Date palm parthenocarpic fruits ( Phoenix dactylifera L.) cv. Deglet Nour: chemical characterization, functional properties and antioxidant capacity in comparison with seeded fruits

摘要

The aim of this study was to unveil the potentialities of the large amount of uneconomical unpollinated or seedless fruits produced in date palm, cv. Deglet Nour. These fruits are seedless and take a longer time to ripen. This study was undertaken on natural maturation seedless fruits and on climacteric ones. The biochemical characteristics were depicted and compared with those of the pollinated or seeded fruits of the same variety. Climacteric seedless fruit humidity was the highest (13.14%). Soluble sugar content was lower in natural seedless fruits, 47.91 g/100 g FW with 53.32 g/100 g FW for climacteric seedless fruits and 60.91 g/100 g FW in seeded fruits. Natural seedless fruits contained the highest content of uronic acids (18.30 g/100 g ethanol insoluble fraction) and the lowest lignin one (30.30 g/100 g ethanol insoluble fraction). However, climacteric seedless and seeded fruits have the same uronic acids and lignin contents. No significant differences were detected in protein content. The studied fruits had similar water holding capacity and solubility. However, oil holding capacity was higher in climacteric seedless fruits. The natural seedless fruits were especially rich in neutral sugars in comparison with the others. Glucose was the main recorded sugar, representing the amount of cellulose of these fruits. The natural seedless fruits had a very high content of phenol which increased their antiradical activity. Natural seedless fruits have demonstrated the highest total antiradical activity: 95.53 mmol Trolox/kg FW with 11.94 mmol Trolox/kg FW and 10.22 mmol Trolox/kgFW for climacteric seedless and seeded fruits, respectively. Furthermore, ferric reducing power was also in the favor of natural seedless fruit. Parthenocarpic Deglet Nour fruits have interesting potentialities which could have economic importance to be taken into consideration either in the fresh consumption or in the date industries.