JP2006025738A - Method for producing drink packed in vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a drink packed in a vessel and capable of more effectively solving conflicting problems comprising the decrease of oxygen in the vessel and the stabilization of inner pressure. <P>SOLUTION: A gas-liquid mixer 4 is connected to a liquid-transfer line from a cushion tank 3 for primarily storing a liquid to be supplied to a filler 5 to the filler 5, an inert gas is pressed into the liquid to be supplied to a filler bowl and the inert gas supersaturated in the liquid is degassed in the filler bowl to lower the dissolved oxygen content in the liquid. The liquid is filled at a temperature controlled to a temperature range satisfying the temperature to suppress the foaming in the filling process and the temperature to stably keep the inner pressure according to the kind of the liquid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a canned beverage such as a canned beverage, and more particularly to a method for producing a canned beverage in which the amount of oxygen in the canned beverage is reduced and the internal pressure variation is suppressed.

  In recent years, from the viewpoint of resource saving and cost reduction, for example, it has been put into practical use to fill thin cans with low-oxidative beverages such as tea beverages that are susceptible to oxidative degradation and milk-containing beverages that are likely to rot. ing. In that case, the strength of the container is ensured by positively pressurizing the inside of the container, but in order to assure the quality of the contents, it is essential to reduce oxygen in the container and reduce variations in internal pressure. In particular, in the case of positive pressure packaging of contents that are easily spoiled, internal pressure variation due to filling with liquid nitrogen must be suppressed as much as possible so that even a slight increase in gas amount due to the spoilage of the contents can be reliably identified. Conventionally, such a method for producing a positive-pressure container-packed beverage has a gas replacement step of substituting headspace gas (air) with an inert gas as means for reducing oxygen in the container, and means for positiveizing the internal pressure. This is performed by a combination of liquefied inert gas (usually liquid nitrogen) filling steps. The present applicant has made various proposals for reducing the amount of oxygen in the container. For example, in a canned production line in which the gas in the can head space after filling the contents is replaced with an inert gas and wound and sealed, the can is transferred from the can feed turret onto the can that has been replaced with gas. Cover the section until the lid is fitted with a semi-sealed cover to form a low oxygen concentration intake zone, fit the lid to the can in an atmosphere maintained at an oxygen concentration of 2% or less, and wind with a seamer in that state It was proposed that tightening was performed (see Patent Document 1). In addition, as a means for producing positive pressure by suppressing variation in internal pressure and enabling production of low positive pressure cans, a method of filling liquid nitrogen in fine particles (mist form) has been proposed (see, for example, Patent Documents 2 and 3). ).

However, it is difficult to satisfy both the reduction in the amount of oxygen and the suppression of variations in internal pressure. For example, in order to reduce the amount of oxygen in the container, it is desirable not only to improve the gas replacement rate of the head space but also to reduce the amount of dissolved oxygen in the content liquid. It is difficult to reduce the amount of dissolved oxygen by the conventional gas replacement method, and other means must be taken. Conventionally, as a method for reducing dissolved oxygen, it is known to perform filling at a high filling temperature. However, filling with a liquefied inert gas at a high liquid temperature has a drawback that internal pressure tends to vary. Therefore, it is desirable that the filling temperature is changed from the hot pack region to the normal temperature region from the viewpoint of suppressing the internal pressure variation. However, in this case, the head space volume is increased and the amount of dissolved oxygen in the liquid is increased as compared with the case of high temperature filling, which causes a problem that the amount of oxygen in the container after sealing is increased. Thus, the reduction of the amount of oxygen and the suppression of the variation in internal pressure are contradictory and it is difficult to achieve both. Also, if there is foaming of the content liquid, the air in the foam will remain in the can as it is, which is extremely disadvantageous for reducing oxygen, so it is desirable to reduce foaming at the time of filling, but at the time of filling Foaming varies depending on the filling temperature, and also varies depending on the type of content liquid, and is not necessarily uniform, which makes it difficult to reduce the amount of oxygen.
JP 2004-123217 A JP-A-12-128122 JP 2001-48120 A

  Therefore, in order to more effectively reduce the amount of oxygen in the packaged beverage and suppress the variation in the internal pressure, it is not sufficient to simply devise the gas replacement step and the liquid nitrogen filling step, reducing the dissolved oxygen, Although it is necessary to comprehensively improve the filling temperature and foaming suppression at the time of filling, conventionally, a satisfactory method for achieving a reduction in the amount of oxygen in a packaged beverage and a reduction in internal pressure variation from that point of view is Not yet proposed.

  The present invention was devised in view of the above circumstances, and in a production line for packaged beverages, the filling temperature of the content liquid, foaming suppression at the time of filling, etc. are also comprehensively improved, It is an object of the present invention to provide a method for producing a packaged beverage that can effectively achieve the problems of reducing dissolved oxygen, reducing the amount of oxygen in the container head space, and stabilizing the internal pressure with little variation in internal pressure.

  In order to effectively achieve (1) removal of oxygen in the liquid, (2) removal of oxygen in the head space, and (3) ensuring positive pressure stability, the present inventor conducted research to solve the above problems. We investigated whether there is an effective solution from the viewpoint of the state of the liquid to be filled, not just the conventional gas replacement means and liquid nitrogen filling means. As a result, in the removal of oxygen in the liquid (1), instead of the conventional method of reducing the amount of dissolved oxygen by increasing the temperature of the content liquid, the content liquid is removed from the content liquid before filling without heating. We have found a method that can forcibly remove oxygen. Thereby, as will be described later, it is possible to remove the dissolved oxygen by lowering the filling temperature, and it is possible to reduce the dissolved oxygen and suppress the variation in the internal pressure.

  In addition, in the head space oxygen removal of (2), the replacement of the gas existing in the head space can be effectively performed by adopting the method described in Patent Document 1 previously proposed. , If bubbles exist in the head space, the amount of air that cannot be replaced by gas is increased by being trapped inside the bubbles. Therefore, as a more effective oxygen reduction method, research was conducted from the viewpoint of preventing bubbles during filling. As a result, the temperature range in which foaming of the content liquid at the time of filling can be effectively suppressed was found, and the temperature of the content liquid was controlled within that temperature range, thereby making it possible to further reduce the amount of oxygen.

  Furthermore, for ensuring positive pressure stability in (3), the amount of head space after sealing is affected by the temperature of the content liquid at the time of sealing, and the residual amount in the container until sealing of liquid nitrogen to be filled is also the temperature of the content liquid. As a result, the temperature control of the content liquid was an important factor for ensuring the internal pressure stability, and the solution was achieved by controlling the temperature of the content liquid.

  The present invention has been achieved as a result of the above-described research, and the method for producing a packaged beverage of the present invention that solves the above-described problems is the production of a packaged beverage that is sealed by replacing the gas in the head space with an inert gas. In the method, an inert gas is injected into the content liquid supplied to the filler bowl to forcibly reduce dissolved oxygen in the liquid.

  Various methods can be adopted for injecting the inert gas into the content liquid supplied to the filler bowl. As a preferred example, the content liquid supplied to the filler is primarily sent from the cushion tank to the filler. Connect the gas-liquid mixer to the liquid stroke, press the inert gas into the content liquid to be supplied to the filler bowl, and reduce the dissolved oxygen in the liquid by discharging the over-dissolved inert gas in the filler bowl. Can do. At that time, a gas venting mechanism is provided at the top of the filler bowl, and the gas in the head space of the filler bowl is forcibly evacuated to remove the inert gas that has been dissolved in the liquid and the dissolved oxygen in the liquid. Can be promoted. In addition, an inert gas blowing pipe that blows out inert gas in the cushion tank is arranged, and the inert gas in the liquid is forced in the cushion tank by injecting the inert gas into the liquid in the cushion tank. It can be removed and dissolved oxygen can be further reduced.

  As another method for injecting an inert gas into the content liquid supplied to the filler bowl, in the case of a high-temperature content liquid, the inert gas is blown out into a cushion tank that primarily stores the content liquid supplied to the filler. An inert gas ejection pipe is arranged, and a cooling pipe is connected during the liquid feeding process from the cushion tank to the filler, and an inert gas is press-fitted into the high-temperature content liquid in the cushion tank. By cooling the high-temperature content liquid into which the gas has been injected while being supplied to the filler, the dissolved oxygen in the liquid can be reduced. Furthermore, as another method, a gas-liquid mixer is connected to the liquid supply process to the cushion tank, and an inert gas is press-fitted into the content liquid supplied to the cushion tank so that the over-dissolved inert gas is contained in the filler bowl. It is also possible to employ means for reducing dissolved oxygen in the liquid.

  Filling the content liquid by controlling the filling temperature of the content liquid to a temperature at which foaming during filling can be suppressed according to the type of the content liquid reduces the generation of bubbles in the container, and gas replacement The rate can be improved. When the container-packed beverage is a positive-pressure-filled container-packed beverage filled with a liquefied inert gas and sealed, the filling temperature of the content liquid is suppressed according to the type of the content liquid, and foaming during filling is suppressed. By controlling to a temperature range satisfying both the temperature capable of ensuring the stability of the internal pressure and the internal pressure, and filling the content liquid, it is effective in reducing the amount of oxygen in the container and stabilizing the internal pressure. Specifically, the temperature range to achieve this is 15 ° C to 45 ° C for drinks with milk, 45 ° C to 65 ° C for tea-based beverages, 30 ° C to 45 ° C for black coffee, and foaming during filling is temperature dependent. A low beverage is preferably in the range of 15 ° C to 45 ° C.

  As described above, according to the inventions of claims 1 to 9 of the present application, the dissolved oxygen in the liquid is removed by forcibly injecting the inert gas into the content liquid before filling. Oxygen can be removed. At that time, the content liquid does not need to be heated, and any low temperature can be selected. Therefore, it is possible to select a good filling temperature for suppressing foaming at the time of filling and positive pressure stability. It is possible to reduce both the amount of oxygen and the variation in internal pressure.

  Further, according to the invention of claim 2, the inert gas can be forcibly dissolved in the content liquid by a gas-liquid mixer such as a static mixer in the liquid supply process to the filler bowl. When the inert gas over-dissolved in the liquid is released, the dissolved oxygen is also released, and the dissolved oxygen can be effectively reduced. According to the invention of claim 3, it is possible to further promote the escape of dissolved oxygen in the liquid by forced exhaust. Further, according to the invention of claim 4, since the inert gas is blown into the liquid in the cushion tank, the dissolved oxygen is removed even at this point. Therefore, by combining with the structure of claim 2 or 3, it is possible to further reduce the dissolved oxygen. Furthermore, according to the invention of claim 5, it is more effective in reducing dissolved oxygen when the content liquid is at a high temperature. According to the invention of claim 6, since the inert gas is forcibly injected by the gas-liquid mixer, the same effect as that of the structure of claim 2 is obtained. Further, according to the invention of claim 7, since the content liquid is filled at a temperature that can suppress foaming during filling, the generation of bubbles in the container is reduced, and the gas replacement rate can be improved. . And according to invention of Claim 8 and Claim 9, according to the kind of content liquid, the filling temperature of the said content liquid is the temperature which can suppress the foaming at the time of filling, and the temperature which can ensure stability of an internal pressure. Since the content liquid is filled by controlling to a temperature range satisfying both, reduction of the oxygen amount and stabilization of the internal pressure can both be effectively improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a process diagram of a production line for positive pressure beverage canned food according to an embodiment of the present invention. The liquid content is controlled to a predetermined temperature by passing through the heat exchanger 1, and in the case of a beverage containing milk, it is homogenized by the homogenizer 2 and sent to the cushion tank 3. As schematically shown in FIG. 2, the cushion tank 3 is configured so that dissolved oxygen can be reduced by feeding nitrogen gas into the liquid and expelling oxygen present in the liquid with the nitrogen gas. Has been. That is, a nitrogen gas ejection pipe 15 having a large number of nozzles for ejecting nitrogen gas is arranged in the vicinity of the bottom in the cushion tank 3, and as schematically shown, nitrogen gas is blown from the bottom. , Nitrogen gas is dissolved in the content liquid, dissolved oxygen dissolved in the liquid is extruded, and dissolved oxygen can be reduced. In order to prevent oxidation of the contents, it is desirable to replace the gas in the cushion tank 3 in advance with a nitrogen gas atmosphere.

  The content liquid in which dissolved oxygen is reduced in the cushion tank 3 is then sent to the filler 5 and packed in the container. In the present invention, the gas-liquid mixer 4 is disposed between the cushion tank 3 and the filler 5. Nitrogen gas is injected into the liquid. As the gas-liquid mixer 4, a conventionally known static mixer (for example, see JP-A-2003-292506) can be used. By passing through the gas-liquid mixer 4, nitrogen gas is contained in the liquid. It is designed to be press-fitted. The content liquid that has passed through the gas-liquid mixer 4 is sent to the filler 5. Since the filler bowl has a head space and is released to the atmosphere, the nitrogen gas that has been over-dissolved in the liquid escapes from the liquid into the head space in the filler bowl, and at the same time, dissolved oxygen in the liquid also dissolves in the head space. Get inside. In order to further facilitate degassing from the liquid, it is desirable to provide a degassing mechanism for extracting the gas in the head space of the filler bowl to the outside at the top of the filler bowl. The liquid temperature at the time of filling is preferably controlled to 15 ° C. or higher, preferably 25 ° C. or higher so that oxygen does not dissolve again in the liquid after the gas injection step. According to the experiment of the present inventor, it was confirmed that when the liquid temperature is 15 ° C. or lower, oxygen is easily redissolved even after the dissolved oxygen is reduced by gas injection.

  The container 5 is filled with the content liquid by the filler 5 and sent to the seamer 8, while liquid nitrogen filling for gas replacement of the head space and positive internal pressure is performed. The container transportation process from the gas replacement process to the winding process is the vicinity where the can and the lid join from the gas replacement position where inert gas (nitrogen gas) is blown into the head space as described in Patent Document 1 previously proposed. It is surrounded by a semi-enclosed gas replacement tunnel 6 up to the position, and a low oxygen concentration zone is formed by blocking the intrusion of outside air between them, and a liquid nitrogen filling device 7 is arranged downstream of the gas replacement position to perform gas replacement. The container is filled with liquid nitrogen, and sealed with a seamer 8 in a state where a predetermined amount of liquid nitrogen is filled in the container. By adopting a liquefied gas spray filling device, for example, as described in Patent Document 2 as a liquid nitrogen filling device, a small amount of liquid nitrogen can be filled stably without variation. Canned food can be stably obtained with little variation. The positive-pressure container-packed beverage thus produced (positive-pressure beverage canned product) is retort-sterilized in the retort kettle 9 as necessary, and packed in a box 10 before shipment.

By the way, in the manufacturing process described above, in order to stabilize the internal pressure by further reducing the amount of oxygen and variation in the internal pressure, filling in order to achieve both the removal of residual oxygen and the suppression of the variation in the internal pressure of the container-packed beverage product. Whether there is a correlation between temperature and oxygen removal in liquid, filling temperature and headspace oxygen removal (filling temperature and bubble suppression), filling temperature and positive pressure stabilization Confirmed by experiment.
As a result, when the dissolved oxygen is removed by injecting an inert gas with a gas-liquid mixer as in the above embodiment, the relationship between the filling temperature and the removal of oxygen in the liquid is as follows: Low and any filling temperature can be employed. However, since the oxygen is easily dissolved when the liquid temperature is 15 ° C. or lower, in order to prevent re-dissolution of oxygen when the container is filled with the content liquid after injecting the inert gas, the liquid temperature is 15 ° C. or higher. Desirably, the temperature is controlled to 25 ° C or higher.

Next, the effect of filling temperature on foaming during filling is as follows: liquid temperature at filling for milk tea, milk coffee, dairy drink, green tea, barley tea, mixed tea, black coffee, sports drink, fruit juice drink, vegetable drink As shown in Table 1, the experiment was carried out in 5 stages between 10 and 75 ° C.
In the experiment, assuming the foaming at the time of filling with the filler, the ease of foaming of the liquid by gravity dropping was evaluated by the dropping method shown below.
200 ml of a test solution having a predetermined temperature was dropped from a certain height into a 300 ml measuring cylinder through a funnel, and the foaming state after a certain time (20 seconds) after the total amount of the solution was dropped was evaluated according to the following criteria.
◎: The liquid level appears almost completely and almost no bubbles remain. ○: The liquid level is visible and bubbles remain around. △: The bubbles remain thin on the entire liquid level. Table 1 shows the results of covering.

  As a result, in the case of beverages containing milk (milk tea, milk coffee, dairy beverages), the lower the temperature, the less foaming, and at 45 ° C or lower, there is little foaming in the state where bubbles remain, and there is almost no foaming at 10 ° C. Although it did not remain, when it reached 60 ° C. or higher, bubbles remained on the entire liquid surface. Therefore, in the case of a milk-containing beverage, the filling temperature is desirably 45 ° C. or lower in order to suppress the generation of foam. Conversely, in the case of tea-based beverages (green tea, barley tea, mixed tea), the higher the temperature, the less foaming, and a filling temperature of 60 ° C. or higher, preferably 75 ° C. or higher, is desirable for suppressing the occurrence of foaming. In addition, in the case of black coffee, the temperature dependence was less than that of the above two types of beverages, but there was less foaming at 45 ° C. or higher. Furthermore, sports drinks, fruit juice drinks, and vegetable drinks had little foaming during filling, and had almost no temperature dependence. Therefore, from the results of this experiment, in order to reduce the generation of bubbles and reduce the amount of oxygen in the headspace when filling these beverages, the filling temperature is 45 ° C. or less for milk beverages and 60 ° C. for tea beverages. As described above, it was found that the temperature of black coffee is preferably 45 ° C. or higher, and sports beverages, fruit juice beverages, and vegetable beverages have low temperature dependency, and the filling temperature can be arbitrarily selected.

  In addition, the relationship between the filling temperature and the positive pressure stabilization is that when the container is filled, the volume of the head space increases as the liquid temperature is lower, so that the liquefied inert gas to be added can be prevented from scattering outside the container. In the positive pressure filling by the liquefied inert gas filling method, the lower the filling temperature, the less the variation in the internal pressure of the container. As a result of the experiment, the stability of the positive pressure was extremely stable at a filling temperature of 45 ° C. or lower, stable at 65 ° C. or lower, and slightly unstable at 65 ° C. or higher. Therefore, in order to stabilize the positive pressure, the filling temperature is 65 ° C. or lower, more desirably 45 ° C. or lower.

  From the above results, when comprehensively evaluating the removal of oxygen in the liquid, the removal of oxygen in the head space, and ensuring positive pressure stability, the appropriate filling temperature range of the content liquid is 15 ° C to 45 ° C for drinks with milk, It was found that the tea-based beverage was 45 ° C. to 65 ° C., the black coffee was 30 ° C. to 45 ° C., and the beverage having low foaming temperature dependency was 15 ° C. to 45 ° C. The above results are summarized in Table 2. Therefore, when manufacturing a packaged beverage, the above temperature range is set by the heat exchanger 1 according to the type of contents to be filled, and the temperature at the time of filling is controlled to be within the above range.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the technical idea. For example, in the above embodiment, the gas-liquid mixer is provided on the downstream side of the cushion tank, but it may be provided on the upstream side. In addition, when the content liquid is hot, an inert gas blowing pipe is arranged in the cushion tank in the same manner as in the above embodiment, and a cooling pipe is connected to the downstream side of the cushion tank so that the high-temperature content in the cushion tank. An inert gas may be injected into the liquid, and the high-temperature content liquid into which the inert gas is injected may be cooled to a predetermined temperature while being supplied to the filler bowl. Moreover, although the above embodiment demonstrated the manufacturing method of positive pressure canning, this invention is not limited to it, The container packing manufacturing method of this invention is effective in reducing the oxygen amount of a container. Therefore, it is not necessarily limited to positive pressure canning, but is also effective in reducing the amount of oxygen in negative pressure canning. Needless to say, the container is not limited to canned food but can be applied to plastic container-packed beverages and the like.

  The method for producing a packaged beverage of the present invention is effective in removing dissolved oxygen and oxygen in the headspace of the packaged beverage, and is applicable not only to the production of a gas replacement packaged beverage, but also at a low liquid temperature. Since the amount can be reduced and it is compatible with stable internal pressure, it is particularly applicable to the production of gas-substituted positive-pressure container-packed beverages, and the containers can be applied to canned, bottled, and other methods for producing bottled beverages.

It is a block diagram which shows the process of the production line of the positive pressure drink canned goods based on embodiment of this invention. It is a conceptual diagram of the cushion tank part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Homogenizer 3 Cushion tank 4 Gas-liquid mixer 5 Filler 6 Gas replacement tunnel 7 Liquid nitrogen filling device 8 Cima 9 Retort device 10 Packing device 15 Nitrogen gas ejection pipe

Claims (9)

  In a method for producing a container-packed beverage in which the gas in the head space is replaced with an inert gas and sealed, the inert gas is injected into the content liquid supplied to the filler bowl to forcibly reduce dissolved oxygen in the liquid. A method for producing a packaged beverage.   A gas-liquid mixer is connected to the liquid supply process from the cushion tank that primarily stores the content liquid to be supplied to the filler to the filler, and an inert gas is injected into the content liquid to be supplied to the filler bowl to prevent overdissolution. The method for producing a packaged beverage according to claim 1, wherein dissolved oxygen in the liquid is reduced by allowing the active gas to escape in the filler bowl.   A gas venting mechanism is provided at the upper part of the filler bowl, and the gas in the head space of the filler bowl is forcibly evacuated so as to promote the removal of the inert gas dissolved in the liquid and the dissolved oxygen in the liquid. The method for producing a packaged beverage according to claim 2.   An inert gas jet pipe for blowing out inert gas is disposed in a cushion tank that primarily stores the content liquid supplied to the filler, and the inert gas is pressed into the room temperature content liquid in the cushion tank. The method for producing a packaged beverage according to any one of claims 1 to 3, wherein dissolved oxygen in the liquid is forcibly reduced.   An inert gas jet pipe for blowing out inert gas is disposed in a cushion tank that primarily stores the liquid content to be supplied to the filler, and a cooling pipe is provided between the cushion tank and the filler. Connected, pressurizes an inert gas into the high-temperature content liquid in the cushion tank, and cools the high-temperature content liquid into which the inert gas is injected during supply to the filler, thereby reducing dissolved oxygen in the liquid. The manufacturing method of the container-packed drink of Claim 1 to reduce.   A gas-liquid mixer is connected to the liquid supply process to the cushion tank, an inert gas is press-fitted into the content liquid supplied to the cushion tank, and the over-dissolved inert gas escapes in the filler bowl, thereby The manufacturing method of the container-packed drink of Claim 1 or 4 which reduces the dissolved oxygen of.   The filling temperature of the content liquid is controlled to a temperature at which foaming at the time of filling can be suppressed in accordance with the type of the content liquid, and the content liquid is filled. A method for producing a containerized beverage.   The container-packed beverage is a positive-pressure-filled container-packed beverage filled and sealed with a liquefied inert gas, and the filling temperature of the content liquid is a temperature at which foaming during filling can be suppressed according to the type of the content liquid, The method for producing a packaged beverage according to any one of claims 1 to 6, wherein the content liquid is filled by controlling to a temperature range that satisfies both a temperature at which the internal pressure can be stably secured.   The temperature ranges are 15 ° C to 45 ° C for milk-containing beverages, 45 ° C to 65 ° C for tea-based beverages, 30 ° C to 45 ° C for black coffee, and foaming during filling has low temperature dependence. The method for producing a packaged beverage according to claim 8, wherein the beverage is 15 ° C to 45 ° C.

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