effect of green tea extract on chemical and microbial quality of surimi prepared from silver carp (hypophthalmichthys molitrix)

in this study, the effect of green tea extract was studied on quality of surimi produced from fish silver carp during refrigerated storage. surimi was prepared and immersed with various concentrations of tea extracts (0, 2 and 4%). samples were refrigerated for 15 days and were performed chemical tests include ph, total volatile bases nitrogen (tvb-n), thiobarbitoric acid (tba) test and total bacterial count (tvc) every 3 days. the results showed that the ph in the control treatment more than samples treated with the extract, significantly in all test days except day 3. control treatments tvb-n levels exceed the acceptable limits of 9 stored, the samples treated with tea extract was not exceeded until the end. during the entire period, except for the first and third days, thiobarbitoric acid in samples treated with the extract significantly lower than the control. most of the control treatment was tba 8.57 and the samples treated with the extract were 2.06 mg per kg malone aldehyde of fish. tvc levels increased during storage in all treatments, but were not exceeded. the maximum value of this index in the control treatment 5.08 log cfu/g and the samples treated with tea extract 4.84 log cfu/g was observed. based on the findings, green tea extract can be used as a natural preservative to maintain the quality of silver carp surimi during short-term storage in the refrigerator.