Effect of Gamma Irradiation on Some Biochemical Components of Seed Extracts and Microbial Load of Fenugreek (Trigonella foenum-graecum L.) Seeds*

Abstract

The work was carried out to study the effects of gamma
irradiation on microbial load and the content of some biochemical
constituents of fenugreek (Trigonella foenum-graecum) seeds. It was
conducted at the Department of Botany and Agricultural Biotechnology,
Faculty of Agriculture, University of Khartoum and Institute of Botany,
Technische Universität Dresden. Seeds were treated with gamma
irradiation at the doses of 5, 10 and 15 kGy. Bacterial load was reduced
from 1.44 x 106 , in untreated seeds, to 1.5 x 104 , 9.0 x 103 and 5.0 x 102
cfu/g, in seeds treated with5, 10 and 15 kGy, respectively. The stability of
glycosides, phenols and tannins constituents of treated seeds was
evaluated using thin layer chromatography (TLC) and high performance
liquid chromatography (HPLC). The results of TLC analysis revealed that
application of 15 kGy doses of gamma radiation to fenugreek seeds
methanol-extract had no effect on glycosides patterns, and slight
reduction in total phenol and increase in tannins content were observed.
Analysis of methanol extractable compounds by HPLC revealed
variations in the metabolite profile at different wavelengths after
irradiation. While the content of several compounds increased slightly
after gamma irradiation that of some decreased and some constituents
showed no change. Accordingly, there were no major differences in
chemical constituents between the irradiated and un-irradiated samples.