Silkmoth pupae: potential and less exploited alternative source of nutrients and natural antioxidants

Abstract

Increasing global populations and decreasing sources of nutrients to feed them, has necessitated the drive for alternative and more sustainable sources of nutrients. Such alternatives should contribute to meet the demand for food and minimise negative effects on the environment. Edible insects, which have been traditionally part of human diets, stand out as the most probable and sustainable alternative. Silkmoth pupae, by-products of the sericulture sector are among the traditional foods consumed in Asia. In this study we determined the nutritional composition, phytochemical contents, and antioxidant activities of freeze-dried pupae from 2 domesticated and 3 wild silkmoth species. Our results showed that both Bombyx mori L. and Samia cynthia ricini Boisduval pupae had the highest amounts of proteins, 78.9 and 76.0 mg bovine serum albumin equivalents /g, respectively. Significantly high amounts of lipids (26.7%) were observed in B. mori pupae. Domesticated silkworm species recorded significantly high amounts of protein compared to the wild species. In addition, all silkmoth pupae had substantial amounts of phytochemicals that varied significantly between the studied species. We further demonstrated that all pupae samples exhibited antioxidant activities for both 50% methanolic and 100% hexane extracts, at very low concentrations of 2.5 and 30 mg/ml, respectively, with Anaphe panda pupae samples recording the highest activities. The multivariate analysis confirmed significant differences in the chemical composition of silkmoth pupae between species and type of diet they consume. Therefore, our findings suggest that the studied silkmoth pupae are rich alternative source of nutrients and natural antioxidants.