Irradiation-induced Cured Ham Color Fading and Regeneration

ABSTRACT: Color stability of cured ham as a result of irradiation, packaging atmosphere, and storage time was evaluated. Sliced cured ham was packaged in aerobic or vacuum atmospheres, irradiated at 0, 1.2, 2.3, and 4.5 kGy and stored for 0 and 7 d. The ham treatments were evaluated for cured color, oxidation-reduction potential, and residual nitrite content. Irradiation decreased cured color as irradiation dose increased from 0 to 4.5 kGy as evidenced by lower a*/b* ratios and cured pigment analysis regardless of packaging atmosphere. Residual nitrite levels were also lower for the 4.5-kGy treatment compared with nonirradiated control following irradiation. Cured color was regenerated over time and resulted in higher a*/b* ratios on day 7 compared with day 0 for the 4.5-kGy treatment. Oxidation-reduction potential was decreased on day 0 and day 7 for the vacuum-packaged treatment that was irradiated at 4.5 kGy compared with the 0-kGy treatment.     

The Effects of Irradiation at 1.6 kGy on Quality Characteristics of Commercially Produced Ham and Pork Frankfurters over Extended Storage

ABSTRACT: Commercially produced sliced ham and all-pork frankfurters were obtained from a national meat processor and irradiated at 1.6 kGy. The samples were evaluated for color, lipid oxidation, odor, flavor, and the production of volatiles over an 8-wk storage period. Irradiation processing did not affect color values for the ham or frankfurters. Lipid oxidation as measured by 2-thiobarbituric acid-reactive substances (TBARS) did not increase for either the ham or frankfurters. Irradiation processing increased off-odor scores for the ham but not for frankfurters. On the other hand, off-flavor scores were not significantly different for ham but were higher in frankfurters after irradiation processing. Dimethyl disulfide content increased as a result of irradiation in both the ham and frankfurters but decreased during the 8-week storage period. Irradiation processing resulted in the formation of new volatile compounds in the ham samples including heptane, trans -1-butyl-2-methylcyclopropanone, 2-octene, and toluene, which were not present in nonirradiated ham. In the case of frankfurters, irradiation treatment resulted in the formation of 2-butanone, which was not present in the nonirradiated frankfurters. Most volatile compounds that were affected by irradiation processing of either the ham or frankfurters were increased when compared with nonirradiated controls. Although color and lipid oxidation (TBARS) did not seem to be affected by irradiation processing at 1.6 kGy, changes in odor, flavor, and the production of volatiles are of concern if irradiation is to be used to control microbial growth in ready-to-eat pork products.