Temperature Abuse Affects the Quality of Irradiated Pork Loins

The influence of temperature abuse on the quality of irradiated pork loins was investigated. Pork loins were obtained directly from a local packing plant, sliced and vacuum-packaged. Pork loins were randomly separated into 3 groups, sliced, and assigned to receive 0, 1.5, or 2.5 kGy electron-beam irradiation. Then, each chop was further cut into three equal pieces and assigned to three temperature treatments: Trt I was placed in a refrigerator directly after irradiation; Trt II was left at room temperature for 3 h before refrigeration; and Trt III was exposed at room temperature for 1 h three consecutive days with intermittent storage at 4 °C between exposures. Before irradiation, each loin pieces were vacuum-packaged. Color, 2-thiobarbituric acid reactive substances (TBARS), and volatiles were measured after 0, 14, 28 and 42 days of storage, and water-holding capacity and sensory characteristics of the loins were measured after 0, 14 and 28 days of storage. Temperature abuse had no significant effect on color, oxidation, and volatiles of irradiated pork loins. However, temperature abuse improved water-holding capacity of meat, which could be caused by the accelerated hydrolysis of muscle proteins at higher temperature. Irradiation increased redness, sulfur contents in volatiles and off-odor of pork loin. Off-odor and redness induced by irradiation sustained during storage. Among sulfur compounds, the content of dimethyl disulfide decreased gradually while the level of thiourea remained relatively constant. Irradiation also increased water loss, which might be related to the structural damage in membrane during irradiation. This study shows that temperature abuse has little effect on the quality of irradiated pork.