基于近红外光谱对老陈醋的pH值和可溶性固形物定量与定性的检测研究

Qualitative and Quantitative Detection Research of Mature Vinegar's pH and SSC Based on Near Infrared Spectroscopy

采用近红外光谱结合判别分析(DA)和主成分分析(PCA)在不同光谱预处理方法下分别对山西老陈醋醋龄进行定性判别分析,和对陈醋中可溶性固形物(SSC)及pH值进行定量分析。结果表明:原始光谱、5点平滑以及SNV校正建立的DA模型性能良好,校正集判别正确率为100%,预测集判别正确率为88.89%;原始光谱建立的可溶性固形物的定量模型最优,校正集和预测集的相关系数r分别为0.99988和0.99960,RMSEC、RMSEP和RMSECV分别为0.0421,0.0911和0.0777;5点平滑建立的pH值的定量模型最优,校正集和预测集的相关系数r分别为0.99733和0.97411,RMSEC、RMSEP和RMSECV分别为0.0151,0.0386和0.0468,表明采用近红外光谱对老陈醋的pH值和可溶性固形物进行定量分析以及对老陈醋的醋龄进行定性判别是可行的。

Our present study is about qualitative and quantitative detection research of Shanxi mature vinegar based on near infrared spectroscopy. Firstly, near infrared spectroscopy combined with discriminant analysis （DA） was used for vinegar age through different pre-processing methods, at the same time it established the Principal components analysis （PCA） model of soluble solids content （SSC） and the effective acidity （pH）. The result indicated that 100% recognition ratio for calibration and 88.89% recognition ratio for validation were achieved by DA for vinegar age. Quantitative model of the SSC which was established by original spectroscopy was the best, the correlation coefficients of calibration and prediction respectively were 0.99989 and 0.99884, RMSEC, RMSEP and RMSECV respectively were 0.0400, 0.0581 and 0.132. Quantitative model of the effective acidity （pH） by 5 points smooth have a better result. The correlation coefficients of calibration and prediction were 0.99733 and 0.97411 respectively. RMSEC, RMSEP and RMSECV were 0.0151, 0.0386 and 0.0468.