反复冻结-解冻对黄鳍金枪鱼肉品质的影响

Effect of Freeze-thaw Cycles on Quality of Yellowfin Tuna Meat

为了研究反复冻结-解冻对金枪鱼品质的影响,对金枪鱼(分别贮藏于-60℃和-18℃)做4次冻结-解冻处理后测定理化指标[解冻汁液流失,红度值a*,质构特性(包括硬度,咀嚼性,黏着性和弹性)],挥发性气味成分(电子鼻),菌落总数。结果表明:随着冻结-解冻次数增加,解冻汁液流失增加,-60℃下汁液流失更多;-18℃贮藏a*值显著降低,-60℃下降趋势不明显;硬度,咀嚼性和弹性都显著降低,然而黏着性变化不大;-60℃相对-18℃贮藏下反复冻结-解冻后挥发性气味差异较显著;菌落总数变化不明显,且在安全范围内。因此,金枪鱼贮藏加工、运输和贮藏过程中保持温度的稳定要避免温度反复波动,且-60℃是作为维持品质的较佳贮藏温度。

In order to explore the effect of freeze-thaw cycles on tuna meat,physicochemical properties,such as thawing loss,a＊ value,textural properties-Hardness,Cohesiveness,Springiness and Chewines,volatile odor（Electronic nose）,total viable count（TVC） were carried out.Yellowfin tuna（stored at-18℃,-60℃,respectively） was subjected to a total of 4 freeze-thaw cycles.The results showed that with the number of freeze-thaw cycles increased,thawing loss increased and the highest was at-60℃.a＊ value decreased significantly after 4 freeze-thaw cycles at-18℃,and showed no significant change at-60℃.Hardness,Springiness and Chewiness decreased significantly,while Cohesiveness remained unchanged.Electronic nose analysis showed that there was a significant difference in volatile odor of tuna stored at-60℃when compared to-18℃.TVC showed no significantly change,and it was below Industry Standard Limits.Therefore,the temperature should be kept stable during processing,transportation and storage of tuna.The best temperature is-60℃.