Non-destructive measurement of reducing sugar of apple using Vis/NIR-spectroscopy techniques

In this research, the potential of using the Visible/Near Infrared Spectroscopy (Vis/NIRS) was investigated for measuring the reducing sugar of Fuji apple (from Shanxi of China), and the relationship was established between nondestructive Vis/NIR spectral measurement and the reducing sugar of apple. Intact apple fruit were measured by reflectance Vis/NIR in 325-1075 nm range. The data set as the logarithms of the reflectance reciprocal (absorbance (logl/R)) was analyzed in order to build the best calibration model for this characteristic, using some spectral pretreatments and multivariate calibration techniques such as partial least square regression (PLS). The models for the reducing sugar (r= 0.915), standard error of prediction (SEP) 0.562 with a bias of 0.054; shown the excellent prediction performance. The Vis/NIR spectroscopy technique had significantly greater accuracy for determining the reducing sugar. It was concluded that by using the Vis/NIRS measurement technique, in the spectral range (325-1075 nm), it is possible to assess the reducing sugar content of apple.