Abstract:

The synthesis of plastein from hydrolysates of soybean protein isolate and oat protein isolate was investigated
in this work. Of the reaction conditions substrate concentration, temperature, pH and time, 3 were identified as main
variables by one-factor-at-a-time design. The main variables were optimized by response surface methodology based on a
Box-Behnken design. Meanwhile the synthetic plastein was analyzed for animo acid composition. The observed yield of
plastein was 31.46% under the optimal conditions of 31 g/100 mL of substrate concentration, 45 ℃, pH 4.7 and 12 h. The
plastein obtained exhibited significantly different amino acid composition in comparison with both starting raw materials; in
particular, the content of essential amino acids was increased by 17.7% and 16.5%, respectively. Therefore, the nutritional
value of both raw materials was increased.

Key words: soybean protein, oat protein, plastein, response surface methodology, amino acid analysis