1-Deoxynojirimycin and polyphenolic composition and antioxidant activity of different native Thai silkworm (Bombyx mori) larvae

1-Deoxynojirimycin (DNJ) and polyphenolic compound are extensively found at different levels in many silkworm races. The present investigation comprises, estimation of DNJ, polyphenol, total phenolic (TPC) and total favonoid contents (TFC), antioxidant activities (DPPH, ABTS, and FRAP). The results showed that the fifth larval instars of Samrong and Nangsiw had high content of DNJ (96.42 mg/100 g dw and 65.23 mg/100 g dw, respectively). Nangsiw had the highest content of quercetin (82.94 mg/100 g dw) and (+)-catechin (81.88 mg/100 g dw). Nangsiw contained relatively highest (p < 0.05) TPC and TFC and exhibited highest scavenging free radical DPPH activity (58.96%), and highest ABTS radical scavenging capacity (12.35 mg TE/100 g dw) and highest ferric reducing antioxidant power (FRAP) (2.03 mg Fe (II)/g dw). This experiment suggests that Samrong and Nangsiw are a valuable source of natural alkaloid and phenolic antioxidants for commercial exploration. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of King Saud University.