DE2347219A1 - Proteinaceous foodstuffs from soya bean - prepd. from cheese-like product obtained by fermenting soya milk - Google Patents

Abstract

Proteinaceous foodstuffs from soya bean are prepd. by (a) subjecting soya flour to extraction with an aq. soln.; (b) adjusting the pH of the aq. extract to pH 6.5-7.0 whereby soya milk is formed; (c) sterilising soya milk; (d) fermenting soya milk with lactic acid bacteria; (e) separating the resulting card; and nf) converting it into the desired product. Proteinaceous spreads - hard cheese-like products and ss sausage-like products can be prepd. by the method.

Description

Process for the production of soy products

The present invention relates to a new method of manufacture of soy quark made from soy flour and soy products obtained from this quark. The preferred for the invention is soy flour the so-called uncalcined flour, which is made by heating the soy flour to below 70 ° C while removing the solvent is obtained. '

It is now widely accepted that soybeans become a major contributing factor as a source of protein as it is one of the best and cheapest sources of protein in terms of unit cost of production are. The biggest obstacle to the use of soybeans as a source of food for humans is the bitter one bean-like taste and the unpleasant smell and imperfect color of such products. For example, the Soymilk commonly available in the market has an unsightly appearance and is very different in taste and aroma from Cow's milk and is often used by consumers who are used to cow's milk are perceived as inedible.

The main forms of soy protein products are soy flour and

509813/06 5 8

-meal, such as defatted soy flour, soy concentrates and soy isolates. The full fat soy flour and soy concentrates are relatively cheap protein and high-calorie food components that are produced in simple processing plants but they have the disadvantage of having a certain bean-like taste. The soy isolates that are commercially available as the main protein fraction of soybeans and which are made from high quality peeled beans taste better than soy flour, but are much more expensive.

The separation of the protein or protein fraction of the soybeans is currently being carried out in Pernost for the production of soy quark and Chinese cheese or so-called tofu. Recently, a new direction has been reported in the production of soy cheese from raw soybeans under controlled conditions and using a lactic acid starter organism. According to this method, the raw soybeans are washed and the resulting solution is boiled under pressure, whereby a soybean milk is obtained. The soy milk is converted into soy curd by three different methods: (1) adding CaSOj ,, (2) adding acetic acid, and (3) adding lactic acid fermentation reagent. The yield of total precipitated protein obtained by the addition of acetic acid was about 68 % compared to 54-55 % of the protein obtained by the addition of calcium sulfate or lactic acid fermentation reagent. The disadvantage of the method using lactic acid fermentation reagent is the long time it takes for the curds to coagulate or coagulate and for the whey to separate. The long clotting time increases the chances of contamination by undesirable microorganisms normally present in raw soybean soy milk or in the environment. Some improvements in palatability and physical and microbiological aspects of the obtained curd are also needed. For these reasons, the addition of rennet extract and skimmed milk has been suggested. By adding rennet extract and skimmed milk, the total time it took to make the quark was actually reduced by 40 minutes. This addition

also improved the taste and aroma of the final product. However, this method still has the disadvantage that the overall yield of protein precipitation is only 55 % . From a commercial and economic standpoint it is desirable to recover virtually all of the protein from the soybean feedstock, but this has resulted in rigorous isolation procedures. In these thorough isolation processes, not only protein but also malodorous aroma material, pigment material, slimy material and the like are extracted. In addition, the introduction of rennet extract and skimmed milk leads to an enzymatic decomposition of casein and soy protein.

One aim of the present invention is to create a new process for the production of soy quark, starting from soy flour, and converting it into various soy products.

Another object of the invention is to make debittered soy curd with improved taste properties that can be processed into various soy foods.

Yet another object of the invention is to provide a soy curd with a high protein content.

The present invention relates to a process for the production of soy products from soy flour which comprises in combination the following steps: (a) leaching of soy flour with an aqueous solution and separation of the solid residue, (b) pH adjustment of the soy extract to a value between 6 , 5 and 7> 0, to obtain a j soy milk, (c) sterilization of the soy milk, (d) ^per-: mentation by a milk or lactic acid culture, (e) removing j of soy curd and (f) conversion of this quark in edible soy products.

The soy products obtained are characterized by an improved consistency and improved flavor and generally have much better palatability properties than the soy products, obtained from curd made from soybeans by the usual methods.

5 0 9 8 13/0658

In general, any type of soy flour can be used. In particular result in uncalcined soy flour, which is generally defined as soy flour that has been freed from solvent below 70 C, the best results in terms of the yield of the protein component.

Step (a) is preferably carried out with a dilute alkaline earth hydroxide solution, but other neutral aqueous solutions or other alkaline substances or mixtures thereof can be used, such as ordinary water, sodium hydroxide, calcium hydroxide, ammonium hydroxide and the like. The efficiency of the leaching depends on the temperature , the leaching time, the ratio of solution to soy flour and the concentration of the solution. For example, a leaching time of 30 minutes was required with a 0.01m solution of Ca (OH) p at a temperature of 55.degree. When using calcium hydroxide, a better milk yield from soy flour was achieved than when using a neutral aqueous solution. In addition to this, the presence of calcium ions is also advantageous, taking into account that one of the main complaints about the use of soy milk as a substitute for cow's milk was that its calcium content is extremely low, namely less than a quarter of the calcium content of cow's milk. On the other hand, if a high concentration of Ca (OH) p is present in the aqueous solution used for leaching, a hard curd will be obtained. A relatively high concentration of calcium ions also reduces the solubility of the quark. Preferred concentrations to be used are in the range from 0.003m to 0.02m Ca (OH) ₂ or 0.01m to 0.04m NaOH, and preferred temperatures are in the range from 50 to 60 ° C.

If necessary, one or more additional leaching processes can be carried out with fresh alkali hydroxide or ordinary water with the moist one obtained after decanting the soy extract Make backlog. However, large amounts of solvent dilute the soymilk ultimately obtained and lead to certain Difficulties in the further stages of the process.

5098 13/0658

The soy extract can be separated from the residue by filtration under vacuum or on a filter press or by centrifugation. It has been found that the preferred mode of operation is a combination of filter presses and centrifugation, in which case more than 90 % of the volume of the extract is obtained.

The pH adjustment is an important critical stage required in the process. The lowering of the pH to 6.5 enables rapid growth of the bacteria in the further stage, but a pH value below 6.5 leads to precipitation of protein during the sterilization stage. So there was a compromise between bacterial growth and avoidance a protein precipitation chosen. It has been found that the pH of the solutions is between 6.5 and 7 * 0 and preferably should be between 6.6 and 6.8.

The pH adjustment can be done with an edible acid such as Citric acid, hydrochloric acid and the like., Can be made. The concentration of acid used is not critical, but it should not be so high as to cause damage to the soymilk, on the other hand, however, is a the smallest possible volume of aqueous acid to be handled is preferred. The preferred concentration of the acid is between 0.3n and In.

The sterilization stage is absolutely necessary. Because the soy milk Rich in protein, sugars and salts, it provides a suitable medium for the growth of microorganisms that normally occur in Soybeans are present. The heat treatment sterilizes the soybean milk and destroys the antidigestive factors present in the soybeans. At the same time this heat treatment to some extent removes the bean-like aroma that the flour contains. It has been found that the sterilization also has a beneficial effect on the coagulation in the subsequent stage. The sterilization time depends on the temperature, but overheating should be avoided as protein will precipitate - 509813/06 58 ---

can cause. It has been found that the preferred conditions for 'autoclave sterilization'
Periods of 2 to 5 minutes are.

gene for the 'sterilization in the autoclave 110 to 120 ⁰ C for a

The fermentation by lactic acid cultures, which are used as a starter for the coagulation of the curd, is an essential one Feature in the method according to the invention. The ones known so far Commercial processes for the precipitation of curd from soymilk are carried out with the addition of salts and the application of heat. The quark obtained is white in color, but has a bitter and bean-like taste. According to level (d) of the present invention, the quark is precipitated from the soymilk obtained after sterilization by adding a Starter chosen from a lactic acid culture. The lactic acid culture added as a starter belongs to the Lactoba family? cillaceae of the lactic acid group. According to the invention, the bacteria which can be used as coagulants or coagulants are Meet the main requirement of utilizing a sugar present in soy milk as a source of carbohydrates (sucrose and raffinose). Examples of these bacteria are: Species Streptococcus thermophilus (at pH 4.5), Lactobacillus arabinosus (at pH 4.2), Lactobacillus casei (at pH 5 * 2) and the like. A person skilled in the art can easily choose the right bacteria depending on the end product you want. The lactic acid culture lowers the pH of the soy milk 5.2 to 4.2 after 4 to 18 hours at a temperature of 37 ° C to 40 ° C. This lowering of the pH is a consequence of the conversion of carbohydrates present in soy milk into the ■ corresponding ·;:! Acids. It was surprisingly found that By using the lactic acid culture alone the separation of the curd from the soy whey is easy by a combination of

ι Gravity filtration and centrifugation can be carried out.

j A slight increase in temperature improves the separation rate.

; The obtained curd is very rich in protein. More than 90 % of the protein from the soy milk can be precipitated in the curd; will. This is a very high protein recovery that cannot be found in any other known method. It was too

509813/0658

_M 7 _

• tried to use the well-known acid precipitation instead of the lactic acid culture at this stage, but only 80 % protein from the soy milk was found in the quark under the same test conditions. The soy quark produced by the process according to the invention is therefore characterized by its high nutritional value, in particular in the form of protein, and has better taste properties and digestibility than the known soy quark, as was determined by a trained test group.

The entire process is carried out under controlled and relatively very mild conditions in terms of temperature and reaction time carried out in order to achieve the desired improvement in taste, aroma and smell without damaging the protein. Although the Reasons for the success of the improved palatability are not fully understood, it should be noted that a reasonable hypothesis, which is based on the evidence available, is that the organic responsible for the bad taste and smell Materials under the catalytic influence of the enzyme content of the lactic acid culture, with the formation of organic acids, the less have adverse organoleptic properties removed and it appears that new desirable flavors and fragrances are simultaneously formed under the controlled fermentation conditions.

; Various products can be obtained from the present invention

: improved curds with high protein content are made.

j Among these products the following can be mentioned: Bread

j spreads, especially cheese-like and processed cheese-like

j products, meat-like products, sausages, beverages, baby food,

; Whipped toppings and the like.

! In the production of spreads, the quark is mixed with melting ι salts (e.g. sodium phosphate) homogenized. Fats and starches nen are also added. The entire mixture is further mixed with vegetables and spices. This is how you get spreads with flavor additives with different aromas. These spreads can be preserved and canned. . . . ..._ ... ...

509813/0658

In the same manner as described above, by performing heat treatment in an autoclave at a temperature higher than 120 ° C for 15 minutes, it is possible to obtain a hard product such as hard cheese that can be sliced. It is also possible to use the quark as an additive in the production of various meat products, such as, for example, meat substitutes that are similar to chicken, and in particular in the production of V'ürstchen or frankfurters. The curd made from soy flour according to the invention can be used in amounts of up to 25 wt.

The purpose of soy protein in the meat industry is twofold: (1) to transform existing meat products or to improve and (2) to stretch or replace meat. Every seasoning and flavoring agent can be used with the quark containing mass can be added so that the end product can have a beef, chicken, garlic or onion flavor. It is possible, by customary methods, to use the quark obtained according to the invention to produce special soy proteins which are emulsifying ' and have binding properties that add to the texture of the finished meat products.

To other, edible additives that are used with advantage may include starch, flours, vegetable gums, polysaccharides and the like, fats, proteinaceous materials such as oilseed protein, gelatin, biscuit flour, breadcrumbs, and oilseed flour. Coloring materials and reinforcing ingredients such as Vitamins can also be added. By adding. different flavoring or flavoring materials and spices it is possible to get different dishes in the form of balls (grains).

It is also possible to make the curd a proteolytic enzymatic Treatment either by adding an enzyme reagent (such as pepsin, molsin) or by external proteolysis with

509813/0658

Using a suitable microorganism such as Actinomucor elegans or Aspergillus sojae.

In general, the quark can be used as an additive for any food that requires a source of protein to be used as is common in the food industry.

The following examples serve to further illustrate the invention.

Example 1

Making curd

1000 g of soy flour with a content of 42 % total protein, obtained from uncalcined soybeans (soy flour freed from solvent at below 70 ° C.), were leached with 10 1 of an aqueous 0.0Im-Ca (OH) p solution at 55 ° C. for 30 minutes. There was constant mixing during the leaching. The residue was separated off by means of gravity and finally pressed through a screw press. The filtrate was centrifuged with a basket centrifuge. The piltrate was further adjusted to pH 6.7 by slowly adding 100 ml of 0.5N HCl with constant stirring. The soymilk obtained had a white, milky color. It was placed in 4 bottles and sterilized in an autoclave at 116 ° C. for 4 minutes. Then the milk was rapidly cooled to 40 ⁰ C.

The contents of the bottles were placed in an open vial and mixed with 225 ml of a freshly prepared culture of Strepto-. coccus thermophilus as a lactic acid starter inoculated. The mixture was placed in an incubator for 5 hours at 40 ° C. Complete coagulation occurred. The gel formed was divided into small cubic pieces and the curd was separated by filtering it through a cheesecloth. The quark obtained contained 18 % solids with 78 % protein. The total yield of protein obtained, based on the total proprotein contained in the flour, was 65 %.

509813/0658

- ίο ■ -

Example 2 Making curd

5000 g of the same uncalcined soybeans as used in Example 1 were leached with 35 l of tap water at 55 ° C. for 60 minutes. Stirring was carried out continuously during the leaching. The experiment was continued as in the previous example. The soymilk obtained was placed in 12 bottles and sterilized in an autoclave at 116 ° C. for 4 minutes. The inoculation was carried out with 750 ml of a freshly prepared culture of Streptococcus thermophilus. The procedure was the same as in the previous example and a corresponding product was obtained, but the overall yield of protein recovered was only 30 %.

Example 3 Making curd

The experiment of Example 1 was repeated using 1000 g of the same uncalcined soybeans, but the leaching was carried out with 10 1 of a 0.02N NaOH solution. The same procedure as in Example 1 was carried out, the only difference being that the pH was adjusted with 100 ml of 0.5N citric acid. The same lactic acid culture was used. A product similar to that in Example 1 was obtained, but the total yield of protein recovered was 70 % in this case.

In game 4 making quark

The experiment of Example 1 was repeated with the difference that the lactic acid starter used in this case consisted of 225 ml of Lactobacillus arabinosus, with 16 hours at 40 ° C was incubated (a pH of 4.2 was reached).

509813/0658

- li -

A similar product was obtained as in Example 1, the total yield also being 65 % of the total protein present in the flour.

Example 5 Making curd

The same experiment as in Example 1 was repeated with the difference that the lactic acid culture in this experiment consisted of a mixture of 100 ml of freshly produced culture of Streptococcus thermophilus and 125 ml of Lactobacillus arabinosus. Incubation was carried out for a period of 7 hours at 40 ° C. The total yield of protein recovered based on the total protein present in the flour was 68 %.

Example 6 Manufacture of soy spread

330 ml of ordinary water were added to 67O g of the quark prepared according to Example 1 (18 % solids). The slurry was mixed with 20 g of Na ₂ HPO ₁₁ and homogenized again. 75 ml of sunflower oil, 37.5 g of corn starch and 20 g of NaCl were added to the resulting mixture. All ingredients were re-homogenized to give a spread with an improved butter-like texture.

Various flavors or spices were added to the resulting spread: dehydrated onions ($ 4), garlic flavor, concentrated tomato paste, synthetic Roquefort flavor (0.6 %) , garlic-flavored monosodium glutamate, and / or smoked flavor. The spreads were filled into cans, sealed and ^{heated at about 90 °} C. for 15 minutes.

50 9 813/0658

Example 7 Manufacture of hard cheese-like product

This product was produced as in the previous example, but the cans were ^{heated to 120 °} C. for 15 minutes.

Example 8 Production of sausages

500 g of the quark obtained according to Example 1 (18 % pesticides) were added to 1000 g of sausage mass and milled by extrusion. The following spices were added to the resulting mixture: Ί, 5 g salt, 1.5 g of pepper, 0.15 g of garlic, 0.11 g of marjoram and 0.3 g of sodium glutamate. The entire mass was homogenized again and processed in the manner known in the sausage industry.

509813/0658

Claims (10)

- 13 patent claims 1. Process for the production of soy products from soy flour, characterized in that (a) soy flour is leached with an aqueous solution and the solid residue is separated off, (b) the pH of the soy extract is adjusted to a value between 6.5 and 7.0 to form a soy milk, (c) the soy milk sterilized, (d) fermented by means of a lactic acid culture and (e) the soy quark is separated and optionally (f) this quark is converted into soy products. 2. The method according to claim 1, characterized in that ₃ is obtained that the flour used by solvent removal from soy flour by heating at a temperature below 70 ⁰ C. 3. Method according to claim 1, characterized in that the soy flour is leached with an aqueous alkaline solution in which the alkaline substance is Ca (OH) ₂ or NaOH or a mixture of these. 4. The method according to claim 1, characterized in that the H) ₂ -L.
having. Ca (OH) ₂ solution has a concentration in the range from 0.003 to 0.02m 5. The method according to claim 1, characterized in that the pH adjustment of the soy extract to a range from 6.6 to 6.8 is made. 6. The method according to claim 5, characterized in that the pH adjustment is made with an edible acid from the group of hydrochloric acid and citric acid. 7 · 'Method according to claim 1, characterized in that the Fermentation with a lactic acid culture from the group of Streptococcus thermophilus, Lactobacillus arabinosus, Lactobacillus casei and mixtures thereof is made. 5098 13/0658 8. Process for the production of soy protein-based spreads, characterized in that soy quark produced according to claim 1 is used. 9. Process for the production of hard cheese-like products Soy protein base, characterized in that soy quark produced according to claim 1 is used. 10. Process for the production of sausage products based on soy protein, characterized in that soy quark produced according to claim 1 is used. 509813/0658