Abstract
Suppressive effects of green tea polyphenols (GTP), which contain (+) -catechin, (-) -epicatechin, (-) -gallocatechin, (-) -epigallocatechin, (-) -gallocatechin gallate, (-) -epicatechin gallate and (-) -epigallocatechin gallate, on microbial growth and volatile basic nitrogen (VBN) content in the cultured fish meat were investigated. The moist pellets supplemented with different concentrations of GTP (0, 0.02 and 0.2% (w/w)) were fed to young yellowtails (Seriola quinqueradiata) of 0-year fish. These fish were killed on the 4th week after feeding. The numbers of microbial and psychrophilic bacteria in their meat were counted during ice storage of the round fish. The contents of VBN, which are known as their bacteria metabolites, content in the meat, were also determined. The increase of microbial counts and psychrophilic bacteria counts in their meat were suppressed by GTP feeding. The increase in VBN of their meat were also suppressed. The feeding of 0.2% GTP were more effective than that of 0.02% GTP. Thus, it was suggested that GTP were effective to control microbial growth and to maintain freshness of the meat during delivery of cultured fish.
