Physicochemical Changes and Antioxidant Activity of Juice, Skin, Pellicle and Seed of Pomegranate (cv. Mollar de Elche) at Different Stages of Ripening

Luana Fernandes¹, José Alberto C. Pereira¹, Isabel Lopéz-Cortés², Domingo M. Salazar² and Elsa C. D. Ramalhosa¹*


¹Mountain Research Centre (CIMO), School of Agriculture, Polytechnic Institute of Bragança, Campus de Sta Apolónia, Apartado 1172, PT-5301-855 Bragança, Portugal
²Department of Agronomy, Polytechnic University of Valencia, Camino de Vera s/n, ES-46022 Valencia, Spain




Article history:
Received January 9, 2015
Accepted May 22, 2015




Key words: 
Mollar de Elche cultivar, fruit constituents, ripening stages, physicochemical properties, antioxidant activity




Summary:
In the present work, we investigate how the degree of ripeness (low, low-medium, medium and medium-high) affects the physical and compositional changes, as well as antioxidant properties of pomegranate fruit (cv. Mollar de Elche). The skin, pellicle, seed and juice were analysed. The fruit mass increased and the fruit skin became reddish (higher a* and lower h*) as the fruit ripening progressed. The lowest concentrations of flavonoids and hydrolysable tannins were recorded in skin and pellicles at medium-high maturity stage, which explains the decrease in the total phenols and reducing power during ripening of pomegranate. On the contrary, the highest concentration of flavonoids (165 mg of quercetin equivalents per 100 mL of juice) was determined in the juice at the most advanced ripening stage, concomitant with the highest total phenols (1695 mg of gallic acid equivalents per 100 mL of juice). Higher DPPH scavenging activity and an increase in the reducing power of juice were also observed during ripening. The trend of the above-mentioned properties allowed describing the fruit development and maturity.





*Corresponding author:      elsa@ipb.pt
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