不同产地大果山楂总黄酮含量及抗氧化活性

为测定不同产地大果山楂总黄酮含量及其体外抗氧化活性，选用广西、广东10种不同产地的大果山楂鲜果，采用回流提取法和超声提取法对大果山楂总黄酮进行提取；对可见分光光度法进行方法学考察，并采用DPPH自由基清除法和氧自由基吸收法来评价大果山楂体外抗氧化活性。结果表明，超声提取法耗时短、效率高、操作简便，优于回流提取法，适用于大果山楂总黄酮的提取；芦丁在0.008—0.064 mg/mL范围内线性关系良好，R²=0.998 3，平均加样回收率为99.78%（RSD=1.07%），表明可见分光光度法适用于大果山楂总黄酮含量测定；10种产地大果山楂总黄酮含量存在显著差异（P<0.05），其中广西靖西市大果山楂总黄酮含量高达38.61 mg/g，大部分产地的大果山楂总黄酮含量为20.91—32.63 mg/g。体外抗氧化活性结果表明，不同产地大果山楂总黄酮提取液均具有良好的DPPH自由基清除能力和氧自由基吸收能力，以广西靖西市大果山楂总黄酮提取液体外抗氧化效果最佳，其DPPH自由基清除能力的半数清除浓度IC₅₀=（0.048±0.006）mg/mL，氧自由基吸收能力为（39.35±0.42）mg TE/g FW。本研究为大果山楂的原料、产品质量控制，以及功能性食品的开发利用提供一定的理论基础。

Total Flavonoids Content and Antioxidant Activity of Malus doumeri Fruit from Different Producing Areas

In order to determine the total flavonoids content and in vitro antioxidant activity of Malus doumeri fruits from different producing areas, the fresh fruits of M.doumeri from 10 different places in Guangxi and Guangdong were selected, and the total flavonoids extracted by reflux extraction method and ultrasonic extraction method. Methodological investigation was given to visible spectrophotometry. DPPH free radical and oxygen free radical absorption method were adopted to evaluate the in vitro antioxidant activity of M.doumeri fruits. The results showed that compared with the reflux extraction, the ultrasonic extraction was shorter in time, higher in efficiency, and simpler in operation. It was suitable for the extraction of total flavonoids in M.doumeri fruits. Within the range from 0.008 mg/mL to 0.064 mg/mL, the rutin had a good linear relationship, its R² was 0.998 3, and the average recovery rate was 99.78% (RSD=1.07%), which showed that the visible spectrophotometry was suitable for the determination of total flavonoids in M.doumeri fruit. There were significant differences in the total flavonoids of M.doumeri fruit in 10 producing areas (P<0.05). Among them, the total flavonoids content of M.doumeri fruit in Jingxi City of Guangxi was as high as 38.61 mg/g. And in most places the total flavonoids of M.doumeri fruit was between 20.91 mg/g and 32.63 mg/g. The in vitro antioxidant activity results showed that the total flavonoid extract solution of M.doumeri fruits from different production places had good DPPH free radical scavenging ability and oxygen free radical absorption ability. The total flavonoids extract solution of M.doumeri fruits from Jingxi City of Guangxi had the best in vitro antioxidant effect. Its DPPH free radical scavenging ability was as follows: IC₅₀=(0.048±0.006) mg/mL, and the absorption capacity of oxygen free radicals was as follows:(39.35±0.42) mg TE/g FW. This study can provide a certain theoretical basis for the quality control of raw materials and products of M.doumeri fruit and the development and utilization of functional food.