Study On The Antioxidation And Ten Kinds Of Metal Content Of The Herbs Yielded In Guizhou

Nowadays people is more and more worried about the problem of biosafety of the synthetic antioxidants.So more attentions have been paid to find effective and safe natural antioxidants, which has become one of the main topics in the field of the food chemistry.18 plants yielded in Guizhou has been chosen to evaluate their antioxidant activities.According to plants' function,those herbs were divided into three kinds: potherbs,heat-clearing and toxic-resolving herbs,Chinese tonic herbs.The experiments of eliminating DPPH·,·OH were conducted on the 18 herbs respectively,whose antioxidant activities were evaluated by the value of IC₅₀.The antioxidant activities of the 18 herbs in rapeseed oil were determined by Schaal oven-storage and free radical scavenging test.With the development of the industry,the pollution of environment is becoming more and more serious.The contamination of heavy metals is one of the problem.Much more attention has been paid to the concentrations of heavy metals in the edible plants.Meanwhile the contents of nutritious metals contained in food are concerned,too.In order to provide scientific data for the further development of the 18 plants, the contents of five heavy metals and five nutritious metals have been determined by atomic fluorescence spectrometer and atomic absorption spectrometer.The results of the experiment are as follow:1.The water or 95%ethanol extract from the 18 plants all have certain antioxidant activities in the system of hydroxyl radical—salicylic acid.And the antioxidant activities of water extract is different from ethanol extraction from the same plants.As to scavenging activities towards hydroxyl radical of water extract,cress is the strongest,while ophiopogon root is the weakest;in terms of the ethanol extract, Indigowoad root is the strongest,while Manyflower Solomonseal Rhizome is the weakest.2.DPPH·spectrophometric analysis has been used to evaluate the antioxidant capacity of the water and ethanol extract from the 18 herbs.The results indicate that all water or ethanol extract from the herbs shows certain antioxidant capacity,which varies each other.Regarding the capacity of scavenging DPPH·radical,the water extract from Polygonum capitatum and Chinese knotweed is the strongest,while the water extract of Heterophylly Falsestarwort Root is the weakest;the ethanol extract from Polygonum capitatum and Chinese knotweed is the strongest,while the ethanol extract from ophiopogon root is the weakest.3.According to Arrhenius equation and the connection of reaction velocity constant and shelf lives,the guarantee period of rapeseed oil mixed with herb powders can be predicted. The shelf lives of rapeseed oil added with different plant powders can be prolongated to certain extent.As regards the antioxidant capacity of the 18 plants,Chenopodium album linn is the strongest,while Epimedium brevicornum maxim is the weakest.When it's 20℃,the shelf lives of rapeseed oil with Chenopodium album linn powder could be increased from 5.22 months to 18.62 months.The shelf lives of rapeseed oil with Epimedium brevicornum maxim powder could only be increased from 5.22 months to 5.72 months.4.The contents of heavy metals in the 6 potherbs are generally lower than those in 12 the Chinese medicinal herbs. But the allowed contents of the heavy metals in the plants are less than those in the Chinese medicinal herbs.As a result,except Picris divaricata Vaniot and cress,several index of heavy metals in the other 4 potherbs are beyond the allowed limitation.For example,the content of Hg in Chenopodium album Linn and Pteridum aquilinum var latiusculum is more than standard value to a certain degree. The content of Cd in Chenopodium album Linn,Purslane,Pteridum aquilinum var latiusculum and bengal waterdropwort herb is beyond the allowed scope.The content of Pb in Purslane and Pteridum aquilinum var latiusculum is more than standard index too.The contents of five heavy metals in Chinese medicinal herbs are within standard value except Gentiana scabra,Atractylodes macrocephala Koidz and Polygonum multiflorum.The content of Cd in Gentiana scabra is 10.33 times the standard value.The content of As in Atractylodes macrocephala Koidz is 2.3 times the standard value.The content of As in Polygonum multiflorum is 1.7 times the standard value.The results of the experiments also shows that the 18 plants contain abundant nutritious elements,such as Ca,Fe,Mg,Mn,Zn.