Nondestructive determination of flesh color in clingstone peaches Original Research Article

A nondestructive optical method, based upon visible and near infrared interactance spectroscopy, was developed for rapid determination of flesh color in clingstone peaches. Flesh color is currently used by the Californian canning peach industry as a destructive maturity index for clingstone peaches inspected at harvest and as a predictor of sensory flavor quality. Results show that skin ground color becomes uncorrelated with flesh color for skin ground color hue angles below 70°. Cultivar-specific models using nondestructive, log-transformed, interactance measurements at two wavebands in the visible region produced good predictive performance of flesh hue (r = 0.92), while a global model required information at five wavebands to achieve this same level of performance (r = 0.92 and RMSECV = 1.35° hue). The nondestructive method does not require a separate measurement of skin reflectance and is suitable for flesh color grading tasks at inspection stations prior to canning and shows good potential for on-line sorting tasks.