Abstract
The effects of chitin hydrolysates made from shell of crustaceans (King crab, Paralithodes camtschatica and Japanese fan lobster, Ibacus ciliatus) and cartilage of cephalopods (Spear squid, Doryteuthis bleekeri) on the denaturation and the state of water of lizard fish myofibrillar protein (Mf) during drying process were investigated. Five grams (dried matter) of each chitin hydrolysate was added to 100g of Mf, and water activity (Aw) of Mf and Mf Ca-ATPase activity were examined during drying process. The addition of each chitin hydrolysate caused a decrease in Aw at the same moisture content, and an increase in the amount of multilayer and monolayer sorbed water obtained from a desorption isotherm curve as compared to a control (without chitin hydrolysates). The activity of Ca-ATPase of the control decreased rapidly, on the other hand, that of chitin hydrolysate containing groups lowered gradually in all Aw area. These results suggest that a chitin hydrolysate decreases Aw and suppresses Mf denaturation during dehydration process. The protection effect by chitin hydrolysates may be caused by stabilizing hydration water around Mf by added chitin hydrolysates.
