Title of Invention

SOYBEAN FLOUR AND A METHOD FOR ITS MANUFACTURE

Abstract

The invention relates to a method for producing soybean flour from soybeans consisting in peeling soybeans to a peeling ratio equal to or higher than 95 %, breaking and standardising the size of the peeled soybeans until achieving a particle size distribution in which 90 % of soy particle sizes range from 100 mu m to 1 mm by exposing the peeled soybeans to impact forces, deactivating the enzymatic system of the thus obtained and size-standardised soy particles and in grinding said size-uniformed soy particles until achieving a particle size distribution in which 95 % of soy particles have sizes of less than 100 mu m by exposing said deactivated, ground and uniformed particles to shearing forces. Said invention also relates to a soybean flour which is produced preferably by the inventive method, wherein the maximum particle size distribution is less than 100 mu m, the soybean enzymatic system is at least partially deactivated by heat and the peel content is less than 0.5 mass %.

Full Text

SOYBEAN FLOUR AND A METHOD FOR ITS MANUFACTURE This invention relates to soybean flour and a method for its manufacture. Numerous methods are known for manufacturing soybean flour. Primarily enzyme activity is responsible for the at times unpleasant taste of soybeans. When enzymes are not activated correctly, unacceptable changes can arise in product taste. However, enzyme inactivation runs the risk of destroying valuable soybean phytochemicals. Hence, during the manufacture of soybean flour or any soybean flour extract for basic use in foods and nutraceutics, the problem becomes that it is very difficult and expensive, if not impossible, to obtain a product that has the full nutritional value of the parent material, while at the same time lacking the typical bean taste of soybean products. The object of this invention is to provide a new method for manufacturing soybean flour not associated with these disadvantages. This object is achieved by the method according to claim 1, and the soybean flour according to claim 21. The method according to the invention for manufacturing a soybean flour out of soybeans involves the following steps: a) Shelling of soybeans to a shelling level exceeding 95 %; b) Comminution and dimensional standardization of the shelled soybeans to a particle size distribution in which 90 % of the soybean particles range from 100 jam to 1 mm by exposing the shelled soybeans to impact forces; c) Deactivation of an enzyme system of the comminuted and dimensionally standardized soybean particles; and d) Fine comminution of the comminuted and dimensionally standardized soybean particles to a particle size distribution at which 95 % of the particles are smaller than 100 |im by exposing the deactivated, comminuted and dimensionally standardized soybean particles to shearing forces. Shelling the soybeans to a shelling level exceeding 95% (step a) is a precondition for subsequently comminuting the soybeans with the use of shearing forces (step d). Since more than 95 % of the shells are removed, only a very few shell particles remain in the mixture once the steps for purposes of comminution and dimensional standardization as well as deactivation have been performed. If too many such shell particles were to remain in the comminuted mixture, it would be impossible to achieve a correct comminution level. 90 % of the particles are preferably smaller than 50 |um after step d). Comminuting and dimensionally standardizing the shelled particles to a particle distribution at which 90 % of the soybean particles range from 100 |im to 1 mm by exposing the shelled soybean particles to impact forces (step b) is a precondition for subsequent deactivation having as uniform an effect as possible on the product to be deactivated (step c) . It has surprisingly been found that finely comminuting (micro-comminuting) the previously comminuted and dimensionally standardized particles to a particle size distribution with 95 % of the particles less than 100 jxm by exposing the previously (steps b to c) deactivated, comminuted and dimensionally standardized soybean particles (step d) to shearing forces has a favorable effect on the chewing consistency of the obtained soybean flour without detracting from its nutritional value. Therefore obtained is soybean flour that has no soybean taste after thermal treatment, but rather has a neutral taste, if any, and does not have a sandy consistency in the mouth when used in products. In this text, the term "nutritional value" relates to the entire spectrum of physiologically useful constituents of soybeans, including typical soy phytochemicals, e.g., isoflavins, saponins, etc. As a rule, shelling step (a) is performed on whole soybeans. Shelling in step a) can take place using an impact shelling machine, e.g., an OTWZ impact shelling machine from Biihler. The soybean temperature should be kept under 3 0°C while shelling in step a) , preferably at an air temperature ranging from about 115-120 °C. However, this "cold shelling" can also be replaced by a "hot shelling" at soybean temperatures exceeding 100 °C-110 °C, preferably at an air temperature ranging from 14 0 to 160 °C. The shelled soybeans are preferably comminuted and dimensionally standardized in step b) in an atmosphere with less than 10 %v/v of oxygen, preferably in a mixture of air and nitrogen, to in turn avoid oxidative damage to the product, and prevent deterioration in its nutritional value. Comminution and dimensional standardization in step b) can take place using a hammer mill. The shelled soybeans are preferably comminuted and dimensionally standardized, yielding a particle size distribution in which 80 % of the soybean particles range from 100 |im to 500 mm. Comminuting and dimensionally standardizing the product to such an average size and narrow size distribution prior to thermal deactivation ensures that the comminuted and dimensionally standardized product particles undergo essentially the same thermal treatment both on the outside and inside. This makes it possible to achieve a uniform product deactivation, as already mentioned further above. The comminuted and dimensionally standardized soybean particles are preferably deactivated at temperatures of 90 to 100 °C in step c) , preferably at a relative humidity of 95 to 100 %. Deactivation in step c) preferably takes place via the moistening, heating and moisture immersion of the comminuted and dimensionally standardized soybean particles, preferably in a BCTC preconditioner from Biihler. This essentially reduces or eliminates the lipoxygenase content in the product. Deactivation in step c) can also take place using an extruder instead of the preconditioned or in addition to the preconditioner. The fine comminution in step d) is preferably carried out using a distributing roll mill, e.g., a DNWA distributing roll mill from Biihler. The fine comminution step d) is preferably preceded by a moisture adjustment step, in which the moisture of the deactivated, comminuted and shelled soybeans (steps a and b) is set to a moisture level of 8 to 12 %w/w, preferably 9 to 11 %w/w. In most cases, the soybean particles must be dried, and the moisture adjustment step is performed thermo-pneumatically, for example. It was surprisingly shown that fine comminution at such moisture levels improves the taste of the products by eliminating the soybean flavor, leaving a neutral or empty taste and/or generating a somewhat more malty flavor instead. Such an empty or "neutral" taste is important when using the soybean flour as an additive in foods that can vary in terms of flavor, and should not be impaired by the taste of the additive. Fine comminution in step d) preferably yields particles ranging from 0.05 Jim to 150 (j,m, preferably from 10 to 50 jim. Shelling in step a) preferably takes place to a shelling level exceeding 98%. As a result, fine comminution in step d) can be performed more efficiently in the distributing roll mill, preferably in a single pass, minimizing the risk of thermal damage to the product and an impairment of the nutritional value of the product. According to the invention, a soybean flour is prepared in which the maximum particle size is less than 150 p,m, the soybean enzyme system is at least partially deactivated by heat, and the shell content measures less than 0.5 %w/w. The maximum particle size of the soybean flour preferably ranges from 0.05 |um to 150 pm, preferably from 10 to 50 jam. The shell content preferably measures less than 0.2 %w/w. The protein content of the fabricated soybean flour preferably exceeds 10 0 % of the protein content of the initial soybeans (protein enrichment) . The nutrient fiber content of the fabricated soybean flour is preferably less than 70 % of the nutrient fiber content of the initial soybeans. The lipoxygenase content of the fabricated soybean flour is preferably less than 0.1 % of the lipoxygenase content of the initial soybeans. The oil content of the fabricated soybean flour preferably exceeds 90 % of the oil content of the initial soybeans. The nitrogen solubility index (NSI) of the fabricated soybean flour preferably exceeds 60 % of the NSI of the initial soybeans. The isoflavon content of the fabricated soybean flour preferably exceeds 70 % of the isoflavon content of the initial soybeans. The particle size distribution of the fabricated soybean flour is preferably such that more than 30 % of the flour particles are less than 10 \im. The trypsin inhibitor content of the fabricated soybean flour preferably exceeds 50 % of the trypsin inhibitor content of the initial soybeans. The above soybean flour is preferably fabricated using the method according to the invention as described above. The method according to the invention preferably involves a continuous process. The soybean flour according to the invention can be used as an additive in foods, such as milk products, fruit products, beverages, soups, pastas, food bars, meat substitutes, snacks, frozen deserts and bakery products. Additional aspects, advantages and applications of this invention are described in the following paragraphs. The soybean process according to the invention comprises the shelling, milling, thermal deactivation of enzymes to reduce an undesired soybean flavor (by controlling the supply of heat and moisture to the milled soybeans, thereby inactivating certain enzymes, while at the same time retaining the nutritional and functional integrity of the macro-nutrients and bioactive constituents of the soybean), and micro-milling, to generate soybean flour particles ranging from 0.05 jam to 150 |Lim, preferably from 10 to 50 (im. The soybean flour according to the invention can also be used to fabricate economic and nutritional soybean milk by adding water and active ingredients to adjust the taste consistency of the product and the viscosity in special mixing processes, in which mixing takes place at a higher shearing force, and a ball mill is used, for example. For example, the following two methods can be used to manufacture soybean milk: The soybean flour according to the invention is suspended in an aqueous system using a hydrocolloid. Sweeteners and/or other flavorings can be added. This yields a beverage having the same thick consistency as a powdered milk beverage. The soybean particles according to the invention are encapsulated with a hydrocolloid using a ball mill. This ball milling process utilizes a relatively high-viscosity mixture of soybean flour, water and a hydrocolloid. After milling with the ball mill, the mixture is diluted to a specific protein content, which provides a certain quantity of protein per portion. Since the soybean flour according to the invention has a neutral or pleasant taste, it is suitable for mixing with numerous food additives, such as flavorings, vegetable powder, fruit powder, phytonutrients, plant extracts, hydrocolloids, vitamins, minerals, trace elements, etc., to fabricate a dispersible, instant food mix. The soybean flour according to the invention can be used to manufacture soybean products at reduced costs. For example, it is possible to substitute expensive soybean isolates with isoflavon-enriched soybean protein extracts, etc. The soybean flour has a high percentage of bioactive substances. The soybean flour according to the invention can also be used to fabricate stable emulsions and provide a moisture control function in food products. The soybean flour can trigger a low-glycemic reaction when properly combined with hydrocolloids. The soybean flour according to the invention is easily digestible. The soybean flour according to the invention produces no sandy taste in the mouth when used in other products. It is assumed that the soybean flour according to the invention or flours containing it are characterized by a high bioavailability of bioactive substances and micro-nutrients. The soybean flour according to the invention produces improved textural properties as a finely milled additive combination. The soybean additive need not necessarily take the form of soybean flour. Rather, it can be provided at the end of soybean fabrication as a paste or liquid preferably sterilized beforehand through the addition of a liquid, e.g., oil or grease. In a manner similar to the soybean flour according to the invention, it is possible to manufacture flours based on cereal grains, lentils, etc. with similar properties in terms of flavor as the soybean flour according to the invention. CLAIMS 1. A method for manufacturing a soybean flour out of soybeans, wherein the method involves the following steps: a) Shelling of soybeans to a shelling level exceeding 95 %; b) Comminution and dimensional standardization of the shelled soybeans to a particle size distribution in which 90 % of the soybean particles range from 100 |am to 1 mm by exposing the shelled soybeans to impact forces; c) Deactivation of an enzyme system of the comminuted and dimensionally standardized soybean particles; and d) Fine comminution of the comminuted and dimensionally standardized soybean particles to a particle size distribution at which 95 % of the particles are smaller than 100 jam by exposing the deactivated, comminuted and dimensionally standardized soybean particles to shearing forces. 2. The method according to claim 1, characterized in that the shelling step a) is performed on whole soybeans. 3. The method according to one of the preceding claims, characterized in that shelling in step a) takes place using an impact shelling machine. 4. The method according to claim 3, characterized in that shelling in step a) takes place in a BSSA impact shelling machine from Buhler. 5. The method according to one of the preceding claims, characterized in that the temperature of the soybeans is maintained at 80-85 °C while shelling in step a) , preferably by exposing them to air temperatures of about 115-120 °C. 6. The method according to one of the preceding claims, characterized in that comminution and dimensional standardization in step b) take place in an atmosphere having less than 10 %v/v of oxygen, preferably in a mixture of air and nitrogen. 7. The method according to one of the preceding claims, characterized in that comminution and dimensional standardization in step b) take place using a hammer mill. 8. The method according to one of the preceding claims, characterized in that the shelled soybeans are comminuted and dimensionally standardized to a particle size distribution at which 80 % of the soybean particles range from 100 jam to 500 (im. 9. The method according to one of the preceding claims, characterized in that the comminuted and dimensionally standardized soybean particles are deactivated at temperatures of 90 to 100 °C in step c) . 10. The method according to one of the preceding claims, characterized in that the comminuted and dimensionally standardized soybean particles are deactivated at relative humidities of 95-100% in step c) . 11. The method according to claim 9 or 10, characterized in that deactivation in step c) takes place over a duration of less than 5 minutes. 12. The method according to one of the preceding claims, characterized in that deactivation in step c) takes place via the moistening, heating and moisture immersion of the comminuted and dimensionally standardized soybean particles. 13. The method according to one of the preceding claims, characterized in that deactivation in step c) takes place in a BCTC preconditioner from Biihler. 14. The method according to one of the preceding claims, characterized in that deactivation in step c) takes place using an extruder. 15. The method according to one of the preceding claims, characterized in that fine comminution in step d) takes place using a distributing roll mill. 16. The method according to claim 15, characterized in that fine comminution in step d) takes place in a DNWA distributing roll mill from Biihler. 17. The method according to one of claims 15 or 16, characterized in that fine comminution in step d) is preceded by a moisture adjustment step, in which the moisture of the deactivated, comminuted and shelled soybeans (steps a and b) is set to a moisture level of 8 to 12 %w/w, preferably 9 to 11 %w/w. 18. The method according to one of the preceding claims, characterized in that the moisture adjustment step takes place thermo-pneumatically. 19. The method according to one of the preceding claims, characterized in that fine comminution step d) generates particles ranging from 0.05 (am to 150 (am, preferably from 10 to 50 |nm. 20. The method according to one of the preceding claims, characterized in that shelling in step a) takes place up to a shelling level exceeding 98 %. 21. A soybean flour, in particular manufactured with the method according to claim 1, in which the maximum particle size is less than 150 |LLm, the soybean enzyme system is at least partially deactivated by heat, and the shell content measures less than 0.5 %w/w. 22. The soybean flour according to claim 21, characterized in that the maximum particle size of the soybean flour ranges from 0.05 jam to 150 jam, preferably from 10 to 50 (am. 23. The soybean flour according to one of claims 21 or 22, characterized in that the shell content measures less than 0.2 %w/w. 24. The soybean flour according to one of claims 21 to 23, characterized in that the protein content of the fabricated soybean flour is less than 100% of the protein content of the initial soybeans. 25. The soybean flour according to claim 24, characterized in that the nutrient fiber content of the fabricated soybean flour is less than 70 % of the nutrient fiber content of the initial soybeans. 26. The soybean flour according to one of claims 24 and 25, characterized in that the lipoxygenase content of the fabricated soybean flour is less than 0.1 % of the lipoxygenase content of the initial soybeans, 27. The soybean flour according to one of the preceding claims 24 to 26, characterized in that the oil content of the fabricated soybean flour exceeds 90 % of the oil content of the initial soybeans. 28. The soybean flour according to one of the preceding claims 24 to 27, characterized in that the nitrogen solubility index (NSI) of the fabricated soybean flour exceeds 60 % of the NSI of the initial soybeans. 29. The soybean flour according to one of the preceding claims 24 to 28, characterized in that the isoflavon content of the fabricated soybean flour exceeds 70 % of the isoflavon content of the initial soybeans. 30. The soybean flour according to one of the preceding claims 24 to 29, characterized in that the particle size distribution of the fabricated soybean flour is such that more than 30 % of the flour particles are less than 10 jam. 31. The soybean flour according to one of the preceding claims 24 to 30, characterized in that the trypsin inhibitor content of the fabricated soybean flour exceeds 50 % of the trypsin inhibitor content of the initial soybeans. 3 2. The soybean flour according to one of the preceding claims 24 to 31, characterized in that it was fabricated using a method according to one of claims 1 to 20. 3 3. Use of the soybean flour according to one of the preceding claims as an additive in foods, such as milk products, fruit products, beverages, soups, pastas, food bars, meat substitutes, snacks, frozen deserts and bakery products.

Documents:

2871-chenp-2005 abstract duplicate.pdf

2871-chenp-2005 abstract granted.pdf

2871-chenp-2005 claims duplicate.pdf

2871-chenp-2005 claims granted.pdf

2871-chenp-2005 description (complete) duplicate.pdf

2871-chenp-2005 description(complete) granted.pdf

2871-chenp-2005-abstract.pdf

2871-chenp-2005-claims.pdf

2871-chenp-2005-correspondnece-others.pdf

2871-chenp-2005-correspondnece-po.pdf

2871-chenp-2005-description(complete).pdf

2871-chenp-2005-form 1.pdf

2871-chenp-2005-form 3.pdf

2871-chenp-2005-form 5.pdf

2871-chenp-2005-pct.pdf