Screening of South African Food Plants for Antioxidant Activity

ABSTRACT: In a screening of South African indigenous food plants for antioxidant activity by testing for inhibition of lipid peroxidation, the "potherbs" Amaranthus sp., Sisymbrium thellungii , and Urtica dioica had very high activity. This activity was greatest in the boiled extract of Amaranthus sp. and the boilet and aqueous extracts of Sisymbrium thellungii and Urtica dioica. The activity in the aqueous extract of Nasturtium aquatica was lost by boiling. High activity was also obtained with the teas Galium aparine and Aspalathus linearis (Rooibos) and with the tuber Colocasia esculenta.     

6种黔产野菜抗氧化性能的研究

共选取6种黔产野菜灰灰菜、蕨菜、马齿苋、剪刀菜、西洋菜、水芹菜,测定其水提取液和乙醇提取液对·OH和DPPH自由基的清除能力,并采用IC50对其抗氧化能力进行评价,以油脂抗氧化实验研究其抗菜籽油和猪油氧化的能力。结果表明,这6种野菜对·OH和DPPH自由基均具有一定抗氧化作用,并且能很好地抑制菜籽油和猪油氧化,但水芹菜对猪油有一定的促氧化作用。     

贮藏方式对三种野菜品质的影响

实验通过对运城市常见3种野菜荠菜、藜菜和苣荬菜分别进行冷藏、冷冻、盐渍、常温放置4种处理,测定了其Vc、硝酸盐和蛋白质含量。结果表明,4种贮藏方式对野菜品质的影响有显著差异,盐渍对野菜中蛋白质,Vc的含量降低最多,冷藏处理则最少;盐渍对野菜中硝酸盐的含量增加最多,冷冻处理则最少。贮藏后3种野菜中蛋白质、Vc的含量均低于鲜样,硝酸盐均高于鲜样。测定方法简便快速准确,对指导人们合理食用野菜和进一步开发野菜提供了可靠的理论依据。