Non-destructive determination of sugar content in root beet by near infrared spectroscopy (NIRS)

Near infrared reflectance spectroscopy (NIRS) is a nondestructive and rapid technique applied increasingly for food quality evaluation in recent years. In this research optical method based on near-infrared spectroscopy (900-1600 nm) has been used to determine sugar content in sugar beet. A total of 120 samples were used for the modeling، whereas 80 samples were used for the calibration set and 40 samples were used for prediction set. Four pre-processing methods، including average smoothing، multiplicative scatter correction (MSC)، first and second derivatives، were applied to improve the predictive ability of the models. Then models were developed by partial least squares (PLS). The correlation coefficient (r) and root mean square error of prediction (RMSEP) were 0. 84 and 1. 8 for SC، whereas 0. 95 and 1. 7 for SSC، respectively. The results show that NIR can be used as a rapid method to determine soluble solid content and sucrose in sugar beet.