COMPARISON STUDY OF THE EFFECTS OF DIFFERENT CRUDE GREEN TEA POLYPHENOLS ON THE QUALITY OF DRIED CATFISH DURING AMBIENT STORAGE

摘要

The comparative antioxidant effect of adding different crude green teanpolyphenols (GTP) and vitamin C (VC) on the susceptibility of dried catfishn(Clarias gariepinus) quality changes during ambient storage was investigated.nCatfish fillet was treated with different concentrations of GTP: 1% NaCl plusn0.01% GTP, 1% NaCl plus 0.03% GTP and 1% NaCl plus 0.01% of VC beforendrying process. Control muscle sample (CK) was treated only with 1% of NaClnsolution (without GTP extract) contained only 1% NaCl, but not GTP. Samplesnwere oven-dried for 5 days at 45C. The quality change was evaluated over ancourse of 4 weeks for pH, volatile basis nitrogen, peroxide value, thiobarbituricnacid reactive substances and free fatty acid. The results indicated that thenmost effective antioxidant was GTP and there was no significant differencesn(P < 0.01) between laboratory-extracted crude green tea polyphenol and commercialncrude green tea polyphenol. This study pointed out that GTP is a goodnnatural antioxidant in comparison with VC and CK, so, it could be easily usednin food industry to improve quality and shelf life of food products.