61B-23 |
Use of antioxidants to reduce lipid oxidation and off-odor volatile compounds in irradiated pork homogenates and patties |
K. C. NAM and D. U. Ahn. Dept. of Animal Science, Iowa State University, 2359 Kildee Hall, Ames, IA 50010-3150, Ames, IA 50010-3150 Irradiated meats are more susceptible to oxidative changes during storage under aerobic conditions. Sulfur-volatiles were responsible for most of the characteristic irradiation odor. Antioxidants prevent oxidative rancidity and retard development of off-flavors in nonirradiated meat by scavenging free radicals. It is hypothesized that antioxidants,suh as free radical scavengers (gallate, sesamol, and a-tocopherol), metal chelators (Trolox), intrinsic antioxidant (carnosine), or their combinations can minimize lipid oxidation and off-odor volatiles in irradiated pork. However, few studies of antioxidant effects in irradiated meats are available. The objective was to determine the effect of selected antioxidants and their combinations on lipid oxidation and off-odor volatiles in irradiated pork homogenates and patties under aerobic or vacuum conditions. Pork homogenates and patties mixed with antioxidants (final concentration 200 mM) were irradiated at 0 or 4.5 kGy. TBARS values were determined at 0 and 5 d of storage. Volatile compounds were analyzed using a Dynamic Headspace Analyzer connected to a GC/MSD soon after irradiation. Irradiation increased lipid oxidation and produced sulfur-volatiles such as methanethiol, dimethyl sulfide, and dimethyl disulfide in pork homogenates and patties. Most antioxidants or their combinations, except for carnosine, decreased lipid oxidation and sulfur-volatiles by irradiation. The combination of sesamol plus tocopherol reduced TBARS of irradiated pork homogenates by 47% compared with the control at day 5. The combination of sesamol plus gallate was the most effective in reducing sulfur-volatiles in vacuum-packaged irradiated pork patties, and reduced the amounts of carbon disulfide, dimethyl sulfide, dimethyl disulfide, and total volatiles by 53%, 58%, 81%, and 43% of the control, respectively. These results show that addition of antioxidant combination (200 mM) had distinct benefits in improving the quality of irradiated pork patties by controlling lipid oxidation and reducing off-odor volatiles by irradiation.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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