Abstract: In this paper, the nutritional and functional properties of silkworm (Bombyx mori) pupa protein modified by micronization-enzymatic hydrolysis were studied. Results showed that the ratio of essential amino acids to non-essential amino acids and to total amino acids in the modified protein reached the Food and Agriculture Organization/World Health Organization (FAO/WHO) recommended pattern suggesting significantly improved nutritional value compared with the native protein (P < 0.05). The degree of hydrolysis was increased by 65.62%, and solubility, emulsifying capacity and foaming capacity by 402%, 187%, and 141%, respectively; the sulfhydryl group content was increased by 57% whereas disulfide content was decreased by 21%; the amount of random coil secondary structure was increased from 37.46% to 91.33% after the modification. The modified pupa protein at 25 μg/mL enhanced the proliferation of mouse splenocyte by 100%, suggesting a significant improvement of immunity (P < 0.01).

Key words: Bombyx mori pupa protein, micronization, enzymatic hydrolysis, nutritional value, functional properties