Combined Effect of Aging and Irradiation on Physicochemical Quality of Pork Shoulder.

The effect of combined electron-beam irradiation and aging temperature of pork on microbiological and physicochemical properties was investigated. The samples from pork shoulder were irradiated with 0 or 2 kGy, vacuum-packaged, and assigned randomly to an aging temperature (2°C, 10°C, or 25°C) during 8 d. On 4 d of aging at 25°C, total aerobic bacteria of non-irradiated ones reached 7 Log CFU/g which is no salable levels. Shear force values of irradiated meat after aging for 2 and 4 d at 25°C was lower than those aged at 2°C. Irradiated samples at 2°C had lower cooking loss after 2 and 8 d of aging, compared with other aging temperatures. Irradiation did not accelerate 2-thiobarbituric acid reactive substance (TBARS) value when aged up to 4 d. Irradiated samples aged at 10°C and 25°C for 8 d scored significantly higher TBARS values. With an increased aging period, a* and b* in irradiated samples at 2°C slightly increased, but irradiation caused negligible changes in meat color. The highest contents of a desirable nucleotide flavor compounds (inosine-5-phosphate) were observed in pork at 2°C when aged for 4 and 8 d, while the lowest contents were observed at 25°C. Aging in irradiated pork for 8 d at 2°C resulted in optimal condition with improved meat quality and minimal microbiologically negative defect.