CA2167662C

CA2167662C - Process for solubilizing gluten that normally is capable of absorbing water without dissolution

Info

Publication number: CA2167662C
Application number: CA 2167662
Authority: CA
Inventors: Frederick K. Chaundy; Scott P. Melidosian
Original assignee: BASF Corp
Current assignee: BASF Corp
Priority date: 1996-01-19
Filing date: 1996-01-19
Publication date: 2001-07-03
Anticipated expiration: 2016-01-19
Also published as: CA2167662A1

Abstract

An improved technique is provided that is capable of accomplishing the expeditious dissolution of gluten (e.g., vital wheat gluten or corn gluten) in water that normally is capable of absorbing water without dissolution. An effective solubilizing concentration of pectin (e.g., low methoxyl pectin) is dissolved in the aqueous solvent when contacted with agitation with the gluten component at an elevated temperature. The formation of a substantially homogeneous aqueous solution of the gluten is accomplished with ease without the necessity to resort to the introduction of acids, bases, enzymes, or other solvents as practiced in the prior art. The resulting aqueous solution of gluten is completely edible and is suitable for the controlled uniform introduction of such gluten into association with a variety of food products where it can serve a binding, adhesive, microencapsulation, film-forming, and/or coating function.

Description

216~6~~

IMPROVED PROCESS FOR SOLUBILIZING GLUTEN
THAT NORMALLY IS CAPABLE OF ABSORBING
WATER WTTHOUT DISSOLUTION
Background of the Invention Gluten is recognized to be an edible film-forming material that is derived from cereal grains. Such gluten commonly consists of a water-insoluble complex protein fraction that is separated from a cereal grain following grinding.
Gluten commonly is derived from cereal grains such as wheat or corn by known techniques and is a commercially available article of commerce that finds a broad range of applications in the food .and related industries. The separation of the gluten commonly is accomplished by physical means from an aqueous suspension of the ground grain without the introduction of additives, and the resulting gluten product is thus a natural food protein of plant origin. The inherent cohesiveness and elasticity of gluten provide integrity to various doughs, and facilitate protective film formation. Such films can serve to improve the appearance of food products and to retard aging through the blockage of excessive drying to thereby extend shelf life with the concomitant maintenance of an attractive product appearance.
Vital wheat gluten is well known and is approved by the U.S. Food and Drug Administration as Generally Recognized as Safe (GRAS) under 21 C.F.R.
~ 184.1322 for use as a dough strengthener, formulation aid, nutrient supplement, processing aid, stabilizer and thickener, surface finishing agent and texturizing agent at levels not to exceed current manufacturing practice.

See, for instance, "Wheat Gluten, A Natural Protein for the Future-Today" that is published and presently available from the International Wheat Gluten Association, 4510 West 89 Street, Prairie Village, KS, 66207, U.S.A.
Additional representative publications that discuss gluten and its end uses are identified below, (1) "Edible Films and Coatings from Wheat and Corn Proteins" by Aristippos Gennadios and Curtis L. Welter, Food Technology, Pages 63 to 69 (October 1990).
(2) "Uses and Functionality of Vital Wheat Gluten", by Ken M.
Magnuson, Cereal Foods World, Pages 179 to 181 (February 1985).

(3) "Acts as Formulation Aid, Processing Aid, Stabilizer, Thickener, and Surface-Finishing Agent", by Cal Andres, Food Processing, (May 1984).

(4) "A Comparison of Nonmeat Proteins, Sodium Tripolyphosphate and Processing Temperature Effects on Physical and Sensory Properties of Frankfurters", by J.T. Keeton, E.A. Foegeding, and C. Patana-Anake, Journal of Food Science, Vol. 49, Pages 1462 to 1466 (1984).

(5) "Structure & Tolerance a Look at Gluten's Functionality", by Laurie Green, Bakers Digest, (May 31, 1985).

(6) "World Food Uses of Vital Wheat Gluten", by J.M. Hesser, Proceedings of the World Con rg ess: Vegetable Protein Utilization in Human Foods and Animal Feedstocks, edited by Thomas H.
Applewhite, American Oil Chemists' Society, Champaign, IL, U.S.A., Pages 116 to 122 (1988).

(7) "Preparation of Vital Wheat Gluten", by G. Grace, Proceedings of the Wo~ld Congress: Vegetable Protein Utilization in Human Foods and Animal Feedstocks, edited by Thomas H. Applewhite, American Oil Chemists' Society, Champaign, IL, U.S.A., Pages 112 to 115 (1988).
It has been recognized that gluten commonly has the ability to absorb water without dissolution unless an acid, base, enzyme, or solvent (~, propylene glycol) is employed. See, for instance, U.S. Patent Nos. 3,351,531 and 3,653,925, "Water and Glycerol .as P(asticizers Affect Mechanical and Water Vapor Barrier Properties of an Edible Wheat Gluten Film", by Nathalie Gontard, Stephane Guilbert, and Jean-Louis Cuq, Journal of Food Science, Vol. 58, Pages 206 to 211 (1993), and "Improvement of the Functional Properties of Insoluble Gluten by Pronase Digestion Followed by Dextran Coagulation", by Akio Kato, J. Asric. Food Chem., Vol. 39, Pages 1053 to 1056 (1991). Representative acids and bases that have been suggested to accomplish the dissolution of gluten in water include ammonium hydroxide (ammonia), acetic acid, adipic acid, ascorbic acid, aspartic acid, citric acid, lactic acid, succinic acid, tartaric acid, etc. The requirement to introduce such acids and bases in order to solubilize gluten is inconvenient and may introduce an undesirable component into the final product unless a significant effort is made to remove the same. For instance, such solubilizing agents may be flashed off to at least some degree during drying. However, this can lead to further complications, such as the pollution of the atmosphere, and the possible exposure of workers in the area to a harmful environment. Accordingly, a need has remained in the prior art for an improved technique to solubilize gluten.
It is an object of the invention to provide an improved process to solubilize gluten in water.
It is an object of the invention to provide an improved process to solubilize gluten in water that does not require the presence of acids or bases as practiced in the prior art to achieve the dissolution of the gluten.
It is an object of the invention to provide an improved process that facilitates the expeditious dissolution of gluten in water.
It is another object of the invention to provide a process for the production of a substantially homogeneous aqueous solution of gluten that can be utilized to advantage in binding, adhesive, microencapsulation, film-forming, and/or coating applications.
It is a further object of the invention to provide an improved technique for the formation of an aqueous solution of gluten suitable for use in the controlled uniform introduction of such gluten into association with a variety of food products where it serves a binding, adhesive, microencapsulation, film-forming and/or coating function.

~16'~6~2 These and other objects and advantages of the claimed invention will be apparent to those skilled in the relevant art from the following detailed description and appended claims.
Summary of the Invention It has been found that an improved process for solubilizing gluten that normally is capable of absorbing water without dissolution in water ~e.r~., vital wheat gluten or corn gluten) comprises contacting the gluten with agitation with water at an elevated temperature having an effective solubilizing concentration of pectin (preferably low methoxyl pectin) dissolved therein. The presence of conventional acids, bases, enzymes, or solvents to facilitate dissolution of the gluten as practiced in the prior art is rendered unnecessary.
Description of Preferred Embodiments The gluten which is solubilized in accordance with the concept of the present invention is derived from a cereal grain and normally is capable of absorbing water without dissolution. Representative cereal grains from which the gluten can be derived include wheat, and corn. In a preferred embodiment the gluten is vital wheat gluten. Such vital wheat gluten is commercially available as a creamy-tan powder produced from wheat flour by drying freshly washed gluten. For instance, vital wheat gluten can be obtained from Ogilvie Mills, Inc., Baker Technology Plaza, 6121 Baker Road, Suite 101, Minnetonka, MN

55345, U.S.A., under the PROVIM ESP and WHETPRO - 80 trademarks.
Alternatively, corn gluten (zein) is similarly commercially available from Freeman Industries, Inc., 100 Marbledale Road, Tuckahoe, NY 10707, U.S.A., and is amenable for solubilization in accordance with the concept of the present invention.
When the gluten is contacted with water in the absence of pH adjustment as practiced in the prior art, it absorbs water and is essentially insoluble over moderate pH ranges. Excess water is repelled and the gluten molecules tend to associate closely together and to resist dispersion in an aqueous solvent.
In accordance with the concept of the present invention it surprisingly has been found that gluten can readily be dissolved in water with agitation in the presence of an effective solubilizing concentration of pectin that is dissolved in the aqueous solvent. The pectin component offers the further advantage that it is edible and no further effort need be expended for its removal as commonly is necessary with the acids, bases, enzymes, and solvents utilized to facilitate gluten dissolution in the prior art. Any water-soluble pectin may be utilized to facilitate the dissolution of gluten when practicing the present invention. The pectin may be a low methoxyl pectin having an esterification degree lower than 50 percent, or a high methoxyl pectin wherein the esterification degree is greater than 50 percent. However, the viscosity of resulting gluten solution commonly will be influenced by the nature of the specific pectin that is utilized. Also, some pectins are better able to withstand an increase in viscosity in the presence of ~1~;~
_7_ other ions (~, calcium ions) as will be apparent to those skilled in the art.
The low methoxyl pectins are more sensitive to the presence of polyvalent cations e(-.rg_., Ca++) than high methoxyl pectins and the total soluble solids level is less important in determining gelling properties with such pectins. In a preferred embodiment the pectin is a low methoxyl pectin that optionally may be amidated.
A particularly preferred pectin suitable for use in accordance with the present invention is a low methoxyl amidated pectin extracted from the rind of citrus fruits that is commercially available from TIC Gums, 4609 R.ichlynn Drive, Belcamp, MD 21017, U.S.A., under the TIC PRETESTED PECTIN
LM 35 trademark. A preferred high methoxyl pectin is available from the same source under the TIC PRETESTED PECTIN HM SLOW trademark that offers considerably slower gelation than the low methoxyl pectin. In this product some of the carboxyl groups are esterified with methyl alcohol, while the remaining carboxylic units exist in the free acid form or as an ammonium salt. The pectin choice is influenced by the speed of gelation that is desired in the contemplated end use. Sugar sources optionally can be included with the pectin so as to modify the speed of gelation and the resulting viscosity as will be apparent to those skilled in the relevant technology.
When accomplishing the dissolution of gluten in water in accordance with the concept of the present invention, one need only contact the gluten with agitation with water at an elevated temperature having an effective concentration of pectin dissolved therein. Such agitation can be accomplished by any _g_ convenient means such as the use of a high shear mixer, homogenizes, etc. The aqueous solvent conveniently can be provided at an elevated temperature of at least approximately 40°C. at the time of the dissolution e.~., at a temperature of approximately 40 to 60°C. in preferred embodiments).
In accordance with the concept of the present invention, the pectin commonly is provided in the water in an effective solubilizing concentration of approximately 1 to 10 percent by weight of the total solution, and preferably in a concentration of approximately 1 to 3 percent by weight of the total solution.
The gluten commonly is dissolved in the water in a concentration of approximately 1 to 26 percent by weight of the total solution, and preferably in a concentration of approximately 19 to 22 percent by weight of the total solution.
The resulting aqueous solution is substantially homogeneous in nature and is suitable for use in the controlled uniform introduction of gluten into association with a variety of products. Once the solution of the gluten is applied, a portion of the aqueous component optionally can be simply removed by volatilization in order to leave behind a hydrated gluten component that exhibits highly attractive binding, adhesive, microencapsulation, film-forming, and/or coating properties.
For instance, edible protective films can be formed on the surfaces of food products such as meats, fruits, etc., by spraying or other application techniques in order to retard the loss of moisture and to thereby enhance the overall appearance of the product that is being offered to the consumer. The resulting solution alternatively may be utilized to introduce the gluten into food products, 2~~~~~
_g_ such as doughs for breads, tortillas, pizzas, and pastas; sausages; breakfast cereals; nutritional snacks; protein fortified beverages; pet foods, etc.
There are further non-food applications in cosmetics, pharmaceutical tablet formations, wallpaper adhesives, etc. Additionally, the resulting solution offers the potential for forming a product via the spray drying of the dissolved gluten in conjunction with other components where it serves the function of a binding agent and/or as a nutritional supplement. For instance, the resulting solution also can be used in the microencapsulation of water-soluble or fat-soluble oils or vitamins e(-._~., vitamin A) or other ingredients via spray drying.
The following Examples are presented as specific illustrations of the invention. It should be understood, however, that the invention is not limited to the specific details set forth in the Examples that follow.
EXAMPLE I
Initially 2 grams of low methoxyl amidated pectin commercially available from TIC Gums, Inc. under the TIC PRETESTED PECTIN LM 35 trademark are dissolved with stirring in 160 grams of water provided at 40°C. The pectin solution is placed in a high shear mixer and agitation is commenced. To the pectin solution next is gradually added 40 grams of vital wheat gluten commercially available from Ogilvie Mills, Inc. under the WHETPRO-80 trademark while maintaining the temperature between 40 and 50°C. A
substantially homogeneous solution results within approximately 15 minutes that contains approximately 20 percent by weight of the vital wheat gluten, and approximately 1 percent by weight of the low methoxyl amidated pectin based upon the total weight of the solution.
The resulting vital wheat gluten solution is well suited for forming a protective film upon a food product following the volatilization of a substantial portion of the aqueous component.
EXAMPLE II
Example I is repeated with the exception that high methoxyl pectin available from TIC Gums, Inc. under the TIC PRETESTED PECTIN HM
SLOW trademark is substituted for the low methoxyl amidated pectin.
Substantially the same dissolution results are achieved.
EXAMPLE III
Example I is repeated with the exception that zein corn gluten is substituted for the vital wheat gluten component. The corn gluten is commercially available as zein from Freeman Industries, Inc. Substantially the same dissolution results are achieved.
Although the invention has been described with preferred embodiments, it is to be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications are to be considered within the purview and scope of the claims appended hereto.

Claims

1. An improved process for solubilizing gluten in water that normally is capable of absorbing water without dissolution, comprising contacting said gluten with agitation with water provided at an elevated temperature of at least approximately 40°C having an effective solubilizing concentration of pectin dissolved therein.

2. The improved process of Claim 1 wherein said gluten is vital wheat gluten.

3. The improved process of Claim 1 wherein said gluten is corn gluten.

4. The improved process of any one of Claims 1 to 3, wherein said pectin is low methoxyl pectin.

5. The improved process of any of one of Claims 1 to 4, wherein said elevated temperature is approximately 40 to 60°C.

6. The improved process of any one of Claims 1 to 5, wherein said pectin is dissolved in said water in a concentration of approximately 1 to 10 percent by weight of the total solution.

7. The improved process according to Claim 6, wherein said pectin is dissolved in said water in a concentration of approximately 1 to 3 percent by weight of the total solution.

8. The improved process of any one of Claims 1 to 7, wherein said gluten is dissolved in water in a concentration of approximately 1 to 26 percent by weight.

9. The improved process of Claim 8, wherein said gluten is dissolved in water in a concentration of approximately 19 to 22 percent by weight.

10. An improved process for solubilizing vital wheat gluten in water that normally is capable of absorbing water without dissolution to form an edible solution comprising contacting said vital wheat gluten with agitation with water provided at an elevated temperature of at least approximately 40°C. having an effective solubilizing concentration of pectin dissolved therein wherein said pectin is dissolved in said water in a concentration of approximately 1 to 10 percent by weight of the total solution and said vital wheat gluten is dissolved in said water in a concentration of approximately 1 to 26 percent by weight of the total solution.

11. The improved process of Claim 11 wherein said pectin is dissolved in said water in a concentration of approximately 1 to 3 percent by weight of the total solution and said vital wheat gluten is dissolved in said water in a concentration of approximately 19 to 22 percent by weight of the total solution.

12. The improved process of Claim 10 or 11, wherein said pectin in low methoxyl pectin.

13 13. The improved process of any one of Claims 10 to 12, wherein said elevated temperature is approximately 40 to 60°C.