【摘要】 为研究枣渣干燥方式对红枣色素活性成分含量及抗氧化活性的影响,选用自然、50℃热风、70℃热风、微波和真空冷冻干燥方式处理枣渣,采用Folin-Ciocalteu法、pH示差法和NaNO₂-Al（NO₃）₃-NaOH法分别测定红枣色素总多酚、花色苷和总黄酮含量,并比较其清除DPPH·、·OH、O₂^-·的能力和还原力。结果表明,不同干燥方式处理提取的红枣色素活性成分含量存在显著差异（P<0.05）,其中真空冷冻干燥提取的红枣色素总多酚、花色苷和总黄酮含量均最高,分别为2.46、5.10、9.84 mg/g,微波干燥次之,50℃热风干燥最低。不同干燥方式处理提取的红枣色素抗氧化活性差异显著（P<0.05）,真空冷冻干燥和微波干燥提取的红枣色素清除DPPH·、·OH、O₂^-·的能力和还原力较强,而50℃热风干燥提取红枣色素清除DPPH·和O₂^-·的能力最低,70℃热风干燥提取红枣色素清除·OH的能力和还原力最低。表明不同干燥方式处理枣渣对红枣色素活性成分含量及抗氧化活性的影响差异较大,其中真空冷冻干燥提取的红枣色素活性成分损失最少,抗氧化活性最强,微波次之,热风干燥相对较差。更多还原

【Abstract】 To study the effects of different drying methods of jujube residues on active component contents and antioxidant activities of jujube pigment. The jujube residues were dried by natural drying, 50 ℃ hot air drying, 70 ℃ hot air drying, microwave drying and vacuum freeze drying. The total polyphenol, anthocyanin and total flavonoid contents of jujube pigment extracted by different drying methods were determined by folin-ciocalteu method, pH differential method and NaNO₂-Al（NO₃）₃-NaOH method, respectively. The scavenging capacity of DPPH radical, hydroxyl radical, superoxide anion radical and reducing power of jujube pigment were determined and compared. The results showed that the active component contents of jujube pigment extracted by different drying methods had significantly difference with each other（p<0.05）. The total polyphenols, anthocyanins and total flavonoids contents of jujube pigment extracted by vacuum freeze drying were the highest,（2.4, 5.10 and 9.84 mg/g, respectively）, followed by microwave drying, while 50 ℃ hot air drying contained the lowest. The jujube pigment extracted by different drying methods had a significant difference on antioxidant activities（p<0.05）, the jujube pigment extracted by vacuum freeze drying and microwave drying had better the scavenging capacity of DPPH radical, hydroxyl radical, superoxide anion radical and reducing power. The jujube pigment extracted by 50 ℃ hot air drying had the worst scavenging capacity of DPPH radical and superoxide anion radical. The jujube pigment extracted by 70 ℃ hot air drying had the worst the hydroxyl radical scavenging capacity and reducing power. The results indicated that there were significant differences in active component contents and antioxidant activity of jujube pigment among different drying methods. The lowest loss of active component and the strongest antioxidant activity of jujube pigment were found in vacuum freeze drying method, followed by microwave drying. The active component contents and antioxidant activity of jujube pigment extracted by hot air drying method were relatively poor.更多还原