Breeding of the Silkworm Race “Sericin Flavo” for Production of Sericin Cocoons Containing Flavonol

Abstract

Sericin accounts for about 25% of the total composition of silkworm cocoon shells. It has recently been found to be a natural attracting material on cosmetic fields because of its skin moisturizing effect, and inhibitory effects against lipid peroxidation and tyrosinase activity. The silkworm race “Sericin Hope” possibly provides undestroyed natural sericin, which is easily gelled and emulsified at lower concentrations. In order to improve this race, we developed “Sericin Flavo” by cross-breeding it with the green-cocoon strain “Daizo (Matsumura)”. This new race spins a high ratio of green sericin cocoons, each of which contains about 4.1mg of flavonol. These green sericin cocoons show higher antioxidant activity and a wider UV shielding effect.