Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/12/2005
Publication Date: 9/14/2005
Citation: Fan, X. 2005. Volatile sulfur compounds contribute to the irradiation-induced off-odor in orange juice. IFT/EFFoST Nonthermal Processing Division Workshop, Septerm 15-16, 2005, ERRC, Wyndmoor, PA 19038. Abstract #4, p. 79.
Technical Abstract: Ionizing radiation is an effective technology that inactivates foodborne pathogens in fruit juices and other foods. Some studies have shown that ionizing radiation can cause the development of an off-odor, and volatile sulfur compounds have been suggested to be a possible cause of the off-odor. However, there is no clear evidence connecting sulfur compounds with the off-odor development. In addition, quantitative determination of volatile sulfur compounds in juices has not been reported. Therefore, the objectives of this study were to quantify the effect of ionizing radiation on sulfur compounds, and to study the contribution of the sulfur compounds to the sensory properties of irradiated orange juice. Fresh squeezed ‘Valencia’ orange juice was irradiated at the doses of 0, 0.5, 1.0, 2.0 and 3.0 kGy at 5 C. The juices were analyzed by GC-pulsed flame photometric detection and sensory evaluation. Results showed that 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. The results suggested that volatile sulfur compounds were involved in the development of irradiation-induced off-odor.