Color and oxidative rancidity were determined for chilled (3 ‫ע‬ 2ЊC) and frozen (Ϫ17 ‫ע‬ 3ЊC) boneless pork chops packaged in vacuum or air and irradiated to an absorbed dose of 0, 1.5 or 2.5 kGy (chilled) or 0, 2.5 or 3.85 kGy (frozen) of electron beam or cobalt 60 irradiation. Irradiation of vacuum-packaged chops produced redder, more stable (color and rancidity) product. More pronounced oxidative rancidity and less stable display color were noted for samples irradiated in aerobic packaging. Irradiation source had varying but limited effects on color and rancidity. Optimum packaging conditions can control color and rancidity changes in boneless chops, thereby enabling irradiation to be a useful intervention technology.

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Beef carcass sides (n = 48) were selected randomly on three different days in a commercial processing facility and microbiologically analyzed before being moved to the cooler. Four types of samples were obtained per side from the inside round area: no trim and no wash (NTNW); trim, but no wash (TNW); trim and wash (TW), and no trim but wash (NTW). A flame-sterilized knife, forceps, and scalpel were used for each trimming treatment and sampling. Significant differences (P < 0.05) were observed in mean aerobic plate counts (APCs) between treatments. The greatest reduction in APC (log10 colony forming units [CFU] per cm2) was observed in TNW samples followed by TW and NTW, with the corresponding mean APC reductions relative to NTNW being 3.0, 0.9, and 0.3, respectively, indicating that trimming can be an effective control point in reducing bacterial contamination in the slaughter process. Although TNW samples, had the lowest counts, samples from the same location after wash (TW) had counts 2 log cycles higher than TNW samples. These results indicate that washing spreads contamination to adjacent carcass sites. However, washing of carcasses was effective in lowering microbial populations relative to the NTNW treatment. Escherichia coli and coliform counts in all samples were low (0.03 to 0.4 log10 CFU/cm2); however, the mean E. coli or coliform count in NTNW samples was higher (P < 0.05) than those in the rest of the treatments.

The effects of two doses (2.0 and 3.5 kGy) of nonradioactive irradiation on flavor, texture and aroma were compared to nonirradiated controls for (1)frozen raw and precooked, ground beef patties with 10 and 22% fat packaged in vacuum or aerobically: (2) frozen, vacuum-packaged, boneless beef steaks; and(3) chilled, vacuum-packaged, boneless, beef steaks that were repackaged in an oxygen-permeable film (PVC) after 14 days of storage. Samples were evaluated by a highly trained descriptive panel for fifteen sensory attributes for ground beef patties and eighteen sensory attributes for whole muscle beef. Irradiation had minimal effects on flavor, texture, and aroma offrozen, raw andprecooked, ground beef patties: frozen boneless beef steaks; and vacuum-packaged, chilled, boneless, beef steaks. Reintroduction of oxygen to irradiated beef by repackaging into PVCfilm after vacuum aging increased liver-like (at 3.5 kGy) and toughness (at 2.0 kGy) attributes and slightly decreased beef identity and browned/roasted flavor notes (at 2.0 kGy.) ' Contribution No. 97-31-J from the Kansas Agricultural Experiment Station. Send correspondence to

Flavor, texture, and aroma were determined for chilled (3 ‫ע‬ 2ЊC) and frozen (Ϫ17 ‫ע‬ 3ЊC) boneless pork chops packaged in vacuum or air and exposed to an absorbed dose of 0, 1.5, or 2.5 kGy (chilled) or 0, 2.5, or 3.85 kGy (frozen) of electron beam and cobalt 60 irradiation. Irradiation (≤3.85 kGy) had minimal effects on aroma, flavor, and textural attributes in chilled and frozen boneless pork chops. Irradiation source had limited effects and packaging type had the greatest influence. Consumers reported no difference (PϾ0.05) between irradiated (2.5 kGy cobalt 60 irradiated, chilled, vacuum-packaged, boneless, pork chops) and control samples for overall acceptance, meatiness, freshness, tenderness and juiciness.