Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, Route de soukra, Sfax, Tunisia.
Food Sci Technol Int. 2013 Aug;19(4):323-33. doi: 10.1177/1082013212452477. Epub 2013 May 31.
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.
研究了浓缩温度对枣汁抗氧化活性、类胡萝卜素和酚类化合物的影响。枣汁分别在 100℃和 60℃下在真空条件下浓缩。浓缩后，采用分光光度法测定总酚、单宁、非单宁、类黄酮和类胡萝卜素含量，采用高效液相色谱法测定 5-羟甲基-2-糠醛含量。采用总抗氧化、2,2-二苯基-1-苦基肼自由基清除试验、铁还原抗氧化能力和β-胡萝卜素漂白等多种抗氧化方法评价枣糖浆的抗氧化活性。所有枣糖浆均表现出较强的抗氧化活性，同时总酚含量较高。结果表明，与在 60℃下真空浓缩相比，在 100℃下浓缩显著提高了枣糖浆的抗氧化活性和总酚含量。观察到抗氧化活性与总酚含量和类黄酮之间存在良好的相关性。
