不同品种甜樱桃中不同形态酚酸的比较及其抗氧化性分析

为研究不同品种对甜樱桃酚酸类物质及其抗氧化性的影响,本文采用超高效液相色谱-串联质谱法(UPLC-MS/MS)对5个不同品种甜樱桃,包括彩虹、艳阳、萨米脱、23-51和瓦列里中的游离型、游离酯型和结合型酚酸进行了测定和分析。结果表明,不同樱桃品种间酚酸含量差异较大,5个樱桃品种酚酸总量在115.96~704.94 mg/kg FW之间。其中瓦列里中酚酸总量最高,其次是萨米脱和23-51,艳阳和彩虹中酚酸总量最低。对于三种不同形态酚酸,游离型和游离酯型酚酸含量较高,而结合型酚酸含量较低。不同品种樱桃中的游离型酚酸以新绿原酸为主,可占游离型酚酸总量的90%以上;游离酯型酚酸和结合型酚酸均以咖啡酸含量最高,可占各自形态酚酸总量的50%以上。不同品种中瓦列里樱桃酚酸提取液的DPPH自由基清除能力和FRAP均最高,抗氧化性指标的测定结果与酚酸类物质含量呈现较高的一致性。偏最小二乘判别分析表明,新绿原酸和咖啡酸是区分五个樱桃品种贡献最大的物质(VIP得分>1),且这两个物质均在瓦列里中含量最高。甜樱桃酚酸含量与品种有关,并与其抗氧化特性相一致。

Comparison of Phenolic Acids in different Cherry Cultivars and Analysis of Its Antioxidant Activities

To study the effects of different cherry cultivars on phenolic acids and its antioxidant activities,free,conjugated,and bound phenolic acids of five cherry cultivars,including Caihong,Sunburst,Summit,23-51,and Valeri,were identified and quantified by ultra performance liquid chromatography-tandem mass spectrometry( UPLC-MS/MS).There was great variation of phenolic acid content among different cultivars.The total phenolic acid content ranged from 115.96 to 704.94 mg/kg FW.The highest content of phenolic acids was found in Valeri,followed by Summit and 23-51,and the least amounts were identified in Sunburst and Caihong.The results indicated that both of the free and conjugated phenolic acids showed high levels in all the five cherry cultivars,while bound-form phenolic acids were detected in relatively small amounts.Neochlorogenic acid was the most abundant free phenolic acids in sweet cherries,and accounted for more than 90% of the total free fractions. Caffeic acid was found to be the major compound in conjugated and bound forms,accounting for over 50% of the total content of their respective types.DPPH radical scavenging and FRAP assays indicated that Valeri contained the highest antioxidant activity,which had a higher consistency to the phenolic contents. The different cherry cultivars were well discriminated according to PLS-DA. The compounds for discrimination were neochlorogenic acid and caffeic acid( VIP score > 1),and both of the two compounds showed the highest levels in Valeri. It is suggested that phenolic acid content was related to cherry cultivars,which was also positively related to its antioxidant properties.