Abstract
The synthesis of alpha-farnesene and its degradation to the corresponding oxidation products such as conjugated trienols (CTols) in apple skins is strongly correlated with the incidence of superficial scald, a physiological disorder occurring in apple during and after storage. This study aimed to evaluate the potential of near-infrared spectroscopy (NIRS) for the prediction of alpha-farnesene and CTols (CT258 and CT281) content, developing a rapid and non-invasive method to support the postharvest decision systems. Applying partial least squares (PLS) regression, positive correlations were found for alpha-farnesene and CTols obtaining correlation coefficients of calibration (r(cal)) above 0.90. The calibration model for one apple variety was validated with apples from a second season resulting in correlation coefficients of validation (r(val)) of 0.51, 0.71 and 0.76 for alpha-farnesene, CT258 and CT281, respectively. A global calibration model including two cultivars and two growing seasons led to standard errors of prediction (SEP) of 139, 60 and 59 mu mol m (2) for alpha-farnesene, CT258 and CT281, respectively. These results demonstrate the potential of NIRS for rapid and non-destructive prediction of the scald-disorder-related compounds alpha-farnesene and CTols in apple fruit. (C) 2016 Elsevier B.V. All rights reserved.