重庆地方名柚果肉酚类物质含量及其抗氧化活性分析

Phenolic Compositions and Antioxidant Capacity of the Fruit Pulp of Popular Pomelo Cultivars in Chongqing

通过紫外分光光度计法和高效液相色谱法分别测定10种重庆地方名柚成熟果实囊衣、汁胞2个部位的总酚、总黄酮含量及类黄酮、酚酸组分和含量,并采用1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)、铁离子还原能力(ferric reducing antioxidant power,FRAP)测定、2,2’-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS)3种方法对其抗氧化活性进行评价。结果表明:囊衣的总黄酮含量和类黄酮含量较高,‘琯溪蜜柚’总黄酮含量最高达10.97 mg/g,类黄酮中地奥司明含量最高,均值为1 000.72μg/g,其含量最高为‘五布柚’,达到2 366.77μg/g;汁胞的总酚含量和酚酸含量较高,‘真龙柚3号’总酚含量最高达8.84 mg/g,酚酸中没食子酸含量最高,均值为1 040.16μg/g,其含量最高为‘长寿沙田柚’,达到1 325.89μg/g。利用DPPH法和FRAP法测定2个部位抗氧化活性,汁胞高于囊衣,ABTS法则囊衣高于汁胞。综合抗氧化能力指数表明,‘琯溪蜜柚’囊衣、‘梁平柚78-8’汁胞的抗氧化活性最强。通过本研究,不仅能够了解重庆地方名柚果实囊衣、汁胞部位酚类物质组分和含量,同时为柑橘酚类物质的应用选择提供了一定的理论依据,促进了柑橘果品营养学的发展。

In this study, ultraviolet spectrophotometry and high performance liquid chromatography（HPLC） were used to determine the contents of phenols and flavonoids in the segment membrane（SM） and juice sac（JS） of 10 popular cultivars of pomelo（Citrus grandis） in Chongqing. In addition, the antioxidant capacities of these two parts were evaluated by 1,1-diphenyl-2-picrylhydrazyl radical）（DPPH）, ferric reducing antioxidant power（FRAP） and 2,2＇-azinobis-（3-ethylbenzthiazoline-6-sulphonate）（ABTS） methods. Results showed that total flavonoids and the individual contents of 10 measured flavonoid compounds were higher in the SM. The total flavonoid content of ‘Guanxi＇ pomelo was the highest（10.97 mg/g）. Among the flavonoids, diosmin was the most abundant with an average of 1 000.72 μg/g. Among 10 cultivars, ‘Wubu＇ had the highest diosmin content（2 366.77 μg/g）. However, the contents of total phenolic compounds and phenolic acid were higher in the JS. The highest total phenolic content of 8.84 mg/g was found in ‘Zhenlongyou No. 3＇. Gallic acid was the most predominant phenolic acid with an average of 1 040.16 μg/g and its highest level of 1 325.89 μg/g was noted in ‘Changshou Shatian＇. The JS was found to have stronger DPPH radical scavenging and FRAP capacity, but exhibit weaker ABTS radical scavenging capacity than the SM. Overall, the segment membrane of ‘Guanxi＇ and the juice sac of ‘Liangpingyou 78-8＇ possessed the highest antioxidant activity. This study not only reveals the phenolic composition of the SM and JS of the popular pomelo cultivars in Chongqing, but also offers a theoretical basis for utilizing the phenolics in citrus and promoting the development of nutritional studies on citrus fruits.