Pomological, Physico-Chemical And Organoleptic Characterization Of Organic And Conventional Pomegranates (Punica Granatum L.)

Summary

This work aims to assess the pomological, physico-chemical and organoleptic characteristics of organic and conventional pomegranates (Punica granatum L.) and to determine the effect of organic farming system on the quality of pomegranates production. The trial was set up in the South-East of Tunisia and more precisely in the region of “Gabès” which is well known by the pomegranate variety “Gabsi”. The production of this variety was monitored under the organic and the conventional farming systems with the same pedoclimatic conditions.Quality of pomegranates’variety “Gabsi” was assessed in the two production systems by the pomological parameters (fruit weight, fruit size, peel thickness, juice yield ...), the physicochemical characteristics of the juice (pH, titrable acidity, soluble solids content (°Brix) reducing sugar content, polyphenols, anthocyanin content, antioxidant activity ...) and by the sensory aroma profile.Results have revealed significant differences between organic and conventional pomegranates in several parameters. In fact, pomological descriptors have shown that organic pomegranate fruits were characterized by a thicker and a redder peel than those of the conventional ones. Physico-chemical characteristics were also influenced by the farming systems except for the parameter of reducing sugar content. Acidity, total soluble solids (°Brix) and dry matter content were higher in organic pomegranate juice than in the conventional one respectively with the values (0.61 vs 0.48, 16.17% vs 12.83% and 28.93% vs 25.73%). In addition, polyphenols and anthocyanins were more present in the Organic pomegranate juice compared to the conventional one (1287.63 vs. 1089.53 mg gallic acid / L and 52.88 vs 40, 04 mg cyanidin-3-glucoside / 100 ml respectively). For consumer panel test, descriptive sensory analysis have shown that organic pomegranate juice was bitter and more acid than the conventional one due to its higher richness on antioxidants, but not different in the other organoleptic parameters.