Abstract text

Disclosed are a fibroin with increased molecular weight and improved antioxidant activity, tyrosinase inhibitory ability and cytotoxicity to cancer cells, which has a molecular structure modified by irradiation, a method for production thereof, use of the irradiated fibroin in various applications for enhancing antioxidant activity, tyrosinase inhibitory ability and/or cytotoxicity to cancer cells such as foods, cosmetics, medicines, etc.