Colorimetric indicator for classification of bananas during ripening

Considering the rise in exports of fruits, the standardization and the improvement of fruit quality are becoming an important requirement. Several countries use rules for grading, labeling and packing, with the aim of standardizing the quality of commercial products and in order to meet consumer demands. Studies have been conducted aiming to define parameters for the characterization of the ripening stages of fruits and to standardize classification during packing. In the case of bananas, their classification involve besides ripening stage, quantity and size. This paper presents a new indicator of the ripening stages of bananas on the basis of calorimetric analyses, bringing standardization to the grading process. The results from the daily monitoring of the evolution of color and spectral radiance of the Brazilian 'Prata' banana peel (Musa sapientum AAB) are presented. The banana peel was classified according to the seven subclasses of the Von Loesecke ripening scale. On the basis of these analyses, the RCI (Ripening Color Index) was proposed as a practical index for the grading of bananas, based on the CIELAB system. The RCI index for banana 'Prata' varies from 140 to 300 and each ripening subclass have their limits defined, allowing a direct correlation to Von Loesecke classification. The results show that a scientific index is a feasible alternative to be used as a practical measurement system in the packing, avoiding eventual human errors. The same approach can be developed to other cultivars and fruits. (C) 2012 Elsevier B.V. All rights reserved.