不同采收期宁夏枸杞果实品质差异及抗氧化特性分析

Study on the quality differences and antioxidant properties of Lycium barbarum fruits at different harvesting periods

以宁夏枸杞(Lycium barbarum)果实为试材,通过理化指标的测定比较了不同采收期果实品质及抗氧化能力的差异。结果表明,采收季初期的枸杞果实(头茬果)的纵径、单果表面积、百粒鲜重和百粒干重最大,干果粒度最小,外观品质相对较好;采收季末期的果实中总酚、维生素E、类胡萝卜素、氨基酸、蛋白质和糖类物质的积累较为丰富,营养品质相对较好;采收季中期的果实中抗坏血酸(AsA)含量较高,采收季初期和末期的果实中谷胱甘肽(GSH)积累丰富且抗氧化能力较强,在食品保健价值方面更具优势。L-半乳糖-1,4-内酯脱氢酶(GalLDH)、脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)的活性变化及其基因表达趋势与AsA和GSH积累趋势相似,其中GalLDH活性及其基因表达量与AsA含量有较高的正相关关系,DHAR和GR活性及其基因表达量分别与AsA、GSH含量呈显著正相关关系。该研究结果为改善宁夏枸杞果实品质和开发利用其药用价值提供了参考。

The differences in fruit quality and antioxidant capacity between different harvesting periods were compared by the determination of physicochemical indexes using Lycium barbarum fruits as test material.The results showed that the longitudinal diameter,surface area of single fruit,100-grain fresh weight and 100-grain dry weight were the largest,the grain size of dried fruit was the smallest,and the appearance quality of wolfberry fruits(the first crop fruits)at the beginning of the harvesting season was relatively good.The accumulation of total phenols,vitamin E,carotenoids,amino acids,proteins and saccharides in the fruits at the end of the harvesting season was relatively abundant,and the nutritional quality was relatively good.The ascorbic acid(AsA)content was higher in fruits at the middle of the harvesting season,and the accumulation of glutathione(GSH)was abundant and had strong antioxidant capacity in fruits at the beginning and end of the harvesting season,which were more advantageous in terms of food health value.The activity changes and gene expression trends of L-galactono-1,4-lactone dehydrogenase(GalLDH),dehydroascorbate reductase(DHAR),and glutathione reductase(GR)were similar to the accumulation trends of AsA and GSH.Among them,GalLDH activity and its gene expression level were positively correlated with AsA content,DHAR and GR activities and their gene expression levels were correlated with AsA and GSH content,respectively.The results of this study provide reference for the improvement of fruit quality and the development and utilization of medicinal value of Lycium barbarum.