Monitoring Harvesting degree of red ‘Scarlet’ Apples using DR-UV–Vis and NIR Spectroscopy

The identification of the harvest date has a fundamental role in the agro food chain as the quality of fruits depends primarily on the right harvesting time and storage conditions in post-harvest period. The marked need and the importance of rapid, reliable and non destructive tools for the determination of the ripeness level become apparent. This work is focused on the study of red apples ripening (Scarlet cv), with the aim of better identifying harvest date characterizing each stage of fruit ripening on trees using classical analysis and non destructive analysis. Non destructive NIR analysis has been applied to starch and sugar content and firmness, while UV-Vis analysis was applied to monitor variation of chlorophyll concentration in the skin of red apples. A further approach was tested considering UV-Vis and NIR data together, and using GA-PLS algorithm to elaborate a multivariate model based on the difference (in days) between every sampling and the harvest.