Submitted to: Journal of Radiation Physics and Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/2/2012
Publication Date: 9/14/2012
Citation: Yun, J., Li, X., Fan, X., Zhang, M., Il, W. 2012. Growth and quality of soybean sprouts (Glycine max L. Merrill) as affected by gamma irradiation. Journal of Radiation Physics and Chemistry. http://dx.doi.org/10.1016/j.radphyschem.2012.09.004. Interpretive Summary: The consumption of sprouts has led to a large number of outbreaks of foodborne disease, and irradiation may be used to inactivate pathogens on seeds and sprouts. However, limited information is available regarding the feasibility of irradiation on soybean. This study was conducted to investigate the quality and yield of sprouts as affected by irradiation of seeds and sprouts. Results showed that irradiation of soybean seeds would have limited commercial use due to reduced germination and yield. However, direct irradiation of sprouts at doses up to 3.0 kGy seems feasible to enhance microbial safety. The information is useful for the sprout industry to produce safer sprouts.
Technical Abstract: Soybean sprouts are considered as natural and healthy food by Asian consumers. However, sprouts are often associated with outbreaks of foodborne illnesses and recalls due to contamination of seeds with human pathogens. Irradiation may be used to inactivate pathogens on seeds and sprouts. In this study, soybean seeds and sprouts (Glycine max L. Merrill) were exposed to radiation doses up to 3.0 kGy. The irradiated and non-irradiated seeds were germinated, and then germination rate, sprout length, vitamin C content and antioxidants were determined after irradiation. Visual quality of irradiated sprouts and those from irradiated seeds was also evaluated. Results indicated that there was no significant difference in the germination rate and sprout length between the control and 0.3 kGy treated soybeans, however, the reductions in sprout length of the 1.0 and 3.0 kGy treated samples were quite significant with reductions of 20.4% and 58.8%, respectively, at 5th day of germination. Gamma irradiation of seeds reduced vitamin C content of sprouts while antioxidant potential of sprouts was either not affected or increased by irradiation of seeds. Irradiated sprouts had similar visual quality as the non-irradiated one. Therefore, irradiation of seeds for producing safe soybean sprouts would have limited value in terms of commercial use due to reduced germination and yield. However, direct irradiation of sprouts at doses up to 3.0 kGy seems feasible to enhance microbial safety of sprouts.