الفهرس 
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Abstract
Recently there has been a growing interest in the study of the effects of ionizing radiation because there were numerous polluted nuclear-legacy sites leading to the rise in radioactively contaminated sites with the scientific community has a significant interest in the improvement of useful properties by irradiation and the ionizing radiation effects on bioactive compounds. Electron beam radiation processing is used in sterilization, contamination control and the modification of materials, and gamma irradiation is used in sterilization. Also, radiation processing has been widely accepted as an effective means to enhance hygienic quality, extension of shelf-life and overcome quarantine barriers to international trade. Only a few studies are available in the literature about the effect of gamma radiation and electron beam on the molecular structure and antioxidants of seeds. For this reason, the aim of the thesis is to study the effects of gamma radiation ranging from 50 to 500 Gy and from 3 to 11 kGy and electron beam ranging from 3 to 11 kGy on phenolic compounds, antioxidants, chemical composition and morphological structure of Peganum harmala and Portulaca oleracea seeds. To verify these aims, these materials and methods were used Peganum harmala and Portulaca oleracea seeds were used as research samples at gamma doses ranging from 50 to 500 Gy and from 3kGy to 11 kGy, using a cobalt-60 source with a dose rate of 0.863 kGy/h, and electron beam doses (3, 5, 7, 9 and 11 kGy) with dose rate, (4mA - 12.73 m∕min, 8mA- 15.53 m∕min, 8mA- 10.27 m∕min, 8mA- 7.68 m∕min, 8mA- 6.13 m∕min) respectively, at the Egyptian Atomic Energy Authority. Internal structural studied by scanning electron microscope (JEOL JSM-6510LV, Japan), while molecular structure by Nicolet™ iS™ 10 FT-IR Spectrometer from the USA. To quantify the phenolic contents, Folin-Ciocalteu (F-C) assay was used following the procedure reported by Wolfe et al and Issa et al., in which the standard curve of Gallic acid was used. To determine flavonoid content, an aluminum chloride colorimetric assay following the standard curve of Catechin “secondary metabolite” was used. The tannin content was analyzed following the procedure of vanillin-hydrochloride assay in which the absorbance of the sample was measured after treatment with freshly prepared vanillin-hydrochloride. A chemical composition such as fiber, protein, carbohydrate, fat, etc… was determined according to the method described by AOAC (2019). The Results show that : Exposure to gamma radiation ranging from 50 to 500 Gy improved phenolic compounds, superoxide dismutase, DPPH scavenging activity (%) and IC50 with a decline in anthocyanin and ascorbic acid in Peganum harmala and Portulaca oleracea seeds. Superoxide dismutase, DPPH scavenging activity (%) and IC50 for Peganum harmala and Portulaca oleracea seeds increased but phenolic, flavonoid, tannin, anthocyanin and ascorbic acid content varied change after exposure to gamma radiation at 3, 5, 7, 9 and 11 KGy doses. Anthocyanin and ascorbic acid in Peganum harmala and Portulaca oleracea seeds decreased but superoxide dismutase increased after exposure to an electron beam at 3, 5, 7, 9 and 11 KGy doses. Phenolic, flavonoid and tannins contents in Peganum harmala and Portulaca oleracea seeds varied after exposure to an electron beam at 3, 5, 7, 9 and 11 KGy doses. The effect of gamma radiation (G.R) at 5 KGy doses and electron beam (E. B) at 7 KGy doses on the Portulaca oleracea seeds extract, has positive or negative effects on different kinds of bacteria.