Combined compositional analysis and threshold of regulation as a possible control measure for microwave susceptors

A testing scheme is described whereby the susceptor is heated in an enclosed system and potential volatile migrants detected by GC-FID or GC-MS. This compositional information is then combined with knowledge on the relationship between volatility and transfer to foods to predict migration levels. The scheme can be simplified to a threshold of regulation approach by addition of internal standards at suitable concentrations. This approach could be of value in screening new susceptor compositions for potential migrants, followed, as required, by more exhaustive testing using foods or food simulants. In support of this approach, 15 model substances with a boiling range of 77-440 degrees C were incorporated into susceptors via the vapour phase or by formulation into the adhesive. Migration to microwaved foods was measured to provide the required information on the approximate relationship between the boiling point of a potential migrant and its migration level. The impregnated susceptors were also used to measure migration of the model substances to the test simulants Tenax and a semi-solid simulant of olive oil and water absorbed on an inert support. Migration to both simulants was much higher than to foods, indicating that for volatiles analysis at least, both simulants are suitable for screening purposes and err on the side of safety.