Digestibility of Water-soluble Fibroin Prepared from Silk Yarn

• Published in: Nihon Eiyō, Shokuryō Gakkai shi Vol. 57; no. 5; pp. 215 - 220
• Main Authors: Maekawa, Akio, Yamamoto, Yuji, Tadokoro, Tadahiro, Minagawa, Hirohisa
• Format: Journal Article
• Language: Japanese
• Published: Japan Society of Nutrition and Food Science 2004
• Subjects: digestibility; silk protein; water-soluble fibroin
• ISSN: 0287-3516; 1883-2849
• DOI: 10.4327/jsnfs.57.215

Digestibility of water-soluble fibroin has long remained unknown. The present study thus aimed to clarify the digestibility of water-soluble fibroin extracted from silk yarn, and to determine the proximate composition and amino acid composition. In vitro digestibility of water-soluble fibroin was 58% after treatment with pepsin-trypsin-chymotrypsin. In contrast, in vivo true digestibility (TD) of water-soluble fibroin was 65.7% in rats. Moreover, water-soluble fibroin exhibited lower food efficiency, TD, protein efficiency ratio, biological value, and net protein utilization as a protein source than the casein group. The present study has thus clarified the digestibility of water-soluble fibroin.