Antioxidative effect of added tea catechins on susceptibility of cooked red meat, poultry and fish patties to lipid oxidation

The comparative antioxidant activity of added tea catechins on susceptibility of cooked and overwrapped red meat (beef and pork), poultry (chicken, duck and ostrich) and fish (whiting and mackerel) to lipid oxidation was investigated. Fresh meats, poultry and fish, purchased from a local market, were trimmed to remove bones, skin and visible fat and minced through a 4-mm plate. The minced muscle from each species was treated with either 1% NaCl (S), 300 mg tea catechins kg(-1) minced muscle (TC) or 1% NaCl plus 300 mg tea catechins kg(-1) minced muscle (TCS). Control minced muscle samples (C) contained neither NaCl nor tea catechins. Patties (50 g), prepared from treated and untreated minced muscle, were cooked until the core temperature reached 75 degreesC, cooled down to room temperature and held in a refrigerated (4 degreesC) and illuminated (616 lux) display cabinet for 10 days. Oxidative stability (TBARS) was measured at 3-day intervals. The susceptibility of cooked patties to lipid oxidation was closely related to lipid content, concentration of unsaturated fatty acids and presence of iron in different species. Addition of NaCl to raw minced muscle significantly (P < 0.05) promoted lipid oxidation for cooked patties regardless of species sources. Tea catechins added at a level of 300 mg kg(-1) minced muscle significantly (P < 0.01) inhibited the pro-oxidation caused by NaCl and controlled lipid oxidation for all cooked muscle patties examined. Tea catechins at concentrations greater than 300 mg kg(-1) were necessary to reduce oxidation for mackerel patties containing high levels of lipids and unsaturated fatty acids. The high affinity of tea catechins for the lipid bilayers of muscle and the radical scavenging abilities of tea catechins may be possible mechanisms to explain the oxidative stability in cooked muscle foods. (C) 2001 Elsevier Science Ltd. All rights reserved.