Formation of Chitin Oligasaccharides during Long fermentation of Toha-jeot(Salt-Fermented Toha Shrimp)

Toha-jeot, salt-fermented Toha shirmp(caridina denticulata denticulata DeHAAN) is a traditional fermented food in Korea. Samples of Toha-jeot used in the present study were a low-salt group of 15% sodium chloride(L), a high-salt group of 23% sodium chloride(H), a 50% conventional soybean sauce group(S), a low-salt group contraining 2% wheat bran (W2%-L) , a high -salt group containing 2% wheat bran(W2%-H), a low-salt group containing 4% wheat bran(W4%-L)and a high-salt group containing 4% wheat bran (W4%-H). These seven groups were refrigerated at 4 $\pm$1$^{\circ}C$ and then taken out for analysis at theree month intervals. We investigated the functional components of Toha-jeot during fermentation . Long fermentation of Toha-jeot lowered the viscosity of chitin and tended to reduce the distribution of molecular weight. THe formation of chitin oligosaccharides on the other hand, increased significantly. After nine months of fermenttion, chitin oligosaccharides(M.W. 823~1789) constituting 24.75% of Toha chitin were produced in the sample of W2%-H. During the same period, chitin oligosaccharides(M.W.1436-1879) constituting 66.30% of Toha chitin were produced in the samples of S. However, chitin oligosaccharides were not produced in Jeotsaeu-jeot made of sea-water shrimp when fermented for six months.