电子束辐照对充氮包装冷鲜牛肉品质的影响

为探究电子束辐照对充氮包装冷鲜牛肉品质的影响，取6 头黄牛背最长肌，在高能电子加速器下辐照，4 ℃贮藏，评估不同辐照剂量和贮藏时间条件下微生物学、生物化学和感官特性的变化。辐照处理组和对照组相比，菌落总数显著下降，在贮藏第0天，处理组的菌落总数分别下降了0.766、1.801、2.673（lg（CFU/g）），差异显著（P＜0.05）；电子束辐照对牛肉样的贮藏损失、色泽、pH值、脂肪氧化并未产生显著性的影响，对TVB-N值的影响较小；但感官评价分析发现，随着辐照剂量的增加，色泽、气味、接受性得分下降。综合分析各品质指标，2.5 kGy左右的低剂量电子束辐照可以在杀灭微生物的同时，较好地确保牛肉品质，提高冷鲜牛肉的货架期。

Effect of Electron Beam Irradiation on the Quality of Chilled Beef Packaged in Nitrogen Atmosphere

Longissimus dorsi muscles (n = 6) from Chinese yellow cattle were irradiated at doses of 1.241, 2.300 and 3.429 kGy
using a high-energy electronic irradiation accelerator and then stored at 4 ℃ in a nitrogen atmosphere. The changes in
microbial, biochemical and sensory characteristic of chilled beef during each storage period were monitored. Compared
with the control group, total bacterial counts of three treated groups declined significantly (P < 0.05). At 0 day of storage,
total bacterial counts of the low-, middle- and high-dose groups decreased by 0.766, 1.801 and 2.673 (lg(CFU/g)) compared
with the control group. The effects of electron beam irradiation on purge loss, surface color, pH value and thiobarbituric
acid reactive substances (TBARS) value of chilled beef were not significant. In addition, there was a small difference in
total volatile basic nitrogen (TVB-N) values between the control and tested groups. However, sensory scores for color, odor
and acceptability declined with irradiation dose. Comprehensive analysis of various quality indicators revealed that electron
beam irradiation at low dose of 2.5 kGy improved the microbiological quality and extended the shelf-life of chilled beef
packaged in modified atmosphere.