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

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 were0.99989 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.