RU2058082C1 - Method of soybean milk preparing - Google Patents

Abstract

FIELD: food industry. SUBSTANCE: soybean seeds were peeled and soaked in buffer solution at pH 8.2-8.6 containing hydrogen peroxide and sodium hydrocarbonate. After soaking the swollen soybean seeds were washed out and grinding and fermentation is carried out simultaneously in an aqueous solution containing 100 U peroxidase activity (not less) in 1 l water. Grinding is carried out up to suspension preparing at particle size 50 mcm or less. EFFECT: improved method of soybean milk preparing. 6 cl, 3 tbl

Description

 The invention relates to the food industry, namely to the production of edible vegetable milk from soybean seeds.

 Raw soybean seeds are known to contain a number of substances causing an unpleasant soybean taste and smell, saponins (natural glycosides), polyphenols, aromatic amines, as well as antinutrients: trypsin and chymotrypsin inhibitors, phytic acid, phytohemagglutinins (lectins protein complexes and carbohydrates) urease, lipoxidase, pesticides, as well as unwanted oligosaccharides raffinose and stachyose. The presence of these substances eliminates the consumption of soy in an unprocessed (raw) form and requires the use of various technological methods.

 Known methods for producing analogues of dairy products from pre-soaked soybean seeds and further production (based on analogues of dairy products) of bean curd (tofu); frozen bean curd (kori-tofu) and other derivatives of yuba, sifu, etc.

 To obtain analogues of dairy products, soybean seeds are cleaned of impurities, washed with water and soaked in 2-3 times the amount of water. Swollen for 6-12 hours, soybean seeds are crushed in eight times the amount of water to obtain a thin suspension. The extract is filtered and soy milk is obtained, which is the basis for obtaining derivatives of cottage cheese, etc.

 Reducing the level of anti-nutritional substances is achieved by heat treatment of the extract. The methods do not provide for the removal of unpleasant soy smell and taste.

 A known method of removing unpleasant odors from soy milk (US patent N 4229451, CL A 23 J 1/14). In this method, raw soybeans are soaked in water, ground in a volume of fresh water, glucose, glucose oxidase and catalase are added to reduce dissolved oxygen, the ground beans are steamed, filtered and milk is obtained without an unpleasant odor, but with a soy flavor. The method involves the elimination of soy smell, but does not eliminate the bean taste due to the presence of saponins, polyphenols and possibly aromatic amines. In this case, according to the method provided in the prototype, it is not intended to reduce the level of anti-nutritional substances by their partial elimination and enzymatic destruction.

 The objective of the invention is to reduce the level of saponins and polyphenols, causing bean taste and unpleasant odor by partially removing and enzymatically changing (destroying) to achieve high organoleptic and tasting characteristics of the final product, as well as reducing the level of anti-nutritional substances (trypsin inhibitors, lectins and oligosaccharides) .

 The task of obtaining soy milk with no soy taste and odor in the presence of a low level of anti-nutritional substances is solved by pre-soaking the seeds in a buffer solution at pH 8.2-8.6 with the content of hydrogen peroxide and sodium bicarbonate. After soaking, soybean seeds are washed with water, and then crushed in an aqueous solution containing at least 100 units. peroxidase activity in 1 liter of water, until a thin suspension is obtained. In this case, fermentation of soybean seeds occurs simultaneously. Then carry out filtration and heat treatment according to existing technology.

When soaking soybean seeds, a buffer solution containing 0.15-0.30% hydrogen peroxide and 2-3% sodium bicarbonate is used. Exposure by grinding soybean seeds is 10-15 minutes at a solution temperature of 30-35 ^C to obtain a suspension with a particle size ≅ 50 microns. As a source of peroxidase, you can use the homogenized root tissue of Armoracia rusticana.

 When seeds swell in a buffer solution of pH 8.2-8.6, the destruction of phytohemagglutinins occurs, leading to a decrease in their activity, while the activity of trypsin inhibitors and partial hydrolysis of raffinose oligosaccharides decrease.

 The selected pH range of 8.2-8.6 is necessary to reduce the level of lectins (phytohemagglutinins) and oligosaccharides, as well as to reduce the activity of trypsin inhibitors and active urease. Monitoring the levels of oligosaccharides and lectins according to the "Food Test" (Boenringer mannheim, lmb H, Wien, 1988, p. 25) showed that the use of solutions with pH values outside the pH range of 8.2-8.6 leads to ( at pH ≅ 8.2 and> 8.6) 0.3-0.5% of the initial amounts of oligosaccharides and does not provide a significant decrease in the activities of hemagglutinin and trypsin inhibitors (Table 1).

 The choice of hydrogen peroxide concentration of 0.15-0.30% is due to the need to inactivate the undesired lipoxidase enzyme (possibly involved in the formation of aldehydes and ketones of unsaturated fatty acids of soybean oil, causing an unpleasant smell of soybean milk), as well as for the accumulation of oxygen peroxide, diffused in the seed tissue during their swelling and for further fermentation with peroxidase, which reduces the taste of soy milk (table. 2).

к

Пероксидаза

где

железо в закисной форме, входящее в состав активной группы пероксидазы;
AH₂ субстрат, обусловливающий соевый вкус и запах, который окисляет пероксидаза;
A избирательно (специфично) окисленный продукт с модифицированными вкусовыми качествами.The elimination of soybean flavor is observed during subsequent fermentation with peroxidase, which oxidizes phenols and some aromatic amines, presumably responsible for the soya flavor and smell. The oxidation of certain compounds by peroxidase occurs with the help of oxygen, hydrogen peroxide or other organic peroxides. With peroxide, peroxidase forms a complex compound, resulting in the activation of peroxide, which acts as a hydrogen acceptor in accordance with the following mechanism of action of peroxidase

to

Peroxidase

Where

ferrous iron, which is part of the active group of peroxidase;
AH ₂ substrate, causing soy taste and odor, which oxidizes peroxidase;
A selectively (specifically) oxidized product with modified palatability.

 The choice of enzymatic treatment when grinding in an aqueous solution containing at least 100 units active peroxidase in 1 liter of water, due to the specific action of peroxidase on polyphenols, saponins, aromatic amines and other substances that determine the smell and taste of legumes. The mechanism of action is shown above and provides a higher specificity of action in comparison with the glucose oxidase used in the prototype, which is specific for glucoside residues, but not for saponins, polyphenolic substances, aromatic amines.

 The choice of the concentration of peroxidase in an aqueous solution containing at least 100 units. activity, due to the results of enzymatic effects (oxidation), are given in table. 3.

 As a source of peroxidase during enzymatic treatment, it is possible to use homogenized tissue of the root part of the plant Armoracia rusticana in amounts equivalent to an activity of 100 units. peroxidase activity in 1 l of water, which corresponds to an average of 3.0 g of homogenized Armoracia rusticana tissue in 1 l of water, the safety of the plant is confirmed by its use for food for seasoning (table horseradish). The separation of the insoluble part of the root tissue is carried out with regular filtration in the production of soy milk. Due to the low concentration of tissue, the occurrence of side taste effects was not noted.

 The degree of grinding upon receipt of the suspension is limited to a particle size of 50 μm. Larger grinding reduces the efficiency of extraction of protein substances.

Exposure for grinding seeds is 10-15 min at a temperature of 30-35 ^{° C} due to obtain under these conditions most of the final effect.

PRI me R. 50 kg of pre-refined soybean seeds are added to 150 L of a buffer solution containing 0.45 L of hydrogen peroxide and having a pH of 8.4, achieved by adding 1.6 kg of sodium bicarbonate. Seeds are kept in a buffer solution at ⁴⁰ ° C for 6 hours, washed with running water, separated from the wash water, and homogenized (to a particle size 50 .mu.m) in 200 kg of an aqueous peroxidase solution (at 180 units. Peroxidase activity in 1 liter solution) . The resulting suspension is separated by filtration through a fabric filter and subjected for at least 10 minutes to heating at 100 ^about C. Get a product characterized by the following indicators: Yield of soy milk, 300 kg
Protein level, dry matter 4.2
The level of lipids, on a dry matter 2.4
Phytohemag activity
glutinins, units activity 10 Urease activity, ΔрН 0,05 Presence of soya flavor None Presence of soybean odor None
The resulting product according to the proposed method has lower levels of anti-nutritional substances and is characterized by a high level of organoleptic characteristics, namely, trace manifestations of taste and smell, which compares favorably with products obtained by existing methods.

 Tasting assessment by experts of samples of soy milk obtained by the proposed method showed their higher quality in terms of organoleptic characteristics “taste” and “smell” in comparison with samples made by existing methods, including the prototype method.

Claims (6)

 1. A METHOD FOR PREPARING SOYA MILK, including cleaning soybean seeds, soaking them, wet grinding, fermenting, filtering and heat treatment, characterized in that the soaking the purified soybean seeds is carried out in a buffer solution at pH 8.2 to 8.6 containing hydrogen peroxide and sodium bicarbonate, after soaking, the swollen soybean seeds are washed, and the grinding and fermentation process is combined by grinding in an aqueous solution containing at least 100 units. peroxidase activity in 1 liter of water, until a suspension with a particle size of less than and equal to 50 microns is obtained.  2. The method according to p. 1, characterized in that they use a buffer solution containing 0.15 0.30% hydrogen peroxide.  3. The method according to p. 1, characterized in that they use a buffer solution containing 2 to 3% sodium bicarbonate.  4. The method according to claim 1, characterized in that the washing is carried out until the initial pH is restored.  5. The method according to claim 1, characterized in that as a source of peroxidase using homogenized root tissue of Armoracia rusticana in amounts equivalent to an activity of 100 units peroxidase activity in 1 liter of water. 6. The method according to claim 1, characterized in that the exposure when grinding seeds is 10 15 minutes at a solution temperature of 30 35 ^o C.

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