Cropping system contributes largely to fruit composition and sensory properties of pomegranate (Punica granatum L. var. Gabsi)

Abstract

The oasis, where pomegranate is grown simultaneously with several crops, is considered as an ecosystem with particular properties. No research has been made to investigate the relationship between pomegranate fruit quality and oasis environment. A comparison between full shade oasis (pomegranate trees were intercropped with date palm trees and other fruit species), partial shade oasis (pomegranate trees grown under date palm trees) and regular orchards with full sun conditions has been investigated in terms of fruit quality. The full shade oasis microclimate was more favourable to obtain pomegranate arils with an attractive red colour and high total anthocyanin content. Pomegranates under these conditions contained total volatile content (79–144 μgL−1 ) which was about 2 times higher than that in full sun exposed fruits (47–64 μgL−1 ). Particularly, hexanal and limonene were the most abundant compounds characterizing the aroma profile of fruits cultivated under full shade oasis, and their arils were the most appreciated in terms of colour, odour and taste by Tunisian consumers. However, fruits from partial shade oasis provided the sweetest juices with high concentrations of glucose (59.8–63.3 g L−1 ) and fructose (108–111 g L−1 ). Titratable acidity and total organic acids content were also higher in fruits grown under Zarat 3 characterized by partial shade conditions. PCA analysis was used to identify which physicochemical and sensory attributes were more closely linked to oasis conditions. Red colour intensity, monoterpenes, hexanal, citric and quinic acids were useful to discriminate full shade oasis. These compounds seem to contribute to the typical organoleptic properties of oasis pomegranate fruits