Nutrient composition and protein quality evaluation of eri silkworm (Samia ricinii) prepupae and pupae.

Eri silkworm (Samia ricinii) is a traditional source of food in northeast India, where it is grown primarily for silk and food uses. Nutrient analysis showed that the proximate composition of eri silkworm prepupae and pupae grown on either castor or tapioca were comparable and it was a good source of protein (16g%), fat (8g%) and minerals. The amino acid scores of eri prepupae and pupae protein were 99 and 100, respectively, with leucine as the limiting amino acid in both cases. Net protein utilisation (NPU) of prepupae and pupae was 41 as compared to 62 in casein. Protein digestibility corrected amino acid score (PDCAAS) was 86. The high protein content in the defatted eri silkworm meal (75%) with 44% total essential amino acids makes it an ideal candidate for preparing protein concentrate isolates with enhanced protein quality that can be used in animal nutrition.