Submitted to: Journal of Radiation Physics and Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/13/2011
Publication Date: 8/1/2012
Citation: Yun, J., Li, X., Fan, X., Yao, T., Xiao, Y., Wan, S. 2012. Effect of gamma irradiation on microbial load, physicochemical and sensory characteristics of soybeans (Glycine max L. Merrill). Journal of Radiation Physics and Chemistry. 81:1198-1202. Interpretive Summary: Ionizing irradiation is an effective technology in reducing spoilage microorgasms of various foods. However, the impact of irradiation on many phytochemicals of soybeans is not clear. In this study, the effects of irradiation on microbial load, sensory properties, 'atulence-causing factors, and other phytochemicals of soybeans were investigated. Results showed a 10.0 kGy dose of gamma irradiation is effective for microbial decontamination of soybean seeds and for reducing 'atulence-causing compounds. However, for maintaining acceptable sensory properties, doses at 5 kGy or lower should be used. The information may be used by the food industry in considering irradiation as a preservation technology for soybean.
Technical Abstract: Gamma irradiation is highly effective in inactivating microorganisms in various foods and offers a safe alternative method of food decontamination. In the present study, soybeans (Glycine max L. Merrill) were treated with 0, 1.0, 3.0, 5.0 and 10.0 KGy of gamma irradiation. Microbial populations on soybeans, iso'avone, tocopherol contents, raffinose family oligosaccharides, color and sensory properties were evaluated as a function of irradiation dose. The results indicated that gamma irradiation reduced aerobic bacteria and fungal load. Irradiation at the doses applied did not cause any significant change (p is greater than 0.05) in the contents of iso'avone of soybeans, but decreased tocopherol contents. The content of key flatulence-producing raffinose family oligosaccharides in irradiated soybeans (10.0 kGy) decreased by 82.1% compared to the control. Sensory analysis showed that the odor of the soybeans was organoleptically acceptable at doses up to 5.0 kGy and no significant differences were observed between irradiated and nonirradiated samples in flavor, texture and color after irradiation.