The increasing interest in plant phenolics and flavonoids outlined the necessity of determining their contents and biological activity in Mauritanian date palm fruits. Methanolic extracts of fruit of six date palm cultivars commonly grown in Mauritania were screened for their antioxidant activity, total phenolics, and flavonoid content at two edible ripening stages. Polyphenols and flavonoids were higher in theBlah stage, corresponding toKhalal in the standard Iraqi Arabic nomenclature, compared to the fully matureTamr stage regardless the cultivar. The average of total phenolics atBlah andTamr stages were 728.5 and 558.9 mg gallic acid equivalents (GAE) per 100 g dry matter (DM), whereas the average flavonoid content was 119.6 and 67.3 mg quercetin equivalents (QE) per 100 g DM, respectively. TheBlah stage also exhibited the highest total antioxidant activity with a Trolox equivalents antioxidant capacity (TEAC) value of 129.3 μmol/100 g DM founded in Bou seker's Blah date, followed by Tijib cultivar with TEAC value of 114.3 μmol/100 g DM and an average TEAC value of 107.5 μmol/100 g DM. Furthermore, a high positive correlation was found between total phenolics inTamr (r = 0.92) andBlah (r = 0.87) stages and TEAC of fruit methanolic extracts compared to the flavonoids, suggesting that phenolics were the major contributor to the antioxidant activity.

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Date palm is an important food and economical crop in Mauritania. Date palm cultivars show great diversity in fruit morphological characteristics in the 'Adrar' region of Mauritania. Fruits of twenty-eight date palm cultivars were collected at Tamar stage, from three different oasis of the 'Adrar' region in 2010 and 2011 and their physical and chemical diversity was assessed by using different data analysis techniques. Analysis of variance revealed statistically significant differences between cultivars for the 13 examined characters indicating the high diversity in the physicochemical properties of their fruit. Duncan's multiple range test allowed clustering of cultivars into different groups depending on the parameters. Principal component analysis and cluster dendrogram performed on the basis of studied parameters showed a distribution of date palm cultivars independently of their oasis origin and a continuous variation in their fruit physical and chemical traits. Date varieties under 'Ahmar' denomination showed diverse fruit properties. Characters that can discriminate the best cultivars were fruit water content, reducing sugars, total sugars, non-reducing sugars, ashes, calcium and magnesium contents. Results also give evidence of the existence of common date varieties such as 'Sekanni', 'Bou seker', 'Sembahmoud', 'Tenwazidi' and 'Sel medina' with fruit properties matching or even higher than the elite cultivar 'Ahmar'. The possible use of date palm fruits characteristics either in the description of local date palm germplasm or the valorisation of common date varieties are discussed.