Changes in physicochemical and nutritive parameters and bioactive compounds during development and on-tree ripening of eight plum cultivars: a comparative study

BACKGROUND: There is no literature on changes in organoleptic, nutritive and functional properties during plum development and on-tree ripening. In this work a comparative study on the evolution of physical, chemical and nutritive parameters and bioactive compounds of eight plum cultivars (yellow and dark-purple) was performed. RESULTS: The main changes related to ripening (colour, total soluble solids, acidity, firmness and bioactive compounds) started at the early stages of fruit development, with significant differences among cultivars. Colour hue angle was highly correlated with increase in anthocyanins or carotenoids (in both skin and flesh). Total antioxidant activity (TAA) was determined in the hydrophilic (H-TAA) and lipophilic (L-TAA) fractions separately, and values were always higher in the skin than in the flesh. A continuous increase in both H-TAA and L-TAA during the process of ripening occurred. H-TAA was about twofold higher than L-TAA in the dark-purple cultivars, while the opposite was found in the yellow cultivars. In addition, H-TAA was correlated with total phenolics and total anthocyanins, while L-TAA was positively correlated with total carotenoids. CONCLUSION: In order to achieve the optimal organoleptic, nutritive and health-beneficial properties of plum consumption, it would be advisable to harvest the fruits at the fully ripe stage. (c) 2008 Society of Chemical Industry