发酵处理对毛豆异黄酮苷元含量及其乙醇提取物抗氧化活性的影响

Effect of fermentation on isoflavone aglycone contents in edamame and antioxidant activity of ethanol extracts

【目的】测定毛豆、发酵处理毛豆和大豆中的大豆苷元、黄豆黄素与染料木素3种异黄酮苷元以及多酚类化合物的总含量,并分析其乙醇提取物的抗氧化活性。【方法】利用回流法酸水解样品中的大豆异黄酮,通过高效液相色谱法测定大豆苷元、黄豆黄素和染料木素的含量;利用福林酚法测定3种样品中的多酚类物质总含量,并通过测定清除DPPH自由基、ABTS自由基和还原力比较样品乙醇提取物的抗氧化活性。【结果】毛豆、发酵处理毛豆和大豆的大豆苷元含量分别为255.96,286.04和358.08μg/g,黄豆黄素含量分别为57.96,65.51和59.73μg/g,染料木素含量分别为12.88,26.40和4.62μg/g。发酵处理毛豆中染料木素含量增加明显,分别为毛豆和大豆染料木素含量的2.05和5.71倍。发酵处理毛豆、大豆、毛豆中的多酚类化合物总含量分别为(3.31±0.138)mg/g、(1.148±0.028)mg/g和(2.69±0.011)mg/g,发酵处理毛豆的多酚类化合物含量约是大豆和毛豆的2.9和1.2倍。抗氧化活性比较表明,发酵处理毛豆清除ABTS自由基与DPPH自由基的能力优于大豆和毛豆。发酵处理毛豆、大豆和毛豆还原力大小依次表现为发酵处理毛豆>毛豆>大豆。【结论】经过发酵处理后,毛豆中的3种异黄酮含量均有所增加,但以染料木素的增加最为明显;发酵处理毛豆中多酚类化合物总含量升高,自由基清除活性增强。

[Objective] This study aimed to determine the contents of daidzein, glycitein, genistein, and total polyphenols in edamame, fermented edamame and soybean and analyze the antioxidant activities of ethanol extracts. [Method] Soybean isoflavones in samples were hydrolyzed by acid reflux, and daidzein, glycitein and genistein were quantified by high-performance liquid chromatography. The total polyphenols in edamame, fermented edamame and soybean were determined by Folin-Ciocalteu colorimetric. The antioxidant activities of ethanol extracts were compared by scavenging of DPPH and ABTS radicals and testing reducing power. [Result] The contents of daidzein in edamame, fermented edamame and soybean were 255.96,286.04 and 358.08 μg/g,the contents of glycitein were 57.96,65.51 and 59.73 μg/g,and the contents of genistein were 12.88,26.40 and 4.62 μg/g,respectively. The content of genistein increased significantly after fermentation and was 2.05 and 5.71 times of those in edamame and soybean,respectively. The total contents of polyphenolic compounds in fermented edamame, soybean and edamame were （3. 31± 0. 138） mg/g,（2.69±0. 011） mg/g,and （1. 148±0. 028） mg/g. The content in fermented edamame was about 2.9 and 1.2 times of those in soybean and edamame. Ethanol extracts from fermented edamame had stronger antioxidant activity in scavenging of DPPH and ABTS radicals than those from edamame and soybeans. The reducing power was in a decreasing order of fermented edamame〉edamame〉soybean. [Conclusion] After fermentation, the contents of three isoflavone aglyeone in edamame increased,and genistein increased the most. The total content of phenolic compounds in fermented edamame was higher than edamame and radical scavenging activity was increased.