薄壳山核桃种仁中酚类成分含量和抗氧化能力差异分析及优株筛选

Analyses on phenolics content and difference in antioxidant ability of kernel of Carya illinoinensis and superior individuals screening

以南京地区的76株薄壳山核桃[Carya illinoinensis (Wangenh.) K. Koch]单株为研究对象,比较各单株种仁中总黄酮、缩合单宁、总酚、没食子酸、儿茶素、表儿茶素、表没食子儿茶素没食子酸酯和鞣花酸含量以及总酚提取物对DPPH·和ABTS+·清除能力共10个指标的差异,并对各指标的相关性进行分析;分别依据这10个指标对76株单株进行排序,筛选出高酚类含量和高抗氧化能力的单株。结果显示:供试76株单株种仁中总黄酮、缩合单宁和总酚含量的平均值分别为3. 08、18. 65和11. 73 mg·g-1,其变异系数分别为34. 22%、40. 11%和31. 75%; 5种酚类化合物中,儿茶素含量的平均值最高(1. 39 mg·g-1),没食子酸含量的平均值最低(0. 09 mg·g-1),变异系数均在48%以上,以表儿茶素含量的变异系数最高(90. 26%);总酚提取物对DPPH·和ABTS+·清除能力的平均值分别为249. 61和207. 77μmol·g-1,其变异系数分别为44. 14%和34. 80%。排序结果显示:供试76株单株具有不同的优势特征,且各指标排名前10的单株均不相同。其中,除表没食子儿茶素没食子酸酯含量外,70号单株种仁的其他9个指标均排名前3,其中5个指标排名第1; 30号和29号单株也有6个酚类成分含量指标排名前6; 62号、69号和34号单株的2个抗氧化能力指标均排名前10。相关性分析结果显示:除表没食子儿茶素没食子酸酯含量外,其他7个酚类成分含量与总酚提取物的抗氧化能力均呈极显著(P<0. 01)正相关,而果实性状指标与总酚提取物抗氧化能力总体上无显著相关性。研究结果表明:薄壳山核桃单株种仁中酚类成分含量与总酚提取物抗氧化能力密切相关,且不同单株种仁中各指标差异明显。根据各单株的优势特征和不同的选育目标,建议将70号单株作为高酚类含量和高抗氧化能力的双优单株,30号和29号单株可作为高酚类含量的优选单株,62号、69号和34号单株可作为高抗氧化能力的优选单株。

Taking 76 individuals of Carya illinoinensis （Wangenh.） K. Koch in Nanjing as research objects, differences in ten indexes of total flavonoids, condensed tannins, total phenolics, gallic acid,（ ＋）-catechin, （-）-epicatechin, （-）-epigallocatechin gallate and ellagic acid contents, and scavenging abilities of total phenolic extracts to DPPH·and ABTS＋·from kernel of individuals were compared, and correlations among each index were analyzed. 76 individuals were ranked according to these ten indexes,respectively, and individuals with high phenolics content and high antioxidant ability were screened out.The results show that mean of contents of total flavonoids, condensed tannins and total phenolics in kernelof 76 individuals tested are 3. 08, 18. 65 and 11. 73 mg·g^-1, and their coefficients of variation are34. 22%, 40. 11% and 31. 75%, respectively. Among five phenolic compounds, mean of content of （＋）.catechin is the highest （1. 39 mg·g^-1）, and that of gallic acid is the lowest （0. 09 mg·g^-1）, theircoefficients of variation are all above 48%, and that of （ - ）.epicatechin content is the highest（90. 26%）. Means of scavenging ability of total phenolic extracts to DPPH·and ABTS＋·are 249. 61 and207. 77 μmol·g^-1, and their coefficients of variation are 44. 14% and 34. 80%, respectively. Theranking result shows that 76 individuals tested have different advantage characteristics, and top 10 individuals of each index are different. In which, except （-）-epigallocatechin gallate content, other nineindexes of kernel of No. 70 individual all rank top 3 with five indexes of top 1. No. 30 and No. 29individuals also have six phenolics content indexes rank top 6. Two antioxidant ability indexes of No. 62,No. 69 and No. 34 individuals all rank top 10. The correlation analysis results show that except （ -）-epigallocatechin gallate content, there are extremely significantly （P〈0. 01） positive correlations of otherseven phenolics contents with antioxidant ability of total phenolic extracts, however, there is nosignificant correlation of fruit trait indexes with antioxidant ability of total phenolic extracts in general. The research results show that phenolics content in kernel of individuals of C. illinoinensis is closely related to antioxidant ability of total phenolic extracts, and differences in each index of kernel of differentindividuals are obvious. According to advantage characteristics of each individual and different breeding targets, it is suggested that No. 70 individual can be used as double superior individual with high phenolics content and high antioxidant ability, No. 30 and No. 29 individuals can be used as superiorindividuals with high phenolics content, and No. 62, No. 69 and No. 34 individuals can be used as superior individuals with high antioxidant ability.