Formation of Hydrocarbons in Irradiated Brazilian Beans:  Gas Chromatographic Analysis To Detect Radiation Processing

Radiation processing of beans, which are a major source of dietary protein in Brazil, is a valuable alternative to chemical fumigation to combat postharvest losses due to insect infestation. To ensure free consumer choice, irradiated food will be labeled as such, and to enforce labeling, analytical methods to detect the irradiation treatment in the food product itself are desirable. In two varieties of Brazilian beans, Carioca and Macaçar beans, the radiolytic formation of hydrocarbons formed after α and β cleavage, with regard to the carbonyl group in triglycerides, have been studied. Using gas chromatographic analysis of these radiolytic hydrocarbons, different yields per precursor fatty acid are observed for the two types of beans. However, the typical degradation pattern allows the identification of the irradiation treatment in both bean varieties, even after 6 months of storage. Keywords: Food irradiation; irradiation identification; beans; Phaseolus vulgaris L.; Vigna unguiculata L. Walp; gas chromatography; hydrocarbons