2006 Annual Report 4d.Progress report. This report serves to document research conducted under a nonfunded agreement between ARS and Illinios State University. Additional details of research can be found in the report for the parent CRIS 3620-41000-108-00D entitled Advanced Starch-Based Materials for Non-food Applications. The behavior of the corn protein zein in ethanol/water solutions was determined. Zein is a water-insoluble protein obtained from corn processing, which has various potential applications. The light scattering experiments allowed us to understand the variables influencing the aggregation and gelation of zein solubilized in ethanol/water mixtures. Initial experiments were performed to establish in what concentration range we would be able to distinguish gelation and aggregation in 9:1 ethanol/water mixture. It was found that at 23 deg C, a concentration of zein above or equal to 10% induces the formation of gels in a period of days without noticeable aggregation. No gels were formed at lower concentrations, but in all cases there was noticeable aggregation. Similar results were observed at 4 deg C. There was however, a critical concentration of less than 8.5% zein in which both aggregation and gelling occurred simultaneously. Finally, we increased the amount of water to 20%. An increase of water increased gelation. We then carried out static light scattering experiments to establish the apparent size of the particles as they slowly aggregated in a 1% solution of zein in a 9:1 ethanol/water mixture. At day 1 the radius of gyration (RG) was measured to be 168 nm. This had decreased to 120 nm after 4 days and to 110 nm after 7 days, when the formation of aggregates had settled down. As the amount of protein decreases in solution the apparent size of the protein in solution decreases, which reflects the dependence of the amount of light scattered on the variation of protein concentration. Dynamic light scattering experiments will be performed to establish the actual hydrodynamic radius of the particles in solution. Even though gelation occurs very slowly (over days) we followed the initial stages of the process (20% zein in 9:1 ethanol/water at 10 deg C). It is evident that there is an initial (less than 2 hrs) stage in which the protein and solvent reorganize to initiate the gelation process. After this initiation stage, gelling proceeds at a rate of 2200 cps/hr until it starts to level off after 13 hours.