Effects of added tea catechins on colour stability and lipid oxidation in minced beef patties held under aerobic and modified atmospheric packaging conditions

The colour stabilizing and antioxidant effects of added tea catechins (TC) on susceptibility of fresh minced beef patties to lipid oxidation and colour stability during refrigerated (4 °C) display under aerobic and modified atmosphere packaging (MAP, 80:20, O2:CO2) conditions were investigated. Fresh minced beef muscle (M. Longissimus dorsi) was supplemented with TC at levels of 0 (T0), 200 (T200), 400 (T400), 600 (T600), 800 (T800) and 1000 (T1000) mg/kg minced muscle. Treated samples were held in a refrigerated (4 °C) display cabinet under aerobic or MAP conditions for 7 days. Lipid oxidation (TBARS) and proportion of metmyoglobin (MetMb) and oxymyoglobin (MbO2) were measured each day. TC-treated groups had consistently lower (p < 0.01) lipid oxidation, compared to controls, for 2 days under both aerobic and MAP packaging conditions, thus showing the positive antioxidant activities in minced beef. TC at levels of 200 (T200) mg/kg delayed the formation of MetMb under aerobic and MAP conditions. However, TC at levels greater than 400 mg/kg meat did not show colour stabilizing effects in minced beef. The delay effect on discolouration was much more significant in MAP. The results obtained showed that TC not only improved lipid stability but also improved colour stability in minced beef.