Hyperspectral Reflectance as a Tool to Measure Ripeness of Orange Fruits

Abstract

This work assesses the availability of depending hyperspectral indices to predict the chemical content of orange fruit under different growth stages. Using hyperspectral indices measurements to quantify varying chemical components of orange fruit including (chlorophyll, Ascorbic acid, Carotenoids, pH, Soluble Solids (%), juice percentage (%), titratable acidity results were expressed and maturity index. R 672 /R 550 gave the maximum correlation value for predicting the concentration of chlorophyll (a) with R 2 = 0.92. For predicting chlorophyll (b) that (NDI) indices show strong significant relationships with R 2 =0.84. PSR gave the highest correlations for predicting the concentration of total chlorophyll of orange fruit at different growing stages with R 2 = 0.88 while for predicting the carotenoid concentration of orange fruit, it should depend on R 672 /R 550 which produced the highest correlation R 2 = 0.85. R 672 /R 550 was the best indices for predicting the ascorbic acid content of orange fruit at different growing stages with R 2 = 0.947. for predicting Soluble solids (SS) there is a high correlation with R 672 /R 550 and PSI, respectively which give the same R 2 =0.939. R 672 /R 550 showed high correlations for predicting the pH value of orange fruit with R 2 = 0.94 Predicting Juice content and maturity index of orange fruit should depend on R 672 /R 550 which produced the highest correlations R 2 = 0.91 and 0.96 respectively. PSR produced the highest correlations for predicting the titratable acidity of orange fruit were R 2 = 0.92.