Effect of Type I and Type II Antioxidants on Oxidative Stability, Microbial Growth, pH, and Color in Raw Poultry Meat

Abstract

Meat color is an intrinsic property that plays a major role in consumer’s perception. Lipid oxidation by-products as well as free iron can adversely affect meat color. This study was to compare the effect of Type I (radical quenching) antioxidants eugenol and rosmarinic acid (RA) to that of Type II (metal chelating) antioxidants milk mineral (MM), phytate, and sodium tri-polyphosphate (STPP) in raw ground chicken patties packed with a single layer of polyvinylchloride (PVC) overwrap. Packaged patties were stored at 4℃ and analyzed on 0, 1, 4, 7, and 10 days for pH, surface color, extent of lipid oxidation, oxymyoglobin content, and microbial load. Color stability was measured using Hunter MiniScan calorimeter (L*, a*, b* values). An effect was observed in L* values (P < 0.05) of meat color between treatments due to the type of antioxidant. Lightness values for STPP and phytate were low and differed (P < 0.05) from eugenol and rosmarinic acid. Milk mineral effectively preserved fresh color and slowed lipid oxidation in chicken patties by day 10. Aerobic plate counts increased over the entire testing period while values for lightness, redness, yellowness and chroma decreased indicating an increase in pH favored microbial spoilage of the meat or vice versa. By day 10, eugenol and MM were more effective and significantly different (P < 0.05) than STPP in controlling lipid oxidation measured as thiobarbituric acid reactive substances (0.198 mg/kg, 0.198 mg/kg, and 0.268 mg/kg, respectively). A positive correlation (r = 0.24, P < 0.005) between lipid oxidation and color saturation was observed indicating that poultry color darkened with increasing lipid oxidation levels.