典型冷链温度下南美白对虾品质劣变规律及相关性分析

Quality deterioration of Litopenaeus vannamei stored at typical cold chain temperatures and the correlation analysis

目的探究典型冷链贮藏温度下南美白对虾品质劣变规律及相关性。方法采用感官评价、仪器分析和理化分析的方法对南美白对虾在-23、0、5℃贮藏温度下的感官、色差、挥发性盐基总氮(total volatile basic nitrogen,TVB-N)含量进行分析与检测,并采用Pearson线性回归分析三者之间的相关性。结果 3种典型冷链贮藏温度下南美白对虾的感官品质变化差异显著,-23℃条件下感官评分一直处于8.0左右;0℃下感官评分在前3 d基本维持在7.0以上,之后快速下降,至第5 d时下降至4.0以下,失去商品价值;5℃条件仅在第1 d维持在7.0以上,第2 d时开始迅速下降。亮度值自贮藏第2 d起不同冷链温度下都有显著性差异(P<0.05)。TVB-N值在-23℃条件下第9 d仍在20 mg/100 g以下,而0℃第3 d即发生显著升高(P<0.05)。Pearson相关系数表明,TVB-N值与感官评分及亮度变化存在显著相关性。结论与理化检验法相比,感官评价结合色差测定的方法可准确、快速反映对虾鲜度,预测产品货架期。

Objective To monitor the quality degradation of Litopenaeus vannamei stored at the typical temperatures of cold chain and elucidate their correlation. Methods The sensory, chromatic aberration and TVB-N content of L. vannamei stored at the typical temperatures of cold chain（-23, 0 and 5 ℃） were analyzed by sensory evaluation, instrumental analysis, and physical and chemical analysis, respectively. And Pearson regression analysis was used to analyze the correlation among the three. Results There were significant differences in sensory quality deterioration among the 3 kinds of typical cold chain temperatures for L. vannamei storage. At storage temperature of-23 ℃, the sensory score constantly remained at about 8.0, and the counterpart rapidly decreased from 7.0 after the first three days＇ storage at 0 ℃, less than 4.0 on the fifth day and lost the market value. At 5 ℃, however, it remained above 7.0 only on the first storage day and drastically dropped since then. As for brightness, there were significant differences among the 3 typical storing temperatures of cold chain since the second storing day. The total TVB-N content underwent a significant rise on the third day at-23 ℃（P0.05）, and it was still in a lower level less than 20 mg/100 g on day 9. At 0 ℃, it exhibited a significant rise on the third day（P0.05）. The variations of TVB-N content, sensory sore and brightness had significant correlation（P0.05）. Conclusion Compared with the biochemical determination, sensory evaluation associated with chromatic assay can accurately reflect the quality deterioration of L. vannamei and efficiently predict the shelf life.