The Freshness of Penaeus vannamei Boone during cold storage (5℃) was analyzed by near infrared spectroscopy analyzer (DA7200).The near infrared spectral curve variation of whole shrimp and minced shrimp during storage time was studied,the characteristic peaks and corresponding absorbance were selected.Combined with volatile nitrogen (TVB-N) content,the shrimp freshness was then determined.The impact of whole shrimp and minced shrimp on the results were discussed.The results showed that,with the increase of the storage time,the spectral curve showed certain regularity; the absorbance indicated the clear downward trend,more obvious changes of minced shrimp.The figures of the two dimensions were drawn with the ratio (A980 nm/A1450nm)of peak parameter in 980nm and 1450 nm as the X axis,the ratio(A1200nm/A1350 nm) of peak parameter in 1200 nm and 1350 nm as the Y axis,shrimp freshness could be correctly discriminated and the results were consistent with the discrimination of TVBN.Besides,the minced shrimp discriminating diagrams could reflect freshness changes of the shrimp,from freshness to rotten,which indicated that the near-infrared spectroscopy for minced shrimp freshness determination was better than that for whole shrimp.%利用DA7200近红外光谱仪,对冷藏温度(5℃)下的南美白对虾进行光谱采集,探讨近红外光谱曲线随虾贮藏时间增加的变化规律,确定特征峰及相应的吸光度,结合虾体中挥发性盐基氮(TVB-N)的含量,判别南美白对虾的新鲜度,并且讨论采集对象分别为完整虾和虾糜时对近红外光谱曲线规律和判别结果的影响.结果表明:随着贮藏时间的增加,南美白对虾近红外光谱曲线呈现出一定的规律,吸光度有明显的下降趋势,虾糜的变化更为明显；以光谱中980 nm与1 450 nm处吸光度的比值(A980nm/A1450nm)为横坐标,1 200 nm与1 350 nm处吸光度的比值(A1200nm/A1350nm)为纵坐标,绘制二维分析判别图,可以正确地判别出虾新鲜度,与TVB-N的判别结果基本一致,并且虾糜判别图可以正确地反映出虾由新鲜到腐败的渐变规律,表明以虾糜为样品采集近红外光谱较优于完整虾.
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