研究了电子束辐照剂量率对真空包装冷鲜牛肉品质的影响，为电子束辐照在冷鲜肉保鲜中的应用提供理论依据。将真空包装的冷鲜牛肉在2 kGy的辐照剂量下分别经不同剂量率(0、700、1500、2500、3500 Gy/s)处理，然后再置于2 ℃冰箱内贮存15 d。贮藏期内分别对微生物指标（菌落总数（TBC））和理化指标 (挥发性盐基氮含量（TBA-N）、硫代巴比妥酸值（TBARS）、过氧化值（POV）、巯基（SH）、二硫键（SS）、色泽（L*和a*））进行测定，对比不同剂量率处理对辐照效果的影响。结果表明，在2 kGy的辐照剂量下，在一定剂量率范围内随着剂量率的不断增大，冷鲜牛肉的TBC、TVB-N、TBARS、POV、SS和L*值均显著降低, 而SH和a*值增加（p<0.05）。综合分析各指标说明电子束辐照剂量率对冷鲜牛肉品质有显著的影响；同时可得出，在2 kGy的辐照剂量下，剂量率为2500Gy/s处理组，贮藏15 d后，细菌总数5.161 log(CFU/g)，TVB-N值为16.6 mg/100g，POV值为1.126 meq/kg，TBARS值为0.218 mg/100g，SH和SS分别为0.395和0.379 mmol/g pro，L*和a*值分别为40.34和19.57，综合辐照效果最佳。

The effect of the dose rate of electron beam irradiation on the quality of vacuum-packaged chilled fresh beef was studied, providing a theoretical basis for the application of electron beam irradiation to the preservation of chilled fresh meat. Vacuum-packaged chilled fresh beef was treated with a 2-kGy irradiation dose at a dose rate of 0, 700, 1500, 2500, or 3500 Gy/s and stored in a refrigerator at 2°C for 15 days. During the storage period, physicochemical indicators (i.e., total volatile basic nitrogen (TVB- N) content, peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), sulfhydryl (SH) groups, disulfide bonds (SS), lightness L*, and redness a*) and a microbiological indicator (total bacterial count (TBC)) of quality were estimated, and the impacts of various dose rates on the effect of irradiation were compared. For a dose of 2 kGy, increasing the dose rate resulted in significantly reduced values of TBC, TVB-N, TBARS, POV, SS, and L*, but increased values of SH and a* (p < 0.05). After 15 days of storage, the treatment group (irradiated with a dose of 2 kGy and a dose rate of 2500 Gy/s) exhibited TBC, TVB-N, POV, TBARS, SH, SS, L*, and a* values of 5.161 colony-forming units (CFU)/g, 16.6 mg/100 g, 1.126 meq/kg, 0.218 mg/100 g, 0.395 mmol/g pro, 0.379 mmol/g pro, 40.34, and 19.57, respectively, representing the optimal irradiation effects.

公益性行业（农业）科研专项经费（201103007）