title: Effect of concentration temperature on some bioactive compounds and antioxidant proprieties of date syrup.
abstract: The effect of the concentration temperature on the antioxidant activity, carotenoid and phenolic compounds of date syrup was investigated. Date juice was concentrated at 100  and at "60  in vacuum". After concentration, total phenolic, tannin, non-tannin, flavonoid and carotenoid content were determined spectrophotometrically and high-performance liquid chromatography was used for determination of 5-Hydroxymethyl-2-furfuraldehyde content. The antioxidant activity of date syrup was evaluated by various antioxidant methods including total antioxidant, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging test, ferric reducing antioxidant power and β-carotene bleaching. All date syrups showed strong antioxidant activity accompanied by high total phenolic contents. Results showed that concentration at 100  significantly enhanced the antioxidant activities and total phenolic contents of date syrups compared to vacuum concentration at 60 . A good correlation between the antioxidant activity and total phenolic content and flavonoid was observed.
authors.affiliation: Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, Route de soukra, Sfax, Tunisia.
authors.forename: Fatma
authors.initials: F
authors.lastname: Abbès
authors.forename: Souhail
authors.initials: S
authors.lastname: Besbes
authors.forename: Bchir
authors.initials: B
authors.lastname: Brahim
authors.forename: Wissal
authors.initials: W
authors.lastname: Kchaou
authors.forename: Hamadi
authors.initials: H
authors.lastname: Attia
authors.forename: Christophe
authors.initials: C
authors.lastname: Blecker
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D028023:Arecaceae / Q000737:chemistry*; D002338:Carotenoids / Q000032:analysis; D005419:Flavonoids / Q000032:analysis; D005511:Food Handling / Q000379:methods*; D016166:Free Radical Scavengers / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000032:analysis; D015416:Maillard Reaction; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D013634:Tannins / Q000032:analysis; D013696:Temperature
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D010936:Plant Extracts; D013634:Tannins; D002338:Carotenoids; C008046:5-hydroxymethylfurfural; D005662:Furaldehyde
keywords: 2; 2-diphenyl-1-picrylhydrazyl free radical; 5-Hydroxymethyl-2-furfuraldehyde; Date syrup; antioxidant activity; ferric reducing antioxidant power; β-carotene bleaching