Abstract: The determination of pectin and total sugar in Fuling mustard tuber samples by Fourier transform near-infrared spectroscopy (FT-NIRS) was studied. The original spectra of 50 Fuling mustard tuber samples were obtained by using FT-NIRS machine. Through math analysis, spectrum noise was decreased. Finally, the regression method was used by partial least square. Regression models between product quality and pectin or total sugar were established. The determination coefficients (R2) of the established model were 98.31 and 98.35. Its root mean square errors of cross-validation (RMSECV) were 0.513 and 0.0531, respectively. While the R2 and root mean square errors of prediction set (RMSEP) were 96.69, 95.63, 0.572 and 0.0671 in test set validation, respectively. Internal and external cross-validation tests exhibited that near-infrared quantitative analysis had high accuracy and could meet the requirement for predicting pectin and total sugar contents in Fuling mustard tuber products.

Key words: near infrared spectroscopy, fuling mustard tuber, pectin, total sugar