菱茎多酚的提取工艺及其抗氧化、抑菌活性研究

目的:研究菱茎多酚的超声波辅助提取工艺及其体外抗氧化、抑菌活性。方法:以菱茎为材料,采用正交实验对菱茎多酚的提取工艺进行优化;通过测定菱茎多酚的DPPH、ABTS自由基清除力及还原力来评价其体外抗氧化活性;采用滤纸片扩散法测定菱茎多酚对6种腐败微生物的抑菌活性。结果:菱茎多酚的最佳提取工艺条件为乙醇浓度60%、pH1、提取温度70 ℃、提取时间35 min、料液比1:35 (g/mL),此工艺条件下多酚的提取得率为67.31 mg GAE/g DW;菱茎多酚对DPPH、ABTS自由基清除力和对Fe3+还原力(FRAP)的IC₅₀值分别为228.34、220.57、152.00 μg/mL;对金黄色葡萄球菌、蜡样芽孢杆菌、大肠杆菌、腐败希瓦氏菌、青霉和酿酒酵母的最小抑菌浓度(MIC)分别为6.25、3.13、0.20、0.39、1.56、0.78 mg/mL。结论:菱茎多酚具有良好的抗氧化和抑菌活性,可作为潜在抗氧化剂和抑菌剂的来源进一步开发利用。

Study on extraction of polyphenols from stems of Trapa bispinosa Roxb. and its antioxidant and antimicrobial activities

Objective:To optimize the ultrasonic-assisted extraction conditions of polyphenols from the stems of Trapa bispinosa Roxb.and evaluate the antioxidant and antimicrobial activities of extracted polyphones in vitro. Methods:The ultrasonic-assisted extraction process was optimized using orthogonal test. The antioxidant activity was evaluated by determination of DPPH, ABTS radical scavenging and ferric reducing antioxidant potential assay (FRAP). The antimicrobial activity against six spoilage microorganisms was tested by the method of disk diffusion. Results:The optimal extraction processing parameters were ethanol concentration of 60%, pH of 1, extraction temperature of 70℃, extraction time of 35 min, solid-to-liquid ratio (g/mL) of 1:35.Under these conditions, the highest extraction yield value reached 67.31 mg GAE/g DW. Furthermore, the polyphenols obtained from Trapa bispinosa Roxb presented significant antioxidant activity through DPPH, ABTS and FRAP methods with the IC₅₀ values of 228.34, 220.57 and 152.00 μg/mL, respectively. The minimal inhibitory concertration (MIC) against Staphyloccocus aureus, Bacillus cereus, Escherichia coli, Shewanella putrefaciens, Penicillium glaucum and Saccharomyces cerevisiae were 6.25, 3.13, 0.20, 0.39, 1.56 and 0.78 mg/mL, respectively. Conclusion:The polyphenols from the stems of Trapa bispinosa Roxb. showed excellent antioxidant and antimicrobial activities, which could be used as a source of potential antioxidant and antimicrobial agents.