单花蜂蜜多酚类物质的抗氧化活性

以5种中国单花原蜜，不同产地的42个样本通过Amberlite XAD-2吸附树脂得到的多酚提取物为原料，采用分光光度法，测定总酚酸和总黄酮含量、还原能力、抗氧化活性(清除DPPH自由基、O2－ ·能力)，评估蜂蜜多酚类物质抗氧化活性及蜂蜜品种、颜色和地域差异对清除自由基的影响。结果表明：样本总黄酮含量为(9.41±0.18)～(92.76±0.13)mg/kg；总酚酸含量为(9.10±0.05)～(149.57±0.14)mg/100g；深色枣花蜜抗氧化能力最强，对DPPH自由基、O2－ ·清除作用分别为EC50＝(0.042±0.014)g/mL和EC50＝(0.038±0.009)g/mL。提示蜂蜜的多酚类物质影响抗氧化活性，酚酸、黄酮含量与抗氧化能力呈现正相关系；色深原蜜的酚酸、黄酮含量高于色浅原蜜，抗氧化能力也强于浅色原蜜。

Antioxidant Activities of Phenolic Compounds in Unifloral Honey

A total of 42 samples were collected from honey samples of 5 different unifloral origins(each unifloral origin consisted of different geographic origins in China).Phenolic extract was obtained from these selected samples using Amberlite XAD-2 absorption resin.The contents of total phenolic acids and total flavonoids were spectrometrically determined,and reducing power and the scavenging activity against DPPH and superoxide anion free radicals were tested to evaluate the effects of floral origin,sample color and geographic origin on the antioxidant activity of honey.Total flavonoids content ranged from(9.41 ± 0.18) to(92.76 ± 0.13) mg/kg as determined using quercetin as the reference standard.The content of phenolic compounds ranged from(9.10 ± 0.05) to(149.57 ± 0.14) mg/100 g as determined using protocatechuic acid as the reference standard.Dark honey had the highest scavenging activity on DPPH and superoxide anion free radicals with EC50 of(0.042 ± 0.014) g/mL and(0.038 ± 0.009)g/mL,respectively.Conclusion: phenolic extracts from honey samples have impact on their antioxidant activity.The antioxidant potential is positively correlated with the contents of phenolic or flavonoid compounds.Dark honey has higher contents of phenolic and flavonoid compounds as well as stronger antioxidant potential than other light honey.