23个品种柑橘果皮黄酮类含量及抗氧化活性比对研究

Comparative study on flavonoids content and antioxidant activity of 23 kinds of Citrus reticulata Blanco peels

目的确定超声辅助提取柑橘皮黄酮的最佳工艺条件,基于最佳工艺参数,比对研究23个品种柑橘果皮中黄酮类物质含量及抗氧化活性。方法通过单因素及正交实验优化超声辅助乙醇提取柑橘黄酮的最佳工艺条件,使用1,1-二苯基-2-苦基肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)法、铁离子还原法测定体外抗氧化活性,并进行相关性分析和聚类分析。结果总黄酮提取的最优条件为:料液比1:35(g/mL)、乙醇浓度50%、超声时间90 min、超声温度70℃,在此条件下柑橘果皮总黄酮提取量达到8.91 mg RE/g。23种柑橘果皮的总黄酮含量存在较明显差异,介于(4.07±0.01)~(10.92±0.17)mg RE/g之间,其中广西红心蜜柚果皮总黄酮含量最高;在抗氧化能力的表达上,半最大效应浓度(concentration for 50%of maximal effect,EC_(50))值介于(0.36±0.00)~(2.27±0.08)g/L之间;EC1值介于(0.01±0.00)~(0.14±0.00)mmol Fe^(2+)/g之间,广东皇帝柑和马水桔DPPH自由基清除能力最强;云南沃柑的总黄酮含量最低、DPPH自由基清除能力最弱;浙江椪柑皮铁离子还原能力最强,且优劣解距离算法(technique for order preference by similarity to ideal solution,TOPSIS)分析结果显示其综合抗氧化性在23种柑橘皮中表现最优;聚类分析结果显示,柑橘种类与黄酮含量、抗氧化活性之间无明显关联,依据黄酮含量和抗氧化活性差异可将23种柑橘果皮分为3类;总黄酮含量与DPPH自由基清除能力、铁离子还原能力呈显著正相关。结论正交优化后的超声辅助技术可以提高柑橘皮总黄酮的提取效率,提高提取量,23种柑橘皮黄酮中第一、二类黄酮含量较高,具有较好的抗氧化活性,浙江椪柑皮综合抗氧化性最强。

Objective To determine the optimal process conditions for ultrasound-assisted extraction of flavonoids from honey orange peel,and compare the differences in flavonoid content and antioxidant activity among 23 kinds of Citrus reticulata Blanco peels.Method The optimal process conditions for ultrasonic assisted ethanol extraction of Citrus reticulata Blanco flavonoids were optimized by single factor and orthogonal experiments,total flavonoid content,1,1-diphenyl-2-picrylhydrazyl(DPPH)method and Fe3+reduction method were used to determine in vitro antioxidant activity was used for correlation analysis and cluster analysis were investigated.Results The optimum conditions for total flavonoid extraction were the liquid to material ratio of 1:35(g/mL),ethanol concentration of 50%,ultrasound time of 90 min,ultrasound temperature of 70℃,the total flavonoid extraction amount of tangerine peel was 8.91 mg RE/g.The total flavonoid of 23 kinds of Citrus reticulata Blanco peels varied significantly,ranging from(4.07±0.01)to(10.92±0.17)mg RE/g;the concentration for 50%of maximal effect(EC_(50))values of DPPH radical scavenging ability ranged from(0.36±0.00)to(2.27±0.008)g/L;the EC1 values of ferric ion reduction ability ranged from(0.01±0.00)to(0.14±0.00)mmol Fe^(2+)/g.The total flavonoid of Guangxi red heart grapefruit was the highest,and the DPPH radical scavenging ability of Guangdong emperor mandarin and Ma Shui orange was the strongest;the total flavonoid and the DPPH radical scavenging ability of Yunnan wok mandarin was the weakest;the iron ion reducing ability of Zhejiang ponkan peel was the strongest,and the weakest was Fujian red heart grapefruit peel.Technique for order preference by similarity to ideal solution(TOPSIS)analysis showed that Zhejiang ponkan peels had the strongest comprehensive antioxidant capacity.Based on the differences in flavonoid content and antioxidant activity,there was no correlation between Citrus reticulata Blanco species and flavonoid content and antioxidant activity.And the peels of 23 different Citrus reticulata Blanco varieties could be divided into 3 categories;total flavonoid content was proportional to the DPPH radical scavenging ability and iron ion reducing ability.Conclusion The orthogonally optimized ultrasound-assisted technique can improve the efficiency and increase the extraction of total flavonoids from Citrus reticulata Blanco peels,and 23 kinds of Citrus reticulata Blanco flavonoids with higher content of the first and second flavonoids have better antioxidant activities,and the Zhejiang ponkan peels have the strongest comprehensive antioxidant properties.