Anti-oxidant activity of added tea catechins on lipid oxidation of raw minced red meat, poultry and fish muscle

The comparative anti-oxidative effects of added tea catechins (TC) and alpha -tocopherol to raw minced red meat (beef and pork), poultry (chicken, duck and ostrich) and fish (whiting and mackerel) muscle on susceptibility to lipid oxidation were investigated during 10 days of refrigerated (4 degreesC) display. Fresh meats, poultry and fish, purchased from a local market, were trimmed to remove bones, skin and surface fat and minced through a 4 min plate. The minced muscle of each species was treated with either the addition of 300 mg TC kg(-1) minced muscle (TC300) or 300 mg alpha -tocopherol kg(-1) minced muscle (VE300). Minced muscle without any additives served as control (C). Oxidative stability (TBARS) was measured at 3-day intervals. Total lipids, fatty acid composition, total iron and haem iron from minced muscle for each species were also analysed. The susceptibility of untreated minced muscle to lipid oxidation was in the decreasing order: mackerel > beef > duck- > ostrich > pork greater than or equal to chicken > whiting. This may be because of the different content of total fat, iron and fatty acid composition between species. The TC300 significantly (P < 0.05) reduced lipid oxidation compared with controls for all seven species as shown by lower TBARS values. The anti-oxidant potential of TC was two to fourfold greater than that of -tocopherol at the same concentration and this potential was species dependent. The VE300 showed limited capacity in inhibiting lipid oxidation for pork, chicken, duck and whiting. The results obtained show that TCs are powerful natural antioxidants when used in minced muscle food.