超高压处理对茶多酚提取率和抗DPPH自由基活性的影响

Effects of Ultra-high Pressure Treatment on Extraction Rate Tea of Polyphenols and Antioxidant Activity of Ethanol Extract of Tea

研究超高压处理对茶多酚提取率和抗自由基活性的影响。结果表明,茶多酚的最佳提取工艺参数为:提取压力500MPa,保压时间10min,提取溶剂为体积分数50%乙醇水溶液,在此最优工艺条件下茶多酚的提取率为19.43%。较高的处理压力和较长的处理时间均有利于茶多酚的溶出。另外,随着处理时间的延长,提取液对DPPH自由基的清除率明显提高,保压时间5min以上时,抗自由基活性趋于稳定。实验范围内,随着处理压力的上升,提取液对DPPH自由基的清除率呈逐渐上升趋势。

Ultra-high pressure technology was applied to the extraction of effective components from tea for the purpose of improving their dissolution and keeping natural quality of tea at the same time. The effects of ultra-high pressure treatment on extraction rate of tea polyphenols and DPPH radical scavenging activity of 50% ethanol extract of tea were studied. A maximum extraction rate of tea polyphenols of 19.43% was obtained under the optimized conditions： extraction pressure, 500 MPa; pressure holding time, 10 min; and extraction solvent, 50% ethanol solution. High pressure and long treatment time both were effective for the dissolution of tea polyphenols. Moreover, the DPPH radical scavenging activity went up significantly, with the prolongation of pressure holding time at the initial stage, and then it tended to stable when the holding time was over 5 min. In the experimental range, the DPPH radical scavenging activity tended to increase progressively, with the increase of treatment pressure.