Nutritional properties, aromatic compounds and in vitro antioxidant activity of ten date palm fruit (Phoenix dactylifera L.) varieties grown in Tunisia

Abstract

Phoenix dactylifera L. has traditionally been used as a medicine in many cultures. The aim of this study was to evaluate the nutritional properties, aromatic compounds, total phenolic content and the antioxidant activity of ten ripe date fruit varieties grown in Tunisia. Sugar profiles were analyzed by high performance liquid chromatography, while fatty acid compounds were detected by gas chromatography and aromatic compounds were analyzed by GC-Electron Impact Mass Spectroscopy. Total phenolic contents were measured using colorimetric methods, whereas antioxidant capacities were evaluated in vitro using DPPH and ABTS radicals. It has been found that total sugars are the predominant component in all date varieties, followed by moisture, along with moderate amounts of proteins, ash, and fats. Multivariate tests based on the volatile compounds profile showed significant differences among varieties. Between the sixty-two volatile compounds detected, alcohols, aldehydes and unsaturated hydrocarbons constituted the main chemical classes. The date varieties exhibited strong antioxidant potential that correlated with phenolic content. In conclusion date varieties can play a major role in human nutrition and health because of their wide range of valuable nutritional components and natural antioxidants that could potentially be considered as a functional food ingredient.

Keywords:
Date palm fruits; Varieties; Chemical composition; Aromatic compounds; Phenolic content; Antioxidant activity