Antioxidative Effect of Dietary Tea Catechins on the Quality of Enulsified Pork Meatballs under Refrigeration

After meat products are heated and placed in storage, the lipid contained inside undergoes oxidation, which causes the meat to become malodorous and reduces its acceptability in the market. In this study, catechin was added to emulsified pork meatballs in the hope of reducing lipid oxidation. The influence that catechin additions at different concentrations (0, 400 and 800 ppm) have on the pH value, color, texture profiles, microbial testing, sensory analysis, thiobarbituric acid reactive substance value, and antioxidant capacity of the emulsified pork meatball is investigated in this study. The test results on lipid oxidation indicated that after 15 days of refrigerated storage at 4°C, oxidation in the control group was 2.46 mg malondialdehyde equal (MDA eq.)/kg meatball. The 400 ppm and 800 ppm of catechin-treated groups yielded 0.56 and 0.31 mg MDA eq./kg, respectively, which were significantly lower than the control group. The results were similar after 90 days of frozen storage at -20°C, where the 400 ppm and 800 ppm of catechin-treated groups yielded 0.60 and 0.25 mg MDA eq./kg, respectively, which were significantly lower than the oxidation level in the control group (1.39 mg MDA eq./kg). Regarding the antioxidant capacity tests, the meatballs that were treated with 400 ppm and 800 ppm of catechin displayed a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity of 1.31 and 1.97 mg of ascorbic acid/g, respectively, whereas the total antioxidant capacity was 2.63 and 4.53 mg of Trolox/g, respectively. The results of both groups were significantly higher than the DPPH radical scavenging capacity (0.07 mg as ascorbic acid/g) and the total antioxidant capacity (0.36 mg as Trolox/g) of the control group. After 90 days of frozen storage at -20°C, the antioxidant capacity of catechin-treated groups were still higher than the control group. The mentioned results indicate that adding catechin to emulsified pork meatballs inhibits lipid oxidation and can help boost the quality and functionality of these emulsified pork meatball products.