Physicochemical characterisation of gulupa (Passiflora edulis Sims. fo edulis) fruit from Colombia during the ripening

Gulupa (Passiflora edulis Sims. fo edulis) is a tropical fruit native to America. This study was undertaken to characterize the physicochemical properties of this fruit in three maturity stages. In all stages, the pH, degrees Brix, texture, and titratable acidity were determined. pH value and solid soluble content increased during ripening and titratable acidity decreased during this process; in contrast, texture values did not show significance variance. It was confirmed the presence of cyanidin-3-O-beta-D-glucopyranoside as major anthocyanin. The changes on colour were followed by tristimulus colorimetry using image analysis, a very useful new approach for the measurement of non-homogeneous colours. By using PCA (Principal Component Analysis), clusters of data corresponding to each stage could be defined. Additionally, the volatile composition was followed by HS-SPME (Headspace-Solid Phase Microextraction) and GC/MS (Gas Chromatography/Mass Spectrometry) analyses. The results showed an increase in the amount of volatile during fruit ripening, with aliphatic esters as major constituents. (C) 2010 Elsevier Ltd. All rights reserved.