The objective of this study was to determine the effect of electron-beam irradiation on the oxidation of cholesterol in raw and cooked chicken meats with different packaging and storage times. Patties were prepared with skinless chicken breasts and legs. Half of the patties were used for raw meat study and the other half for cooked meat work. For cooked samples, patties were cooked in an electric oven to an internal temperature of 70 C. Raw and cooked meat patties were either aerobically or vacuum-packaged before irradiation. Irradiated patties were stored at 4 C up to 2 wk, and the amounts of cholesterol oxides in the patties were analyzed at 0, 7, and 14 d of storage. In raw chicken meat with vacuum packaging, 7beta-hydroxycholesterol and beta-epoxide were the only two cholesterol oxides present in significant amounts. In raw chicken meat with aerobic packaging, 7alpha-hydroxycholesterol and 7-keiocholesterol, which were not detected in vacuum-packaged raw chicken meat, were found. 7beta-Hydroxycholesterol in raw chicken meat was increased by irradiation and storage time, regardless of packaging. The kinds of cholesterol oxides found in cooked meat were basically the same as those found in raw chicken, but the levels in cooked meats at all storage time were higher than those of the raw meats. With vacuum packaging, irradiation had no consistent effect on the amount of beta-epoxide, 7alpha-hydroxycholesterol, or 7-ketocholesterol, but storage significantly influenced the amount of 7-ketocholesterol, 7beta-hydroxycholesterol, and total cholesterol oxides in cooked chicken meat. With aerobic packaging, irradiation significantly increased the formation of 7alpha-hydroxycholesterol, 7beta-hydroxycholesterol, and 7-ketocholesterol in cooked meat stored for 0 and 7 d. After 14 d of storage, however, irradiation had minor effects on the formation of cholesterol oxides in aerobically packaged cooked chicken.

The purpose of this study was to identify the ideal storage period for frozen minced beef products and to under-stand key factors affecting their quality. Frozen minced beef products with 10 and 15% of fat content were kept at ?5, ?15, and ?23°C, and over a 6-month period, they were assessed for moisture content (MC), peroxide values (POV), acid values (AV), 2-thiobarbituric acid (TBA) value, total volatile basic nitrogen content (TVB-N), and the sensory test in order to identify the effect on quality. This helped to determine their appropriate storage duration at a given temperature. Multiple regression analysis was used to assess the correlations between storage tempera-ture, fat meat percentage, characteristic factors, and overall acceptance (OA). Five months for ?23°C, 4 months for ?15°C, and 2 months for ?5°C met 3.7 points or more of OA, in accordance with global sensory analysis stan-dards, and were determined as acceptable frozen storage durations. The very high multiple regression analysis R2 (0.97–0.99) verified the correlation between the characteristic factors and OA. In addition, TVB-N, MC, and POV, respectively, were the main quality factors affecting OA at ?5, ?15, and ?23°C (R2 > 0.8). These findings may prove useful and practical for manufacturers to improve storage and distribution practices in maintaining the quality of frozen minced beef products.