Definition of minimum maturity indices for harvesting of early-season sweet pomegranate (Punica granatum L.) fruit

Abstract

SummaryThere are no defined maturity indices for harvesting early-season “sweet” pomegranate (Punica granatum L.) varieties, and this often results in the harvesting and marketing of inedible, immature fruit. We evaluated the changes in various maturity indices, and in sensory quality, during the ripening of two commercial, early-season “sweet” pomegranate varieties: ‘Acco’ and ‘Shani–Yonay’. The results showed that, during the last 5 weeks of fruit ripening, only slight changes occurred in peel and aril colour, and in the total soluble solids contents and titratable acidity of the juice. In contrast, during ripening, we observed gradual increases in fruit and aril fresh weights (FWs), and a decrease in hydrolysable tannin contents. Furthermore, these changes were accompanied by a gradual increase in fruit flavour preference, which mainly reflected a parallel decrease in the undesirable mouth-feel sensation of astringency. Finally, we found a high correlation (r 2 = 0.99) between the observed increases in fruit flavour and aril FW, and therefore suggest that an average mean aril FW of > 0.23 g may serve as a simple and reliable index of maturity for timing the commercial harvesting of these two early-season “sweet” pomegranate varieties.