Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 22, 2004
Publication Date: September 14, 2004
Citation: Fan, X. 2004. Involvement of volatile sulfur compounds in ionizing radiation-induced off-odor of fresh orange juice. Journal of Food Science. 69(8):C593-C598. Interpretive Summary: Ionizing radiation effectively inactivates foodborne pathogens in fruit juices. However, some studies have shown that ionizing radiation can cause the development of an off-odor. It is unclear what compounds are actually responsible for the off-odor. Therefore, this study was conducted to investigate the involvement of volatile sulfur compounds in the development of off-odor in orange juice using instrumental analysis and sensory evaluation. Results showed that irradiation of fresh orange juice induced formation of several volatile sulfur compounds. Introduction of these volatile compounds to non-irradiated juice caused an odor difference, suggesting that volatile sulfur compounds induced by irradiation play an important role in the development of off-odor in irradiated orange juice. The information will be used by juice industry and researchers to develop strategies to minimize the formation of volatile sulfur compounds.
Technical Abstract: The influences of ionizing radiation on volatile sulfur compounds in fresh Valencia orange juice were analyzed using GC-pulsed flame photometric detection and sensory evaluation. Methyl sulfide (MS) and methanethiol (MT) were induced most followed by dimethyl disulfide and dimethyl trisulfide. Carbon disulfide was reduced by irradiation while hydrogen sulfide was not consistently affected. Sensory evaluation indicated that the odor of irradiated juice differed from the non-irradiated samples at 0.5, 1, 2 or 3 kGy. Addition of the two major irradiation-induced sulfur compounds (MS and MT) into fresh juice made the juice smell different, indicating that those two compounds were probably involved in the development of off-odor.