基于叶序变化的枇杷叶抗氧化性研究

研究不同品种以及不同叶序枇杷叶之间抗氧化指标的变化，为枇杷叶的合理高效利用提供理论依据。以生长在同一地区的6个枇杷品种为研究材料，分别自顶端向下采集树冠外围枝条上的第1、第3、第5、第7、第9叶序的叶片，检测总酚、黄酮、总三萜酸质量分数，并用FRAP法、ABTS法和DPPH法分析抗氧化活性。结果表明，6个抗氧化指标在供试枇杷品种枝条不同叶序叶片间存在差异。‘大五星’、‘马克’、‘佳伶’3个品种枇杷叶6个抗氧化指标均随叶序的增加而上升，但此趋势在其他3个品种枇杷叶中变化不明显。6个枇杷品种间各个抗氧化指标大小顺序一致，‘大五星’枇杷叶片最高，其次为‘马克’、‘佳伶’，‘白茂木’与‘麦后黄’相差不大，‘长崎早生’最小。枇杷叶FRAP值、ABTS值和DPPH值与总酚、黄酮和总三萜酸质量分数均存在极显著正相关关系。因此在进行枇杷叶抗氧化开发利用时，应考虑枇杷叶品种和采摘叶序的影响。

Antioxidant Activity of Loquat Leaf Based on Leaf Arrangement Change

The changes of antioxidant indexes among different loquat cultivars and leaves with different leaf arrangements were studied to provide theoretical basis for rational and efficient utilization of loquat leaves.Six loquat varieties growing in the same area were used as research materials,and leaves with the leaf arrangements of the 1^st,3^rd,5^th,7^th and 9^th on the outer branches of the crown were collected from the top to down.Six antioxidant indexes were measured,including the contents of total phenolics,flavonoids,and triterpenic acid,FRAP value,ABTS value and DPPH free radical scavenging activity.The results showed that 6 antioxidant indexes were different among different leaf arrangements and loquat cultivars.The 6 antioxidant indexes of the leaves of the cultivar ‘Dawuxing’,‘Mark’ and ‘Jialin’ increased with the increase of leaf arrangement,but this trend was not obvious in the leaves of the other 3 cultivars.Among the 6 loquat cultivars,the order of antioxidant indexes was the same,the leaves of the cultivar ‘Dawuxing’ were the highest,next were ‘Mark’ and ‘Jialin’ and little difference was found between cultivar ‘Baimaomu’ and ‘Maihouhuang’,while the leaves of cultivar ‘Changqizaosheng’ were the lowest.The values of FRAP,ABTS and DPPH free radical of loquat leaves were highly significantly and positively correlated with total phenolic,flavonoids and total triterpenic acid.Therefore,the effects of loquat leaf cultivar and picking leaf arrangement should be considered in the antioxidant development and utilization of loquat leaves.