JP2871379B2 - How to improve the flavor and color of soy products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Object of the invention]

The present invention relates to a method for improving the unpleasant taste and color of soybeans.

[0002]

[Prior art]

(1) Background Soybeans contain high-quality proteins called "field meat" and do not contain cholesterol, so they are not only high-health foods but also soybean proteins, especially those with emulsifying power and viscoelasticity. Since it has functionality, it is useful as a food material.

[0003] However, on the other hand, soy milk made from soybeans,
Products such as soy protein isolate have unpleasant tastes such as 2-hexenal and a few kinds of saponins, such as green grassy taste and savory taste, and inferior whiteness, which are obstacles in use. .

In order to improve the taste and color tone of soy products, Japanese Patent Publication No. 57-49189 and Japanese Patent Application Laid-Open No.
-30639, JP-A-3-43053, etc.
Many suggestions have been made.

[0005] However, these known methods cannot sufficiently solve the problem of unpleasant odor and unpleasant taste derived from soybean, and there is still a need to solve this problem. In addition, the flavor improving method by lactic acid fermentation which has been separately proposed also requires a long culturing time required for flavor improvement, has poor fermentation flavor, and its aroma is not very favorable. Moreover, in order to enhance the growth of lactic acid bacteria, milk components, lactose, and sugars such as glucose are added to the substrate for fermentation, and fruit juice and organic acids are added after fermentation, so that the soybean's natural rich taste and The result is a product far from soybeans, with umami removed.

[0006]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a method for improving the taste and color of a soybean product by lactic acid bacteria, and in particular, by improving the taste and color of lactic acid bacteria without using additives other than soybean components. It is an object of the present invention to provide a means for effectively improving the unpleasant taste and color possessed.

[0007]

[Means for Solving the Problems]

(1) Concept To achieve the above object, the present inventor, among many lactic acid bacteria, does not require an auxiliary component other than the soybean component for growth, and produces a strong and favorable aroma, and furthermore, a soybean-specific discomfort. As a result of searching for lactic acid bacteria that can significantly improve odor, unpleasant taste and color tone, it was found that Streptococcus thermophilus grows well only with soy components, and among them, especially
The present inventors have found that Streptococcus thermophilus 3261 has excellent lactic acid productivity, flavor aroma and productivity, and has remarkably high flavor improving effect and color tone improving effect.

(2) Outline Based on the above findings, the present invention provides a soybean product comprising Streptococ
thermophilic lactobacilli belonging to cus thermophilus, preferably
The gist of the present invention is a method for improving the flavor and color tone of a soybean product, which comprises contacting with a culture of Streptococcus thermophilus 3261 strain. Hereinafter, the main requirements constituting the invention will be described separately.

(3) Lactococcus lactis Streptococcus pneumonia The main matter in the present invention is thermophilic streptococcus lactococci (Streptococcus
(Sept. eptococcus thermophilus 3261 ) is used as a flavor and color tone improver for soy protein products.
Incidentally, there are considerable types of microorganisms that cause lactic acid fermentation, but they are roughly classified according to the keys in Table 1 below.

[0010]

[Table 1] ---------------------------------------------- ------------------------- Key item Generic name --------------------- ------------------------- Form Catalase Viable spores Fermentation form * Remarks Reaction ---------------- -------------------------------------------------- ----- Bacillus Bacillus Non-lactic acid bacterium Sporolactobacillus Same as above-+ Lactobacillus Same as above--Homo, hetero Streptococcus Streptococcus Homo Leuconosotoc Same as above -------------------------------------------------- --------- * Homo: Homofermentation (produces only lactic acid) Hetero: Produces ethanol, etc. in addition to lactic acid

(4) Strain of Streptococcus thermophilus 3261 The present inventors proposed that Streptococcus thermophilus
Among the many strains belonging to ilus, especially Streptococcus ther
mophilus 3261 (hereinafter abbreviated as "3261 strain") was found to be the best strain in terms of flavor and color tone improving effects.
That is, unlike the lactic acid bacteria that have been used so far, the 3261 strain does not include a milk component and a substrate component such as a saccharide,
It grows efficiently only with soybean components, and has a good aroma and a remarkable flavor improving effect.

Therefore, by using the present lactic acid bacterium, unpleasant odors and unpleasant tastes, which have been problems of soy products, are not felt at all, and soy products having a very good flavor utilizing the original richness and umami of soybeans can be obtained. Provision is possible. Furthermore, this fermented product was found to have a masking effect on soy products (soy milk and isolated soy protein), and was also found to be useful as a color tone and flavor improver. In particular, the fact that the present invention can provide a refreshing and suitable drink using soybean whey (whey) as a raw material has a high economic significance as a development of a use of soybean whey that has hardly been used except as a conventional feed. Having.

[0013] The 3261 strain isolated by the present inventors is a new strain which has not been described in the literature. Therefore, the present inventors sent the strain to the Microbial Industry Laboratory for FERM P-1343.
No. 0 (Deposit and acceptance February 16, 1993
Day). Hereinafter, the bacteriological characteristics of this strain are listed.

I Bacteriological properties Except for special ones, the following broth medium except for the following bouillon medium: meat extract 10 g peptone 10 g salt 5 g distilled water 1000 mL pH 7.2 Culture period 1 to 3 days after observation Form: spherical 0.8 to 1.0 μm in diameter, Large long-chain fermentability: Homofermentation (Lactate rotation: D-type) Gram stain: Positive (+) Nitrate reducing ability: Negative (-) Catalase reaction: Negative (-) Surface growth: Negative (-) Gas Occurrence: Negative (-) Hemolysis: False positive (±) Gelatin liquefaction: Negative (-) Litmus milk (after 24 hours) Coagulation: + Reduction: + Redness: + Maximum acidity in milk: 0.846 Temperature characteristics 8-10 ℃ 22 ℃ 30 ℃ 40 ℃ 45 ℃ 50 ℃ Growth temperature: − − ++ +++ ++ ++ Production temperature: 40 ℃ Death temperature: 80 ℃ or more Resistance to heating for 60 and 30 minutes: Yes Salt tolerance: negative (Does not grow at 2% salt concentration) Alkali resistance: Does not grow at pH 9.2 Methylene resistance Lou resistance: negative (-) (not develop in 0.01 density) acetoin and diacetyl-producing: negative (-) sugar availability starch (-), Dekisurin (-), inulin (-),
Salicin (-), finose (-), maltose (-), sucrose (+), lactose (+), glucose (+), mannose (-), galactose (-), arabinose (-), xylose (-) , Mannit (-)

Oxygen demand: facultative anaerobic II. Comparison with known streptococci. The results of comparison of the above mycological properties with known streptococci are shown in Table 2 below.

[0016]

[Table 2] ---------------------------------------------- ------------------------ 60 l Dze Representative strains Production temperature range Chemical resistance ℃ C (30 ℃) Sulfuric acid ---------------------------- Non-reversible liquid salt Naphthium methylene blue Thermo-enzyme (%) (%) Performance 10 22 40 45 50 2 4 6.5 9.2 9.6 0.01 010 ----------------------------------- ----------------------------------- Lactic group S.cremiris + +---+---- + + − + −− S.lactis + + +--+ +-+-+ + − + −− ------------------------- ----------------------------------------------- Enterococcus group S faecalis + + + +-+ + + + + + + + + +-S.liovefacens + + + +-+ + + + + + + + + +--------------- -------------------------------------------------- -------- Virians group S.bovis-± + +-+--+-+-+ ± −− --------------------- -------------------------------------------------- -S.thermophils--+ + +-------+ --------------------------------------------------- ---------------------- (Table 2) (continued) --------------------- --- ------------------------------------------ Sugar utilization ability Peptone Representative Production of Mamasima Sasa Ammonia Lun Ritane from stock name ------------------------------ Sex Roots------------------ --------------------------------------- Lactic group S.cremiris ＋ − − − ± − − − S.lactis ++ + − + + − − + ------------------------------------- ------------------------------- Enterococcus group S. faecalis ++ ++ ++--+ S.liovefacens ++ ++---+ --------------------------------------------- ----------------------- Virians group S.bovis ++++++++ ------------------- -------------------------------------------------- ---- S.thermophils − − + − − − − ± ------ -------------------------------------------------- ------------

Further, FIG. 1 shows the state of increase in acidity when a culture of various lactic acid bacteria was added to soymilk at a ratio of 3%.
As shown in the figure, the increase in acidity caused by Streptococcus thermophilus is much larger than that of typical lactic acid bacteria such as Lactobacillus bulgaricus and L. lactis.
The rate of rise of the stock is maximum.

[0018] In addition, Streptococcus thermophilus is superior in growth by soy components alone compared to known strains belonging to the lactic acid bacteria group. And, as described in the section of "mycological properties" above, there is no fear of adding cheese smell or butter smell to the substrate because it does not produce acetoin or diacetyl,
These results suggest that this bacterium can be used for foods with undesirable cheese odor and butter odor.

(5) Target soybean products The soybean products to be improved in flavor, smell and color tone by the method of the present invention are generally processed agricultural products mainly containing soybean protein, that is, mainly soybean milk, defatted soymilk, It refers to concentrated soy protein, isolated soy protein and soy whey or whey, and tofu and sour, yogurt or cheese-like foods derived therefrom, but is not limited to those specifically exemplified. In addition, known means can be freely used for preparation of these processed food materials or foods, and a strain of another lactic acid fermentation bacterium suitable for fermentation of a target food or material can also be used as a starter.

(6) Treatment method In the practice of the present invention, the soybean protein product to be treated (substrate)
Is sterilized as a solution (usually solid content of 1% or more)
This is inoculated with a seed of a fungus and fermented. Since agricultural products such as soybeans are usually contaminated with soil spores derived from the soil in which they grew, high temperature conditions sufficient to kill the spores of the bacteria are desirable for sterilization. There are various methods for sterilization for this purpose, but it is considered to be preferable to use high-temperature flash sterilization such as VTIS in terms of workability and color tone improvement. As heating conditions at this time, a temperature and a time of 120 to 160 ° C. for about 10 seconds to 5 minutes are selected. The pH of the liquid to be treated during sterilization is usually adjusted to 6 to 8, preferably 6.5 to 7.3.

As the starter, it is preferable to use a sterile solution having the same composition as the soybean product solution to be treated, inoculated with, for example, a pure culture of 3261 strain and incubating at 37 ° C. for about 20 hours. The amount of the starter is usually 1 to 10%, preferably 3 to 5%, based on the soybean product solution to be treated.

The addition of other substrates to the soy product is usually not necessary. However, when isolated soybean protein is used as a substrate, sugars and trace nutrients are scarcely contained. Therefore, it is exceptionally preferable to add lactose or glucose in an amount of about 1 to 8% per solution.

The fermentation usually takes 2 to 8 hours, preferably 3 to 6 hours.
Done for hours. Acidity becomes 0.15-0.30% by fermentation,
As a result, the unpleasant odor and unpleasant taste derived from soybeans are completely eliminated, and the solution has a refreshing flavor unique to lactic acid fermentation. Further, the whiteness is increased and the color tone is improved as compared with before the fermentation.

The obtained fermentation liquid can be used as it is for beverages and soups, but it can also be dried and powdered if desired. In addition, this fermented product was added to
% Or more, a remarkable color tone and flavor improving effect is also observed.

[0025]

[Action] Streptococcus thermophilus 3261 strain grows well using soybean components as a substrate, decomposes polyphenolic substances involved in color tone by the action of cell enzymes, and produces many hydrophilic substances. It is effective in reducing the unpleasant taste of the food. In addition, the bacterium is excellent for the purpose of the invention because of its excellent aroma productivity.

[0026]

EXAMPLES Examples of the invention will now be described by way of examples, but the illustrations are for explanation and are not intended to limit the inventive idea.

Example 1 Japanese soybeans were immersed in water overnight to swell, then molted and decotyledoned, and only cotyledons were taken out. Next, the swollen soybean cotyledons were sufficiently ground with a mixer together with 9 times the amount of water. After heating at 100 ° C. for 10 minutes, okara was removed with a filter cloth to prepare full fat soymilk.

The whole fat soy milk obtained was treated with a direct heating steam sterilizer (“VTIS (trade name))” at 140 ° C. for 10 seconds to sterilize the whole fat soy milk. Inoculate the sterilized solution and incubate at 37 ° C for 20 hours.
%, And fermented at 37 ° C. for 5 hours.

The resulting fermentation liquor formed curds having an acidity of 0.25%. The solution obtained by pulverizing this curd with a homomixer was a fresh fermented soymilk having no peculiar odor and a peculiar aroma while having no soybean peculiar off-flavor. The whiteness and lightness of the product were also improved by the main fermentation as shown in Table 3 below.

[0030]

[Table 3]

Example 2 A defatted soybean (manufactured by Fuji Oil Co., Ltd.) was added to a 10-fold amount of warm water (50
℃), extract with stirring for 40 minutes, remove okara with filter cloth,
Skim soy milk was prepared. To this substrate solution obtained by sterilizing the defatted soy milk in the same manner as in Example 1, a starter strain 3261 similar to that in Example 1 was added at a ratio of 5%, and cultured at 37 ° C. for 5 hours. Was formed.

The solution obtained by pulverizing this curd with a homomixer was fermented skim soy milk having a refreshing aroma without any offensive odor peculiar to soybean, and both whiteness and brightness were remarkably improved.

Example 3 A 5% solution of isolated soybean protein (Fujipro R (registered trademark) manufactured by Fuji Oil Co., Ltd.) was prepared and subjected to high-temperature flash sterilization.
After heat sterilization at 140 ° C. for 10 seconds, glucose was added thereto in an amount of 2% with respect to the solution.

Next, 3261 was added to the sterilized separated soybean protein solution.
After inoculating a pure culture of the strain and culturing at 37 ° C. for 10 hours, the solution after the culture (acidity: 0.15%) was neutralized with a 20% sodium hydroxide solution and spray-dried.

The obtained fermented and separated soybean protein powder had a lesser yellowish color and whitened compared to the separated soybean protein before fermentation, and was excellent in flavor without the peculiar off-flavor of soybean.

Example 4 A 10-fold amount of warm water (50 ° C.) was added to defatted soybeans and stirred for 40 minutes.
After extraction, the mixture was filtered to prepare defatted soymilk. Next, the pH of the soy milk was adjusted to pH 4.5 using 20% hydrochloric acid to precipitate the protein, followed by centrifugation to separate whey (soy whey) and curd.

The whey was adjusted to pH 7.0 with a 20% sodium hydroxide solution, heat-sterilized with HTST at 140 ° C. for 10 hours, and cultured in advance using the same whey as a substrate at 37 ° C. for 10 hours. The 3261 strain starter was added in an amount of 5% with respect to the solution, and cultured at 37 ° C. for 5 hours.
%.

The fermented defatted soy milk thus obtained was a fermented whey beverage having a fruity refreshing fragrance, having no peculiar off-flavor peculiar to soybean, and having a favorable color tone.

Example 5 5 g of fermented whey prepared according to Example 4 was added to 100 g of a 5% isolated soybean protein (Fujipro R) solution.
g and 30 g each, and add 20% sodium hydroxide to pH 7.0.
After adjustment, the effect of adding fermented whey on color tone and flavor was examined.

As shown in Table 4 below, improvement of color tone and reduction of off-flavor and odor were observed when 5% was added, and the effect became more remarkable when added at 10% or more.

[0041]

[Table 4] ---------------------------------------------- --------------------- Fermented whey Color improvement effect Addition amount ---------------------- ------------- Flavor improvement effect (%) L value a value b value ------------------------- ------------------------------------------ 0 (control) 58.88 − 4.36 5.00 Strong off-flavor 5 63.71 -3.80 5.13 Off-flavor 10 66.35 -3.50 5.61 No off-flavor 30 68.55 -3.33 6.00 Same as above- -------------------------------------------------- ----------------

[0042]

As described and demonstrated above, the present invention can provide a means for effectively improving the flavor and color of a soy protein-containing product, thereby expanding the use of the soy protein product, Can contribute to health promotion.

[Brief description of the drawings]

FIG. 1 is a graph showing changes in the acidity of Streptococcus thermophilus 3261 strain and other lactic acid bacteria.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A23L 1/20 A23C 11/10

Claims (3)

(57) [Claims] 1. The method of claim 1, wherein the soybean product is Streptococcus thermophilus 3
A method for improving flavor and color tone of a soybean product, which is brought into contact with a culture of 261 strains . 2. The method of claim 1 wherein the soy product is selected from the group consisting of full fat soy milk, skim soy milk, concentrated soy protein, isolated soy protein and soy whey. 3. The method according to claim 1, wherein the culture of lactic acid bacteria is mixed with the soybean product in an amount of 5% or more per solid content.