39B-31

J. MONTECALVO and T. Flax. Department of Food Science and Nutrition, California Polytechnic State University, 261 Agricultural Sciences Blvd., San Luis Obispo, CA 93407

With the increasing expansion of the wine industry, volume of wine produced has steadily increased over the past five years. As a consequence of increased production, increases in wine by-products and its utilization has presented a challenge to the wine industry. Approaches for utilization of grape seeds have been considered in only a few studies. Grape seeds, a by-product of wine processing constitute 2-3% of the grape weight and contain 11-17% oil and 7.7-15.4% protein.

Objectives of this work were to determine and assess effects of processing conditions and protein extraction conditions upon protein recovery in the form of full fat and defatted flours. Comparative emulsification characteristics were compared to commercial soy flour products.

Seeds of Cabernet Sauvignon were used throughout the study and air-dried followed by milling before and after NH₄OH seed treatment to determine optimum yields of 40 mesh (Tyler) flour. Comparative proximate analysis was conducted. Comparative emulsification capacity (BC), emulsion activity (EA) and emulsification stability (ES) of full fat (EFF) and defatted flours (DEF) were evaluated.

Results indicate that air-drying reduced the moisture content from 38.26% to an avenge of 9.78%. Dried seeds contained 9.62% protein, 13.06% fat and 2.12% ash. Yield of 40-mesh flour was 88.19%. Treatment of seeds with 1.1% NH4OH to remove phenolic compounds followed by drying indicated an avenge milling yield of 91.55% with a 14.97% protein content. DFF untreated with NH₄OH provided 11.89% protein while the treated flour gave a protein content of 16.69%. The emulsification capacity of untreated FFF was 42.34-ml. oil per 100-mg. protein that was significantly higher than the treated FFF EC of 35.11. The BA of untreated flour 66.94% and ES of 70.08 were significantly greater than the NH₄OH treated FFF, EA, 54.95 and ES, 63.57%.

These results suggest that pre-treatment of grape seeds with a 1.1% solution of NH₄OH resulted in increased yield of 40 mesh flour as well as increased protein content. Decreases in EC, EA and ES were observed for both full fat and defatted flour samples.