title: Detailed polyphenol and tannin composition and its variability in Tunisian dates (Phoenix dactylifera L.) at different maturity stages.
abstract: The polyphenol profile of two Tunisian varieties of dates including flavanols, flavonols, flavones, and hydroxycinnamates was characterized. Three tissue zones (flesh, peel, and stone) and three maturity stages were considered. Phenolic compounds were analyzed using reversed phase high-performance liquid chromatography coupled to UV-visible and electrospray mass spectrometry. Procyanidin oligomers and polymers were characterized and quantified using phloroglucinolysis prior to HPLC analysis. Procyanidin polymers based on (-)-epicatechin structure were by far the most concentrated polyphenols in ripe dates, accounting for 95% of total polyphenols with an average concentration of 14 g/kg in the fresh edible parts of the fruit. Interestingly, procyanidins were also highly concentrated in the stones. The concentration and average degree of polymerization (DPn) of the procyanidins decreased according to maturity. Other phenolics, including caffeoylshikimic acid hexoside, caffeoyl-sinapoyl monohexoside and dihexoside, and acetylated flavonols, were tentatively identified for the first time in the fruit.
authors: INRA, UR117 Recherches cidricoles et biotransformation des fruits et légumes, Le Rheu, France.
authors: Hédi
authors: H
authors: Hammouda
authors: Jamila Kalthoum
authors: JK
authors: Chérif
authors: Malika
authors: M
authors: Trabelsi-Ayadi
authors: Alain
authors: A
authors: Baron
authors: Sylvain
authors: S
authors: Guyot
mesh_terms: D028023:Arecaceae / Q000737:chemistry* / Q000254:growth & development; D002851:Chromatography, High Pressure Liquid; D059808:Polyphenols / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D013634:Tannins / Q000032:analysis*; D014416:Tunisia
chemical_list: D059808:Polyphenols; D013634:Tannins