Correlations of quality indicators of winter jujube slices during drying process

Correlations between color, vitamin C content (VC, dry base, db), reducing sugar (dry base, db) and total acid (dry base, db) during the drying process of winter jujube were studied at different temperatures (55, 60, 65 and 70 degrees C). Then models of quality prediction for winter jujube slices were established by Partial Least Squares Regression (PLSR), Stepwise Multiple Linear Regression (SMLR) and Principal Component Regression (PCR). Finally, the optimal model was obtained by analysis and comparison. Results showed that: the correlation coefficient (Rp) of the prediction model for the vitamin C content (db) was 0.769; the predicted Root Mean Square Error (RMSEP) was 0.59; the predicted relative deviation (RPD) value was 2.1. The Rp of the prediction model for the reducing sugar content (db) was 0.816, the RMSEP was 0.56, and the RPD value was 2.2. PLSR model was the most suitable for the prediction of the vitamin C content (db), and the PCR model was better for predicting reducing sugar content.