Optimization of the alkaline extraction of silkworm (Bombyx mori L.) pupae protein

Optimization of the extraction of silkworm (Bombyx mori L.) pupae protein was investigated using response surface methodology and central composite design. The influences of the variables of protein extraction processes were studied and the regression equation of protein extraction rate was established. Protein extraction rate was primarily affected by alkali concentration and liquid/solid ratio(P＜0.05), and was remarkably improved to 78.69% under the optimum conditions, when alkali concentration, liquid/solid ratio, temperature and NaCl concentration were 1.03%, 70︰1, 50℃, and 0.070 mol/L, respectively. The protein content of silkworm (Bombyx mori L.) pupae protein concentrate was 96.70%.The percentage of the total essential amino acids to the total amino acids and the ratio of the total essential amino acids to the total non-essential amino acids of silkworm (Bombyx mori L.) pupae protein concentrate were 47.1% and 0.9, respectively. It suggests a potential use of this silkworm pupae protein concentrate in the food industry.