Spectroscopy of the visible and near infrared to evaluate soluble solids and flesh firmness in peach according to harvest season

Abstract

This study aimed to establish calibration models to assess soluble solids contents and flesh firmness in a non destructive way in peaches from 'Chimarrita', 'Maciel', 'Eldorado' and 'Jubileu' varieties, watching the harvest season effect on these models. Thereunto, in the first year of execution it was used the spectrophotometer Nir-Case (SACMI) in order to determine the calibrations equations for each cultivar from the non destructive and destructive evaluations. After that the performance of these models were evaluated through the procedure of validation with the remark of the results of determination coefficient (R2) and standard error of the predicted values (SEP). In the second year of experiment, using the same equipment and methodology, harvest dates along the peach maturation period were stipulated and calibrations models were developed for each cultivar studied. According to the results it can be concluded that the proposed models for evaluation of quality of fruit were satisfactory and the same result was not observed in the flesh firmness in the first year. In the second year it was observed that the statistics parameters values relative to the validation of the established models change along different periods during harvest seasons. However, the R2 and SEP values were considered acceptable to estimate the content of soluble solids in all cultivars. The parameter of flesh firmness was only satisfactory for the cultivars Eldorado and Jubileu.