, it has been common technical knowledge to operate a centrifuge so that bubbles such as gas are not entrained (not left) in raw milk when processing with a centrifuge. On the other hand, in the present invention, in spite of having the above technical common sense, the raw milk and the inert gas are continuously supplied, and the raw milk is mixed by processing them in the same manner as described above. The dissolved oxygen concentration can be effectively reduced.

The method for mixing raw milk and inert gas using the centrifuge of (c) is, for example, raw milk in which part of dissolved oxygen is replaced with inert gas by blowing inert gas or the like Is supplied to a centrifuge in which the inside of the apparatus is filled with an inert gas, and the dissolved oxygen concentration of the raw milk is reduced while processing in the same manner as described above, and the dissolved oxygen is replaced with the inert gas. There is a method of reducing the dissolved oxygen concentration of raw milk while supplying raw milk that has not been supplied to a centrifuge in which the inside of the device is filled with an inert gas and processing the same as described above.

The method for mixing raw material milk and inert gas using the pump of (d) is, for example, by continuously supplying raw material milk and inert gas and passing through the pump, The method of reducing the dissolved oxygen concentration of raw material milk by stirring and mixing by is mentioned. Here, examples of the pump (d) for mixing the raw material milk and the inert gas include non-volumetric pumps such as a centrifugal pump, a mixed flow pump, and a friction pump. In addition, the concrete method for mixing raw material milk and inert gas using the pump of said (d) is, for example, a stirring blade (impeller) rotating inside a stationary pump such as a spiral pump. ) To reduce the dissolved oxygen concentration of the raw milk by stirring and mixing the raw milk and the inert gas.

In mixing raw material milk and inert gas using the proportional mixing device of (a) above, the superficial speed of the raw material milk supplied to the proportional mixing device is preferably 0.5 to 2.5 m / sec. Preferably, it is 0.7 to 2.3 m / sec, more preferably 0.8 to 2.1 m / sec, and further preferably 1 to 2 m / sec. Here, it is preferable that the superficial speed of the raw material milk supplied to the proportional mixing device is 0.5 m / second or more because the dissolved oxygen concentration of the raw material milk can be greatly reduced. Moreover, it is preferable that the superficial speed of the raw milk supplied to the proportional mixing device is 2.5 m / sec or less because foaming of the raw milk generated during the production process can be effectively suppressed.

Here, the superficial velocity is a linear velocity obtained by dividing the liquid processing flow rate by the cross-sectional area of the pipe, as shown in the following equation.
[Superficial velocity (m / s)] = [Processing flow rate of liquid (m ³ / s)] ÷ [Cross sectional area of pipe (m ² )]
(In the formula, the sectional area of the pipe means the sectional area of the space portion through which the liquid flows, and does not include the sectional area of the elements of the static mixer.)

In the mixing of raw material milk and inert gas using the proportional mixing device of (a) above, the supply rate of inert gas (supply amount per unit time) relative to the supply rate of raw material milk (supply amount per unit time) Is preferably 5 to 70%, more preferably 10 to 60%, and even more preferably 20 to 60%. (Volume ratio of inert gas (volume) / feed amount of raw material milk (volume) × 100) is there. Here, it is preferable that the volume ratio of the inert gas supply rate to the raw material milk supply rate is 5% or more because the dissolved oxygen concentration of the raw material milk can be greatly reduced. In addition, it is preferable that the volume ratio of the inert gas supply rate to the raw material supply rate be 70% or less because foaming of the raw material milk generated in the production process can be effectively suppressed.

In mixing raw material milk and inert gas using the proportional mixing apparatus of (a) above, by mixing raw material milk with a low degree of foaming into raw material milk with a high degree of foaming, as a result, raw material milk While greatly reducing the dissolved oxygen concentration, foaming of the whole raw material milk generated during the production process can be suppressed. That is, an inert gas treatment was performed under operating conditions in which the volume ratio of the feed rate of the inert gas to the feed rate of the raw material milk supplied to the proportional mixing device and the feed rate of the raw material milk does not belong to the above preferred range, Even when the raw milk is partially included, mixing two or more raw milks with different degrees of foaming results in a significant reduction in the dissolved oxygen concentration of the raw milk. Foaming of the entire raw material milk that occurs can be effectively suppressed.

Examples of the method of mixing two or more kinds of raw material milks having different degrees of foaming include the following series of methods. In the following, “L / h” means liter / hour, and “L / min” means liter / minute. First, in a proportional mixing device equipped with a static mixer (inner diameter: 11 mm, 30 elements), raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 280 L, 280 L / H (superficial velocity: 0.8 m / sec) while bubbling nitrogen gas and bubbling proportionally at 3.5 L / min (volume ratio of nitrogen gas / raw milk: 75%) (mixed) And the raw milk mixed with nitrogen gas is stored in a storage tank (500 L capacity). Next, in the proportional mixing device, raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 105 L, 280 L / h (superficial velocity: 0.8 m / h) Nitrogen gas was bubbled while passing the liquid at a rate of 1.4 liters / min (nitrogen gas / raw milk volume ratio: 30%), and the raw milk was mixed with nitrogen gas. Is stored in the milk storage tank (500 L capacity). Thereafter, raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 105 L was added to the proportional mixing apparatus at 280 L / h (superficial velocity: 0.8 m / second). ) And bubbling nitrogen gas, and aerated (mixed) proportionally at 0.7 L / min (nitrogen gas / raw milk volume ratio: 15%). And stored in the milk storage tank (500 L capacity). And the raw material milk with a small foaming degree can be finally obtained by the above series of methods.

In the injection and / or spraying of raw material milk into the apparatus having the space filled with the inert gas (b), the oxygen concentration (upper limit value) in the tank filled with the inert gas is preferably 10 % Or less, more preferably 8% or less, and further preferably 7% or less. Here, it is preferable that the oxygen concentration in the tank filled with the inert gas is 10% or less because the dissolved oxygen concentration of the raw milk can be greatly reduced. In addition, in the injection and / or spraying of raw material milk into the apparatus having the space filled with the inert gas (b), the lower limit value of the oxygen concentration in the tank filled with the inert gas is particularly Although not limited, it is preferably 0%, more preferably 0.1%, still more preferably 0.5%.

In the spraying of raw milk into the apparatus having a space filled with the inert gas (b) above, it is preferable to reduce the dissolved oxygen concentration of the raw milk by treating the raw milk with an inert gas in advance. Conventionally, in the spraying of raw milk into the apparatus having the space filled with the inert gas (b) above, the raw milk is treated with the inert gas in advance, so that the foaming of the raw milk itself is hardly lost. It was a common technical knowledge that the foaming of the whole raw milk generated during the manufacturing process could not be effectively suppressed. On the other hand, in the present invention, in spite of having the above technical common sense, the raw milk is treated with an inert gas to reduce the dissolved oxygen concentration of the raw milk, and then the inert gas of (b) is used. By spraying raw milk into a device that has a filled space, it was possible to effectively suppress foaming of the whole raw milk that occurred during the manufacturing process, while greatly reducing the dissolved oxygen concentration of the raw milk It is.

Dissolved oxygen concentration (upper limit value) of raw milk in which raw oxygen is sprayed into the apparatus having a space filled with the inert gas (b) and the dissolved oxygen concentration is reduced in advance by treatment with an inert gas. Is preferably 10 ppm or less, more preferably 8 ppm or less, further preferably 6 ppm or less, further preferably 4 ppm or less, and further preferably 2 ppm or less. In the spraying of raw material milk into the device having a space filled with the inert gas (b) above, the dissolved oxygen concentration of the raw material milk is 10 ppm or less, in which the dissolved oxygen concentration is reduced by treating with an inert gas in advance. If it exists, the dissolved oxygen concentration of raw material milk can be reduced greatly, and it is preferable at the point which can implement this invention easily. In addition, the lower limit of the dissolved oxygen concentration of the raw milk, in which the dissolved oxygen concentration is reduced in advance by, for example, inert gas treatment in the spraying of the raw milk into the apparatus having the space filled with the inert gas of (b). Although a value is not specifically limited, Preferably it is 0.1 ppm, More preferably, it is 0.5 ppm, More preferably, it is 1.0 ppm, More preferably, it is 1.5 ppm. When the dissolved oxygen concentration of the raw material milk is 0.1 ppm or more, it is possible to effectively suppress foaming of the raw material milk generated during the production process while greatly reducing the dissolved oxygen concentration of the raw material milk. This is preferable because it can be easily implemented.

In the spraying of raw material milk into the device having a space filled with the inert gas of (b) above, an apparatus for spraying raw material milk in which the dissolved oxygen concentration is reduced by treating with an inert gas in advance, For example, a device obtained by improving the nitrogen gas replacement device described in Japanese Patent Application Laid-Open No. 2001-078665 (the above-mentioned Patent Document 2), in which the dissolved oxygen concentration in the raw milk is reduced, The raw material milk sprayed from above into the nitrogen gas replacement device can be preliminarily treated with an inert gas by a proportional mixing device for mixing milk and an inert gas. Specifically, nitrogen gas is directly mixed and dispersed in raw material milk, and raw material milk in which nitrogen gas is directly mixed and dispersed in advance is injected into a tank having an atmosphere of nitrogen gas and stored (supplied). At the same time, the raw material milk in which nitrogen gas is directly mixed and dispersed in advance is sprayed from above with a nozzle in a tank having an atmosphere of nitrogen gas, and these raw material milks are mixed to dissolve dissolved oxygen and nitrogen in the raw material milk. It is an apparatus that can reduce the amount of dissolved oxygen (dissolved oxygen concentration) of raw milk by replacing with gas.

Conventionally, in order to reduce the dissolved oxygen concentration of raw material milk by the nitrogen gas replacement device described in Japanese Patent Application Laid-Open No. 2001-077865 (the above Patent Document 2), the raw material sprayed from above into the nitrogen gas replacement device With the proportional mixing device for mixing raw milk and inert gas of (a) above with milk, the inert gas treatment or the like was injected into the tank and stored (supplied). In the raw milk to be defoamed, bubbles will be generated, and it is considered that foaming of the whole raw milk generated during the manufacturing process cannot be effectively suppressed. It was common knowledge that the inert gas treatment was not performed in advance. On the other hand, in the present invention, in spite of the above technical common sense, the raw material milk sprayed from above into the nitrogen gas replacement device is preliminarily treated with an inert gas so that the dissolved oxygen concentration of the raw material milk is reduced. While greatly reducing, the foaming of the whole raw milk generated during the production process could be effectively suppressed.

In the mixing of raw milk and inert gas using the centrifuge of (c) above, the raw milk in which some dissolved oxygen is replaced with inert gas by blowing inert gas, etc. Supplying the centrifuge filled with inert gas to reduce the dissolved oxygen concentration in the raw milk, and the raw milk in which the dissolved oxygen is not replaced with the inert gas, the inside of the equipment is inert gas Any one of the methods for reducing the dissolved oxygen concentration of the raw milk can be used, or both of them can be used in combination. Here, the raw milk in which some dissolved oxygen is replaced with inert gas by blowing inert gas, etc. is supplied to a centrifuge in which the inside of the device is filled with inert gas, and general operations are performed. In the method of reducing the dissolved oxygen concentration of raw milk by processing in the same manner as the conditions, the inert gas (inert gas used before processing in the centrifuge) with respect to the raw milk supply speed (supply amount per unit time) The volume ratio of the supply speed (supply amount per unit time) (the supply amount of inert gas / the supply amount of raw milk × 100) is preferably 10 to 200%, more preferably 30 to 180%. More preferably, it is 50 to 150%. Here, it is preferable that the volume ratio of the supply rate of the inert gas to the supply rate of the raw material milk is 10% or more because the dissolved oxygen concentration of the raw material milk can be greatly reduced. It is preferable that the volume ratio of the inert gas supply rate to the raw material supply rate be 200% or less because foaming of the entire raw material milk generated during the production process can be effectively suppressed. In addition, raw milk in which dissolved oxygen is not replaced with inert gas is supplied to a centrifuge in which the inside of the equipment is filled with inert gas, and processed in the same manner as general operating conditions. In the method of reducing the dissolved oxygen concentration, the oxygen concentration (upper limit value) inside the centrifuge is preferably 10% or less, more preferably 8% or less, and even more preferably 7% or less. Here, it is preferable that the oxygen concentration inside the centrifuge is 10% or less because the dissolved oxygen concentration in the raw milk can be greatly reduced. The lower limit value of the oxygen concentration inside the centrifuge is not particularly limited, but is preferably 0%, more preferably 0.1%, and still more preferably 0.5%.

In mixing raw material milk and inert gas using the pump of (d) above, the volume of the inert gas supply rate (supply amount per unit time) relative to the supply rate of raw material milk (supply amount per unit time) The ratio (supply amount of inert gas / supply amount of raw material milk) is preferably 3 to 50%, more preferably 4 to 40%, and still more preferably 5 to 30%. Here, it is preferable that the volume ratio of the supply rate of the inert gas to the supply rate of the raw material milk is 3% or more because the dissolved oxygen concentration of the raw material milk can be greatly reduced. Moreover, it is preferable that the volume ratio of the supply rate of the inert gas to the supply rate of the raw material milk is 50% or less because foaming of the raw material milk generated in the production process can be effectively suppressed.

In mixing raw material milk and inert gas using the pump of (d) above, mixing raw material milk with a low degree of foaming into raw material milk with a high degree of foaming results in dissolution of raw material milk. While greatly reducing the oxygen concentration, it is possible to suppress foaming of the entire raw material milk generated during the production process. That is, the volume ratio of the inert gas supply rate to the raw milk supply rate is treated with an inert gas under operating conditions that do not belong to the above preferred range, and even if the raw milk is partially contained, the degree of foaming As a result, by mixing two or more kinds of raw material milks having different varieties, it is possible to effectively suppress foaming of the whole raw material milk generated in the production process while greatly reducing the dissolved oxygen concentration of the raw material milk. .

The volume of the space in the tank (the tank when the raw material milk is not stored in the space in the tank) in the blowing (bubbling) of the inert gas into the raw material milk stored (stored) in the tank of (e) above The volume ratio (volume of raw milk stored / volume of space in tank × 100) of the stored amount (volume) of raw material milk to the total volume) is preferably 20 to 90%, more preferably 30 to 80 %, More preferably 40 to 70%. Here, it is preferable that the volume ratio of the liquid storage amount of the raw material milk to the volume of the space in the tank is 20% or more because foaming of the raw material milk generated in the production process can be effectively suppressed. Moreover, it is preferable that the volume ratio of the liquid storage amount of the raw milk to the volume of the space in the tank is 90% or less because the dissolved oxygen concentration of the raw milk can be greatly reduced. And while jetting the raw material milk that has been treated with inert gas or deaerated (depressurized) toward the liquid level of the raw material milk stored in the tank, the dissolved oxygen concentration of the raw material milk is greatly reduced. The foaming of the whole raw material milk generated during the production process can be effectively suppressed, which is preferable. In addition, as a device for blowing inert gas into the raw milk stored in the tank of (e) above, a known bubble dispersing device can be used, for example, a sintered metal element, a filter, a sparger, a narrow flow A road nozzle or the like can be used.

In the supply of the inert gas to the raw material milk accommodated in the tank of (e) above, the supply rate of inert gas (supply per unit time) relative to the supply rate (supply amount per unit time) of the raw material milk to the tank Volume ratio (feed rate of inert gas / feed rate of raw material milk × 100) is preferably 10 to 100%, more preferably 20 to 90%, and still more preferably 30 to 80%. Here, it is preferable that the volume ratio of the supply rate of the inert gas to the stored amount of raw material milk is 20% or more because the dissolved oxygen concentration of the raw material milk can be greatly reduced. Moreover, it is preferable that the volume ratio of the supply rate of the inert gas to the liquid storage amount of the raw milk is 100% or less because foaming of the raw milk generated during the production process can be effectively suppressed.

In the blowing of the inert gas into the raw material milk accommodated in the tank of (e) above, the amount of the inert gas blown relative to the amount of raw material milk stored (unit volume: 1 liter) (supply amount per unit time: liter) / Min) is preferably 0.005 to 0.1 liter / minute, more preferably 0.006 to 0.08 liter / minute, further preferably 0.008 to 0.05 liter / minute, and more preferably 0. 0.01 to 0.03 liter / minute, more preferably 0.015 to 0.025 liter / minute. Here, it is preferable that the amount of the inert gas blown to the stored amount of raw material milk is 0.005 liter / min · or more because the dissolved oxygen concentration of the raw material milk can be greatly reduced. In addition, it is preferable that the amount of the inert gas blown relative to the amount of raw material milk stored is 0.1 liter / min · or less because foaming of the raw material milk generated during the production process can be effectively suppressed.

In order to effectively suppress foaming of the raw material milk generated in the blowing of the inert gas into the raw material milk accommodated in the tank (e) above, the raw material milk can be defoamed. Moreover, in the 1st oxygen concentration reduction process of a process (A), in order to suppress the foaming of the raw material milk which generate | occur | produces here effectively, the defoaming process of raw material milk can be performed. At this time, for example, the raw material milk obtained in the first oxygen concentration reduction step of step (A) is injected into a (small) tank installed after the first oxygen concentration reduction step of step (A). By storing (supplying) and spraying and / or dropping a part of the raw milk discharged from the tank onto the liquid level of a part of the raw milk stored in the tank from above the tank. The raw milk obtained in the first oxygen concentration reduction step of step (A) can be defoamed. Moreover, while supplying the raw material milk obtained at the 1st oxygen concentration reduction process of the process (A) to the (small) tank installed after the 1st oxygen concentration reduction process of the process (A), gas (for example, Inert gas such as nitrogen gas) is sprayed from above the tank onto the surface of the raw milk stored in the tank to obtain the first oxygen concentration reduction step of step (A). The raw milk can be defoamed. Further, for example, the raw material milk obtained in the first oxygen concentration reduction step of step (A) is allowed to stand for a predetermined time, and the raw material milk obtained in the first oxygen concentration reduction step of step (A) The raw milk obtained in the first oxygen concentration reduction step of the step (A), the raw material milk obtained in the first oxygen concentration reduction step of the step (A), the raw material obtained in the first oxygen concentration reduction step of the step (A) By depressurizing milk with a known tank or pipe, blending (adding) an antifoaming agent or the like into the raw milk obtained in the first oxygen concentration reduction step of step (A), etc. The raw milk obtained in the first oxygen concentration reduction step can be defoamed.

By performing the defoaming treatment of the raw milk obtained in the first oxygen concentration reduction step of the step (A), it is assumed that the raw milk is foamed immediately after the first oxygen concentration reduction step of the step (A). Even if it occurs greatly, foaming of the raw material milk is efficiently suppressed before the second oxygen concentration reduction step of the step (B).

In the first oxygen concentration reduction step of the step (A), from the viewpoint that it is easy to reduce the dissolved oxygen concentration of the raw material milk and it is easy to suppress foaming of the raw material milk, the above (a) Among the inert gas treatments (e) to (e), the inert gas treatment (a) (mixing of raw milk and inert gas using a proportional mixing device) is preferable.

The degree of foaming of the raw material milk obtained in the first oxygen concentration reduction step of step (A) can be evaluated using the bubble rate as an index. Here, the bubble rate of the raw material milk is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, and further preferably 5% or less. Here, if the foam rate of the raw material milk is 10% or less, the foaming of the raw material milk is not excessively generated, and the foaming of the raw material milk is effectively suppressed. Defoaming treatment or the like can be simplified or omitted, which is preferable. In addition, if the raw material milk with excessive foaming is indirectly heat sterilized with a plate-type heat sterilizer, etc., the components derived from the raw material milk may be attached or burnt on the inner surface (plate, piping, etc.) of the plate-type heat sterilizer. It tends to occur. At this time, in these plate-type heat sterilizers and the like due to adhesion and scorching, the thermal conductivity is lowered, and in order to maintain the temperature of heat sterilization at a predetermined temperature, a medium (hot water, It is necessary to increase the temperature of the water vapor or the like, or increase the amount of medium used to heat the raw milk. That is, in order to heat these media, a large amount of energy is used, resulting in a decrease in production efficiency and an increase in manufacturing costs. In addition, due to adhesion and scorching, the operation time is shortened in a plate-type heat sterilizer, etc., and the frequency of cleaning, the frequency of parts replacement, etc. are increased, the production efficiency is reduced, and the manufacturing cost is reduced. To increase.

Here, the bubble rate of the raw milk is a volume ratio obtained by dividing the volume of the bubbles by the total volume of the raw milk as shown in the following formula.
[Rubber ratio of raw milk (unit: volume%)] = [bubble volume (m ³ )] × 100 ÷ [total volume of raw milk containing bubbles (m ³ )]
And the bubble rate of raw material milk inject | poured raw milk of unprocessed or predetermined processing (for example, sterilized) into a transparent glass measuring cylinder, for example, and hold | maintained for predetermined time (5 minutes) Later, in the raw milk injected into the graduated cylinder, the height of the liquid phase in the lower layer and the height of the bubble phase in the upper layer are measured with a ruler or the like, and then calculated by the following formula.
[Bubble ratio of raw milk (unit: volume%)] = [height of bubble phase (m)] × 100 ÷ ([height of bubble phase (m)] + [height of liquid phase (m)])

The raw material milk obtained in the step (A) (first oxygen concentration reduction step) can be stored. At this time, for example, using a tank in which the internal space is filled (replaced) with an inert gas, or using a tank in which an oxygen scavenger or the like is applied or pasted to the internal wall surface, Raw material milk obtained in one oxygen concentration reduction step) can be stored. Here, since it is preferable to perform the step (B) (second oxygen concentration reduction step) immediately before the step (C) (heat sterilization step), the step (A) (first oxygen concentration reduction step). Until the time of performing the step (B) (second oxygen concentration reduction step) after performing the step, for example, adjusting the production time of the milk-containing beverage according to the shipment status of the milk-containing beverage as the final product For the purpose of, etc., the raw material milk obtained in the step (A) (first oxygen concentration reduction step) is made to stand by and the raw material milk obtained in the step (A) (first oxygen concentration reduction step) is stored. To do. In addition, from the viewpoint of suppressing an increase in the dissolved oxygen concentration of the raw material milk obtained in the step (A) (first oxygen concentration reduction step), in an inert gas atmosphere (for example, in a nitrogen gas atmosphere) It is preferable to store the raw material milk obtained in the step (A) (first oxygen concentration reduction step). However, in the atmosphere (normal conditions), the step (A) (first oxygen concentration) Even if the raw material milk obtained in the reduction step) is stored, the purpose of the present invention is to appropriately determine the conditions of the inert gas treatment in the step (B) (second oxygen concentration reduction step). A milk-containing beverage can be obtained.

[Step (B): Second oxygen concentration reduction step]
The step (B) controls the supply method of inert gas treatment (for example, treatment using a proportional mixing device) and supply conditions (for example, the feed rate of raw milk and the amount of supply of inert gas), and the step (A ) (2) to obtain a raw material milk having a reduced dissolved oxygen concentration by subjecting the raw material milk to an inert gas treatment so that the bubble rate of the raw material milk obtained in the first oxygen concentration reduction step is 10% or less. This is an oxygen concentration reduction process. At this time, the dissolved oxygen concentration of the raw material milk obtained in the step (B) is preferably 1 ppm or less, more preferably 0.8 ppm or less, more preferably from the viewpoint of maintaining the fresh flavor of the milk-containing beverage over a long period of time. Preferably it is 0.6 ppm or less, More preferably, it is 0.5 ppm or less, More preferably, it is 0.4 ppm or less, More preferably, it is 0.3 ppm or less, More preferably, it is 0.2 ppm or less. Normally, after the raw milk is discharged from the processing means (processing apparatus) in the step (A), the raw milk obtained in the step (A) is guided to the processing means (oxygen concentration reducing apparatus) in the step (B). Thus, step (B) is performed.

Although the lower limit of the dissolved oxygen concentration of the raw material milk obtained at the process (B) is not specifically limited, Preferably it is 0.01 ppm, More preferably, it is 0.03 ppm, More preferably, it is 0.05 ppm. When the dissolved oxygen concentration of the raw material milk is 0.01 ppm or more, it is possible to effectively suppress foaming of the raw material milk generated during the manufacturing process while greatly reducing the dissolved oxygen concentration of the raw material milk. This is preferable because it can be easily implemented. When the dissolved oxygen concentration of the raw material milk is significantly lower than 0.01 ppm, a small amount of inert gas remains in the raw material milk obtained in the step (B) by the inert gas treatment method. When the inert gas remains, foaming of the milk-containing beverage cannot be effectively suppressed.

In the step (B), the inert gas treatment is performed so that the dissolved oxygen concentration of the raw material milk obtained in the step (B) is smaller than the dissolved oxygen concentration of the raw material milk obtained in the step (A). It is not necessary to excessively increase the supply amount of the inert gas, and while reducing the dissolved oxygen concentration of the raw material milk supplied to the step (C), the foaming of the raw material milk generated during the production process is effective. It is preferable in that it can be suppressed and the present invention can be easily implemented. Here, the difference between the dissolved oxygen concentration of the raw material milk obtained in step (A) and the dissolved oxygen concentration of the raw material milk obtained in step (B) (that is, the width of reduction of the dissolved oxygen concentration of the raw material milk) is It is preferably 0.5 to 7.8 ppm, more preferably 0.6 to 5.6 ppm, still more preferably 0.8 to 3.6 ppm, and still more preferably 1.0 to 3.2 ppm. When the difference in dissolved oxygen concentration of the raw material milk is 0.5 ppm or more, it is possible to effectively suppress foaming of the raw material milk generated during the production process while greatly reducing the dissolved oxygen concentration of the raw material milk. This is preferable because the invention can be easily implemented.

In the present invention, the reason for adopting the method of reducing the dissolved oxygen concentration of the raw material milk by the two-stage inert gas treatment of the step (A) and the step (B) is as follows. In addition to the fact that foaming of milk-containing beverages generated during the production process can be effectively suppressed and the present invention can be easily carried out (the effect of the present invention can be obtained efficiently), the step (A) (first oxygen By going through the (concentration reduction step), the raw milk and inert gas can be easily adapted, and after that, it can be processed stably and efficiently in step (B) (second oxygen concentration reduction step). It has a characteristic. Such a feature cannot be predicted only by the one-step inert gas treatment described in Patent Document 1, and has been found as a remarkable effect for the first time by the present invention. In particular, after the dissolved oxygen concentration of the raw material milk obtained in step (A) (first oxygen concentration reduction step) is reduced to 6 to 8 ppm, it is obtained in step (B) (second oxygen concentration reduction step). In the step (A) (first oxygen concentration reduction step) and / or step (B) (second oxygen concentration reduction step), by reducing the dissolved oxygen concentration of the raw material milk to 1 ppm or less, the liquid raw material Since there is no need to bring a large amount of gaseous inert gas into contact with milk, and there is no need to install or operate (operate) large-scale equipment, it is possible to suppress equipment costs and manufacturing costs associated therewith. . And finally, it is preferable because generation of excessive foaming can be suppressed in the milk-containing beverage obtained in the step (B) and / or the step (C).

The inert gas treatment in the step (B) is performed in the same manner as in the step (A), for example,
(A) mixing raw milk and inert gas using a proportional mixing device;
(B) spraying raw milk into a device having a space filled with an inert gas;
(C) mixing raw milk and inert gas using a centrifuge,
(D) mixing raw milk and inert gas using a pump;
(E) Blowing inert gas into raw milk contained in the device,
It can carry out by the 1 type selected from these, or the combination of 2 or more types. In the step (B), one kind of method selected from (a) to (e) (for example, the method (a)) can be performed once or twice or more. In the present invention, the combination of the methods (a) to (e) in the step (A) and the methods (a) to (e) in the step (B) is not particularly limited. In (A), any one of the above (a) to (e) or two or more methods are arbitrarily adopted, and in step (B), any one of (a) to (e) above or Two or more methods can be arbitrarily adopted.

Details of each of the above methods (a) to (e) in the step (B) (for example, a device actually used, a preferable superficial velocity of the raw milk, etc.) are described in (a) to (e) of the step (A). These are the same as the details of each method (for example, a device actually used, a preferable superficial velocity of raw milk, etc.). Here, among the methods (a) to (e) in the step (B), in the method (e) (inert gas blowing into the raw milk contained in the apparatus), the inert gas By adjusting the supply time and the supply amount of the inert gas, the dissolved oxygen concentration of the milk-containing beverage can be easily reduced, the supply rate of the inert gas (the supply amount per unit time) (for example, the unit volume of raw milk (1 By adjusting the amount from 0.005 to 0.1 liters per minute), it is possible to sufficiently suppress foaming, and by improving only the liquid storage tank (surge tank) after sterilization of raw milk and its surroundings This is preferable because it can be realized by effectively improving the equipment in a space-saving manner. In addition, among the methods (a) to (e) in the step (B), in the method (a) (mixing raw material milk and inert gas using a proportional mixing device), supply of inert gas It is preferable because the dissolved oxygen concentration of the milk-containing beverage can be easily reduced by adjusting the time and the supply amount of the inert gas, and foaming can be suppressed by adjusting the supply rate of the inert gas. In addition, the method of carrying out a defoaming process after a process (C) and / or a process (C), and this detail are the same as that of the method of carrying out a defoaming process at a process (A).

As for the degree of foaming of the raw material milk obtained in the step (B), the bubble rate can be used as an index in the same manner as the degree of foaming of the raw material milk obtained in the step (A). Here, the foam ratio of the raw material milk obtained in the step (B) is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, and further preferably 5% or less. Here, it is preferable that the foam rate of the raw milk is 10% or less, while effectively suppressing the foaming of the milk-containing beverage generated in the production process and reducing the production efficiency. On the other hand, if the foam ratio of the raw milk exceeds 10%, the raw milk is excessively foamed, and subsequent defoaming or defoaming is required, or the raw milk with excessive foaming is heated by the plate type. When indirect heat sterilization is performed with a sterilizer or the like, scorching due to foaming is likely to occur on the inner surface of the plate or the like, and this scoring causes a decrease in thermal conductivity during heating. Therefore, in order to heat the raw milk to a constant temperature, the heating medium must be set to a higher temperature than usual, and the plate must be washed and replaced more frequently than usual, which increases production efficiency. There may be a problem such as a decrease or an increase in manufacturing cost due to equipment renewal.

A known oxygen concentration reduction treatment other than the inert gas treatment can be applied to the oxygen concentration reduction step corresponding to the step (A) and the step (B) of the present invention, for example, a vacuum degassing (vacuum degassing) treatment. Or a membrane deaeration process (a gas separation membrane such as a hollow fiber membrane) can be applied. Here, when the vacuum degassing process is applied to the oxygen concentration reduction process, foaming of the raw material milk is less likely to occur than the inert gas process, and the raw material milk is indirectly heated and sterilized with a plate-type heat sterilizer or the like. However, on the inner surface of the plate, it is difficult for scorch due to foaming of raw material milk to occur, but aroma components derived from raw material milk are likely to dissipate, which may affect the flavor of milk-containing beverages. There is. In addition, when membrane degassing is applied to the oxygen concentration reduction process, the processing speed is reduced and the separation membrane is frequently washed and replaced rather than inert gas treatment due to clogging of the separation membrane. There are cases in which production efficiency decreases, production costs increase due to equipment renewal, and the like.

[Step (C); Heat sterilization step]
Step (C) is a heat sterilization step in which the raw milk obtained in step (B) (second oxygen concentration reduction step) is heat sterilized. The heat sterilization method is not particularly limited as long as it is a heat sterilization method usually used in the production of milk. For example, a low temperature long time sterilization method of treating at 61 to 65 ° C. for 30 to 60 minutes, 70 to 75 Examples thereof include a high-temperature short-time sterilization method in which treatment is performed at 15 ° C. for 15 to 60 seconds, and an ultra-high temperature sterilization method in which treatment is performed at 130 to 150 ° C. for 1 to 5 seconds. In these heat sterilization methods, the temperature and time of heat sterilization can be appropriately adjusted as long as a predetermined level of hygiene is maintained and the quality of the milk-containing beverage is maintained. At this time, the dissolved oxygen concentration of the milk-containing beverage obtained in the step (C) is preferably 1 ppm or less, more preferably 0.8 ppm or less, from the viewpoint of maintaining the fresh flavor of the milk-containing beverage over a long period of time. More preferably, it is 0.6 ppm or less, more preferably 0.5 ppm or less, further preferably 0.4 ppm or less, further preferably 0.3 ppm or less, and particularly preferably 0.2 ppm or less. Normally, after the raw milk is discharged from the processing means (processing apparatus) in the step (B), the raw milk obtained in the step (B) is guided to the processing means (heat sterilization apparatus) in the step (C). Thus, the step (C) is performed.

The lower limit value of the dissolved oxygen concentration of the milk-containing beverage obtained in the step (C) is not particularly limited, but is preferably 0.01 ppm, more preferably 0.03 ppm, still more preferably 0.05 ppm, still more preferably 0.00. 1 ppm. When the dissolved oxygen concentration of the milk-containing beverage is 0.01 ppm or more, while greatly reducing the dissolved oxygen concentration of the milk-containing beverage, it is possible to effectively suppress foaming of the milk-containing beverage generated in the production process, This is preferable in that the present invention can be easily implemented.

Examples of milk-containing beverages include milk, milk beverages containing milk, animal milk other than cows, milk beverages containing animal milk other than cows, vegetable beverages such as soy milk, artificial milk, beverages containing artificial milk, and the like. . In addition, raw materials other than raw milk can be added before heat sterilization, during heat sterilization, or after heat sterilization.

After step (C), if necessary, replace the internal space of the tank (surge tank, filler tank, etc.) before storing the milk-containing beverage in the tank with inert gas, and store the milk-containing beverage in the tank. After replacing the internal space (head space) of the tank with inert gas, replacing the internal space of the container before filling the tank with milk-containing beverage with inert gas, filling the container with milk-containing beverage The inner space (head space) of the container after the replacement can be replaced with an inert gas, and an oxygen scavenger can be applied to the inner surface of the tank and / or the container.

In the present invention, any one of the following treatments (i) to (iv) or a combination of two or more thereof can be performed. At this time, the following treatments (i) to (iv) can be carried out as step (A) and / or step (B), and the following treatments (i) to (iv) are carried out as steps (A) and / or It can also be performed as a new process different from the process (B).
(I) After performing the 1st process which makes a milk-containing drink microparticles | fine-particles, the 2nd process which puts the milk-containing drink after a 1st process in a pressure-reduced atmosphere can be performed. By this treatment, the dissolved oxygen concentration of the milk-containing beverage can be further reduced.
(Ii) After storing the milk-containing beverage in a storage tank or the like, the inside of the storage tank can be depressurized, and the dissolved oxygen contained in the milk-containing beverage can be released into the internal space of the storage tank. By this treatment, the dissolved oxygen concentration of the milk-containing beverage can be further reduced.
(Iii) After the inert gas of the milk-containing beverage is blown and the dissolved oxygen concentration of the milk-containing beverage is reduced, bubbles formed in the milk-containing beverage can be broken using a decompression pump or the like. . By this treatment, the dissolved oxygen concentration of the milk-containing beverage can be further reduced.
(Iv) After step (C), an inert gas can be blown into the milk-containing beverage stored in a tank (such as a surge tank or a filler tank). By this treatment, the dissolved oxygen concentration of the milk-containing beverage can be further reduced.

In the present invention, a milk-containing beverage can be filled (contained) in a container and stored in a refrigerator or at room temperature as a milk-containing beverage in a container. In the present invention, since the dissolved oxygen concentration of the milk-containing beverage is greatly reduced, as a container used for this storage, a container having low oxygen permeability, for example, a bottle, a steel can, an aluminum can, PET (polyethylene terephthalate), vinyl A container made of nylon or the like is preferable. When milk-containing beverages in containers are refrigerated or stored at room temperature, it is easy to maintain a state in which the dissolved oxygen concentration of milk-containing beverages is reduced, and it is possible to suppress the growth of cryogenic bacteria present in milk-containing beverages. is there. In the present invention, when a milk-containing beverage is filled in a paper container, for example, as compared with a normal milk paper container, such as a container formed by a laminated sheet including a paper base material layer and a nylon resin layer. Thus, it is preferable to use a paper container having low oxygen permeability. In the present invention, as a laminated sheet constituting a paper container, for example, a laminated sheet in which a polyethylene layer, a paper base layer, a nylon resin layer, an adhesive layer, a polyethylene layer are laminated in this order from the outside to the inside of the container Is mentioned. Examples of the resin forming the nylon resin layer include various nylons (polyamide resins) such as nylon MXD6, nylon 6, nylon 6,6, nylon 4,6, and the like.

In the present invention, by reducing the dissolved oxygen concentration of the milk-containing beverage, for example, the occurrence of abnormal flavor associated with heating and / or storage that occurs in milk that tends to change flavor due to oxygen and / or heating is reduced. it can. The abnormal flavor here is, for example, a spontaneous oxidation odor called bean odor, a heating odor, or the like. Further, carbonyl compounds such as hexanal are known as causative substances of spontaneous oxidation odor, and sulfur compounds such as dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide are known as causative substances of heating odor, and the milk-containing beverage of the present invention is Moreover, generation | occurrence | production of the causative substance of a spontaneous oxidation odor and / or a heating odor can be suppressed because the dissolved oxygen concentration is reduced.

That is, the present invention
(A) After controlling the supply method and supply conditions of the inert gas treatment and performing the inert gas treatment on the raw milk so that the foam rate of the raw milk is 10% or less, the raw milk is A first oxygen concentration reduction step for discharging and obtaining raw milk with reduced dissolved oxygen concentration;
(B) The inert gas treatment is performed on the raw milk so that the supply method and supply conditions of the inert gas treatment are controlled and the bubble rate of the raw milk obtained in the first oxygen concentration reduction step is 10% or less. And a second oxygen concentration reduction step for obtaining raw milk with reduced dissolved oxygen concentration,
(C) a heat sterilization step for heat sterilizing the raw milk obtained in the second oxygen concentration reduction step,
It is also a manufacturing method of the milk-containing drink which reduced generation | occurrence | production of the abnormal flavor accompanying heating and / or storage containing.

In this invention, while being able to reduce the dissolved oxygen concentration of a milk-containing drink efficiently, generation | occurrence | production of the abnormal flavor accompanying the heating and / or preservation | save of a milk-containing drink can be reduced.
That is, the present invention
(A) After controlling the supply method and supply conditions of the inert gas treatment and performing the inert gas treatment on the raw milk so that the foam rate of the raw milk is 10% or less, the raw milk is A first oxygen concentration reduction step for discharging and obtaining raw milk with reduced dissolved oxygen concentration;
(B) The inert gas treatment is performed on the raw milk so that the supply method and supply conditions of the inert gas treatment are controlled and the bubble rate of the raw milk obtained in the first oxygen concentration reduction step is 10% or less. And a second oxygen concentration reduction step for obtaining raw milk with reduced dissolved oxygen concentration,
(C) a heat sterilization step for heat sterilizing the raw milk obtained in the second oxygen concentration reduction step,
It is also a method for reducing the dissolved oxygen concentration in a milk-containing beverage containing

The present invention also provides:
(A) After controlling the supply method and supply conditions of the inert gas treatment and performing the inert gas treatment on the raw milk so that the foam rate of the raw milk is 10% or less, the raw milk is A first oxygen concentration reduction step for discharging and obtaining raw milk with reduced dissolved oxygen concentration;
(B) The inert gas treatment is performed on the raw milk so that the supply method and supply conditions of the inert gas treatment are controlled and the bubble rate of the raw milk obtained in the first oxygen concentration reduction step is 10% or less. And a second oxygen concentration reduction step for obtaining raw milk with reduced dissolved oxygen concentration,
(C) a heat sterilization step for heat sterilizing the raw milk obtained in the second oxygen concentration reduction step,
It is also a method for reducing the occurrence of an abnormal flavor associated with heating and / or storage of a milk-containing beverage containing.

The present invention also provides:
(A) a first oxygen concentration reduction step of controlling the supply method and supply conditions of the inert gas treatment and performing the inert gas treatment on the raw material milk;
(B) a heat sterilization step for heat sterilizing the raw milk obtained in the first oxygen concentration reduction step;
(C) The supply method and supply conditions of the inert gas treatment are controlled, the raw milk obtained after the heat sterilization process is subjected to the inert gas treatment, and the milk-containing beverage whose dissolved oxygen concentration is 1 ppm or less A second oxygen concentration reduction step to obtain an oxygen concentration reduction step;
It is also a method for reducing the generation of spontaneous oxidation odor and / or heating odor of milk-containing beverages containing sucrose.

The present invention also provides:
(A) a first oxygen concentration reduction step of controlling the supply method and supply conditions of the inert gas treatment and performing the inert gas treatment on the raw material milk;
(B) a heat sterilization step for heat sterilizing the raw milk obtained in the first oxygen concentration reduction step;
(C) The supply method and supply conditions of the inert gas treatment are controlled, the raw milk obtained after the heat sterilization process is subjected to the inert gas treatment, and the milk-containing beverage whose dissolved oxygen concentration is 1 ppm or less A second oxygen concentration reduction step to obtain an oxygen concentration reduction step;
It is also a method for reducing the generation of carbonyl compounds (such as hexanal) and / or sulfur compounds (such as dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide) in milk-containing beverages that contain.

Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to the following examples, and various embodiments can be adopted as long as they are included in the scope of the claims.

In the present invention, “L / h” means liter / hour, and “L / min” means liter / minute. In addition, the bubble rate of raw milk was determined by pouring raw milk (or pasteurized milk) into a transparent glass graduated cylinder (1L volume) and holding it for 5 minutes, and then poured into the graduated cylinder. In (or pasteurized milk), the height of the liquid phase in the lower layer and the height of the bubble phase in the upper layer were measured with a ruler and calculated by the following formula.
[Bubble ratio of raw milk] (unit: volume%) = [height of foam phase (m)] × 100 ÷ ([height of foam phase (m)] + [height of liquid phase (m)])

[Example 1]
A nitrogen gas displacement device described in Japanese Patent Application Laid-Open No. 2001-077865 (the above Patent Document 2) is provided with a static mixer (inner diameter: 8 mm, 63 elements) (proportional mixing device for mixing and dispersing nitrogen gas) In the following examples and comparative examples, raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.7 ppm, specific gravity) is used. : 1.03): While passing 100 L at 150 L / h (superficial velocity: 0.8 m / sec), nitrogen gas was blown (bubbled) to 1.5 L / min (volume of nitrogen gas / raw milk) Ratio (60%) was aerated (mixed) proportionally (immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 1.5 ppm and a bubble rate of 5% or less. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 12.7 ppm.

Thereafter, the raw milk is temporarily stored in a milk storage tank (100 L capacity), and then passed through the nitrogen gas replacement device again at 150 L / h (superficial velocity: 0.8 m / sec). While being liquid, nitrogen gas was blown in and proportionally aerated (mixed) at 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.1 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 1.5 ppm.

Thereafter, raw milk was passed through a plate-type heat sterilizer (abbreviated as “sterilizer” in the following examples and comparative examples) (heat sterilization conditions: 130 ° C., 2 seconds) at 150 L / h. The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 0.3 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product) (immediately after the end of the step (C)).

[Example 2]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 13.1 ppm, specific gravity: 1.03): 5, with a static mixer (inner diameter: 47.8 mm, 18 elements) installed in a proportional mixing device While passing 000 L through 5000 L / h (superficial velocity: 0.8 m / sec), nitrogen gas was blown in and aeration was performed at a rate of 37.5 L / min (volume ratio of nitrogen gas / raw milk: 45%) ( Mixed). In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 12.7 ppm. Thereafter, raw milk was temporarily passed through a defoaming tank (200 L capacity). Specifically, a spray nozzle (Spraying Systems Co., Ltd .; product name: Fulljet 22) is installed above the defoaming tank, and a portion of the raw milk that has passed through the defoaming tank is removed. Branched to the spray nozzle at the top of the foam tank and sprayed onto the liquid surface at a flow rate of 500 L / h with a back pressure of 0.07 MPa to eliminate the bubbles and store the tank (20,000 L capacity) ) Was passed through (immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 2.1 ppm and a bubble rate of 5% or less.

Thereafter, raw milk is temporarily stored in a milk storage tank (20,000 L capacity), and then the raw milk is again supplied to the nitrogen gas replacement device at 5000 L / h (superficial velocity: 0.8 m / second). While flowing through, nitrogen gas was blown in and aerated (mixed) at a rate of 50 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.1 ppm.

Thereafter, raw milk was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 10,000 L / h (immediately after the end of the step (C)). The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 0.4 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product).

[Example 3]
After filling the inside of a nitrogen replacement tank (50 L capacity) with a spray nozzle (Spraying Systems Co., Ltd .; product name: Fulljet 1.5) at the top with nitrogen gas, raw milk (raw material) is placed in the nitrogen replacement tank. Milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 11 ppm, specific gravity: 1.03): The entire amount was sprayed from the spray nozzle to the nitrogen replacement tank while passing 20 L at 90 L / h ( Immediately after the end of step (A)). In the raw milk after mixing this nitrogen gas, the dissolved oxygen concentration was 2.0 ppm and the bubble rate was 10% or less.

Thereafter, nitrogen gas was blown into the nitrogen gas replacement device at 150 L / h (empty speed: 0.8 m / sec) while blowing nitrogen gas to 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) was aerated (mixed) proportionally (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.1 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.0 ppm.

Thereafter, raw milk was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 150 L / h (immediately after the end of the step (C)). The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 0.4 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product).

[Example 4]
Nitrogen gas was supplied at a rate of 10 L / min to the inside (around the bowl) of the clarifier (Westphalia Separator, trade name SA-1), which is a separator-type centrifuge, and the oxygen concentration was adjusted to 4%. Later, raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 14.7 ppm, specific gravity: 1.03): 30 L was passed through the clarifier (back pressure: 0 MPa) at 100 L / h ( Immediately after the end of step (A)). In the raw milk after mixing this nitrogen gas, the dissolved oxygen concentration was 2.8 ppm, and the bubble rate was 10% or less.

Thereafter, the raw milk is temporarily stored in a storage tank (100 L capacity) and then passed through the nitrogen gas replacement device at a rate of 150 L / h (superficial velocity: 0.8 m / sec). Then, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). The raw milk after the nitrogen gas was mixed again had a dissolved acidity concentration of 0.3 ppm and a bubble rate of 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.8 ppm.

Thereafter, raw milk was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 150 L / h (immediately after the end of the step (C)). The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 0.6 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product).

[Example 5]
Passing raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 14.7 ppm, specific gravity: 1.03): 30 L at 150 L / h (superficial velocity: 0.8 m / sec) through a nitrogen gas replacement device While being liquid, nitrogen gas was blown in and aerated (mixed) in proportion to 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%). In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 14.7 ppm. Thereafter, raw milk was passed through a clarifier (Westphalia Separator Co., Ltd., trade name: SA-1, back pressure: 0 MPa) which is a separator type centrifuge (immediately after the end of the step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 2.1 ppm and a bubble rate of 10% or less.

Thereafter, the raw milk is temporarily stored in a storage tank (100 L capacity) and then passed through the nitrogen gas replacement device at a rate of 150 L / h (superficial velocity: 0.8 m / sec). Then, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.1 ppm.

Thereafter, raw milk was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 150 L / h (immediately after the end of the step (C)). The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 0.3 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product).

[Example 6]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 11.1 ppm, specific gravity: 1.03): 30 L passed through the nitrogen gas replacement device at 150 L / h (superficial velocity: 0.8 m / sec) While being liquid, nitrogen gas was blown in and aerated (mixed) in proportion to 1.1 L / min (volume ratio of nitrogen gas / raw milk: 45%) (immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 2.1 ppm and a bubble rate of 10% or less. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 11.1 ppm.

After that, after the raw milk is temporarily stored in a milk storage tank (100 L capacity), the inside of the device of the clarifier (Westphalia Separator Co., Ltd., trade name SA-1) which is a separator-type centrifuge ( Nitrogen gas was supplied to the periphery of the bowl at 10 L / min and the oxygen concentration was adjusted to 4%, and then raw milk was passed through the clarifier (back pressure: 0 MPa) at 150 L / h (step (B ) Immediately after the end). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk.

[Example 7]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.3 ppm, specific gravity: 1.03): 30 L to 150 L / h (superficial velocity: 0.8 m / second) to the vortex pump (Nikuni) ), And nitrogen gas was blown in front of the vortex pump and aerated (mixed) at a rate of 0.33 L / min (volume ratio of nitrogen gas / raw milk: 10%) (in step (A)) Immediately after termination). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 3.0 ppm and a bubble rate of 10% or less.

Thereafter, the raw milk is temporarily stored in a storage tank (100 L capacity) and then passed through the nitrogen gas replacement device at a rate of 150 L / h (superficial velocity: 0.8 m / sec). Then, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). The raw milk after the nitrogen gas was mixed again had a dissolved acidity concentration of 0.3 ppm and a bubble rate of 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the nitrogen gas substitution apparatus was 3.0 ppm.

[Example 8]
Eddy current pump (manufactured by Nikuni): Two units were connected in series. Among these, the vortex pump on the upstream side is referred to as a first vortex pump, and the vortex pump on the downstream side is referred to as a second vortex pump. Raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.3 ppm, specific gravity: 1.03): 30 L at 200 L / h (superficial velocity: 0.8 m / sec) to the first vortex pump While flowing, nitrogen gas was blown in front of the first vortex pump and aerated (mixed) at a rate of 0.15 L / min (volume ratio of nitrogen gas / raw milk: 5%). Thereafter, while flowing raw milk through the second vortex pump at 200 L / h (superficial velocity: 0.8 m / sec), nitrogen gas was blown in front of the second vortex pump to obtain 0.15 L / h. Aeration (mixing) was performed in proportion (minus nitrogen gas / raw milk volume ratio: 5%) (immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 2.7 ppm and a bubble rate of 10% or less.

Thereafter, the raw milk is temporarily stored in a storage tank (100 L capacity) and then passed through the nitrogen gas replacement device at a rate of 150 L / h (superficial velocity: 0.8 m / sec). Then, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). The raw milk after the nitrogen gas was mixed again had a dissolved acidity concentration of 0.3 ppm and a bubble rate of 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.7 ppm.

[Example 9]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 13.1 ppm, specific gravity: 1.03): 200 L at 703 L / with a static mixer (inner diameter: 11 mm, 30 elements) installed in a proportional mixing device While flowing at h (superficial velocity: 2.1 m / sec), nitrogen gas was blown in and aerated (mixed) proportionally at 1.25 L / min (volume ratio of nitrogen gas / raw milk: 11%) ( Immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 3.4 ppm and a bubble rate of 10% or less.

Thereafter, the raw milk is temporarily stored in a milk storage tank (200 L capacity), and then passed through the nitrogen gas replacement device at a flow rate of 150 L / h (superficial velocity: 0.8 m / sec). Then, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). The raw milk after the nitrogen gas was mixed again had a dissolved acidity concentration of 0.4 ppm and a bubble rate of 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 3.4 ppm.

Thereafter, raw milk was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 150 L / h (immediately after the end of the step (C)). The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 0.8 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product).

[Example 10]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 280 L / 280 L / liter with a static mixer (inner diameter: 11 mm, 30 elements) installed in a proportional mixing device While flowing at h (superficial velocity: 0.8 m / sec), nitrogen gas was blown in and aerated (mixed) in proportion to 3.5 L / min (volume ratio of nitrogen gas / raw milk: 75%). The raw milk mixed with this nitrogen gas was stored in a storage tank (500 L capacity). Next, raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 105 L is added to the proportional mixing apparatus to 280 L / h (superficial velocity: 0.8 m / h). ), Nitrogen gas was blown in and 1.4 L / min (nitrogen gas / raw milk volume ratio: 30%) was aerated (mixed) proportionally, and the raw milk after this nitrogen gas was mixed Was stored in the milk storage tank (500 L capacity).

Furthermore, raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 105 L is added to the above proportional mixing apparatus to 280 L / h (superficial velocity: 0.8 m / second) ), Nitrogen gas was blown in and 0.7 L / min (nitrogen gas / raw milk volume ratio: 15%) was aerated (mixed) proportionally, and the raw milk after mixing this nitrogen gas was mixed. It stored in the said tank for milk storage (500L capacity) (immediately after completion | finish of a process (A)). In the raw milk after mixing these raw milks, the dissolved oxygen concentration was 2.2 ppm and the bubble rate was 10% or less.

Thereafter, nitrogen gas was blown into the nitrogen gas replacement device at 150 L / h (empty speed: 0.8 m / sec) while blowing nitrogen gas to 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) was aerated (mixed) proportionally (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.2 ppm.

[Example 11]
Raw milk (raw milk, temperature: 10 ° C. or less) in a tank for milk storage (100 L volume) in which an antifoaming device (Toyo Kogyo Co., Ltd., Babkes BK100 type) that breaks bubbles with mechanical shearing force is installed at the top. Dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 80 L was stored. Introducing a static mixer (inner diameter: 23 mm, 38 elements) in a proportional mixing device, while feeding raw milk at 2000 L / h (superficial velocity: 1.3 m / sec), nitrogen gas was blown into 14.3 L / Min (nitrogen gas / raw milk volume ratio: 43%) and aeration (mixing) proportionally, and the raw milk mixed with nitrogen gas is stored in the storage tank and circulated (process ( Immediately after the end of A). In the raw milk after mixing this circulated nitrogen gas, the dissolved oxygen concentration was 2.0 ppm and the bubble rate was 10% or less.

Thereafter, the raw milk is temporarily stored in a milk storage tank (200 L capacity), and then passed through the nitrogen gas replacement device at a flow rate of 150 L / h (superficial velocity: 0.8 m / sec). Then, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.0 ppm.

[Example 12]
In the raw material milk sprayed from above the nitrogen gas replacement device, the nitrogen gas replacement device improved so that the raw material milk replaced with nitrogen gas can be used (in the following examples, abbreviated as “improved nitrogen gas replacement device”). Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.7 ppm, specific gravity: 1.03): nitrogen gas while passing 100 L at 150 L / h (superficial velocity: 0.8 m / sec) Was blown in proportion and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 1.5 ppm and a bubble rate of 5% or less. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the improved nitrogen gas substitution apparatus was 1.5 ppm.

Thereafter, the raw milk is temporarily stored in a milk storage tank (100 L capacity), and then passed through the nitrogen gas replacement device again at 150 L / h (superficial velocity: 0.8 m / sec). While being liquid, nitrogen gas was blown in and proportionally aerated (mixed) at 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.1 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the improved nitrogen gas substitution apparatus was 0.1 ppm.

[Example 13]
In the improved nitrogen gas replacement device, in place of the static mixer (inner diameter: 8 mm, 63 elements), in which the static mixer (inner diameter: 47.8 mm, 18 elements) is installed, raw milk (raw milk, temperature: 10 ° C. or less, Dissolved oxygen concentration: 13.1 ppm, specific gravity: 1.03): While passing 5,000 L at 5000 L / h (superficial velocity: 0.8 m / sec), nitrogen gas was blown to 37.5 L / min ( Nitrogen gas / raw milk volume ratio: 45%) was aerated (mixed) in proportion. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 2.1 ppm. Thereafter, raw milk was temporarily passed through a defoaming tank (200 L capacity). Specifically, a spray nozzle (Spraying Systems Co., Ltd .; product name: Fulljet 22) is installed above the defoaming tank, and a portion of the raw milk that has passed through the defoaming tank is removed. Branched to the spray nozzle at the top of the foam tank, sprayed onto the liquid surface at a flow rate of 500 L / h with a back pressure of 0.07 MPa, and passed through the milk storage tank while eliminating the bubbles ( Immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 2.1 ppm and a bubble rate of 5% or less.

Thereafter, raw milk is temporarily stored in a milk storage tank (20,000 L capacity), and then the raw nitrogen is again supplied to the improved nitrogen gas replacement device at 5000 L / h (superficial speed: 0.8 m / second). ), Nitrogen gas was blown in and 50 L / min (nitrogen gas / raw milk volume ratio: 60%) was aerated (mixed) proportionally (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 0.2 ppm.

[Example 14]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 13.1 ppm, specific gravity: 1.03): 200 L at 703 L / with a static mixer (inner diameter: 11 mm, 30 elements) installed in a proportional mixing device While flowing at h (superficial velocity: 2.1 m / sec), nitrogen gas was blown in and aerated (mixed) proportionally at 1.25 L / min (volume ratio of nitrogen gas / raw milk: 11%) ( Immediately after the end of step (A)). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 3.4 ppm and a bubble rate of 10% or less.

After that, the raw milk is temporarily stored in a milk storage tank (200 L capacity), and then the raw milk is passed through the improved nitrogen gas replacement device at 150 L / h (superficial velocity: 0.8 m / sec). However, nitrogen gas was blown in and aerated (mixed) at a rate of 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). The raw milk after the nitrogen gas was mixed again had a dissolved acidity concentration of 0.4 ppm and a bubble rate of 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the improved nitrogen gas substitution apparatus was 0.4 ppm.

[Example 15]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 280 L / 280 L / liter with a static mixer (inner diameter: 11 mm, 30 elements) installed in a proportional mixing device While flowing at h (superficial velocity: 0.8 m / sec), nitrogen gas was blown in and aerated (mixed) in proportion to 3.5 L / min (volume ratio of nitrogen gas / raw milk: 75%). The raw milk mixed with nitrogen gas was stored in a storage tank (500 L capacity). Next, raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 105 L is added to the proportional mixing apparatus to 280 L / h (superficial velocity: 0.8 m / h). Second), nitrogen gas was blown in and 1.4 L / min (nitrogen gas / raw milk volume ratio: 30%) was aerated (mixed) proportionally, and the raw milk after the nitrogen gas was mixed It stored in the said tank for milk storage (500L capacity).

Furthermore, raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.0 ppm, specific gravity: 1.03): 105 L is added to the above proportional mixing apparatus to 280 L / h (superficial velocity: 0.8 m / second) ), Nitrogen gas was blown in and 0.7 L / min (nitrogen gas / raw milk volume ratio: 15%) was aerated (mixed) proportionally, and the raw milk mixed with nitrogen gas was Was stored in a tank for storing milk (500 L capacity) (immediately after the end of the step (A)). In the raw milk after mixing these raw milks, the dissolved oxygen concentration was 2.2 ppm and the bubble rate was 10% or less.

Thereafter, nitrogen gas was blown into the improved nitrogen gas replacement device at a flow rate of 150 L / h (empty speed: 0.8 m / sec) and 1.5 L / min (volume ratio of nitrogen gas / raw milk). : 60%) and aerated (mixed) proportionally (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.2 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the improved nitrogen gas substitution apparatus was 0.2 ppm.

[Example 16]
In the improved nitrogen gas replacement device, raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.7 ppm, specific gravity: 1.03): 100 L at 150 L / h (superficial velocity: 0.8 m / sec) While flowing, nitrogen gas was blown in and aerated (mixed) at a rate of 0.75 L / min (volume ratio of nitrogen gas / raw milk: 30%) (immediately after the end of step (A)). In the raw milk after mixing this nitrogen gas, the dissolved oxygen concentration was 7.1 ppm and the bubble rate was 5% or less. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the improved nitrogen gas substitution apparatus was 7.1 ppm.

Thereafter, the raw milk is temporarily stored in a milk storage tank (100 L capacity), and then the raw nitrogen is again supplied to the improved nitrogen gas replacement device at 150 L / h (superficial velocity: 0.8 m / sec). While flowing, nitrogen gas was blown in and proportionally aerated (mixed) at 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%) (immediately after the end of step (B)). In the raw milk after the nitrogen gas was mixed again, the dissolved acidity concentration was 0.8 ppm, and the bubble rate was 5% or less. At this time, almost no foaming was observed in the raw milk. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper direction of the improved nitrogen gas substitution apparatus was 0.8 ppm.

[Comparative Example 1]
Raw milk (raw milk, temperature: 10 ° C. or less, dissolved oxygen concentration: 12.7 ppm, specific gravity: 1.03): 100 L passed through the nitrogen gas replacement device at 150 L / h (superficial velocity: 0.8 m / sec). While being liquid, nitrogen gas was blown in and aerated (mixed) in proportion to 1.5 L / min (volume ratio of nitrogen gas / raw milk: 60%). The raw milk after mixing this nitrogen gas had a dissolved oxygen concentration of 1.7 ppm and a bubble rate of 5% or less. In addition, the dissolved oxygen concentration of the raw material milk sprayed from the upper part of the nitrogen gas substitution apparatus was 12.7 ppm. Thereafter, raw milk was passed through a sterilizer (heat sterilization conditions: 130 ° C., 2 seconds) at 150 L / h. The milk (sterilized milk) after heat sterilization had a dissolved oxygen concentration of 1.7 ppm, a bubble rate of 5% or less, and a liquid temperature of 10 ° C. or less. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product). However, the milk of Comparative Example 1 did not have a fresh flavor as compared to the milk of Example 1 and the like because the dissolved oxygen concentration exceeded 1 ppm.

[Comparative Example 2]
Raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 12.7 ppm, specific gravity: 1.03): 100 L was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 150 L / h. . In milk (sterilized milk) after this heat sterilization (immediately after the end of step (C)), the dissolved oxygen concentration is 7.1 ppm, the bubble rate is 5% or less, and the liquid temperature is 10 ° C. or less. It was. At this time, almost no foaming was observed in the milk (milk-containing beverage as the final product). However, the milk of Comparative Example 2 did not have a fresh flavor as compared with the milk of Example 1 or the like because the dissolved oxygen concentration exceeded 1 ppm.

[Comparative Example 3]
Passing raw milk (raw milk, temperature: 10 ° C. or lower, dissolved oxygen concentration: 11.0 ppm, specific gravity: 1.03): 100 L at 150 L / h (superficial velocity: 0.8 m / sec) through a nitrogen gas replacement device. While being liquid, nitrogen gas was blown in and aerated (mixed) proportionally at 7.5 L / min (volume ratio of nitrogen gas / raw milk: 300%) (immediately after the end of step (A)). In the raw milk after mixing this nitrogen gas, the dissolved oxygen concentration was 0.8 ppm, and the bubble ratio exceeded 10%.

Thereafter, raw milk was passed through a sterilizer (heat sterilization condition: 130 ° C., 2 seconds) at 150 L / h (immediately after the end of the step (C)). In the milk (sterilized milk) after heat sterilization, the dissolved oxygen concentration was 0.9 ppm, the bubble ratio exceeded 10%, and the liquid temperature was 10 ° C. or lower. At this time, milk (the milk-containing beverage which is the final product) was intensely foamed, resulting in a decrease in production efficiency.

Claims

(A) After controlling the supply method and supply conditions of the inert gas treatment, and performing the inert gas treatment on the raw milk so that the bubble rate of the raw milk is 10% or less, the raw milk is A first oxygen concentration reduction step for discharging and obtaining raw milk with reduced dissolved oxygen concentration;
(B) The inert gas treatment is performed on the raw milk so that the supply method and supply conditions of the inert gas treatment are controlled and the bubble rate of the raw milk obtained in the first oxygen concentration reduction step is 10% or less. And a second oxygen concentration reduction step for obtaining raw milk with reduced dissolved oxygen concentration,
(C) a heat sterilization step for heat sterilizing the raw material milk obtained in the second oxygen concentration reduction step,
A method for producing a milk-containing beverage comprising
The method for producing a milk-containing beverage according to claim 1, wherein raw milk of 8 ppm or less is obtained in the first oxygen concentration reduction step.
The method for producing a milk-containing beverage according to claim 1 or 2, wherein raw milk of 1 ppm or less is obtained in the second oxygen concentration reduction step.
A supply method by an inert gas treatment in each of the first oxygen concentration reduction step and the second oxygen concentration reduction step,
(A) mixing raw milk and inert gas using a proportional mixing device;
(B) spraying raw milk into a device having a space filled with an inert gas;
(C) mixing raw milk and inert gas using a centrifuge,
(D) mixing raw milk and inert gas using a pump;
(E) Blowing inert gas into the raw milk contained in the tank,
The method for producing a milk-containing beverage according to any one of claims 1 to 3, wherein the method is carried out by one or a combination of two or more selected from among the above.
In at least one of the first oxygen concentration reduction step and the second oxygen concentration reduction step, the inert gas treatment includes (a) mixing raw material milk and inert gas using a proportional mixing device. Done,
In mixing raw material milk and inert gas using the proportional mixing device of (a), the supply rate of inert gas relative to the supply rate of supply of raw material milk (supply amount per unit time) (supply amount per unit time) ) Volume ratio (volume of inert gas / volume of raw milk) is 5 to 70%,
The manufacturing method of the milk-containing drink of Claim 4.