JP2008546372A - Stable soy protein beverage composition - Google Patents

Abstract

  In a first embodiment, the present invention relates to an alkaline earth metal reinforced soy protein composition dispersed in an aqueous medium comprising an aqueous slurry of a soy protein material and a hydrated gel of alkaline earth metal phosphate. Related to sex beverages. Here, the soy protein material has a beta conglycinin content of about 40% to about 85%, and a glycinin content of about 5% to about 40%, and the alkaline earth of the alkaline earth metal reinforced soy protein composition. The metalloid content is from about 1.5 to about 12% by weight on a dry basis, and the alkaline earth metal enriched soy protein composition forms a stable suspension in an aqueous medium. In the second embodiment, a soy milk beverage is prepared. Soymilk beverages have a beta conglycinin content of about 40% to about 85% and a glycinin content of about 5% to about 40% combined with water, pulverized in water, and the liquid is used as soy milk. It is prepared by separating.

Description

  The present invention relates to a soy protein-based beverage composition that is smooth, savory, palatable, and has sufficient storage stability in an acidic or neutral environment. Stability is enhanced by adding stabilizers such as starch, pectin, and hydrocolloids. The soy protein is fortified with calcium or magnesium salts. The soy protein used has a low phytic acid content of inositol-6-phosphate, inositol-5-phosphate, inositol-4-phosphate, and inositol-3-phosphate. Further, the soy protein has a beta conglycinin content of about 40% to about 85% and a glycinin content of about 5% to about 40%.

  Protein isolates obtained from plant protein sources such as soybeans contribute substantially to the economic importance of these materials as crops. Soy protein isolate has been found to be a particularly useful nutritional supplement in various foods and beverages. Protein isolates can generally be characterized as products resulting from extraction, subsequent concentration and purification of protein material obtained from a protein source such as plant protein material. Typically, the protein content of the protein isolate will be between about 90% and 98% by weight on a dry basis.

  The usefulness of soy protein isolates in the formation of foodstuffs such as beverages is the production of modified or enzymatically hydrolyzed isolates, or the dispersion of the isolates in certain types of aqueous media used to prepare beverages. This is most often achieved by the addition of materials such as surfactants to promote stability or suspendability.

  An example of this type of protein product is described in US Pat. No. 4,378,378, where a simulated dairy product with improved suspension properties is produced. In this specification, a slurry of plant protein material and milk whey is formed, followed by reaction of the slurry with proteolytic enzymes. Protein isolates are generally dispersible in aqueous media, but certain nutritional and vitamins that may be required when nutritionally complete beverages or drinks such as infant formula are produced. It was more difficult to use these isolates with minerals. For example, because most forms of calcium used for calcium supplementation in nutritional beverages are relatively insoluble in aqueous media, strengthening liquid products using calcium presents unique problems. Because these materials easily settle or settle in aqueous suspension, users often have to shake their drinks to ensure proper intake of minerals in food. .

  The dispersibility of mineral-enriched protein compositions is described in US Pat. No. 4,214,996, where minerals are used for the purpose of improving the dispersibility of minerals in aqueous media such as beverages. Is chelated with organic acids and sugars. It has been shown that the product can be dried and returned with good results.

  An alternative approach to the dispersibility of certain mineral fortifying substances such as calcium phosphate is described in US Pat. No. 2,605,229. This describes the formation of a calcium phosphate gel that, when mixed with water, remains dispersed in the water, resulting in a milky suspension resembling a dispersion of calcium phosphate in milk.

  In a first embodiment, the present invention provides an alkaline earth metal reinforced soy protein composition dispersed in an aqueous medium comprising an aqueous slurry of a soy protein material and a hydrated gel of alkaline earth metal phosphate. Related to neutral beverages. Here, the soy protein material has a beta conglycinin content of about 40% to about 85%, and a glycinin content of about 5% to about 40%, and the alkaline earth of the alkaline earth metal reinforced soy protein composition. The metalloid content is about 1.5-12% by weight on a dry basis, and the alkaline earth metal enriched soy protein composition forms a stable suspension in an aqueous medium.

  In a second embodiment, the present invention relates to a soy protein composition dispersed in an aqueous medium comprising an aqueous slurry of soy protein material. Here, the soy protein material has a beta conglycinin content of about 40% to about 85% and a glycinin content of about 5% to about 40%, and the soy protein composition has a stable suspension in an aqueous medium. A turbid liquid is formed.

  In order to understand some terms used in the specification and claims, the following definitions are provided.

  High beta conglycinin soybean: As used herein, high beta conglycinin soybean refers to soybean seeds that have greater than about 40% protein as beta conglycinin.

  Soy protein isolate (SPI): As used herein, soy protein isolate is a spray-dried powder made from soybeans that contains at least 90% protein on a dry basis (N × 6.25).

  High beta conglycinin soybean seeds are processed into a high beta conglycinin soy protein extract as described below.

Soy protein material Soy protein has four globulin fractions: 2S with a molecular weight of about 8,000 to about 21,500; 7S (beta conglycinin) with a molecular weight of about 150,000 to about 200,000; 11S (glycinin) which is 350,000; and 15S which has a molecular weight of about 600,000. In the present invention, the starting soybean is available from DuPont (Wilmington, DE) and is identified as Version 1 (IA Bean No. 408) with a 7S content of 65.5 and an 11S content of It is a genetically modified food that is 9.7.

  The soy protein material utilized in the present invention for both embodiments has a beta conglycinin content of about 40% to about 85% of the total soy protein weight, and the glycinin content of about soy protein total weight. 5% to about 40%. By using high beta conglycinin soybeans containing about 40% or more beta conglycinin, the beta conglycinin content is about 40% to about 85% without the inefficiency of removing glycinin during processing Soy protein material can be prepared. The high beta conglycinin soy protein material of the present invention contains about 40% to about 85% beta conglycinin relative to 26-29% of the commercial soy protein isolate. Typically, soy protein isolate, a typical starting material for beverages, contains about 40-45% glycinin. The high beta conglycinin soy protein material of the present invention contains less than about 40% glycinin.

First Embodiment In a first embodiment, a ready to drink neutral (RTD-N) beverage is prepared. RTD-N beverages are usually enriched or enriched with minerals. Mineral fortification is performed by adding a hydrated gel of mineral fortified material to a hydrated high beta conglycinin soy protein isolate slurry.

  “High beta conglycinin soy protein isolate”, as the term is used herein, has a protein content of about 90% or more, preferably a soy protein content of about 95% or more, and a beta conglycinin fraction is About 40% to about 85% of total soy protein, preferably about 45% to about 70%, and a glycinin content of about 5% to about 40%, preferably about 15% to about 35% Refers to material. High beta conglycinin soy protein isolate is typically produced from starting materials such as defatted high beta conglycinin soy material. Here, the oil is extracted leaving soy meal or flakes. More specifically, high beta conglycinin soybeans may be first crushed or ground and then passed through a conventional oil press. However, it is preferred to remove the oil contained in the soybean by solvent extraction with an aliphatic hydrocarbon such as hexane or azeotrope, which corresponds to the conventional technique used for oil removal. . The defatted high beta conglycinin soy protein flakes are then placed in a water bath and the mixture having a pH of at least about 6.5, preferably between about 7.0 and 10, to extract the protein. provide. Usually, if it is desired to raise the pH above 6.7, various alkaline reagents such as sodium hydroxide, potassium hydroxide, and calcium hydroxide, or other Generally accepted food grade alkaline reagents can be used. A pH above about 7 is generally preferred because alkaline extraction facilitates protein solubilization. Usually, the pH of the aqueous extract of high beta conglycinin soy protein is at least about 6.5, preferably about 7.0 to 10. The weight ratio of aqueous extraction solvent to soy protein material is usually about 20 to 1, preferably about 10 to 1. In another embodiment, soy protein is extracted from ground defatted flakes with water, ie without pH adjustment.

  In obtaining the high beta conglycinin soy protein isolate used in the present invention, high temperatures may be used during the aqueous extraction step to facilitate soy protein solubilization, with or without pH adjustment. Although desired, ambient temperature is sufficient if desired. Extraction temperatures that can be used can range from ambient temperature to about 120 ° F., with a preferred temperature of 90 ° F. The extraction time is further non-limiting, conveniently a time of about 5 to 120 minutes is used, and a preferred time is about 30 minutes. After extraction of the plant protein material, an aqueous extract of the protein can be stored in a storage tank or suitable container, whereas for an insoluble solid obtained from the first aqueous extraction step, a second Extraction is performed. This improves the efficiency and yield of the extraction process by extracting the protein from the residual solids obtained from the first stage.

  Thereafter, the combined aqueous protein extract obtained from both extraction steps, with no pH adjustment or a pH of at least 6.5, preferably about 7.0 to 10, is added to the soy extract pH. The precipitate was prepared by adjusting the isoelectric point of the high beta conglycinin soy protein or near the isoelectric point to form an insoluble curd precipitate. This pH is usually between about 4.0 and 5.0. The precipitation step can be conveniently performed by adding common food grade acidic reagents such as acetic acid, sulfuric acid, phosphoric acid, hydrochloric acid, or using any other suitable acidic reagent. High beta conglycinin soy protein precipitates from the acidified extract and is then separated from the extract. The separated high beta conglycinin soy protein isolate can be washed with water to remove residual soluble carbohydrates and ash from the protein material. The separated protein is then dried using conventional drying means to form a high beta conglycinin soy protein isolate.

  The soy protein curd is then made into an aqueous slurry for the purpose of mineral enrichment as described below. The protein isolate can be obtained directly from the isolation procedure as described above, in which case the precipitated protein is still in the form of an aqueous suspension. It is likewise possible in the present invention to use a dried protein isolate (dispersed in an aqueous medium to form an aqueous suspension) as a starting material.

  However, an essential aspect of this embodiment is a specific means for mineral enrichment of the protein material. For example, it has been found that when mineral enrichment of a protein material is performed by the addition of a hydrated gel of mineral enrichment material, a product with improved suspension properties is obtained compared to the addition of a dried mineral supplement. is doing. Even after drying the enriched protein composition, the improved suspension properties are retained.

  The hydrated gel is an alkaline earth metal salt. Typical alkaline earth materials used for mineral enrichment and considered essential for nutritional purposes include calcium and magnesium. Calcium is a particular problem for fortifying protein supplements for liquid foods because it is used in aqueous media such as infant formula or nutritional drinks at higher fortification levels than other minerals It has been found. In most cases this is achieved in the prior art by the dispersion of the dried calcium phosphate salt in the dried protein supplement, but when dispersed in an aqueous medium, often still minerals during storage of liquid foods The component will settle.

The first embodiment is particularly directed to the production of calcium-enhanced high beta conglycinin soy protein compositions with improved suspension properties, which are commonly used for mineral enrichment of foods such as magnesium. Other divalent salts such as alkaline earth metal salts can be similarly adapted. The exact means of forming various alkaline earth metal salt hydrated gels is not critical to the practice of the invention, and such gels can be prepared by various chemical reactions. In particular, for calcium, the reaction of calcium chloride and trisodium phosphate according to the following reaction can be used to form a hydrated gel of tricalcium phosphate.
3CaCl ₂ + 2Na ₃ PO ₄ → Ca ₃ (PO ₄ ) ₂ + 6NaCl

Alternatively, a reaction between calcium hydroxide and phosphoric acid according to the following reaction with an equal degree of success can be used to form a hydrated gel of tricalcium phosphate.
3Ca (OH) ₂ + 2H ₃ PO ₄ → Ca ₃ (PO ₄ ) ₂ + 6H ₂ O

  The above reaction represents a typical reaction for the production of hydrated gels of alkaline earth metals such as calcium, which has been found to improve the suspension properties of the enhanced vegetable protein material.

  As for the formation of a hydrated gel of calcium salt, since the salt is not generated in this reaction, it is preferable to use the reaction described above in which calcium hydroxide is reacted with phosphoric acid. Usually, a dilute solution of calcium hydroxide is used for the reaction with phosphoric acid, but the exact concentration of calcium is not critical and the calcium level in the solution is about 0.1 to 3.0 wt. %, Preferably about 1.0% by weight. To this solution, concentrated phosphoric acid (85 wt%) is added dropwise at a uniform and slow rate sufficient to maintain the pH of the reaction mixture above about 7. In order to produce the preferred material tricalcium phosphate for calcium enrichment of the protein composition, the pH of the reaction medium should be maintained above about 7, preferably from about 9.5 to 11.5. desirable. Thereafter, when the pH of the reaction mixture is lowered to less than about 7, mainly mono- and dibasic forms of calcium phosphate are formed, which can also be used with equal success in fortifying protein materials. Can be covered by the present invention, but tricalcium phosphate is preferably used, and this material is the most stable form of calcium phosphate for calcium strengthening purposes.

  The reaction proceeds to initiate the formation of a translucent hydrated gel of tricalcium phosphate. The hydrated gel provides a gel having a solids content of less than about 10% by weight, preferably about 7 to 10 weight percent after centrifugation. This has been found to provide a hydrated translucent tricalcium phosphate that has been found to provide a soy protein composition with improved suspension properties when used to provide mineral enrichment of the soy protein composition. It is a gel. It is important that this hydrated gel not be dried before being added to the high beta conglycinin soy protein slurry. This is because it has been found that it does not result in a mineral-enriched soy protein composition having the desired suspension properties.

  The hydrated mineral gel is then added to the high beta conglycinin soy protein isolate slurry in an amount effective to provide a mineral enriched protein composition. The exact amount to be added should depend on the degree of strengthening desired, usually about 1.5% to about 12% alkaline earth metal on a dry basis. For example, for adults, a level of about 1.5% calcium relative to protein solids in a mineral-enriched protein composition is sufficient to meet daily requirements, but for infants, or For those who wish to have a simulated milk by providing a comparable calcium level, this level is usually about 2.7% to 3.5% or more. Thus, the exact amount of gel added will depend entirely on the degree of reinforcement desired, and the invention is not limited by the specific amount added.

  Although it is preferable to use a heating step as described below, the heating step is not essential for this embodiment and can be omitted if desired. It is immaterial whether the heating step is used before or after addition of the hydrated gel to the high beta conglycinin soy protein isolate slurry. Thereafter, a high beta conglycinin soy protein isolate slurry containing a hydrated gel added for the purpose of strengthening the high beta conglycinin soy protein isolate is added for about seconds to minutes, preferably about 7 to 100 seconds, for about 220 seconds. Heat to a temperature of from ° F to 400 ° F, preferably from 260 ° F to 310 ° F. Preferably, the heating is performed in a jet cooker or similar device in which the mineral-reinforced protein composition slurry is dynamically heated under high temperature and high pressure conditions. A jet of steam crosses the slurry portion. After heating the mineral-enhanced protein composition slurry under dynamic conditions of high temperature and pressure, the slurry with protein and mineral is typically discharged into a lower pressure vessel, thereby being contained in the slurry Some water volatilization is caused, resulting in the slurry being cooled to a temperature of about 150 ° F. or less.

  The cooled mineral-enhanced protein composition slurry can then be dehydrated by any type of drying procedure, but also in order to provide the most uniform mixture of mineral-enhanced salt and protein, an aqueous medium In order to provide a product having excellent dispersion properties in, it is preferred to spray dry the mineral enriched protein composition slurry. The dried product has excellent suspending properties in liquid foods and solves the separation problems normally associated with using mineral-enriched protein compositions in liquid foods such as nutritional drinks.

  Hydrated gels of alkaline earth metal salts are prepared for the purpose of providing a means for mineral enrichment of protein materials and have improved suspension properties when used in the production of liquid foods such as nutritional drinks. A mineral enriched protein composition is formed. Typical alkaline earth materials used for mineral enrichment and considered essential for nutritional purposes include calcium and magnesium. Calcium is found to be a unique problem for the enhancement of protein supplements for liquid foods, as it is used in aqueous media such as infant formula or nutritional drinks at higher fortification levels than other minerals is doing. In most cases this is achieved in the prior art by the dispersion of the dried calcium phosphate salt in the dried protein supplement, but when dispersed in an aqueous medium, often still minerals during storage of liquid foods The component will settle.

  The present invention is particularly directed to the production of calcium-enhanced protein compositions with improved suspension properties, such as alkaline earth metal salts commonly used for mineral enrichment of foods such as magnesium. Other divalent salts can be similarly adapted. The exact means of forming a hydrated gel of alkaline earth metal salt of magnesium or calcium is important for the practice of the present invention. Hydrated gels are formed by reacting phosphoric acid with either magnesium hydroxide or calcium hydroxide during or subsequent to sonication or homogenization.

  An aqueous slurry of calcium hydroxide or magnesium hydroxide is prepared by adding calcium hydroxide or magnesium hydroxide to water, respectively. Alternatively, alkaline earth metal hydroxides can be prepared in situ by reacting water with calcium oxide or magnesium oxide. Alkaline earth metal hydroxides have limited water solubility. However, the alkaline earth metal hydroxide need not be in solution to react with phosphoric acid to form a hydrated gel. An aqueous slurry of alkaline earth metal hydroxide is sufficient. Alkaline earth metal hydroxide slurries prepared from or in situ prepared from alkaline earth metal hydroxides are 2 to up to 10%, preferably up to 8%, most preferably up to 7% by weight. Contains alkaline earth metal hydroxides.

  A 10 to 85% stoichiometric amount of phosphoric acid, with or without sonication or homogenization, can be rapidly and alkaline earth metal hydroxide in 30 seconds to 5 minutes depending on the batch size. Add to slurry. It is not necessary to keep the pH of the reaction on the base side. Sonication and homogenization play a role in reducing the size of alkaline earth metal hydroxides and providing mechanical energy so that all alkaline earth metal hydroxides react with phosphoric acid . Sonication and homogenization also serve to reduce the particle size of the formed alkaline earth metal phosphate hydrated gel.

  The reaction of the alkaline earth metal hydroxide and phosphoric acid produces an alkaline earth metal phosphate, particularly a tri-alkaline earth metal phosphate, with tricalcium phosphate being preferred.

  Homogenization can be performed using a conventional homogenizer. Preferably, the homogenization is performed at 500 to 2000 pounds per square inch using an APV Gaulin homogenizer. Sonication can be performed using a Model A ultrasonic mixing device sold by Sonics Corporation under the trade name Sonolator. For sonication, the pressure is 1000 to 1500 pounds per square inch. Hydrated gels are insoluble in aqueous media, especially as tricalcium phosphate. After the reaction between the alkaline earth metal hydroxide and phosphoric acid, the amount of hydrated gel present as a solid is generally from about 3.0% to about 14.0%, preferably up to about 11%, most preferably Is up to about 10% by weight.

  Mineral enrichment or strengthening of soy protein material using a hydrated gel is accomplished by adding the hydrated gel to the soy protein material. The ratio of hydrated gel to soy protein material on a dry basis depends on the desired alkaline earth metal content.

  The following examples correspond to the first embodiment of the present invention, which is specific but non-limiting.

Example 1
Soy protein isolate is prepared by feeding 150 pounds of defatted soy flakes per hour to an extraction tank, adding 1500 pounds of water per hour, and heating it to 90 ° F. Sufficient calcium hydroxide is added to adjust the pH of the mixture to 9.7. Soy flakes are allowed to extract for 30 minutes, after which the aqueous solution is separated from the extracted flakes by centrifugation. The extracted flake residue is resuspended in 900 pounds of water at a temperature of 90 ° F., while the first aqueous extract is saved. The pH of the mixture is 9.0 at this point.

  A second aqueous extract from the flakes is obtained by centrifugation and combined with the first aqueous extract. To the combined extracts, 37% hydrochloric acid is added to adjust the pH to 4.5 and to precipitate the protein. The precipitated protein is then centrifuged and excess liquid is removed until a solids level of 24-28 wt% is reached. The precipitated protein is then diluted with water to form a slurry having a solids level of 7.5% by weight. Adjust the pH of the slurry to 6.6 by adding sodium hydroxide.

  A 2.3% calcium hydroxide and water mixture is prepared by adding 230 grams of calcium hydroxide to 9536 grams of water with stirring. Calcium hydroxide is dispersed in water for 1 hour. An amount of 85% phosphoric acid (238 grams) is added over 30 minutes. After the acid addition is complete, the contents are allowed to stir for an additional 30 minutes. This slurry is transferred to a Gaulin homogenizer (model 15MR) and homogenized at 1500 pounds per square inch. The resulting tricalcium phosphate hydrated gel has a solids content of 3.21%.

  The hydrated gel is added in an amount sufficient to provide a calcium level of 2.6% on a dry basis relative to the weight of protein solids and the toughened slurry is allowed to equilibrate for 1 hour. The calcium enriched slurry is then passed through a jet cooker at a pressure of 85 pounds per square inch. The slurry in the jet cooker is heated to a temperature of 310 ° F. by steam. After 8-10 seconds, the advancing portion of the heated slurry is secreted into the receiving vessel at less than atmospheric pressure. The mineral enriched slurry is then spray dried to a moisture level of less than 5% by weight.

  The following examples are directed to the preparation of tri-alkaline earth metal phosphate hydrated gels from the reaction of calcium hydroxide and phosphoric acid.

Example 2
The hydrating gel procedure of Example 1 is repeated except that 4% calcium hydroxide (400 grams) is added to 9186 grams of water and reacted with 414 grams of 85% phosphoric acid. After homogenization, the tricalcium phosphate hydrated gel has a solids content of 5.58%.

Example 3
The hydrating gel procedure of Example 1 is repeated except that 5% calcium hydroxide (500 grams) is added to 8982 grams of water and reacted with 518 grams of 85% phosphoric acid. After homogenization, the tricalcium phosphate hydrated gel has a solids content of 6.64%.

Example 4
The hydrating gel procedure of Example 1 is repeated except that the calcium hydroxide and phosphoric acid slurry is subjected to sonication rather than homogenization. The hydrated gel of tricalcium phosphate has a solid content of 3.21%.

  The hydrated mineral gel obtained from any of Examples 2-4 is then added to the protein slurry in an amount effective to provide a mineral-enriched protein composition. The exact amount to be added should depend on the degree of reinforcement desired. For example, for adults, a level of about 1.5% calcium relative to protein solids in a mineral-enriched protein composition is sufficient to meet daily requirements, but for infants, or For those who wish to have a simulated milk by providing a comparable calcium level, this level is usually about 2.7% to 3.5% or more. Thus, the exact amount of gel added will depend entirely on the degree of reinforcement desired, and the invention is not limited by the specific amount added.

  The high beta conglycinin soy protein material used in the present invention is preferably modified to improve the properties of the soy protein material. This modification is a modification known in the art to improve the usefulness or properties of soy protein material and includes, but is not limited to, denaturation and hydrolysis of the protein material.

  High beta conglycinin soy protein material can be denatured and hydrolyzed to reduce viscosity. Chemical denaturation and hydrolysis of protein material is well known in the art and is usually sufficient to denature and hydrolyze protein material to the desired degree under controlled pH and temperature conditions. Processing the protein material with one or more alkaline reagents in an aqueous solution for a time. Typical conditions utilized to chemically denature and hydrolyze the high beta conglycinin soy protein material are as follows: pH up to about 10, preferably up to 9.7; To about 80 ° C .; about 15 minutes to about 3 hours. However, denaturation and hydrolysis of the protein material occurs more rapidly at higher pH and temperature conditions.

  Hydrolysis of the high beta conglycinin soy protein material can also be performed by treating the soy protein material with an enzyme capable of hydrolyzing the protein. A number of enzymes are known in the art of hydrolyzing protein materials, including but not limited to fungal proteases, plant proteases, peptases and chymotrypsins. Enzymatic hydrolysis involves adding a sufficient amount of enzyme (usually about 0.1% to about 10% enzyme to the weight of the protein material) to an aqueous dispersion of protein material, usually about 5 ° C to about 75 ° C. At a temperature of about 3 to about 9 at a pH of about 3 to about 9 wherein the enzyme is active for a time sufficient to hydrolyze the soy protein material. Is). After sufficient hydrolysis has occurred, the soy protein material is precipitated from the solution by inactivating the enzyme by heating and adjusting the pH of the solution to be near the isoelectric point of the protein material.

  A particularly preferred modified soy protein material is enzymatically modified under conditions that expose the core of the protein to enzymatic action as described in EP 0 480 104 B1 (incorporated herein by reference). Hydrolyzed and deamidated soy protein isolate. Briefly, the modified protein isolate material disclosed in EP 0 480 104 B1 is formed by: 1) forming an aqueous slurry of soy protein isolate; 2 ) Adjusting the pH of this slurry to a pH of 9.0 to 11.0; 3) Proteolysis between 0.01% and 5% (based on the weight of dry protein in the slurry) Adding enzyme; 4) This alkaline slurry is effective to produce modified protein material with molecular weight distribution (Mn) between 800 and 4000 and deamidation level between 5% and 48% Treating at a temperature of 10 ° C. to 75 ° C. for a long time (usually 10 minutes to 4 hours); and heating the slurry to above 75 ° C. Be. The modified protein material disclosed in EP 0 480 104 B1 is commercially available from Protein Technologies International, Inc (St. Louis, Missouri).

  It is also preferred to reduce the phytic acid content of the high beta conglycinin soy protein material. Phytic acid or phytate is a hexa-phosphorus ester of inositol (1,2,3,4,5,6-cyclohexanehexol phosphate) found in many cereals and seeds. This serves as the primary storage form of phosphorus and inositol and accounts for 50% of the total phosphorus content. Phytic acid in plants appears in the form of calcium, magnesium, and potassium salts, which are commonly referred to as phytin. Most of the phosphorus content of seeds is stored in these compounds. For example, phytin accounts for about 70% of total phosphorus in soybeans. The term phytate or phytic acid, as used herein, includes salts of phytic acid and molecular complexes of phytic acid with other soy ingredients.

  All legumes contain phytic acid. However, soybean contains higher levels of phytic acid than any other legume. Phytic acid tends to form complexes with proteins and multivalent metal cations. The phytic acid complex reduces the nutritional value of soy protein. Because phytic acid interacts with multivalent metal cations, it interferes with the absorption of various metals such as calcium, iron, and zinc by animals and humans. This can cause deficiencies, especially for vegetarians, the elderly, and infants.

  Phytic acid also inhibits various enzymes in the digestive tract, including pepsin and trypsin, reducing the digestibility of soy proteins. Moreover, the phosphate present in phytic acid is not available in humans. In addition, the presence of relatively large amounts of these unavailable phosphorus in many infant foods results in inappropriate bone mineralization.

  In a typical separation process of commercially available soy protein, defatted soy flakes or soy flour is slurried with water and base at a pH value between 8.0 and 10.0 to solubilize the protein. Extracted. The slurry is centrifuged to separate the insoluble part from the solution. The main fraction is recovered from the solution by precipitation at a pH near the isoelectric point of the protein (4.5), it is separated by centrifugation, the precipitate is washed with water and washed at pH 7. Is resuspended and spray dried to a powder. In such a process, phytic acid will accompany the protein and tend to concentrate the protein product in the resulting soybean. Commercial soybean protein isolates have a phytic acid content of about 1.2-3%, whereas soybeans contain 1-2% phytic acid.

  For beverage compositions, it is important that the phytic acid level of the soy protein material is reduced. In order to remove phytic acid, it is necessary to use a phytate degrading enzyme. Phytate degrading enzymes react with phytic acid to yield inositol and orthoesters, and some forms of inositol phosphates as intermediate products. The phytate degrading enzyme includes at least one of phytase and acid phosphatase. A particularly preferred enzyme is Alko Ltd. Sold under the trademark Finase® S by (Helsinki, Finland); Amano 3000 from Amano Pharmaceutical Co., Ltd. (Nagoya, Japan); and BASF Corp. (Wyandotte, MI.) Nathophos® phytase.

  Phytase and acid phosphatase are produced by various microorganisms such as Aspergillus spp., Rhizopus spp., And yeast (Appl. Microbiol. 16: 1348-1357 (1968); Enzyme Microb. Technol.5: 377-382 (1983)), phytase is also produced by various germinating plant seeds (eg wheat). According to methods known in the art, enzyme preparation can be achieved from the microorganisms described above. In Caransa et al., Dutch Patent Application No. 87.02735, phytase from Aspergillus spp. Degrades phytic acid in grains more efficiently than phytase from wheat at the same amount of enzyme. It was discovered.

  Particularly preferred for the present invention is the Finase enzyme (formerly referred to as the Econase EP 43 enzyme produced by Alko Ltd. (Rajamaki, Finland)). This is described in U.S. Patent Application No. 242,243, filed September 12, 1988.

  Typically, phytase degrading enzymes are added to soy protein extracts prior to acid precipitation to reduce phytic acid. This may be done before or after mineral enrichment. The amount of phytate degrading enzyme required depends on the phytic acid content of the raw material and the reaction conditions. The correct amount is readily estimated by one skilled in the art. Typically, the concentration of phytate degrading enzyme is about 500 to about 2200, preferably about 600 to about 2100, most preferably about 720 to about 1400 units of phytase (phytase unit) / gram of soy protein, Expressed as PU / g. One phytase unit (PU) gives 1 μmol of phosphate per minute under standard conditions (ie, pH 5.5, 37 ° C., substrate concentration of 5.0 mM sodium phytate, and reaction time of 30 minutes). Defined as the amount of enzyme released.

Second Embodiment In the second embodiment, a soy milk beverage is prepared. This soy milk beverage is prepared by combining soybeans with a beta conglycinin content of about 40% to about 85% and a glycinin content of about 5% to about 40% with water. In preparing soymilk, high beta conglycinin soybeans are soaked in water and ground, for example, by using a grinder, mixer, mass-collider, and the like. Grinding high beta conglycinin soybeans in water produces bean juice (go). When the soy juice is separated, soy milk and okara are provided. Okara is a by-product in the production of soy products such as soy milk and tofu. Thereafter, the soy juice is heated and separated into a water-soluble fraction of soy milk and a water-insoluble fraction from okara.

  The soy juice is heated to about 45-65 ° C. for about 10 seconds to about 20 minutes. It is preferred that the heating temperature range from about 50 to about 65 ° C, more preferably from about 55 to about 65 ° C. It is preferred that the heating time range from about 20 seconds to about 10 minutes, preferably from about 3 to about 7 minutes.

  Bean soup can be heated by any method without limitation. That is, it can be put in a pan or the like and then heated indirectly with an electric heating device or the like. Alternatively, it can be heated directly, for example by blowing it on live steam. Either method will result in a processed soy protein food product of superior quality.

  Next, the soy juice heated in this way is separated into okara and soy milk. It is preferable to separate the soup without cooling, but it may be cooled before the separation. When heated, the soy juice can be separated immediately after reaching the desired temperature. Alternatively, it can be maintained at a desired temperature for a certain time and then separated. The soy juice can be separated by conventional methods, for example by using a centrifugal or hydraulic separator.

  In order to reduce the phytic acid content, phytate degrading enzymes are added to the soy juice before separation or to the soy milk after removal from the oats. The phytate degrading enzyme is as shown above.

  In the production process of the present invention, the method for concentration is not particularly limited. For example, vacuum concentration can be performed using an evaporator or a centrifuge. Although it is possible to carry out the concentration under atmospheric pressure, it is not preferable because the soymilk may be denatured by heating. When concentrated soymilk is returned by dilution and the change in properties before and after concentration is tested, no change occurs at concentrations up to about 3.5 times. Thus, according to the production process of the present invention, it is clear that soy milk concentrated to a considerable extent can maintain its properties.

  By diluting with water, the produced concentrated soymilk can be returned to one having the same degree of protein denaturation as before concentration. It can therefore be used in many ways similar to general soy milk.

  In order to obtain powdered soymilk, the liquid soymilk is subjected to spray drying. Preferably, the inlet temperature and the outlet temperature are adjusted to about 90 to about 130 ° C. or less and about 20 to about 65 ° C. or less, respectively. More preferably, the inlet temperature and the outlet temperature are adjusted to about 100 to about 120 ° C. or less and about 50 to about 60 ° C. or less, respectively. More preferably, the inlet temperature and outlet temperature are adjusted to about 120 ° C. and about 60 ° C., respectively. The outlet temperature varies depending on the distance from the inlet to the outlet. Once the inlet temperature is determined, the relationship between the distance from the inlet to the outlet and the outlet temperature can be confirmed by methods well known by those skilled in the art. Spray drying is performed in a conventional manner using a spray dryer commonly used by those skilled in the art.

  Powdered soymilk obtained by spray drying has higher stability, lighter weight, and smaller volume than liquid soymilk. Therefore, powdered soymilk is very suitable for storage. This powdered soymilk can be easily returned to soymilk by dissolving in water. Thus, various foodstuffs can be manufactured by processing this powdery soymilk further. It is also possible to mix powdered soymilk directly with other food ingredients without subsequent conversion back to liquid soymilk, followed by processing.

  It has been found that when soy milk or concentrated soy milk is frozen, it can be stored for a long time in a stable state while inhibiting soy protein denaturation. The present invention also provides frozen soy milk and processed soy protein foods produced by using frozen soy milk.

  Freezing to produce the frozen soy milk of the present invention can be performed by any method that is not limited. For example, soy milk can be slowly frozen in a cooling device. Alternatively, soy milk can be rapidly frozen by blowing a gas (eg, carbon dioxide gas or nitrogen gas) onto it. Both methods have been confirmed to allow soy milk properties to be maintained without any significant differences.

  When stored, the frozen soy milk of the present invention is maintained at a temperature that keeps it frozen. The storage temperature is preferably about −15 ° C. or lower, more preferably about −20 ° C. or lower, more preferably about −25 ° C. or lower, and still more preferably about −30 ° C. or lower. Although it is most common to store frozen soy milk in a freezer, the present invention is not so limited. At high storage temperatures, proteins can denature, thereby reducing the utility value of soy milk. By using such soy milk, a soy protein food with less elasticity and insufficient processing, such as tofu, is produced. Therefore, it is necessary to use frozen soy milk before protein denaturation proceeds to an undesirable level. The relationship between storage temperature and shelf life may be known in some cases by those skilled in the art.

  In order to further illustrate the present invention in more detail and not for purposes of limitation, the following examples are provided. The following examples are from raw soybean (reference) and from soybeans with a beta conglycinin content of about 40% to about 85% and a glycinin content of about 5% to about 40% (this The invention is directed to the preparation of soy milk.

Example 5 (standard)
About 0.4 kg of dried raw soybeans is soaked in 1.0 kg of water at about 15 ° C. Then, while adding 1.12 kg of water to this, the soaked soybeans are ground with a grinder to form bean juice. About 2 kg of bean soup is placed in an enamel pan and heated to about 60 ° C. over 8 minutes with sufficient stirring to prevent the bean soup from burning. Immediately squeeze using a simple press equipped with jack). When okara is separated, 1.47 kg of soy milk is obtained.

Example 6
The procedure of Example 5 is repeated. However, unprocessed soybeans are replaced with high beta conglycinin soybeans identified as DuPont Version 1 (IA Bean No. 408), which has a 7S content of 65.5 and an 11S content of 9.7. .

  The comparative soy milk example 5 is compared with the soy milk example 6 of the present invention in a comparative serum test. Serous levels are determined for samples refrigerated at 4 ° C. The comparison is done by filling a 250 ml narrow mouth square bottle (Nalge Nunc International) with each soymilk. Thereafter, the percentage of serum in each sample is measured to determine the stabilizing effect in each soy milk. Serum is a clear layer of solution that contains little or no suspended protein. Serum proportion is determined by measuring the height of the serous layer in the sample and measuring the height of the entire sample. Here, the serum (%) = (the height of the serum layer) / (the height of the entire sample) × 100.

Table I

  From the data in Table I, it can be seen that the serum (%) of the present invention is significantly improved over the baseline serum (%).

  Although the present invention has been described in terms of its preferred embodiments, it is to be understood that various modifications thereof will be readily apparent to those skilled in the art upon reading this specification. Accordingly, it is to be understood that the invention disclosed herein includes such modifications as fall within the scope of the appended claims.

Claims (14)

  An alkaline earth metal reinforced soy protein composition dispersed in an aqueous medium comprising an aqueous slurry of soy protein material and a hydrated gel of alkaline earth metal phosphate, wherein the soy protein material contains beta conglycinin The alkaline earth metal content of the alkaline earth metal enriched soy protein composition is about 1 on a dry basis, with a percentage of about 40% to about 85% and a glycinin content of about 5% to about 40%. .5 to about 12% by weight, and the alkaline earth metal enriched soy protein composition forms a stable suspension in an aqueous medium.   The composition according to claim 1, wherein the alkaline earth metal of the alkaline earth metal salt is magnesium or calcium.   The composition according to claim 1, wherein the alkaline earth metal salt is tricalcium phosphate.   The composition of claim 1, wherein the hydrated gel is formed by the reaction of an alkaline earth metal hydroxide and a mineral acid at a pH greater than 7.   2. The composition of claim 1, wherein the soy protein material is hydrolyzed with about 0.1% to about 10% protease enzyme based on the weight of the protein material.   The composition of claim 1, wherein the soy protein material is treated with a phytate degrading enzyme.   The composition according to claim 6, wherein the phytate degrading enzyme comprises at least one of phytase and acid phosphatase.   A soy beverage composition prepared by a process of combining soy having a beta conglycinin content of about 40% to about 85% and a glycinin content of about 5% to about 40% with water.   The beverage according to claim 8, wherein soybean is pulverized in water to produce bean juice.   The beverage of claim 9, wherein the bean juice is heated at about 45 ° C to about 65 ° C or less for about 10 seconds to about 20 minutes or less.   The beverage according to claim 10, wherein the heated soy juice is separated into okara and soy milk.   The beverage according to claim 10, wherein the soy milk is spray-dried.   The beverage according to claim 10, wherein the soy milk is treated with a phytate degrading enzyme.   The beverage according to claim 13, wherein the phytate degrading enzyme comprises at least one of phytase and acid phosphatase.