2008 Annual Report 1a.Objectives (from AD-416) The overall goal is to develop processes to enhance the conversion of cereal crops into value added polymers and chemicals, and thus generate expanded markets for cereals and reduce dependence on petroleum. 1b.Approach (from AD-416) Investigate the effects of stirring during cooling on the rheological properties of hot dispersions prepared by jet cooking starch in both the presence and absence of non-starch additives. Further investigate the structure, properties and end-use applications of spherocrystals formed in slowly-cooled solutions of jet-cooked starch. Modify laboratory techniques to permit commerical scale-up of processes used for deposition of thin starch coatings onto plastic surfaces and modification of these coatings by graft polymerization. Prepare starch esters having low to high degree of substitution and controlled substitution patterns with high efficiency and minimal byproducts. Characterize structure-property relationships and identify applications. Prepare new, inexpensive hydrophobic starches by reaction of starch with unsaturated hydrocarbons and characterize utility as adhesives. Prepare starch graft copolymers by reactive extrusion. 3.Progress Report Starch spherulite yields of about 60% could be obtained when high amylose cornstarch was jet cooked with palmitic acid to form a complex with the amylose component of starch. The types of spherulites formed depended upon the method used to cool the hot, jet cooked dispersions. Torus/disc and spherical/lobed spherulites about 5-10 microns in diameter were the major species observed when the dispersions were slowly cooled over a 24 hour period. However, when dispersions were rapidly cooled in ice, spherulites less than 1 micron in diameter were the only particles observed. Microwave radiation was utilized as a pretreatment to enhance the enzymatic saccharification of wheat straw. Microwaves were also utilized to enhance the extraction of antioxidants from buckwheat flour. A variety of reagents have been used to attempt to place suitable moieties on starch to allow points from which controlled graft polymerization could be initiated. These routes produced degraded starch. Current research efforts are being expended on creating polymers of controlled molecular weight and then grafting these onto starch using techniques that have more literature precedence. A continuous reactive extrusion process was used to prepare graft copolymers of starch with acrylamide and itaconic acid. Operating and formulation parameters were identified which gave good reaction efficiency and high yield of graft copolymer. Itaconic acid is derived from renewable resources such as corn. These materials have potential applications as hydrogels, dispersing agents, or flocculants. Several methods were developed to characterize the degree of substitution of hydrophobic starch stearates prepared by transesterification and esterification of starch in the ionic liquid 1-butyl-3-methylimidazolum dicyanamide. Conditions were optimized and the methods (nuclear magnetic resonance (NMR), hydrolysis/weighing, elemental analysis) gave similar results. Hydrophobic modification of starch with dicyclopentadiene was unsuccessful despite several attempts. Attempts to find appropriate reactions conditions are still being carried out. Enzymatic modification reactions of starch (both granular and gelatinized) with glycols and epoxides were carried out in the presence of catalysts such as trypsin and C. Antarctica lipase B. No starch ethers were formed so far. This work was carried out in support of NP 306, Component 2. 4.Accomplishments 1. Adherent, hydrophilic, starch-based coatings for polyethylene. Methods for imparting hydrophilic surface properties to hydrophobic plastics are of interest because of the ability of hydrophilic surfaces to (1) retard the build-up of static electricity, (2) make the surfaces receptive to water-based dyes and inks and (3) improve compatibility with biological fluids. Starch-containing formulations were developed that could be sprayed onto plastic films, such as polyethylene (PE), to make the surfaces water receptive. Coating formulations prepared from jet cooked cornstarch, a water-born epoxy resin, and a fluorinated surfactant adhered tightly to PE film surfaces when dried. Improved adhesion in the presence of water was observed when a cross-linking agent for starch was added to the formulation. These results should be useful to a variety companies in the plastics, packaging and coatings industries. This work was carried out in support of NP 306, Component 2, Problem Area 2c. 2. Starch phosphates as flocculants. Synthetic, petroleum-based polymers such as polyacrylamide (PAM) are used commercially to speed the settling of fine particles from water. It would be desirable to replace PAM with a non-toxic, biobased, biodegradable polymer such as a modified starch. This work showed that corn starch modified with phosphate groups was effective at removing clay particles from water in the presence of a small amount of calcium salts. Although more starch phosphate than PAM was required, the lower cost of starches should make them economically competitive. These results should be useful to companies making flocculants and modified starches and may be of importance to farmers in helping to reduce soil erosion. This work was carried out in support of NP 306, Component 2, Problem Area 2c. 3. Starch graft copolymers via enzyme catalysis. Starch graft copolymers (SGP) have applications as superabsorbents, coatings and thickeners. However, the catalysts normally used to make these can be hazardous and high temperatures may also be required. It was found that horseradish peroxidase, a common natural enzyme, catalyses the graft copolymerization of starch with acrylamide. These novel findings should stimulate more research on SGP's and lead to greater acceptance of starch based materials. This work was carried out in support of NP 306, Component 2, Problem Area 2c. 5.Significant Activities that Support Special Target Populations None 6.Technology Transfer Number of New Commercial Licenses Executed 1 Number of Web Sites Managed 1 Number of Other Technology Transfer 2 Review Publications Stevens, E.S., Willett, J.L., Shogren, R.L. 2007. Thermoplastic starch-kraft lignin-glycerol blends. Journal of Biobased Materials and Bioenergy. 1(3):351-359. Shogren, R.L. 2008. Scandium triflate catalyzed acetylation of starch under mild conditions. Carbohydrate Polymers. 72(3):439-443. 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. Shogren, R.L. 2007. Effect of orientation on the physical properties of amylose and high amylose starch films. Biomacromolecules. 8:3641-3545. Peterson, S.C., Eller, F.J., Fanta, G.F., Felker, F.C., Shogren, R.L. 2008. Comparison of the effects of critical fluid and reflux-extracted techniques on cornstarch pasting properties. Carbohydrate Polymers. 71(1):74-79. Biswas, A., Sharma, B.K., Willett, J.L., Erhan, S.Z., Cheng, H.N. 2008. Room-temperature self-curing ene reactions involving soybean oil. Green Chemistry. 10(3):298-303. Stevenson, D.G., Inglett, G.E., Chen, D., Biswas, A., Eller, F.J., Evangelista, R.L. 2008. Phenolic content and antioxidant activity of supercritical carbon dioxide-treated and air-classified oat bran concentrate microwave-irradiated in water or ethanol at varying temperatures. Food Chemistry. 108(1):23-30. Biswas, A., Brajendra, S.K., Willett, J.L., Adhvaryu, A., Erhan, S.Z., Cheng, H.N. 2008. Azide derivatives of soybean oil and fatty esters. Journal of Agricultural and Food Chemistry. 56(14):5611-5616. Shogren, R.L., Gonzalez, S.O., Willett, J.L., Graiver, D., Swift, G. 2007. Preparation of sorbitol citrate polyesters by reactive extrusion and application as inhibitiors of calcium carbonate precipitation. Journal of Biobased Materials and Bioenergy. 1(2):229-237.