JP7600536B2 - Method for producing low-fat soymilk lactic acid fermentation product - Google Patents

Description

The present invention relates to a method for producing low-fat soymilk lactic acid fermented product.

There is an increasing social sense of crisis regarding issues such as "food resource shortages" and "the environment," and efforts are underway to create a sustainable world.
In particular, due to the global population increase, it is predicted that there will be shortages of food (especially animal protein sources) and water resources in the future.
Efforts are being made to address social issues such as food resource shortages and the environment that arise as the population increases through plant-based food ingredients.

In particular, soybeans are thought to be one of the effective solutions to this social issue facing humanity.
This is because soybeans can be grown in large quantities in a wide range of regions, from cold climates to tropical climates, and with much less fertilizer and water than animal protein sources.

Traditionally, soybeans have been processed in a wide variety of ways for a wide range of uses, including soybean oil obtained by pressing soybeans, soy milk obtained by squeezing soybeans, and powdered soybean protein and granular soybean protein obtained from defatted soybeans.
On the other hand, soy protein is a high-quality protein that does not contain cholesterol and has a low environmental impact, but its use is somewhat limited due to its distinctive grassy and bitter flavor.

In addition, rice harvested from rice fields is used as the raw material, and the mash obtained through saccharification by koji and alcoholic fermentation by yeast is then pressed to produce "sake" and the separated pomace, "sake lees."
Sake lees contain many nutrients and active ingredients, such as various amino acids, vitamins, organic acids, proteins, and various sugars, which are derived from rice, rice koji, and yeast.
However, apart from being used to make sweet sake, pickles, sake lees soup, or as food itself, sake lees are also processed as animal feed and fertilizer, and the demand for and distribution of sake lees as food is low.

On the other hand, for the purpose of making effective use of sake lees, for example, Patent Document 1 proposes a novel sake lees fermentation extract made from sake lees as a raw material, Patent Document 2 proposes a flavor improver using a sake lees fermentation extract obtained by fermenting liquefied sake lees with yeast in parallel with amylolytic enzyme treatment and proteolytic enzyme treatment, and then performing solid-liquid separation to remove the solid components, Patent Document 3 proposes an emulsifier that contains a component derived from sake lees as an active ingredient, and an oil-containing water-soluble composition that contains a fat-soluble substance, and Patent Document 4 proposes an emulsifier characterized by containing a component derived from sake lees as an active ingredient, but their uses are limited.
In addition, sake lees contain 5.2g of dietary fiber per 100g, which is 10 times that of white rice. Due to its texture, such as its roughness and leaving a residue in the mouth, people have tended to avoid using it for food purposes.

JP 2017-143766 A JP 2016-42818 A JP 2012-228228 A JP 2011-115160 A

The objective of this invention is to contribute to solving social issues such as "food resource shortages" and "environmental issues" by effectively utilizing the plant-based food ingredients "soybeans" and "sake lees" to provide new materials for food use.

As a result of intensive research into the above-mentioned problems, the inventors discovered that by adding sake lees to low-fat soymilk, lactic acid fermenting it, and then subjecting it to pressurized homogenization, or by adding sake lees to low-fat soymilk, lactic acid fermenting it, and then subjecting it to pressurized homogenization, or by adding sake lees to the lactic acid fermented low-fat soymilk and then subjecting it to pressurized homogenization, the flavor of the soybeans is improved, and a low-fat lactic acid fermented soymilk product can be obtained that has a richness and flavor not found in animal-based food ingredients, is free of roughness or residual taste, and is smooth and melts in the mouth easily, leading to the completion of the present invention.

That is, the present invention includes the following inventions.
(1) A method for producing lactic acid fermented low-fat soymilk, comprising adding sake lees to low-fat soymilk having a lipid content of 2.5% by weight or less and subjecting the mixture to lactic acid fermentation.
(2) A method for producing a low-fat soymilk lactic acid fermented product according to claim 1, wherein a pressurized homogenization treatment is carried out before and/or after the lactic acid fermentation.
(3) A method for producing lactic acid fermented low-fat soymilk, comprising adding sake lees to lactic acid fermented low-fat soymilk having a lipid content of 2.5% by weight or less, and subjecting the mixture to pressurized homogenization.
(4) A beverage or food, characterized by using the low-fat soymilk lactic acid fermented product according to any one of (1) to (3).

The present invention improves the flavor of soybeans and provides a low-fat lactic acid fermented soy milk product that has a rich flavor and umami taste not found in animal-based food ingredients, and is smooth and melts in the mouth without being rough or leaving a residual taste, as well as beverages and foods that use this product. This makes effective use of soybeans and sake lees, and plant-based food ingredients can be an effective solution to social issues such as food resource shortages and the environment.

The present invention is described in detail below.

(low-fat soy milk)
In the method for producing a low-fat soymilk fermented with lactic acid of the present invention, low-fat soymilk refers to soymilk with a reduced lipid content.
The low-fat soy milk used in the present invention is low-fat soy milk whose lipid content has been reduced to 2.5% by weight or less, preferably 2% by weight, more preferably 1.5% by weight or less, in accordance with the claim labeling.
Low-fat soy milk is a soybean product that has characteristics equivalent to low-fat milk in cow's milk.
Not only does this make it possible to reduce the calories of soy milk, but it also makes it possible to reduce the deterioration of flavor caused by soybean lipids.
The lipid content of the low-fat soymilk is preferably 40% by weight or less, more preferably 20% by weight or less, and even more preferably 10% by weight or less, based on the protein content of the low-fat soymilk. The low-fat soymilk of the present invention includes not only soymilk obtained by extracting whole soybeans or defatted soybeans with water and removing okara, which is an insoluble fiber, but also a slurry-like product obtained by finely pulverizing okara without removing it from soymilk, and preferably soymilk from which okara has been removed.

(Method of measuring lipid content of low-fat soy milk)
Sample (W) is extracted with a mixed solvent of chloroform:methanol (volume ratio: 2:1) at normal pressure and boiling point for 30 minutes, and the extract is dehydrated with anhydrous sodium sulfate and then dissolved in petroleum ether.
This is centrifuged, and the ether layer is collected in a flask (W1) of known weight. After the ether is distilled off, the dry weight (weight of the flask after the ether has been distilled off) (W2) is measured.
Using the measured values of W, W1, W2, and the dry weight (W3) of the sample (W), the value obtained by the following formula is the lipid content (%/dry).
Lipid content (%/dry) = [{(W2-W1)/W×2.5×100}/W3×100(%)]
As the solvent extraction apparatus, a "Soxtec" manufactured by FOSS can be used.
The above measurement method is referred to as the "chloroform/methanol mixed solvent extraction method."

(Method of producing low-fat soy milk)
Soybean raw materials for low-fat soy milk include whole soybeans, halved soybeans, grits, powder, and the like.
Also, soybeans that have been defatted or reduced in fat in advance can be preferably used as the soybean raw material.
Low-fat soy milk can be prepared by a known production method. For example, a method of extracting low-fat soy milk with water from defatted soybeans obtained by defatting with a solvent such as hexane or ethanol can be preferably used.
The water extraction can be performed by a general method, for example, a method in which an aqueous medium is added to the raw soybeans, the mixture is stirred and ground to form a slurry, and the insoluble fraction (okara) is separated and removed by centrifugation, filtration, etc.
Alternatively, low-fat soy milk may be obtained by extracting whole soybeans or reduced-fat soybeans with water, removing the slurry or okara, and then subjecting the resulting mixture to solvent extraction, membrane treatment, or centrifugation for defatting.
Powdered low-fat soy milk can also be used by dissolving it in water.
In the water extraction, water is added in an amount preferably 3 to 20 times, and more preferably 4 to 15 times, the weight of the soybean raw material.
The higher the water addition ratio, the higher the extraction rate of water-soluble components and the better the separation. However, if it is too high, concentration will be required, which will be costly.
Furthermore, by repeating the extraction treatment two or more times, the extraction rate of the water-soluble components can be further increased.
The extraction temperature is not particularly limited, but in order to efficiently extract proteins, it is preferable to carry out the extraction at a temperature of 5°C to 98°C.
It is also possible to obtain low-fat soy milk by extracting whole soybeans with water and then carrying out a defatting operation by solvent extraction or membrane treatment in the slurry state or after removing the okara.
In addition, the method disclosed in JP 2012-016348 A can also be used.
That is, water is added to fat-containing soybeans having a lipid content of 15% by weight or more per dry matter and an NSI (Nitrogen Solubility Index) of 20 to 77 to obtain a suspension, which is then subjected to solid-liquid separation, neutral lipids and polar lipids are transferred to an insoluble fraction and removed, and a water-soluble fraction containing proteins and carbohydrates is recovered.
The low-fat soymilk obtained by this method is characterized in that the total protein and carbohydrate content per dry matter is 80% by weight or more, and the lipid content (as the amount of chloroform/methanol mixed solvent extract) is less than 10% by weight of the protein content.
The protein content herein refers to the value obtained by multiplying the amount of nitrogen measured by the Kjeldahl method by a nitrogen conversion coefficient of 6.25.
In addition, the lipid content may be adjusted by blending low lipid soy milk with high lipid soy milk or soy oil.

The method for producing low-fat soymilk fermented with lactic acid of the present invention is characterized by adding sake lees to low-fat soymilk or lactic acid fermented low-fat soymilk.
By adding sake lees to low-fat soy milk or lactic acid fermented low-fat soy milk, it is possible to obtain a lactic acid fermented low-fat soy milk product having a rich flavor not found in animal-derived food ingredients.
In the present invention, sake lees refers to the solid matter remaining after squeezing the fermented raw materials (moromi) such as rice and koji during the sake production process. A typical example is sake lees that are a by-product in the production of sake. However, examples of sake lees other than sake lees include mirin lees and distilled sake lees (such as shochu lees).
The sake lees may be used in the form of, for example, a liquid, a paste, a dried solid, or a crushed powder.
In the present invention, the low-fat soy milk or the lactic acid fermented low-fat soy milk preferably contains sake lees in an amount of 1 to 30% by weight calculated as solid matter.

The method for producing a lactic acid fermented low-fat soymilk of the present invention is characterized in that low-fat soymilk or low-fat soymilk to which sake lees have been added is used as a raw material, and lactic acid fermentation is carried out by adding lactic acid bacteria and the like.
Either low-fat soymilk or low-fat soymilk with added sake lees can be used as the raw material, but by lactic acid fermenting low-fat soymilk with added sake lees, not only is the undesirable flavor specific to soybeans derived from low-fat soymilk improved, but the lactic acid fermentation can also impart desirable flavors such as umami and richness derived from the sake lees, while further mellowing the harshness of the flavor, resulting in a more delicious lactic acid fermented low-fat soymilk product.

The bacteria used in the lactic acid fermentation in the production method of the present invention are preferably Lactobacillus bacteria such as Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus delbruekii ssp. bulgaricus, Lactobacillus plantarum, Lactobacillus buchneri, Pediococcus acidolacti, and Lactobacillus helveticus.

The bacteria used in the lactic acid fermentation in the production method of the present invention are preferably Streptococcus bacteria such as Streptococcus thermophilus.

The bacteria used in the lactic acid fermentation in the production method of the present invention are preferably bacteria of the genus Lactococcus, such as Lactococcus lactis, Lactococcus lactis ssp. lactis, or Lactococcus lactis ssp. cremoris.

The bacteria used in the lactic acid fermentation in the production method of the present invention are preferably bacteria of the genus Enterococcus, such as Leuconostoc or Enterococcus faecalis.
In the lactic acid fermentation in the production method of the present invention, one or more kinds of bacteria selected from the above can be used.

Lactic acid fermentation is carried out, for example, by adding lactic acid bacteria to a raw material containing low-fat soy milk or low-fat soy milk with added sake lees.
The proportion of lactic acid bacteria is preferably in the range of about 0.01 to 20 parts by weight, more preferably about 0.1 to 15 parts by weight, per 100 parts by weight of the raw material, which includes low-fat soy milk or low-fat soy milk with added sake lees, as the fermentation raw material.
Within the above range, the lactic acid fermentation property and storage stability are good.
The temperature of the lactic acid fermentation is appropriately set depending on the type of bacteria. From the viewpoint of efficient production of lactic acid (good lactic acid fermentation), the temperature of the lactic acid fermentation is preferably in the range of about 5° C. to about 50° C., more preferably about 10° C. to about 50° C., even more preferably about 20° C. to about 48° C., and particularly preferably about 30° C. to 45° C. For example, the culture is performed at about 30° C.
The time for lactic acid fermentation is appropriately set depending on the type of bacteria.
From the viewpoint of efficient production of lactic acid (good lactic acid fermentation), the time for lactic acid fermentation is preferably in the range of about 1 hour to about 30 hours, more preferably about 2 hours to about 20 hours, even more preferably about 3 hours to about 15 hours, and particularly preferably about 4 hours to about 8 hours.
Lactic acid fermentation is usually carried out by static fermentation, but gentle stirring may be carried out for the purposes of uniformizing the temperature distribution of the fermentation liquid and controlling the precipitation of the bacterial cells.

The method for producing a lactic acid fermented low-fat soymilk of the present invention involves adding sake lees to low-fat soymilk and before lactic acid fermentation, and/or adding sake lees to low-fat soymilk and after lactic acid fermentation, or adding sake lees to the lactic acid fermented low-fat soymilk and then subjecting the mixture to pressurized homogenization.
Homogenization refers to the process of thoroughly mixing low-fat soy milk and sake lees to make them homogenous, by mechanically reducing the particles of proteins, dietary fiber, etc. contained in the low-fat soy milk and sake lees to a uniformly dispersed state.
The pressurized homogenization treatment is not particularly limited, but it is preferable to use a homogenizer from the viewpoint of satisfactorily homogenizing particles such as protein and dietary fiber contained in the low-fat soy milk and sake lees.
In the pressurized homogenization treatment, for example, homogenization is preferably performed while applying a pressure of 3 MPa or more and 30 MPa or less, and more preferably 5 MPa or more and 25 MPa or less.

In the method for producing a low-fat soymilk fermented with lactic acid of the present invention, sterilization is carried out as necessary.
The sterilization method is not particularly limited, and examples thereof include a method of injecting high-temperature high-pressure water or high-pressure steam into the raw material liquid, or a direct heating method such as Joule heating by passing electricity through the raw material liquid or heating by high frequency waves (microwaves), and an indirect heating method such as electromagnetic induction heating, plate heating, a scraping-type heat exchanger, or a hot water bath, either alone or in combination.

The low-fat lactic acid fermented soy milk obtained by the manufacturing method of the present invention has an improved soybean flavor, a rich flavor not found in animal-based food ingredients, and is smooth and melts in the mouth without any roughness or residual taste, and can be used in a wide range of beverage and food applications, such as fermented soy milk beverages, soy milk yogurt, and soy milk fillings.

The present invention will be described in more detail below with reference to examples. Note that numbers in the examples are by weight unless otherwise specified.

Example 1
80 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then sterilized at 70-80°C and cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours.
After fermentation, the mixture was homogenized at 5 MPa using a homogenizer, sterilized at 70-80°C, and then cooled to 24°C to obtain a low-fat soymilk lactic acid fermented product.

Example 2
80 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then homogenized at 5 MPa in a homogenizer, sterilized at 70-80°C, and cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours.
The pH of the obtained low-fat soymilk lactic acid fermented product was 4.8.

Example 3
A lactic acid bacteria starter mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to low-fat soy milk ("Binen-nyu", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%) at 0.01% and fermented at 37-40°C for approximately 5 hours.
80 parts of the resulting lactic acid fermented low-fat soymilk with a pH of 4.8, 10 parts of commercially available sake lees (solid content 50%) (manufactured by Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then homogenized at 5 MPa in a homogenizer, sterilized at 70 to 80°C, and cooled to 24°C to obtain a lactic acid fermented low-fat soymilk.

Example 4
65 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 30 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.), and 5 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then sterilized at 70-80°C and cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours.
After fermentation, the mixture was homogenized at 5 MPa using a homogenizer, sterilized at 70-80°C, and then cooled to 24°C to obtain a low-fat soymilk lactic acid fermented product.

Example 5
80 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then sterilized at 70-80°C and cooled to 24°C.
Streptococcus thermophilus was added as a lactic acid bacteria starter at 0.01% to the prepared liquid, and fermentation was carried out at 37-40° C. for about 5 hours.
After fermentation, the mixture was homogenized at 5 MPa using a homogenizer, sterilized at 70-80°C, and then cooled to 24°C to obtain a low-fat soymilk lactic acid fermented product.

Example 6
80 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then sterilized at 70-80°C and cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours.
After fermentation, the mixture was homogenized at 15 MPa using a homogenizer, sterilized at 70-80°C, and then cooled to 24°C to obtain a low-fat soymilk lactic acid fermented product.

(Example 7)
Soy milk cream (Fuji Oil Co., Ltd., solids: 81.0%, protein: 5.6%, lipids: 12.3%) was added to low-fat soy milk ("Bimainette", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), and the lipid content was adjusted to 2.3%. 80 parts of the mixture of low-fat soy milk and soy milk cream was mixed with 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.) and 10 parts of water, and the mixture was heated and stirred at 60°C for 5 minutes, sterilized at 70-80°C, and then cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours.
After fermentation, the mixture was homogenized at 5 MPa using a homogenizer, sterilized at 70-80°C, and then cooled to 24°C to obtain a low-fat soymilk lactic acid fermented product.

(Comparative Example 1)
A low-fat soymilk lactic acid fermented product was obtained using the same composition and production method as in Example 1, except that 5 parts of dextrin and 5 parts of water were used instead of the sake lees used in Example 1.

(Comparative Example 2)
80 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.) and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then homogenized at 5 MPa in a homogenizer, sterilized at 70 to 80°C and cooled to 24°C to obtain a low-fat soy milk composition.

(Comparative Example 3)
80 parts of low-fat soy milk ("Bimainage", Fuji Oil Co., Ltd., solids: 90.2%, protein: 5.1%, lipids: 0.5%), 10 parts of commercially available sake lees (solids content 50%) (Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then sterilized at 70-80°C and cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours to obtain a low-fat soymilk composition.

(Comparative Example 4)
80 parts of unsweetened soy milk ("Unsweetened Soy Milk" manufactured by Fuji Oil Co., Ltd., solids: 90.3%, protein: 4.4%, lipids: 3.0%), 10 parts of commercially available sake lees (solids content 50%) (manufactured by Ozeki Co., Ltd.), and 10 parts of water were mixed and heated and stirred at 60°C for 5 minutes, then sterilized at 70 to 80°C and cooled to 24°C.
A lactic acid bacteria starter containing a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus was added to the prepared liquid at 0.01% and fermented at 37-40° C. for about 5 hours.
After fermentation, the mixture was homogenized at 5 MPa using a homogenizer, sterilized at 70-80°C, and then cooled to 24°C to obtain a lactic acid fermented soy milk product.

In the sensory test, the samples were evaluated and scored on the following 5-point scale by 15 trained expert panelists, and the average score was used as the evaluation score.
Soybean odor: Weak 1-5 Strong Pass criteria (2 or less is good)
Fermentation odor: Weak 1-5 Strong Pass criteria (4 or above is good)
Umami: Weak 1-5 Strong Pass criteria (4 or above is good)
Smoothness: Rough 1-5 Smooth Pass criteria (3 or above is good)
Off-flavor: Weak 1-5 Strong Pass criteria (2 or less is good)
The results of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in the Table.

(Example 8)
10 parts of granulated sugar, 1 part of pectin, and 19 parts of water were added to 70 parts of the low-fat soymilk lactic acid fermented product obtained in Example 1 to make 100 parts, and the mixture was sterilized by heating and stirring at 80 to 90°C, then homogenized in a homogenizer at a pressure of 2 MPa and cooled to obtain a low-fat soymilk yogurt.
The soy milk yogurt obtained had smooth, paste-like properties and a unique richness and flavor not found in yogurt obtained from dairy ingredients. It also had a smooth, melt-in-the-mouth flavor with no roughness or residual taste.
In addition, by using various fruit juices such as blueberry juice instead of water, a wide variety of low-fat soy milk yogurts can be provided.

Claims (2)

A method for producing a lactic acid fermented low-fat soymilk, comprising adding sake lees to low-fat soymilk having a lipid content of 2.5% by weight or less, subjecting the resulting mixture to pressurized homogenization , and/or subjecting the resulting mixture to pressurized homogenization . A method for producing low-fat lactic acid fermented soy milk, comprising adding sake lees to lactic acid fermented low-fat soy milk having a lipid content of 2.5% by weight or less, and subjecting the mixture to a pressurized homogenization treatment.