Chemical and physical changes during ripening raspberry (Rubus caesius L.) fruits

Raspberries (Rubus caesius L.) were harvested a three developmental stages (unripe, semi-ripe, ripe) to study changes associated with (dry mater, soluble solids, titratable acidity, pH, total phenolics and total anthocyanin) in order to understand this behavior during the ripening process. The determination of fruit maturity was based on fruit surface color. Enhanced fruit ripening was reflected by decreased values for titratable acidity, total phenolics and increased concentration of total anthocyanins and soluble solids. Total phenolics displayed their highest values in green fruit. In the early fruit ripening stages, pH decreased, titratable acidity increased, while in the later stage, pH increased, titratable acidity decreased considerably. Analysis of variance (ANOVA) revealed that the effect of ripening stage was significant (P<0.05) on chemical and physical characteristics.