A new application of NIR spectroscopy to describe and predict purees quality from the non-destructive apple measurements

Abstract

The potential of NIRS was investigated on both apples and purees to (i) examine factors involving quality variability (variety, agricultural practice, cold storage, puree mechanical refining level) and (ii) establish the link between quality traits before and after processing in order to predict the quality characteristics of purees from spectral information of raw apples. Apples and purees were well-classified at over 82% and 88% according to varieties and storage times respectively. The PLS models showed a good ability to estimate puree characteristics from spectra acquired on corresponding apples such as viscosity (R² > 0.82), cell wall content (R² > 0.81) and also dry matter (R² > 0.83), soluble solids content (R² > 0.80) and titratable acidity (R² > 0.80). NIR technique should be a useful tool for industry insofar as it can give a reliable assessment of texture and taste of the final products based on the non-destructive fresh materials evaluation.

Keywords: Apples and purees; Discriminant analyses; Malus domestica Borkh; Near infrared spectroscopy; PLS models.