Non-destructive Quality Assessment of Citrus Fruits Using Ft-near-infrared Spectroscopy

Nondestructive method of measuring the internal quality of citrus fruits was developed using fourier transform near-infrared (FT-NIR) spectroscopy. Also the models describing the relationship between quality attributes and the NIR spectra of the fruits were developed and evaluated. Diffuse reflectance measurements (12500–3600 cm -1 ) and biochemical measurements were performed individually on each fruit purchased from a commercial supermarkets. Relationships were evaluated by the application of chemometric techniques based on partial least squares (PLS) regression on fruit set divided randomly into two groups: 60 fruits for calibration and 30 for validation. Spectra preprocessing options include: the vector normalization (SNV), first derivative (FD), and first derivative plus vector normalization (FD+SNV). Good prediction performance was obtained with coefficient of determination (R 2 ) of 0.911 and 0.897 for soluble solids content (SSC) and acidity (pH) respectively and root mean square errors of prediction (RMSEP) of 0.026% Brix and 0.055 respectively. The overall results demonstrate that FT-NIR spectroscopy can be used to evaluate the quality of lemons.