CH670036A5 - - Google Patents

Description

DESCRIPTION

The present invention relates to a method for manufacturing concentrated soy milk. From a filtered emulsion from treated soybeans, possibly gelled, then subjected to lactic coagulation, it is possible to make different food products.

Soy has been known for millennia in Asia and represents the main vegetable protein intake in the majority of everyday food dishes such as: Dau Hu (tofu) or soy paste, Tao Pho or soy cream, Sua Dau Nanh or soy milk, Tuong or soy sauce, etc.

Soy balances the diet by providing a significant amount of vitamins E (150 ppm of the lipid fraction), essential fatty acids (especially 60% polyunsaturated including 53% linoleic acid precursor of prostaglandins), lecithins rich in phosphorus, without forgetting a large protein fraction with a high content of essential amino acids (lysine and leucine in particular).

Light and digestible foods when flatulent sugars, cholesterol free and with marked hypolipidemic and hypocholesterolemic properties are eliminated, soy-based food products are very popular in Asian countries, but still not widespread in Europe. Two examples are worth mentioning regarding the role of soy in food. It is a complete food: it is enough to be convinced of it to observe the food of the bonzes (religious Buddhists) whose whole ration consists of rice and soya; it is a healthy food: the rate of cardiovascular diseases of atheromatous, venous or arthritic origins is indeed very low in the Asian population and the low sodium level (10 ppm) does not interfere with low sodium diets.

The traditional process for preparing an aqueous suspension of soybeans successively involves soaking the beans in water followed by grinding in a stone wheel, after swelling thereof. By decantation, the supernatant is then separated from the residual deposit which can be used for animal feed. This supernatant is a common base for the abovementioned traditional products.

In a modern process, the ground beans are heated to a temperature above 120 ° C followed by cooling and centrifugation to separate the solid from the emulsion. One can wonder if this last treatment does not precipitate a good part of the nutritive elements present in the mixture with the centrifugation pellet, which decreases all the more the nutritive value of the suspension.

Another known method reports grinding the beans in the presence of very hot water (90 to 100 ° C.) until a dispersion of particles is obtained. This is heated with steam and then subjected to a second, finer grinding in a ball mill so as to reduce the size of the protein and fat corpuscles to ten | i and the cell wall debris to a size included between 40 and 100 | i. It is clear that almost all of the flatulent sugars and cellulose debris present in the beans are found in the finished product; this affects its digestibility and its organoleptic qualities.

The present invention proceeds from the search for a process which is simple to implement, not attenuating the nutritive richness of the soybean by subjecting the preparation to treatments which are too drastic, to preserve its aroma while excluding unpleasant tastes and finally to produce a variety of products from a single common substrate.

Unhulled soybeans, previously washed in cold water, are used to rid them of their impurities. These are soaked in water for 6 to 12 hours. The duration of the treatment depends on the temperature and the shorter the time, the higher it will be. The following temperature range can be used (14 to 30 ° C); beyond, self-fermentation phenomena distort the substrate.

After swelling, the beans are ground in water using a rotary knife mill. The speed of rotation conditions the extraction of the protein chains linked to the cellulosic elements. An emulsion is obtained which is filtered under pressure so as to separate solid and liquid. The liquid phase is concentrated soy milk.

This preparation is the basis of many products. After adding starch from rice or green soya flour and intended to ensure the gelling of the medium, the mixture is heated to a boil while stirring vigorously. After cooling, this solution is subjected to lactic fermentation. The formation of a colloidal suspension of soybeans ensures the microorganisms a good dispersion, therefore a homogeneous and concerted fermentation. In addition, the gelled medium tempers the acidity resulting from fermentation and masks the astringency specific to soy. The finished products are particularly sweet in taste without having lost the organoleptic qualities specific to the substrate. The following examples are given by way of illustration.

Example 1

Soak unpeeled and yellow soybeans preferably (Dau Tuong or Dau Nanh), freed of their impurities by rinsing, in an excess of cold water at 20 ° C. After 6 h, these are swollen and softened. 180 g of wet beans mixed with 250 ml of water are then ground in a kitchen mixer mill whose knives rotate at 10,000 rpm. After one minute, the product is poured onto a fine cloth and strongly pressed

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so as to separate the solid from the liquid. The concentration of the filtrate is determined by the amount of dilution water added during grinding. Consumed at this stage after being cut off with an equal volume of water, the filtrate is soy milk. Depending on the consumer's taste or the type of product to be prepared, the concentrated soy milk may or may not be supplemented with sugar.

Example 2

Unshelled and yellow soybeans are preferably placed in an oven at 135 ° C for 30 min. After this heat treatment with dry heat, they will be soaked in an excess of water at 15 ° C for 12 h, then rinsed with cold water to rid them of their impurities.

The process for preparing the concentrated soy milk is then the same as that described in Example 1. The derivative products produced from this substrate will have the same consistency as those prepared according to the method described in Example 1 , but their bean flavor will be less pronounced.

Example 3

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The concentrated soy milk obtained in Example 1 or in Example 2 is cut with an equal volume of water. Rice starch is then slowly poured into the substrate at a rate of 20 g / l while stirring continuously to ensure its dissolution. The mixture is brought to the boil and then cooled to 45 ° C. By introducing lactic ferments such as Streptococcus thermophilus or Lactobacillus bulgaricus, pure or combined, an acidification of the medium and its coagulation are triggered. The preparation is incubated at 45 ° C for 2 h. The time chosen for incubation as well as the temperature depend on the texture and acidity desired for the finished product. Fermentation is stopped by cooling the mixture to 4 ° C.

Example 4

200 ml of a non concentrated soy milk is brought to a boil

670,036

sweet obtained according to the method described in Example 1 or in Example 2. After cooling to 45 ° C, the medium is seeded with lactic microorganisms such as Streptococcus thermophilus and Lactobacillus bulgaricus. The whole is suitably mixed to ensure a homogeneous distribution of the ferments and poured into temperature-resistant containers or trays. After 2 h in an oven at 45 ° C, or more if coagulation is not sufficient, the fermentation is blocked by bringing the product to 80 ° C for 10 min. The product is ready for consumption. Coagulation is obtained by a microbiological process and no longer by acid precipitation as in the traditional method; moreover, it is no longer necessary to resort to pressing the product followed by subsequent cutting, the packaging in trays authorizing the sale as it is.

Example 5

Starting from the preparation described in Example 1 or in Example 2, the procedure is as in Example 3, except that soy milk and cow's milk are mixed in equal amounts. Protein intake is mixed (plant and animal).

Example 6

Soy milk is prepared by following the procedure described in Example 1 or in Example 2 and cut with an equal volume of water. The procedure is then as in Example 2, but the rice starch is replaced by green soy flour (Dau Xanh) as gelling agent, at a rate of 50 g / 1.

Example 7

We proceed exactly as for examples 3, 5 or 6, but we add to the surface of the finished product a coating obtained with ginger syrup or an aqueous solution of essence of banana or almond, which go well with the taste of fermented soy.

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Claims (9)

670,036 1. Process for the manufacture of a concentrated soy milk according to which non-shelled soy beans are soaked in water for 6 to 12 hours at a temperature between 15 and 30 ° C., the swollen beans are ground by means of a knife mill, the product obtained is filtered under pressure in order to separate the two phases and the liquid phase which constitutes the concentrated soy milk is collected. 2. Method according to claim 1, characterized in that the unhulled soybeans are subjected beforehand to the action of dry heat for 30 minutes, at a temperature between 120 and 150 ° C, before being put in soak in water. 2 3. Method according to claim 1 or 2, characterized in that the concentrated soy milk obtained is sweet. 4. Method according to claim 3, characterized in that the soy milk is diluted to 50% with water. 5. Method according to claim 3, characterized in that the soy milk is diluted to 50% with cow's milk. 6. A method of preparing a gelled soy milk, characterized in that rice starch obtained in the proportion of 20 g / 1 is added to the soy milk obtained according to one of claims 1 to 5 or green soy flour at a rate of 50 g / 1, then homogenize the preparation before bringing it to a boil. 7. A method of preparing a fermented soy milk, characterized in that the gelled soy milk obtained according to claim 6 is cooled to a temperature between 40 and 50 ° C before inoculating it with lactic ferments , the preparation is maintained under these temperature conditions until the desired coagulation has been obtained, then the temperature of the product is lowered between 4 and 10 ° C in order to stop the acidification of the medium. 8. Method according to claim 7, characterized in that one adds to the surface of the product a syrup of ginger, essence of banana, almond or another flavor. 9. A method of preparing a fermented soy milk, characterized in that the concentrate obtained according to claim 1 or 2 is brought to a boil and then cooled to a temperature between 40 and 50 ° C; maintained under these temperature conditions, it is inoculated with lactic ferments then, after having obtained the desired coagulation, the milk is brought to 80 ° C. in order to block the acidification of the medium by destruction of the ferments.