Nondestructive Analyses in Monitoring the Ripening Progress of Apple Fruit Grown in Subtropical Areas

This study evaluated the correlation between the nondestructive index of absorbance difference (IAD), obtained via DA-Meter, and conventional destructive quality attributes to determine the ripening of 'Fuji Suprema' apples in subtropical Brazil. During the 2018/2019 and 2019/2020 growing seasons, trials investigated several harvest parameters—including orchard row, tree face, height of fruit collection, days after full bloom (DAFB), and sunlight exposure—against attributes like skin color, flesh firmness, soluble solids, titratable acidity, starch index, and seed color. The results showed that the DA-Meter effectively monitors ripening evolution and establishes harvest onset. Ripening monitoring should begin between 142 and 147 DAFB, with readings taken strictly on the sunlit side of the fruit. Ultimately, the strong correlation between IAD and both flesh firmness and soluble solids content demonstrates that this nondestructive index can successfully replace traditional destructive evaluations for apple maturation assessment.