Non-Destructive Testing of Soluble Solids and Total Acidity in Blueberry by Near-Infrared Diffuse Reflectance Spectroscope

Abstract:

The purpose of this research is to establish mathematical model between near infrared diffuse reflection（NIR） spectroscopy and soluble solids and total acidity in blueberry，and to evaluate its application value. The influence of different spectral preprocessing methods on the model was compared in the spectral region between 400~2500 nm. The results showed that the calibration model with the partial least squares（PLS），the first derivative D1lg（1/R） and weighted multiple scatter correction（WMSC） could provide better prediction performance for SSC，with the correlation coefficient of prediction（Rp2）of 0.8518 and the root mean square error of prediction（SEP） of 0.351 and relative percent deviation of prediction（RPD） of 2.05. The best model of total acidity is the modified partial least squares（MPLS） model，the second derivative D2lg（1/R） and WMSC，with the correlation coefficient of prediction（Rp2）of 0.8776 and the root mean square error of prediction（SEP） of 0.042and relative percent deviation of prediction（RPD） of 2.10. So the near-infrared diffuse reflectance spectroscope can be used for fast nondestructive measurement of soluble solids and total acidity in blueberry.