Fourier Transform Near-Infrared Determination of Total Soluble Solids and Available Acid in Intact Peaches

This research evaluated the potential of a Fourier transform near-infrared (FT-NIR) spectrometer with areflectance fiber optic probe for determination of total soluble solids (TSS) content and available acid (VA) in intact peaches.It also investigated the relative performance of the calibration models with different data preprocessing methods (original,first derivative, and second derivative). Reflectance spectra were collected from two opposite sides of individual peaches,followed by standard destructive methods for analyzing TSS and VA of peaches. Calibration models were developed with theuse of a partial least squares (PLS) technique. The best calibration model for TSS gave good predictions of TSS, with acoefficient of determination (r2) of 0.916 and a standard error of prediction (SEP) of 0.534. The best calibration model forVA prediction yielded r2 = 0.904 and SEP = 0.129. Thus, FT-NIR reflectance can be used to predict the TSS and VA of intactpeaches. Based on the results, it was concluded that FT-NIR spectrometry could be an easy to facilitate, reliable, accurate,and fast method for non-invasive measurement of peach TSS and VA.