JP2010136636A - Method for producing milk-fermented product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably and efficiently producing a milk-fermented product having higher viscosity than a conventional one without addition of any specific additive. <P>SOLUTION: The method for producing the milk-fermented product includes encapsulating raw material consisting mainly of sterilized milk or a milk product, and Lactococcus cremoris in a hermetically sealed container made of material having an oxygen permeability of 50 fmol/m<SP>2</SP>× s × Pa or less, and adjusting initial dissolved oxygen to not more than 10 ppm and then fermenting the mixture. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a fermented milk product, and more particularly to a method for producing a post-fermentation type fermented milk product having a strong viscosity.

  In recent years, a fermented milk named “Caspian Sea Yogurt”, which is derived from the Caucasus region and has strong viscosity and spinnability, has attracted attention.

  From this fermented milk product, Lactococcus lactis subsp. Cremoris (hereinafter referred to as “Cremolis”), which is a kind of lactic acid bacterium producing viscous polysaccharides, has been isolated and identified (non-Cremoris bacterium). Patent Document 1). It has been reported that this viscous polysaccharide (extracellular polysaccharide) has various physiological functions as well as simply imparting sensory characteristics to the fermented milk (Non-patent Document 2).

  In addition, Acetobacter orientalis, a kind of acetic acid bacteria, has been isolated and identified as its coexisting bacteria, and it is known that acetic acid bacteria consume part of lactic acid produced by Cremoris during fermentation. ing. In addition, it has been speculated that by suppressing the decrease in the number of bacteria of Cremoris and maintaining the viscosity of the fermented product by growing near the surface of the fermented product and making the inside anaerobic (non-patent document) 3).

In addition, what is disclosed by patent document 1 and 2 is known as a prior art regarding post-fermentation type | mold fermented milk.
JP 2001-269113 A Japanese Patent Laid-Open No. 2003-158997 T. ISIDA, A. YOKOTA, Y. UMEZAWA, T. TODA and K. YAMADA Identification of the Strains Isolated from Caucasusian Fermented Milk: J. Nutr Sci Vitaminal. 51, 187-193 (2005) Yukio Iemori, “The Truth of Caspian Sea Yogurt” 91-97, 2002 published by Hoken H.NAKAJIMA, Y. SUZUKI, H. KAIZU and T. HIROTA Cholesterol lowering activity of ropy fermented milk.J. Food Sci., 57,1327-1329 (1992)

  In order to increase the viscosity and spinnability of the so-called “Caspian Sea Yogurt”, a conventional technique in which a medium mainly composed of milk is dispensed into a normal paper or plastic container, inoculated with Cremoris bacteria, and post-fermented. Depending on the milk fermented product manufacturing method, the concentration of dissolved oxygen in the milk fermented product cannot be kept low, so there is a limit to increasing the viscosity of the milk fermented product by increasing the viscous polysaccharides produced by Cremoris bacteria. There is.

  In addition, even if acetic acid bacteria such as Acetobacter orientalis are inoculated at the same time and post-fermented, there is a slight effect on stabilizing the properties of the fermented milk product (maintaining the viscosity and spinnability of the fermented milk product). However, it is difficult to increase the viscosity of the milk fermented product by increasing the viscous polysaccharides produced by Cremoris bacteria.

  In addition, in the production method in which Cremoris is inoculated in a milk-based medium and pre-fermented with a low concentration of dissolved oxygen in the fermented milk, the series of steps must be maintained in an anaerobic state at all times. It is impossible to implement on a commercial basis. Moreover, it is difficult to fill the container without breaking the pre-fermented yogurt card.

  The present invention has been made in view of the above circumstances, and provides a method for producing a fermented milk product that stably and efficiently produces a fermented milk product having higher viscosity than before without adding a special additive. With the goal.

  As a result of diligent study, the inventors of the present invention, when post-fermenting in a sealed container made of a material having low oxygen permeability, by adjusting the initial dissolved oxygen to 10 ppm or less, stable milk fermented product with higher viscosity than before The present invention has been completed by finding that it can be manufactured efficiently and efficiently.

Specifically, the present invention
In a sealed container made of a material having an oxygen permeability of 50 fmol / m ² · s · Pa or less,
Enclose the raw material and the Cremoris bacteria which are mainly composed of sterilized milk or dairy products,
The present invention relates to a method for producing a fermented milk product, characterized in that initial dissolved oxygen is adjusted to 10 ppm or less and post-fermented.

  When post-fermentation of pasteurized milk with Cremolis bacteria in a sealed container, if the dissolved oxygen concentration in the raw milk sterilized at the start of culture is adjusted to 10 ppm or less, the fermented product has anaerobic conditions suitable for the growth of Cremoris bacteria. Become. As a result, the production amount of the viscous polysaccharide is increased and the viscosity of the fermented milk product is increased.

If the sealed container is not made of a material having low oxygen permeability, oxygen in the atmosphere is dissolved in the fermented milk product, and the fermented milk product cannot be maintained in an anaerobic state suitable for the Cremoris bacteria. For this reason, it is necessary not only to adjust the dissolved oxygen concentration in the sterilized raw milk to 10 ppm or less, but also to form a sealed container from a material having an oxygen permeability of 50 fmol / m ² · s · Pa or less.

  In the present invention, the “raw material mainly composed of milk or dairy product” is a dairy product produced from animal milk such as milk or animal milk such as cow milk, and is known to be usable as a raw material for yogurt. Means what is being done.

The material having an oxygen permeability of 50 fmol / m ² · s · Pa or less is preferably a material including a laminate of an aluminum foil, an aluminum deposited film, a silica deposited film, or an alumina deposited film.

The sealed container is preferably a pouch container having an injection member that can be opened and closed. This is because it is convenient when taking out a fermented milk product having a higher viscosity than conventional ones, and has less oxygen intrusion when storing the left fermented milk product. In addition, the material or thickness of the injection member that can be opened and closed is not limited as long as the oxygen permeability is 50 fmol / m ² · s · Pa or less.

The viable count of Lactococcus lactis subspices cremollis starter sealed in the sealed container is in the range of 1.0 × 10 ⁶ cfu / g or more and 1.0 × 10 ⁹ cfu / g or less, and the amount of inoculation is sterilized. It is preferable to be 0.3 wt% or more and 20 wt% or less with respect to the raw material milk. In addition, the viable count of Lactococcus lactis subspices cremolith starter is in the range of 1.0 x 10 ⁷ cfu / g to 5.0 x 10 ⁸ cfu / g And more preferably 0.5% or more and 10% or less.

In addition, when Acetobacter orientalis is inoculated at the same time, the starter's viable count is 1.0 × 10 ² cfu / g or more and 1.0 × 10 ⁹ cfu / g or less, and the amount of inoculated raw milk Is preferably 0.3% or more and 20% or less.

  The post-fermentation temperature is preferably 23 ° C. or higher and 33 ° C. or lower because the optimal temperature of Cremoris bacteria is 25 ° C. to 30 ° C., and the post-fermentation time is preferably 5 hours or longer and 24 hours or shorter.

  It is preferable to add glucose or saccharose to the raw material milk in the range of 0.1 wt% to 5 wt%. This is because the viscosity of the fermented milk product can be further increased by adding glucose or saccharose.

  It is preferable to further enclose Acetobacter orientalis in the sealed container. This is because Acetobacter orientalis consumes oxygen during fermentation, and thus it is possible to produce a fermented milk product in a more anaerobic state.

  According to the method for producing a fermented milk product of the present invention, it is possible to produce a fermented milk product of Cremoris having a higher viscosity than before.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The present invention is not limited to the following.

(Medium A)
Mixed with milk 65, skim milk powder 3.5, fresh cream 0.5 and 31 (numbers are% by weight). After mixing, the mixture was heated at 85 ° C. for 15 minutes for sterilization. Further, the mixture was pressurized to 150 kgf / cm ² using a homogenizer (APU, WU-DA100LR-C) and homogenized. The medium in this state was designated as “medium A”.

(Medium B)
Milk was heated at 85 ° C. for 15 minutes for sterilization. Further, the mixture was pressurized to 150 kgf / cm ² using a homogenizer (APU, WU-DA100LR-C) and homogenized. The medium in this state was designated as “medium B”.

[Example 1]
Medium A was inoculated with 3.5% by weight of Cremoris FC strain starter. (The number of viable bacteria in the starter is about 1.0 × 10 ⁸ cfu / g.) Thereafter, 400 mL of a sterile aluminum pouch container 1 having the form shown in FIG. 1 was filled. The material of the main body 2 of this aluminum pouch container was a laminate in which polyethylene terephthalate (thickness 12 μm) / aluminum foil (thickness 9 μm) / stretched nylon (thickness 15 μm) / unstretched polypropylene (thickness 80 μm) were stacked in this order. The oxygen permeability of this laminate was 5 fmol / m ² · s · Pa or less (corresponding to oxygen permeability of first grade).

  An injection member 3 made of polypropylene is provided on the upper portion of the main body 2, and the lid 4 is openable. The injection member 3 has a hollow cylindrical shape. When the lid 4 is opened, the inside of the main body 2 communicates with the outside. The internal volume of the aluminum pouch container 1 is 400 mL.

  The aluminum pouch container 1 after filling with the medium A and Cremolis bacteria was kept at 25 ° C. for 6.5 to 8 hours, and the medium A was post-fermented in the aluminum pouch container 1. The obtained milk fermented product was used as the milk fermented product of Example 1.

[Comparative Example 1]
After inoculating 3.5% by weight of Cremoris bacteria (FC strain) starter into medium A, 400mL is filled into a paper container (corresponding to oxygen permeability grade 5) with an oxygen permeability of 500fmol / m ² · s · Pa, nylon / polyethylene The same operation as in Example 1 was performed except that the material film was placed on top and sealed by a method of thermocompression bonding at 160 ° C. using a cup seal machine (Shinwa Co., Ltd., SN-1). The obtained milk fermented product was used as the milk fermented product of Comparative Example 1.

<Absolute viscosity>
The absolute viscosity (10 ° C.) of the fermented milk of Example 1 and Comparative Example 1 was measured using a B-type viscometer (Brooksfield, spindle No. 4). The result is shown in FIG. In addition, the absolute viscosity shown here is an absolute viscosity in the vicinity of acidity of 0.75.

  From FIG. 2, the fermented milk product of Example 1 has a higher absolute viscosity of 13% to 31% than the fermented milk product of Comparative Example 1 having the same fermentation time, and the difference in absolute viscosity is larger as the fermentation time is shorter. It was.

<Kinematic viscosity>
About the milk fermented product of Example 1 and Comparative Example 1, kinematic viscosity was measured with time by the Zahn cup measurement method during fermentation. Specifically, 43 mL of milk fermented product was poured into a No. 7 Zaan cup made by Kogaisha Co., Ltd., and the time (outflow seconds) for the entire amount to flow out was measured (10 ° C.). The result is shown in FIG.

  In any fermentation time, it was closed that the milk fermented product of Example 1 had a larger outflow second value and a higher kinematic viscosity than the milk fermented product of Comparative Example 1.

[Example 2]
The same procedure as in Example 1 was carried out by adding 3.5% by weight of a starter of Cremoris (FC strain) and 3.5% by weight of a starter of Streptococcus thermophilus (Streptococcus thermophilus). Since the acidity reached 0.75 when fermented for 6 hours, the fermentation was terminated at that point and storage was started in the dark at 10 ° C.

[Comparative Example 2]
The same operation as in Comparative Example 1 was performed on medium A with a Cremollis starter (FC strain) starter of 3.5% by weight and a Streptococcus thermophilus starter that is a lactic acid bacterium. Since the acidity reached 0.75 at the time of fermentation for 7.5 hours, the fermentation was terminated at that point and storage was started in a dark place at 10 ° C.

  About the milk fermented product of Example 2 and Comparative Example 2, kinematic viscosity was measured by the Zahn cup measurement method at the time of the start of 10 degreeC preservation | save and twice after 28-day progress. The result is shown in FIG.

  In Example 2, the kinematic viscosity after 28 days of storage was reduced by only about 13% compared to the 0th day. On the other hand, in Comparative Example 2, it decreased by about 49% compared with the 0th day, and it was confirmed that the texture as what is called "Caspian Sea yogurt" is impaired.

[Example 3]
A starter of Cremoris (FC strain) was added to medium B at 3.5% by weight, and the same operation as in Example 1 was performed. The fermented milk product obtained when the acidity reached 0.75 was designated as the fermented milk product of Example 3. did.

[Example 4]
After adding 1% by weight of glucose to medium B, adding 3.5% by weight of Cremoris starter (FC strain) starter, and performing the same operation as in Example 1 to obtain the milk fermentation obtained when the acidity reached 0.75 The product was the fermented milk product of Example 4.

[Example 5]
After adding 1% by weight of sucrose to medium B and adding 3.5% by weight of Cremoris (FC strain) starter, the same procedure as in Example 1 was performed, and the fermented milk product obtained when the acidity reached 0.75 Was the fermented milk product of Example 5.

[Comparative Example 3]
The starter of Cremoris (FC strain) 3.5% by weight was added to medium B, the same operation as in Comparative Example 1 was performed, and the fermented milk obtained when the acidity reached 0.75 was compared with the fermented milk of Comparative Example 3. did.

[Comparative Example 4]
After adding 1% by weight of glucose to medium B, adding 3.5% by weight of Cremoris (FC strain) starter, the same operation as in Comparative Example 1 was performed, and the fermented milk obtained when the acidity reached 0.75 was obtained. The fermented milk product of Comparative Example 4 was obtained.

[Comparative Example 5]
After adding 1% by weight of sucrose to medium B and adding 3.5% by weight of Cremoris (FC strain) starter, the same operation as in Comparative Example 1 was performed, and the fermented milk obtained when the acidity reached 0.75 was obtained. The fermented milk product of Comparative Example 5 was obtained.

  About the milk fermented products of Examples 3-5 and Comparative Examples 3-5, kinematic viscosity was measured by the Zahn cup measuring method. The results are shown in FIGS.

  In Example 4 to which glucose was added, the kinematic viscosity of 76.6% fermented milk increased compared to Example 3 to which no sugar was added, and the texture (smooth feeling) as so-called “Caspian Sea yogurt” was enhanced. It had been. Similarly, also in Example 5 to which sucrose was added, the kinematic viscosity of the fermented 54.5% milk increased compared to Example 3 to which no sugar was added, and the texture (smooth feeling) as a so-called “Caspian Sea yogurt” ) Was enhanced.

  In addition, when the addition amount of glucose or sucrose added to the culture medium B was increased or decreased within the range of 0.1 wt% or more and 5 wt% or less, it was confirmed that the kinematic viscosity significantly increased as compared with the case where it was not added. In addition, the effect of increasing the kinematic viscosity was not observed when the amount was less than 0.1%, and when the amount exceeded 5% by weight, the sweetness became too strong even if the kinematic viscosity increased, and the taste as a fermented milk product was also impaired. .

  On the other hand, Comparative Example 4 to which glucose was added and Comparative Example 5 to which sucrose was added also showed an increase in the kinematic viscosity of the fermented milk compared to Comparative Example 3 to which no sugar was added. However, even when sugar was added at the same ratio, the kinematic viscosity was lower than that of the fermented milk of Examples 4 and 5.

  INDUSTRIAL APPLICABILITY The present invention is useful in the food field as a method for producing a fermented milk product having an unprecedented strong viscosity and spinnability and a smooth texture.

It is an external view showing an example of the aluminum pouch container which can be used with the manufacturing method of this invention. It is a graph showing the measurement result of absolute viscosity about the fermented milk of Example 1 and Comparative Example 1. It is a graph showing the result of having measured kinematic viscosity over time about the fermented milk of Example 1 and Comparative Example 1. It is a graph showing the kinematic viscosity measurement result at the time of the start of 10 degreeC preservation | save, and after 28-day progress about the milk fermented material of Example 2 and Comparative Example 2. FIG. It is a graph showing a kinematic viscosity measurement result about the milk fermented products of Examples 3-5. It is a graph showing a kinematic viscosity measurement result about the milk fermented products of Comparative Examples 3-5.

Explanation of symbols

1: Aluminum pouch container 2: Main body 3: Injection member 4: Lid of injection member

Claims (7)

In a sealed container made of a material having an oxygen permeability of 50 fmol / m ² · s · Pa or less,
Enclose the raw material and pasteurized lactococcus lactis subspices cremolith with the main component of sterilized milk or dairy products,
A method for producing a fermented milk product, characterized in that initial dissolved oxygen is adjusted to 10 ppm or less and post-fermented. The milk fermentation according to claim 1, wherein the material having an oxygen permeability of 50 fmol / m ² · s · Pa or less is a material including a laminate of an aluminum foil, an aluminum vapor-deposited film, a silica vapor-deposited film, or an alumina vapor-deposited film. Manufacturing method.   The method for producing a fermented milk product according to claim 1 or 2, wherein the sealed container is a pouch container having an injection member that can be opened and closed. The viable count of Lactococcus lactis subsp. Cremoris starter enclosed in the sealed container is in the range of 1.0 × 10 ⁶ cfu / g or more and 1.0 × 10 ⁹ cfu / g or less, and the amount of inoculation is sterilized. The method for producing a fermented milk product according to any one of claims 1 to 3, wherein the content is 0.3% by weight or more and 20% by weight or less based on the raw material milk.   The method for producing a fermented milk product according to any one of claims 1 to 4, wherein the post-fermentation temperature is 23 ° C to 33 ° C, and the post-fermentation time is 5 hours to 24 hours.   The method for producing a fermented milk product according to any one of claims 1 to 5, wherein glucose or sucrose is added to the raw milk in a range of 0.1 wt% to 5 wt%. The method for producing a fermented milk product according to any one of claims 1 to 6, wherein Acetobacter orientalis is further enclosed in the sealed container.

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