Involvement of volatile sulfur compounds in ionizing radiation-induced off-odor of fresh orange juice

The influences of ionizing radiation on volatile sulfur compounds in fresh Valencia orange juice were analyzed using gas chromatography (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 nonirradiated samples at 0.5, 1, 2, or 3 kGy. Addition of the 2 major irradiation-induced sulfur compounds (MS and MT) into fresh juice changed the juice odor, indicating that those 2 compounds were probably involved in the development of irradiation-induced off-odor.