超声处理对琯溪蜜柚果皮中酚酸含量及抗氧化性的影响

Effect of Ultrasonic Treatment on Phenolic Acid Content and Antioxidant Capacity of Guanxi Pomelo Peel Extract

应用超声波强化提取琯溪蜜柚果皮中的酚酸组分,探讨超声因素(超声时间、温度、超声能量)对酚酸含量及抗氧化性的影响。利用高效液相色谱检测琯溪蜜柚果皮中的7种酚酸含量;分别采用福林酚法及铁离子还原力法(FRAP法)对超声提取物的抗氧化性进行评价。结果表明:琯溪蜜柚果皮中芥子酸含量最高,7种酚酸含量均随超声时间和温度的增加而增加,但是在40℃超声处理60min后造成酚酸含量的显著降低,同样超声功率对酚酸含量也有积极的影响。此外,超声时间、温度及超声功率对总酚含量也呈现出显著的影响。超声处理后,总酚与抗氧化能力(TEAC值)有良好的线性关系,在30、40℃的提取温度(分别处理10、20、30、45、60min)和4个超声功率(3.2、8、30、56W)水平下,R2依次为0.8832、0.8874、0.9397,表明琯溪蜜柚皮中提取物的抗氧化性可能与总酚有关,超声处理可以显著提高琯溪蜜柚果皮提取物的抗氧化能力。

Ultrasound technology was applied to extract phenolic components from Guanxi pomelo peels.Effects of ultrasonic treatment parameters including ultrasonic treatment time,ultrasonic treatment temperature and ultrasonic treatment power on the content and antioxidant capacity of phenolic acids were explored.Totally 7 phenolic acids were determined by HPLC-PDA.Folin-Ciocalteu method and ferric reducing antioxidant power（FRAP） assay were adopted to evaluate the antioxidant capacity of the extracts obtained by ultrasonic treatment.The results showed that sinapic acid content was the highest in Guanxi pomelo peels,and the contents of seven phenolic acids were increased with the increase of treatment time and temperature.However,the contents of phenolic acids exhibited a decrease after ultrasonic treatment at 40 ℃ for 60 min.Ultrasonic treatment power revealed a positive effect on the contents of phenolic acids.Furthermore,ultrasonic treatment parameters had significantly effect on the content of total phenolic acids.A linear relationship was observed between Trolox-equivalent antioxidant capacity（TEAC） value and the content of total phenolic acids after ultrasonic treatments with correlation coefficients of 0.8832 at 30 ℃,0.8874 at 40 ℃（the length of treatment time varied from 10,20,30,45 to 60 min at both temperature levels）,and 0.9397 at four ultrasonic power levels,respectively.Therefore,the antioxidant activity of Guanxi pomelo peel extract was correlated with the content of total phenolic acids,and obviously improved by ultrasonic treatment.