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United States Department of Agriculture

Agricultural Research Service

Research Project: NEW AND IMPROVED PROCESSES FOR TEXTURIZING MILK COMPONENTS
2005 Annual Report


1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter?
Milk products, particularly the milk proteins, casein and whey, and non fat dry milk (NFDM), can be blended with other ingredients to create new nutritious foods that serve as an outlet for underutilized milk components. Only 50% of cheese whey solids are utilized, the rest is wasted or used as animal feed. Surpluses of NFDM often persist from month to month. Inclusion of milk proteins to snack or other products to fortify them impart negative textural and functional qualities to many of the finished products because the milk proteins are soluble in the formulation and do not combine well with the other ingredients. Our approach is to texturize the milk proteins alone, or in combination with polysaccharides, starches and/or other proteins, by homogenization, twin screw extrusion, and other processing techniques, to develop new processes and to produce model foods and new product concepts, processes, and model foods to demonstrate the use of milk components in nutritional foods. Such model foods include protein enriched puffed snacks and imitation meat analogues such as hamburger helpers.

This project supports National Program 306, Quality and Utilization of Agricultural Products and Departmental Goal 1 Enhance Economic Opportunities for Agricultural Producers , Objective: Provide the Science-Based Knowledge and Technologies To Generate New or Improved High Quality, Value-Added Products and Processes To Expand Domestic and Foreign Markets for Agricultural Commodities. This Project addresses ARS Strategic Plan Performance Measure 1.1.2., Provide higher quality, healthy foods that satisfy consumer needs in the United States and abroad.

This research addresses components 1 (Quality Characterization, Preservation, and Enhancement) and 2 (New Processes, New Uses, and Value-Added Foods and Biobased Products) of ARS National Program 306, Quality and Utilization of Agricultural Products; the primary focus is in problem areas 1c (Factors and Processes Affecting Quality), 2a (New product technology), and 2c (New and improved processes and feedstocks), and will develop new processes and uses for whey proteins and ultimately nonfat dried milk (NFDM) or fluid milk components.

The purpose of this research is to modify milk proteins, particularly whey proteins, using extrusion processes in a way that preserves nutritionally important minor components and improves their textural, rheological and viscoelastic properties. The specific objectives are: (1) Develop thermal and non-thermal extrusion-based processes that alter the structures of whey proteins (texturize), identify the process conditions, and develop models that relate the conditions to the quality attributes of texturized proteins. (2) Create co-products linking the texturized whey proteins with carbohydrate and protein polymers such as soy proteins to make health-enhancing products. Characterize the rheological and viscoelastic properties of the texturized whey protein co-products as specialized ingredients with improved quality and functionality.

New processes based on extrusion will help reduce surplus dairy proteins that are currently being handled as waste or animal feed, and will increase our understanding of modifying protein function through extrusion texturization. New extruded snacks, meat analogs, and multi-functioning texturized dairy co-products will be created.


2.List the milestones (indicators of progress) from your Project Plan.
Year 1 (FY2005): Initiate work to determine thermal and non thermal extrusion parameters to identify optimal regions of modifying whey proteins and co-products. Initiate work on developing model process parameters by characterizing product variables such as elasticity and gel strength.

Year 2 (FY2006): Continue work to determine thermal and non thermal extrusion parameters for optimal regions of modifying whey proteins and co-products (complete 50%). Continue work on developing model process parameters by characterizing product variables (elasticity, gel strength), complete 50%. Initiate work on characterizing changes in molecular structure. Determine changes in physical and chemical composition and protein profiles.

Year 3 (FY2007): Complete work to determine thermal and non thermal extrusion parameters for optimal regions of modifying whey proteins and co-products. Complete work on characterizing product variables such as elasticity and gel strength. Determine nutritive quality and protein digestibility. Develop response models linking process variables to product characteristics.

Year 4 (FY2008): Initiate work to develop extruded co-products with whey proteins, different grains, and other proteins to create prototype food systems. Initiate work to develop viscoelastic models of co-products made with whey proteins, starches, and other protein combinations for new product application.

Year 5 (FY2009): Complete work to develop extruded co-products with whey proteins, different grains, and other proteins to create prototype food systems. Complete work to develop viscoelastic models of co-products made with texturized whey proteins, starches, and other protein combinations for new product application.


4a.What was the single most significant accomplishment this past year?
New Whey Protein Products Developed. We determined the non-thermal extrusion conditions that allowed us to modify the functionality of whey proteins. Non-thermal extrusion can texturize whey proteins without denaturing them, creating foamy or fibrous physical structures which are not possible by any other processing means. The appeal of non thermal whey protein texturization is that different products can be created while preserving the optimum nutritional qualities of these whey proteins.


4d.Progress report.
1935-41000-065-01S: This report serves to document research conducted under an SCA between ARS and University of Georgia, Athens. To determine the apparent digestibility of extruded proteins, rat studies were conducted with partially and totally denatured whey protein isolates. There was a 12.2 to 14.6% increase in protein intake when rats were fed treatments partially and totally denatured whey protein isolate. There was an increase in protein digestibility when rats were fed diet totally denatured whey protein isolate. The caloric content (calories digestible energy / g dry matter) of the denatured whey protein isolates were 0.96 to 1.22 % greater than the control. No differences were observed in body weight gain but there was an influence of diet on nitrogen retention. Rats fed the control, un-denatured whey protein isolates, retained 24.7 to 34.0% less nitrogen than when fed denatured whey protein isolates.

1935-41000-065-02S-This report serves to document research conducted under an SCA between ARS and Cornell University, Ithaca, New York. Texturized whey proteins were produced under controlled degree of denaturation by manipulating extrusion conditions. These proteins were then linked with food gums and were used to create value-added low-glycemic gummy bear type confectionery products. The effect of adding texturized whey protein to a high solids (sucrose-corn syrup) pectin co-solute system on the rheological (and textural properties) was determined by evaluating the mechanical spectra for soft glassy materials. The physical properties of the elastic network or bulk (undiluted) linear entangled polymers, in the moderate frequency range, and G-G crossover points at higher frequency indicated elastic effects. The results are high-solids confectionery gels that may replace sugars as confectionery ingredients, forming low caloric reduced-sugar products.

1935-41000-065-03R: This report serves to document research conducted under a grant from USDA Foreign Agriculture Service to develop health-enhancing snack products using extrusion technology. The main objective is to develop Protein-Enriched Low Glycemic Snack Products that Mitigate Childhood Obesity and Hidden Hunger. We are accomplishing this by developing protein-enriched extruded snack products using milk components, particularly, whey proteins. We are establishing rheological properties of blends of low glycemic starches including cassava, and whey proteins. We are incorporating cashew pulp as alternate dietary fiber source in extruded snacks. Results show synergistic effect with blending cassava and whey proteins that will produce a more expanded product. The healthy snacks will be fortified with micronutrients such as iron, zinc, and vitamin A. Protein-rich extruded snack products developed will help combat obesity and other associated health problems.


5.Describe the major accomplishments over the life of the project, including their predicted or actual impact.
Some of the work in this new project builds on the accomplishments of earlier research project, 1935-41000-052, that was terminated in FY 2004. The accomplishments of 1935-41000-052 that are pertinent to the new project are stated in the text that follows.

The potential use of cheese whey proteins in expanded snack products is limited by the negative effect of whey proteins on expansion. If whey proteins are not modified by processing prior to addition they cause the products to shrink and become tough instead of crunchy. We developed extruded products containing up to 35% whey proteins by allowing the whey proteins to expand and reducing the amount of water added during extrusion, and improved the crunchiness of products containing whey proteins. This research addresses Action Plan Component 2. New Processes, New Uses and Value – Added Foods, and Biobased Products. Problem Areas 2a. New Product Technology and 2c. New and Improved Processes and Feedstocks. Work was completed on a new process that combines whey protein concentrate and calcium caseinate into syrup-like composites for use in many food applications. One such application is the use of the dairy-based composites to coat dietary fibers, to create a barrier around the fiber, and to reduce their water holding capacity. An innovation disclosure was filled and patent was granted #6,610,347 B1. This research addresses Action Plan Component 2. New Processes, New Uses and Value – Added Foods, and Biobased Products. Problem Areas 2a. New Product Technology and 2c. New and Improved Processes and Feedstocks.

Several texturized dairy proteins were created by extrusion cooling conditions; their new physical properties were determined using texture profile analyses. Because the protein structure remained intact after extrusion, several puffy and foamy structures were created, and these may be used in baked product applications. This research addresses Action Plan Component 2. New Processes, New Uses and Value – Added Foods, and Biobased Products. Problem Areas 2a. New Product Technology and 2c. New and Improved Processes and Feedstocks.


6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Presentations were made to stakeholders, collaborator and CRADA partners, and to an International Protein Panel on the extrusion of milk proteins. Others were made at Scientific Meetings. Information was transferred to food industries.

ARS processing technology for texturized whey proteins has been licensed. The formulation, processing requirements, and resulting products were commercially tested and are ready for marketing.


7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Cheese Reporter, July 2004. ARS Looks to license food product invention.

Men's Health Magazine, March 2004. USDA’S ARS whey protein Technology.


Review Publications
Fishman, M.L., Coffin, D.R., Onwulata, C.I., Konstance, R.P. 2004. Extrusion of pectin and glycerol with various combinations of orange albedo and starch. Carbohydrate Polymers 57:p.401-413.

Onwulata, C., Qi, P.X. 2004. Food protein:interactions and functionality. In:Meyers, R., A.Ed. The Encyclopedia of Molecular Biology: Fundamentals & Applications. Wiley-VCH, Weinheim, Germany. V.4, p.503-519.

Onwulata, C.I., Tomasula, P.M. 2005. Use of texturized whey proteins in expanded snacks. (abstract). 2nd International Symposium on Spray Drying. Paper No. 65-a.

Liu, L.S., Onwulata, C.I., Fishman, M.L., Savary, B.J., Hicks, K.B. Evaluation of sugar beet pulp and poly(lactic acid) biodegradable composites. UJNR Food & Agricultural Panel Proceedings. 2004. p.80-90.

Liu, Z., Akin, D.E., Barton Ii, F.E., Onwulata, C.I., Erhan, S.Z. 2004. Preparation of soy-based composites reinforced with protein coated flax fiber. UJNR Food & Agricultural Panel Proceedings. p. 134.

Tunick, M.H., Onwulata, C.I., Tomasula, P.M. 2005. Rheological properties of extruded milk powders. Abstract. American Chemical Society. Paper No. AGFD075.

Nalesnik, C.A., Onwulata, C.I. 2005. Drying kinetics of extruded dairy proteins. (abstract). AOCS Ann. Mtg. & Expo. Paper No. 53.

Last Modified: 4/21/2014
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