Antioxidant Property of Naked Oat Core Collections

Abstract

Naked oat(Avena nuda L.) originated in China,has a high values in nutrition and medicine.Besides dietary fiber and nutrients,various natural antioxidants,such as phenolic compounds,phenolic acids,avenanthramides(unique to oats) and phytosterols are also contained in naked oat.All these compounds possess potential health-promoting properties,partly attributing to their antioxidant activity.Up to now,China has built the core of naked oat germplasm with the greatest diversity of naked oat types.The objective of this study was to determine the total phenol(TP),total avenanthramides(TAV),β-glucan contents and the antioxidant activity of oat cultivars from main productive areas of China as well as Former Soviet Union and North America.The correlation of antioxidant activities with contents of these components was also statistically investigated,which is benefit for oat breeding.The antioxidant activities,contents of TP,TAV,and β-glucan of 120 naked oat accessions were evaluated by Folin-Ciocalteu method,HPLC analysis and enzymatic method,respectively.Meanwhile,the antioxidant capacity was determined by 1,1-Diphenyl-2-picrylhydrazyl radical(DPPH) scavenging ability method.Significantly genotypic variations were observed,and contents of TP,TAV,and β-glucan were 4.34–179.98 mg L-1,250.99–807.88 mg kg-1,25.21–347.55 mg kg-1,and 0.59–9.69% respectively.The 120 accessions were clustered into six groups using K-mean cluster method,which consisted of 20,39,2,22,12,and 25 accessions respectively.There were significantly positive correlations between antioxidant activity and the contents of TP and TAV.However,the correlation between β-glucan and DPPH was not significant.These results indicated that avenanthramides contributed greatly to the antioxidant property in naked oat grains.A relative wide variations in TAV and TP contents and compositions were mainly due to differences among cultivars.Duji from Sichuan province and Yumai 38 from Qinghai province with high contents of TP and TAV are expected to be used in further quality breeding of naked oat.