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United States Department of Agriculture

Agricultural Research Service

Research Project: PROTEIN PROCESSING USING HIGH-PRESSURE GASES AND SUPERCRITICAL FLUIDS
2006 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? Why does it matter?
Economic pressures on dairy farmers and processors require more effective utilization of dairy products. This research focuses on the means of developing new food and non-food uses for whey and casein, as well as nonfat dry milk (NFDM), through basic research and process development engineering. Specifically, new processing techniques for production of edible films from the milk proteins will be investigated to expand their utilization into new food and nonfood products. High pressure and supercritical carbon dioxide will be investigated as media for creating modified casein and whey proteins to increase the functionality of the proteins for food uses. A new environmentally benign process will be designed based on one that was developed in our laboratory for fractionation of whey protein concentrate into two enriched fractions, alpha-lactalbumin and beta-lactoglobulin. Process simulation will be incorporated into the study to guide process development for the most efficient production scheme. In addition, the possibility of producing a fully soluble form of alpha-lactalbumin and a form in the so-called molten globule state will be investigated. This will ultimately expand the range of products that can be obtained from a single process thereby reducing the costs associated with whey protein concentrate. Finally, casein molecular models developed previously in our lab will be used to guide production of enriched fractions of the individual caseins.

The objectives of this project are:.
1)Develop new, cost effective technologies for processing protein fractions from NFDM into food and non-food products by utilizing concepts from physical chemistry;.
2)Develop new environmentally benign processes for dairy protein modification that utilize supercritical fluids as reaction media and solute carriers; and,.
3)Develop new processes for producing enriched fractions of the whey and casein proteins to utilize NFDM and whey.

This research primarily supports National Program 306, “Quality and Utilization of Agricultural Products” and Departmental Goal 1 “Enhance Economic Opportunities for Agricultural Producers”, Objective 1.1: 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. ARS Strategic Plan Performance Measures 1.1.1: Develop cost effective and functional industrial and consumer products from agricultural and forestry resources and 1.1.2: Provide higher quality, healthy foods that satisfy consumer needs in the United States and abroad. New knowledge obtained from basic research and development of new processing technologies will expand the utilization of surplus milk proteins in food and nonfood products. The development of film processing technologies for proteins may benefit producers and processors of agricultural materials other than dairy because the research will establish the parameters necessary for large-scale continuous processing. New environmentally benign processes based on carbon dioxide for isolating and modifying dairy proteins from surplus milk and whey will lead to new GRAS protein products for food and nonfood applications. These technologies will benefit agriculture because they do not produce waste streams requiring additional treatment prior to disposal or require large amounts of water to wash the solvent from the protein. New knowledge of the properties of dairy proteins and their peptides may guide development of novel products that also will increase utilization of milk.


2.List by year the currently approved milestones (indicators of research progress)
FY 2005

Complete determination of the physical properties for control films with added plasticizer to identify the parameters that impact film properties.

Develop methods for determining the factors that govern adhesion of solutions of proteins and films to belt materials for use in continuous or semi-continuous apparatus. Identify the belt materials that are suitable for processing films on a continuous basis or in casting equipment.

Develop methods for determination of film drying parameters. Identify parameters that would lead to development of strategies for rapid drying of films.

FY 2006

Complete determination of the physical properties for control films comprised of proteins or synthetic materials without added plasticizer or in blends with synthetic materials to identify the parameters that impact film properties.

Complete determination of the effect of plasticizer composition on the physical properties and appearance of edible films. Complete determination of process conditions, such as feed flow rate, drying air velocity, humidity and temperature, for processing films on a continuous basis.

Complete studies on use of mass spectrometry to elucidate interactions of proteins in solutions.

FY 2007

Complete studies to determine the effects of the process on film properties – bench scale, semi-continuous and continuous.

Complete kinetic studies for separation of alpha-lactalbumin and beta-lactoglobulin necessary for design of large – scale pilot/commercial separation equipment based on CO2 and related technologies.

Complete technology transfer activities and cost studies for applications of films and/or coatings based on dairy proteins

FY 2008

Complete studies for environmentally friendly methods of modifying casein proteins.

Complete design of specialized reaction vessel for separation of whey components using CO2.

FY 2009

Complete production runs for alpha-lactalbumin and beta-lactoglobulin enriched fractions.

Complete functionality testing of the enriched fractions and CO2-modified casein and whey.

Complete technology transfer activities for applications of CO2 casein and other materials that are product oriented.

Complete studies on use of molecular modeling to guide separation of the caseins in milk.


4a.List the single most significant research accomplishment during FY 2006.
DESIGN OF EDIBLE, WATER-RESISTANT FILMS. Edible films made from dairy proteins have gas barrier and tensile properties similar to those of synthetic films. Films made from casein precipated from milk using high presure CO2 have better water barrier properties than films made from carbohydrates or other dairy proteins; however, the CO2-casein films have a hazy, opaque appearance that can limit their application potential. In an effort to understand how parameters that affect the molecular structure and conformation of dairy proteins ultimately affects the barrier and tensile properties of the films, researchers from the Dairy Processing and Products Research Unit, Eastern Regional Research Center, ARS, found that by reducing the particle size of CO2-casein to less than l00 microns, the films became significantly more transparent and glossy. Moreover, the water barrier properties of the films also improved. This result, when combined with earlier research that showed that the type of plasticizer added to make the films more flexible and the amount affects the oxygen barrier properties of the films, was used to design films for several proprietary food and nonfood applications. This research addresses NP 306 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.


4b.List other significant research accomplishment(s), if any.
MILK AND THE HUMAN GENOME. Proteins are the molecular machines that run living things. The recent announcement that the human genome has been solved represents not an end in itself, but a beginning. It is now the work of protein chemists and structural biologists to crack the protein code. Scientists at the Dairy Processing and Products Research Unit are working to translate this new information to make significant breakthroughs in dairy applications. Basic studies and the latest ideas on protein structure have been reviewed and applied to ongoing studies on milk proteins. The application to food proteins will help researchers in the food and nutrition areas understand how processing treatments transform protein structure. This research addresses NP 306 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.

CONTROLLING THE DISSOLVING RATE OF EDIBLE FILMS. Edible films made from proteins, with few exceptions, are readily soluble in water. While this characteristic may be useful in some applications, other applications require partial or complete insolubility of the films in water. In an effort to understand how to adjust the water solubility of films made from various dairy proteins, researchers from the Dairy Processing and Products Research Unit, Eastern Regional Research Center, ARS, used modern spectroscopic and microscopic techniques to examine the structure of the films made by varying the salt concentration of the film or the solvent base of the film, using alcohol instead of water. Results showed that addition of salt greatly increased the water solubility of the films while alcohol had the opposite effect. The researchers are using this information to develop new protein – based films which will have applications in the personal care, cosmetic and pharmaceutical areas. NP 306 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.


4c.List significant activities that support special target populations.
Americans are consuming more cheese each year, and these and other dairy products are becoming important sources of calcium in the diet. The major proteins of milk, called caseins, carry calcium in small packages called micelles. In a collaboration with scientists at Prairie View A & M University, Prairie View, Texas, and Kentucky State University, Frankfort, Kentucky, who performed the experiments, and the Dairy Processing and Products Research Unit, ERRC, ARS, Wyndmoor, PA, experiments on the comparison of goat’s and cow’s milk caseins showed that one genetic type of goat’s milk casein, regardless of breed, is much better at carrying calcium than that of other goat’s or cow’s milk. Cheeses with extra calcium were then made from the high calcium carrying goat’s milk and normal cow’s milk. Feeding studies showed that the high calcium carrying goat cheese doubled calcium blood levels in normal rats and also resulted in better bone strength as well. This shows that manipulation of the casein types in milk can lead to stronger bones in animals. Extension of this information to human studies will aid cheese manufacturers who are attempting to enhance the nutritional quality of their products. These studies could also lead to the improved nutritional value for milk proteins in all dairy products and possibly as ingredients in other foods. NP 306 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.


5.Describe the major accomplishments to date and their predicted or actual impact.
CASEIN PROGRAM:

Some of the work in this new project builds on the accomplishments of the earlier research project, 1935-41000-058, that was terminated in FY 2004. The accomplishments of 1935-41000-058 that are pertinent to the new project are stated in the text that follows.

Carbon dioxide (CO2) was used as an agent to remove the milk protein, casein, from milk to investigate the use of this environmentally benign solvent (CO2) as a substitute for acids that are commonly used in protein processing. This process has been licensed by a company. Operating costs for CO2-casein are less than those for acid casein or calcium caseinate obtained using acids, if the CO2 is collected and used again. 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.

Most protein films dissolve readily in water. Films made from the CO2-casein derived from milk yielded a product that is barely soluble in water and is much less permeable to water than films made from the milk salt, calcium caseinate. This is significant because additional chemicals do not have to be added to decrease the film’s solubility in water. It was shown that CO2-casein film is a more effective moisture barrier for food use than calcium caseinate film. 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. Chemical reactions, carried out using CO2-casein and calcium caseinate, indicated that CO2-casein has a more organized structure than acid casein. This gives casein a lower water solubility that may make it useful in an application as a hydrogel in a controlled release formulation. 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.

Controlled release products slowly release drugs or ingredients from a film, patch or gel. Studies showed that the release of a drug from a CO2-casein/gelatin gel was comparable to that of release from materials made from synthetic polymers. This initial study demonstrated that casein/gel structures have the potential of replacing synthetic materials in release applications, not only in the drug industry, but in food formulations, room fresheners, and other applications where timed release is required, such as in pesticide release. 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.

Edible films made from proteins or carbohydrates have potential as replacements for synthetic films, but their use in products was limited because the technology for making them on a large-scale basis was unknown. In this study, new technology was developed that can be used to make rolls or sheets of edible films on a continuous large scale. The critical parameters that govern interactions between a belt material, the edible film solution properties, and drying parameters were also determined. The process was demonstrated for dairy – protein based films using calcium caseinate and CO2-casein, modified caseins from milk, and blends of the caseins with 20% nonfat dry milk (NFDM) substituted for the casein fraction and a plasticizer. A patent application has been filed for this new process that will allow processors to develop new value-added outlets for dairy products and proteins and carbohydrates in general. Two material transfer agreements have been initiated with companies for use of the films in food and nonfood products and two are pending. 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.

WHEY FRACTIONATION PROGRAM

A new environmentally-sound process was developed to separate the whey proteins into two fractions because existing processes contaminate the products with acids or salts. Experiments were performed that used CO2 to separate the whey proteins into two enriched fractions: an alpha-enriched fraction consisting mainly of alpha-lactalbumin and a fraction consisting mainly of beta-lactoglobulin. The alpha-enriched fraction containing over 60% of the alpha-lactalbumin and a beta-enriched fraction containing over 90% of the beta-lactoglobulin were obtained. Preliminary cost studies indicated that the cost of the fractions might be no more expensive than the cost of whey protein isolate but depends on design of an efficient process to carry out the fractionation. Experiments are being conducted with an industrial partner to examine the functionality of the products in food products. 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 Products.


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?
Descriptions of the casein, whey, and films processes are made available to our customers through the DPPRU website and the ARS Technology Transfer website. We have licensed the technology for our continuous CO2 protein production process to a small company. Meetings were held with several companies at which details were disclosed of the CO2 continuous protein process and the continuous film making process. Material transfer agreements were signed with two companies and negotiations are in progress with two others. A patent application is still pending. Ag Day, a nationally syndicated daily, aired a segment on the edible film process to over 150 TV markets. Experiments are being conducted with a large company to explore CRADA and licensing opportunities for the whey protein processes and products.


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).
Berry, D. Research at the Dairy Processing and Products Research Unit, Institute of Food Technologists Dairy Division Newsletter, Jan 2006. Pg 3.

Anon. USDA’s Research Agency Develops new process that uses casein as edible, water resistant coating for various food products. Cheese Reporter, Jan 20, 2006.

Core, J., Article in Agricultural Research, USDA, ARS, November 2005. “Edible, water-resistant film from milk protein. Pg 21

Anon, A continuous process to make biodegradable, edible film from milk protein. Chemical Engineering, Pg 16. December, 2005.


Review Publications
Tomasula, P.M., Datta, N., Luchansky, J.B. 2006. Validation of pilot-plant scale microfiltration to remove spores of bacillus anthracis sterne from fluid milk. Society for Industrial Microbiology Meeting (SIM). p.5.

Dangaran, K.L., Qi, P.X., Tomasula, P.M. 2006. Structure, properties and applications of edible films and coatings from dairy proteins. 2006 Ann AOCS Mtg & Expo. St. Louis, MO. p. 108.

Dangaran, K.L., Cooke, P.H., Tomasula, P.M. 2006. Improving physical properties of co2-precipitated casein films by reducing protein particle size. Journal of Food Science. 71(4:E196-201.

Qi, P.X., Cooke, P.H., Dangaran, K.L., Tomasula, P.M. 2006. Characterization of casein films made by pressurized carbon dioxide: salt effect on water solubility. 97th AOCS Ann Meeting & Expo Book of Abstracts. p. 106

Barone, J.R., Dangaran, K.L., Chin, S. 2006. Protein-transition metal ion networks [abstract]. American Chemical Society Abstracts. Toxics and Materials Paper 80.

Kozempel, M.F., Tomasula, P.M. 2004. Development of a semi-continuous process for co2-precipated-casein. [abstract]. 228th National American Chemical Society Meeting. Paper No. 15.

Farrell, H.M., Malin, E.L., Brown, E.M., Qi, P.X. 2006. Casein micelle structure: What can be learned from milk synthesis and structural biology. Journal of Colloid and Interface Science. 11:135-147.

Qi, P.X., Cooke, P.H., Tomasula, P.M. 2006. Protein-protein interactions in casein precipitated by pressurized carbon dioxide (c02 casein). Nanoscale International Conference. #4b p.15.

Qi, P.X., Farrell, H.M., Uversky, V.N. 2006. New view of protein structure:implications for potential new structure-function relationships:Protein Structure and Functionality American Chemical Society Symposium Book Series.p.1-18.

Farrell, H.M., Gutierrez, A. 2006. K-carrageenan interaction with bovine and caprine caseins:as shown by sedimentation and NMR spectroscopic techniques: Implication of surface charge by a homologous three-dimension model for as2-casein:K-carregeenan-casein interaction American Chemical Society Book Symposium Series. 935:93-114.

Last Modified: 4/17/2014
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