Effects of tea polyphenols on freshness-keeping of partial-frozen silver carp in cold storage

In order to study the effects of tea polyphenols on the quality changes of silver carp during partially frozen storage, silver carp samples, after being gutted and washed, were given a dip treatment in 0.1% tea polyphenols solution for 90 min at 4℃. And then, they were packed in plastic trays and airproofed with Polyvinyl Dichloride (PVDC), stored at -3℃ for partial freezing. The sensory scores, total bacterial count, pH values, Total Volatile Basic Nitrogen (TVB-N), 2-Thiobarbituric Acid (TBA) and freshness quality index (K value) were used to evaluate the fish quality. Results indicated that the total bacterial count, pH value, TVB-N, TBA, and K value of silver carp, which was processed with tea polyphenols, could be significantly restrained, and sensory scores decreased slowly as well. So it can be concluded that tea polyphenols have great effects on the inhibition of bacteria growth and anti-oxidation of fat, and thus significantly delay the spoilage of partial-frozen silver carp.