Antioxidant Properties of Naturally-Colored Domestic Silk

Naturally-colored silks are silk fibers with natural pigments inside, which are produced by silkworms fed with a dye-free diet. Wild silkworms, such as Antheraea pernyi, A. yamamai and Saturniidae, are known for producing silk cocoons with brown, green, and golden yellow colors, respectively. Domestic silkworms Bombyx mori can also produce colored cocoons, with the uptake of synthetic dyes into silk glands through feeding.1–3 A few mutants of B. mori can even transfer the natural pigments in the mulberry leaves into the silk gland and spin cocoons in pink, flesh, yellow, yellow-green, and green colors. The silks produced by these mutant silkworm varieties are naturally-colored domestic silks (NCSs).4,5 The NCSs exhibit brilliant colors and need not be dyed, thus offering economic and environmental benefits to the textile industry.