Fluorescence spectroscopy as a novel non-invasive technology for shelf life estimation of fresh-cut apples

This study aimed to evaluate the ability of fluorescence spectroscopy to predict the shelf life of fresh-cut apples. Changes in fluorescence spectra, colour, and nutritional quality were monitored during the storage at 4, 10, and 15 °C. Kinetic models employing pseudo-zero and first-order equations were developed to describe the quality change over time, and activation energy was obtained using the Arrhenius model. The results showed that the browning index (BI) was the most reliable indicator for predicting the shelf life of fresh-cut apples and was correlated with the fluorescence index computed from the PARAFAC-resolved fluorescence components (r > 0.90). A fluorescence value of 1.79, corresponding to a shelf life of approximately 5 days, was determined as the critical value for discriminating between high- and low-quality products. In conclusion, fluorescence was suggested as a suitable technology for rapid, accurate and non-destructive shelf life monitoring of fresh-cut apples.