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United States Department of Agriculture

Agricultural Research Service

2008 Annual Report

1a.Objectives (from AD-416)
Use starch-lipid composites produced by steam jet cooking to create new products from bio-based resources. Determine the effect of process variables and mechanisms of interactions that influence the properties of starch-lipid composites. Cooperate with licensees and CRADA partners to investigate specific combinations of ingredients designed to provide new applications.

1b.Approach (from AD-416)
Investigate the properties of starch-lipid composites prepared using cereal flour instead of starch, mixtures of starch and polysaccharide gums, and dairy sources of lipids. Vary the starch/lipid ratio and determine the maximum lipid content possible. Vary process variables such as steam pressure, steam and slurry flow rates, temperature, and high-shear mixing before or after jet cooking and determine the effects on composite properties. Cooperate with CRADA partners to develop products based on starch/lipid composites in the areas of food products (meats, dairy products, baked good, etc.), water-based lubricants, cosmetics and drug delivery products, and industrial or environmental microbial delivery systems.

3.Progress Report
Cornstarch was jet cooked with soybean oil at different starch-to-oil ratios to determine the ability of jet cooked starch to form stable dispersions of small diameter oil droplets. Increased oil holding ability of cornstarch was observed if oleic acid was added to form a complex with amylose. Centrifugation of jet cooked dispersions yielded concentrated dispersions of oil droplets that resisted coalescence due to adsorbed starch at the oil-water interface. A commercial-scale cream separator was used to prepare large quantities of a very high oil aqueous starch-oil composite, which will enable the development of products for the first time based on this isolated fraction. A spray release lubricant for waffle baking was developed under a CRADA and was shown to have release properties similar to current commercial products. The material has been commercially bottled and successfully field tested. This product eliminates the fire hazard of aerosol-based materials. A starch-lipid composite was prepared from normal dent cornstarch and butter, and its effect on the fermentation of yogurt was determined. Microscopy showed that the composite participated in the fermentation process and aided in the development of gel structure. Studies on the rheological properties of the crystalline particle pastes formed by jet cooking high amylose corn starch with fatty acids were completed. Understanding the effects of the method of preparation on the flow properties of these pastes will allow us to prepare new compositions for a variety of end-use applications. A procedure was developed to spray starch-oil composites onto metal surfaces to provide dry film lubricants for metal forming applications. The dry coatings exhibited good lubrication and wear properties. Starch-lipid formulations were also prepared for testing as textile lubricants. Jet cooked formulations, prepared from high-amylose starch, lipids and fatty acids were smooth and non-sticky when applied to the skin, and we are working with CRADA partners to commercialize skin lotions prepared by this technology. Starch-paraffin wax composites were tested as phase change materials for storing and releasing thermal energy by the melting and re-solidification of the wax component. Initial tests were successful, and melted wax did not separate appreciably from the composite. Stable aqueous dispersions of carbon black were obtained in the absence of added surfactants by jet cooking waxy cornstarch with carbon black and also by ultrasonic treatment of mixtures prepared from carbon black and jet cooked waxy cornstarch. Aqueous carbon black dispersions are used in water-based inks, paints and coatings. Electrically-conductive polymer films were also prepared by blending aqueous starch-carbon black dispersions with a starch graft copolymer emulsion. A new method of forming starch-lipid composites by high-shear mixing was demonstrated. This procedure allows temperature-sensitive lipid components to be incorporated into products without passing through the steam jet cooker. This research addresses NP 306, Component 2.

1. A practical method for preparing concentrated water dispersions of non-coalescing oil droplets.

Although water dispersions of non-coalescing oil droplets can be prepared in the absence of emulsifiers by steam jet cooking aqueous mixtures of starch and oil, no practical method for preparing and isolating these droplets at high concentrations had previously been developed. This objective has now been achieved by jet cooking starch-oil mixtures at high oil to starch ratios (e.g., 2:1 to 4:1) and then centrifuging the cooled, jet cooked dispersions. The starch-coated oil droplets, with specific gravities less than 1, rise to the surface during centrifugation and can be easily isolated. Smaller oil droplet sizes are obtained when fatty acids are added during jet cooking to complex the amylose component of starch. Experiments have shown that a commercial cream separator can be used to simultaneously carry out the centrifugation and separation processes. Lotions, lubricants and food products are some of the potential end-use applications of these aqueous high-oil fractions. This accomplishment addresses NP 306, Component 2, Problem Area 2a and 2c.

2. Spray release lubricant for food applications.

An aqueous spray release lubricant for waffle baking was developed under a Cooperative Research and Development Agreement, and was shown to have release properties similar to current commercial products. The new product was prepared by jet cooking a mixture of high-amylose starch and soybean oil in the presence of a fatty acid to complex the amylose component of starch. The product has been commercially bottled and successfully field tested. A major advantage of the new product is that it eliminates the fire hazards associated with aerosol-based materials. This accomplishment addresses NP 306, Component 2, Problem Area 2a and 2c.

3. Starch-based formulations with properties suitable for use in skin lotions.

Jet cooked lotion formulations for delivering pharmaceuticals and antimicrobials to the surface of human skin were previously prepared from mixtures of starch, lipid, pectin and xanthan. These lotion formulations, however, exhibited an undesirable, sticky hand-feel when they were applied to the skin surface and allowed to dry. We have now shown that jet cooked formulations, prepared from high-amylose starch and lipid, in the presence of a fatty acid to complex the amylose component of starch, exhibit a smooth hand-feel and do not pass through a sticky phase during drying. We are working with CRADA partners to commercialize skin lotions prepared by this technology. This research addresses NP 306, Component 2, Problem Area 2a and 2c.

6.Technology Transfer

Number of Active CRADAs2
Number of the New MTAs (providing only)2
Number of Invention Disclosures Submitted1
Number of Non-Peer Reviewed Presentations and Proceedings4

Review Publications
Kenar, J.A., Felker, F.C., Biresaw, G., Kurth, T. 2008. Properties of dry film lubricants prepared by spray application of aqueous starch-oil composites. Industrial Crops and Products. 29(1):45-52.

Singh, M. 2008. Particle size characterization of starch-lipid composites. Journal of Food Processing and Preservation. 32(3):404-415.

Fanta, G.F., Felker, F.C., Shogren, R.L., Salch, J. 2008. Preparation of spherulites from jet cooked mixtures of high amylose starch and fatty acids. effect of preparation conditions on spherulite morphology and yield. Carbohydrate Polymers. 71(2):253-262.

Patil, D.R., Fanta, G.F., Felker, F.C., Salch, J. 2008. Application of Hydrophilic Starch-based Coatings to Polyethylene Surfaces. Journal of Applied Polymer Science. 108(5):2749-2755.

Last Modified: 4/18/2014
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