44C-8 |
Characterization of foaming property of commercial soy protein products |
K. H. LEE and K. C. Rhee. Food Protein Research & Development Center, Texas A&M Univ., Cater-Mattil Hall, College Station, TX 77843-2476 Physicochemical property of food proteins which correlates well with their functional property in a given food system generally are sensitive to past processing history during manufacturing process. Soy protein is widely used in the food industry as a functional ingredient. Commercial soy protein products should have functional property different from pure ones made under carefully controlled conditions in the laboratory. The objective of this research is to characterize foaming property of the selective commercial soy protein products so as to provide realistic information helpful to the food industry. Foam was produced with 100 ml dispersion of protein products, comprised 46 soy protein isolates, 13 soy protein concentrates, and seven soy flour products, under various concentrations by mixing with Ultra-Turraxtm mixer for 30 sec. Foaming capacity was determined by subtracting liquid volume from total volume, consisted of liquid and foam, after standing mass-cylinder for 1 min. Foam stability was estimated by the percent ratio of foam volume after 30 min to starting value. Foaming property of soy protein isolate products varied largely among products, which ranged from 50 to 310 ml of foaming capacity and from 0 to 90% of foam stability. Foaming property correlated generally with the solubility of products. Hydrolyzed ones exhibited higher foaming capacity, but lower foam stability, than others. Foaming capacity increased slightly with increase of product concentration, and vice versa for the foam stability. Soy flour products had higher foaming capacity than concentrate products, close to that of isolate products, and their foam stability, about 90%, was the highest among three kinds of soy protein products. This information can be used as an important part of a comprehensive database that both industrial and academic researchers can use in identifying and selecting potential starting raw materials for their product development work.
Session 44C, Fruit & Vegetable Products: Chemistry
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