SPRAY-DRIED SOY PROTEIN ISOLATE SOLUBILITY, GELLING CHARACTERISTICS, AND EXTRACTABLE PROTEIN AS AFFECTED BY ANTIOXIDANTS

With the addition of antioxidants, spray-dried soy protein isolates (S PI) exhibited increased solubilities by 8% over the control in 0.1M Na Cl. Increased solubilities corresponded to a 15% and 8% reduction in p rotein oxidation as determined by protein carbonyl contents. The great est differences in solubility between a spray-dried SPI with antioxida nt (66% protein solubility) and the control (54% protein solubility), as well as the minimum protein solubility, occurred in 0.2M NaCl. Foll owing the initial solubilization step in SPI processing, amount of ext racted proteins was increased by 4.5% over the control with addition o f antioxidants. Gel fracturability, hardness and adhesiveness for heat set gels of 12% SPI processed with added antioxidants were increased by 26.3%, 23.5% and 24.6%, respectively.