USAGE OF GAMMA RAY FOR PRESERVATION OF SOME CROPS CULTIVATED IN EGYPT AND SUDAN.

Abstract

Peanut, maize, fenugreek and coriander crops were choice for their economic important as food, feed, raw materials in food and medicinal industries and cultivated in Egypt and Sudan. Seeds of these crops can be infected by several types of fungi in field, handling & during storage. At post - harvest of the seeds of these crops, percentage of seed invasion was 40.75, 47.75, 27.0 & 39.0% respectively and the average of the fungal count isolates isolated from each type of seeds were 54.5, II 0. 75, 30.0 & 63.0 respectively. The predominant fungi for each type of seeds were A.1pergi!lus jlavus & A.ochraceus for peanut, Fusarium monilijimne & Ajlavus for mazie, Ajimzigatus & Penicillium expansum for fenugreek, A.jinnigatus & F oxysporium for coriander. All these fungi were pathogenic for the seeds from that they were isolated and some of these fungi were mycotoxigenic, whereas Ajlavus produced Aflatoxins (A 1 , A2, G 1 & G2), A.ochraceus produced Oclu•atoxin A. and both the Fusaria species produced zearalenone. In study of the effect of gamma rays on the predominant fungi it was noticed that increasing of the inadiation doses caused significant decrease itthe percentage of spore getmination, mycelial dty weight, enzymatic activity and mycotoxin production Exposure of the tested seeds for different inadiation dose levels (0.0 - 10.0 kGy) and their storage for 12 months under ambient temperature, it was observed that increasing of inadiation doses caused decrease of the total isolated fungal counts according to their sensitivity to irradiation and complete elimination of fungi were at 7.5 kGy dose in all tested seeds at the begging of storage and at 12 months of storage. Also there was a significant decrease in percentage of seed invasion, seed gennination, seed discolouration and seedling length. There was no remarkable changes in the main chemical constituents of the tested seeds as moisture, ash, fiber, total carbohydrates, total soluble sugars, reducing sugars, non-reducing sugars, protein, total free amino acids, fixed oils and their physical and chemical propet1ies, fatty acids composition, volatile oils and their constituents. In screening for the presence of the mycotoxins, it was noticed the absence of these mycotoxins in all the itTadiated tested seeds at dose level 7.5 kGy dose at the begging of storage and tell 12 moths of storage. From these study it was found that using of gamma rays for preservation of agricultural crops during storage for using as food, feed & food, m1d medicinai industries was the best physical preservation method licensed in several countries due to the absenc:: of any chemical changes 111 their constituents or any side effect on the public health.