Non-destructive measurement of surface color of pear by visible/near-infrared diffuse reflectance spectra

Visible/near-infrared (VIS/NIR) diffuse reflectance spectra were applied to non-destructive measurement of surface color of pear. In the wavelength range of 350 similar to 1800 nm, multi-linear regression (MLR), principal component regression (PCR) and partial least squares regression (PLSR), combining with the original absorbance spectra(log(l/R)) and its standardized spectra (l/SD), were used to quantitatively analyze surface color of pear. The prediction results for root mean standard error of prediction(RMSEP) and relative standard deviation RSD% of 24 unknown samples, are 1.4251 and 3.7404% for L*, 0.4569 and 3.3571% for a*, 0.9497 and 2.5877% for b*, based on calibration model with PLSR by using log(l/R). The experiment results show that non-destructive measurement of surface color of pear by using VIS/NIR spectroscopy technique is feasible.