Effect Of Gamma Irradiation On The Ingredients Of Herbs And Detection Analysis Methods For Irradiated Herbs By Thermoluminescence

Herbs, especially Chinese herbs, have been essential in diets, health supplements, andtraditional medicines since ancient times. It is still a common practice in many parts of theworld to collect herbs and store them dried for long periods. In recent years, irradiation oftraditional Chinese herbs with60Co-γrays has been a predominant sterilization methodduring storage and transport against microbial deterioration or insect infestation in order tomaintain hygienic quality, ensure shelf life, and thereby reduce the threat to public health.Unlike other sterilization methods such as fumigation and thermal treatment, these methodscan pose occupational health hazard with environment ally destructive toxic chemicals,irradiation technique is very fast, cost effective, and provides a wild range of disinfectingapplications for dry ingredients.In this paper, we have studied on the chemical composition and analytical techniquesfor identifying irradiated or non-irradiated, including four aspects:1、 The study of sterilization effect by60Co-γ ray irradiationThe samples were irradiated with different doses respectively. The results showed that60Co-γ-ray irradiation has a good effect on sterilization efficiency, and the higher dose ofradiation the better sterilization effect. The initial number of colonies in the sample effectimpact on irradiation sterilization, the number of colonies in the initial sample is higher, theirradiation dose for greater sterilization is more.The samples were stored for3months,6months,9months and18months in order toexamine the effects of irradiation on the microbiological. Irradiation herbs have a muchlonger shelf life. The total bacterial populations of irradiated2、Effect of irradiation on the chemical composition of traditional Chinese medicineThe main chromatographic fingerprint peaks of ginseng, Panax quinquefolius, Panaxnotoginseng FH chen, licorice and schisandra were established for evaluating the stabilityof chemical compositions of Rhizoma gastrodiae with60Co-γ irradiation to control the dosage of60Co-γ irradiation sterilization by high performance liquid chromatography(HPLC). The results show that radiation dose levels have different effects on ginsenosides.Below8kGy, irradiation has little effect on them. Ginsenoside Re and Rd in irradiated at thedose of10kGy, saponin content began to decrease. After irradiation of Panax quinquefolius,four kinds of saponin content changes and the ginsenoside Rg2content increased. Panaxnotoginseng FH chen after irradiation with two kinds of saponin content change. Irradiationpromoted in licorice of liquiritin and glycyrrhizicacid in chemical reaction, which make itscontent to have the change,and with the increase of irradiation dose chemical componentcontent decreased. The composition structure of same original Schisandra in differentradiation dose was same, possibly due to the lignan compound belongs biphenyl cyclooctene,which helps to increase the stability of the benzene ring of anti-radiation.Studies on the chemical constituents of different irradiation doses of ginseng, Americanginseng, Panax, licorice and Schisandra by using high performance liquid ChromatographChanges in composition of dried ginseng, American ginseng, Panax, licorice and schisan andin composition of the irradiated samples chemical composition were analyzed. The resultsshowed that low doses of radiation has no significant effect on the chemical composition offive Chinese medicine ingredients and high dose irradiation causes a change in medicine.Dried herbs has a good ability of anti-radiation,almost no change in the chemicalcomposition of the content. The chemical composition of the irradiated medicine afterstorage at different times did not change significantly.3、Antioxidant activity of irradiated Chinese herbsThe antioxidant activity of different irradiated doses Chinese herbal medicines had beensuccessfully studied by the ferric reducing antioxidant power (FRAP) and radical scavenging(DPPH) methods. The results showed that low doses of radiation has no effect on antioxidantactivity of five kinds of traditional Chinese medicine. When the radiation dose is greater than5kGy, the antioxidant activity of five kinds of Chinese medicine have increased slightly.4、The identification of irradiated herbs by TL analytical methodsThe feasibility of thermoluminescence (TL) to differentiate irradiated Chinese medicinalherbs from non-irradiated was investigated. Thirty different dried Chinese herbs were tested, including root, flower, ramulus, rhizome, cortex, and whole plant samples. Irradiation ofChinese herbs was associated with strong TL peaks at~150-250°C, while TL curves ofnon-irradiated herbs had very low intensities above250°C, which was also confirmed by theTL ratio (non-irradiated, TL1/TL2<0.1). The ability to determine the irradiation dose by theTL method was influenced by the amount and types of minerals in the samples. All levels ofirradiation doses could be detected when between0.1and1.0kGy, except for three herbs at0.1kGy dose. Different blends with small quantities (0.1-10%) of irradiated herbs were alsotested in this study. Samples with powder mixtures containing1%irradiated componentscould be differentiated (TL1/TL2>0.1) except for sterculialychnophora, semen cassia,flosinulae, and anemone root. TL ratios of some herbs indicated irradiation (TL1/TL2>0.1)even if the irradiated components were as low as0.1%. The shape of thermoluminescenceglow curve shape had no obvious change with the storage time and the intensity ofthermoluminescence with the storage time has the tendency to weaken, even if the18months storage time for the irradiated samples, its intensity is far higher than that ofnon-irradiated samples. Sample blind detection results show that irradiation dose, which isused in1kGy after storage for18months, the accuracy rate of TL method is still100%.