冷藏大菱鲆质量指数法的建立及其货架期

通过建立和应用质量指数法（quality index method，QIM），结合挥发性盐基氮（total volatile base nitrogen，TVB-N）值、K值、质构、菌落总数值等指标综合评价冷藏大菱鲆的新鲜度，并确定其货架期。结果显示：综合感官评分（quality index，QI）值与贮藏时间（t）之间呈较高的线性关系，回归方程为QI=1.175t－0.395（R2=0.988 4），该方程对冷藏大菱鲆剩余货架期的预测误差约为1 d（0.816）。贮藏15 d时，QI值达18.28，各感官指标均达到感官拒绝期；此时，TVB-N值、K值和菌落总数值分别达到31.34 mg N/100 g、72.24%和6.45（lg（CFU/g）），均已经达到货架期终点的参考限定标准。QIM评价结果与鲜度指标具有良好的一致性，适用于大菱鲆货架期的研究和鲜度的快速评价，4 ℃冷藏大菱鲆的货架期为15 d。

Establishment of Quality Index Method (QIM) to Evaluate the Freshness and Shelf Life of Refrigerated Turbot (Scophthalmus maximus)

In this article, the freshness and shelf life of turbot (Scophthalmus maximus) stored at 4 ℃ were determined by
the quality index method (QIM) on the basis of total volatile basic nitrogen (TVB-N), K value, 2-thiobarbituric acid (TBA),
texture profile analysis (TPA), and total viable count (TVC). The results showed that QI value displayed a highly linear
relationship with storage time and could be represented by the equation QI = 1.175t ? 0.395 (R2 = 0.988 4). Conclusively, the
QI could predict the remaining shelf life with an accuracy of ±1 day (0.816) at the 95% confidence interval. On the 15th day,
the sensory quality was considered unacceptable. TVB-N value, K value and the TVC reached 31.34 mg N/100 g, 72.24%
and 6.45 (lg (CFU/g)), respectively, which reached the reference limit standard for the endpoint of fish shelf life. The QIM
result had a good coincidence with freshness indices, indicating that QIM is a promising and rapid method for freshness
evaluation and shelf life determination. Meanwhile, a shelf life of 15 days was obtained in this study for turbot stored at 4 ℃.