Use of visible and near-infrared spectroscopy for predicting antioxidant compounds in summer squash (Cucurbita pepo ssp pepo)

Abstract

The food industry and plant breeding programmes require fast, clean and low-cost screening techniques for nutritional compounds determination in food matrices. This is the first report on the study of the potential of near-infrared spectroscopy (NIRS) for the prediction of antioxidant compounds in summer squash tissues collected since 2009-2012. Modified partial least-squares (MPLS) regression was used to correlate spectral information and the different antioxidant compounds in the samples. The coefficients of determination in the external validation (r(2)ev) obtained were for ascorbic acid (0.77 and 0.86), chlorophyll a (0.79 and 0.66), chlorophyll b (0.86 and 0.79) and total phenolic compounds (0.65 and 0.68) in exocarp and mesocarp tissues, respectively, supporting that NIRS is able to predict in a rapid way these components for screening purposes. Major wavelengths influencing the calibration equations showed that chromophores as well as fibre components of the fruits highly participated in developing the NIR equations.

Keywords: Ascorbic acid; Chlorophylls; Near-infrared spectroscopy (NIRS); Summer squash; Total phenolic content.