Abstract
Under normal sealing and storage conditions, nylon-6, poly (caprolactam)-based plastic laminates may release impurities to packaged foods and liquids, and the application of heat for cooking often increases the rate of migration. Epsilon-caprolactam is one of the main contaminates found to migrate from a nylon-6 poly (caprolactam) plastic film. The objectives of this study were to determine the effects of solvent, transportation, and storage time on the concentration of ε-caprolactam from a nylon-6-based lidding material in water or a white wine substitute (12 % ethanol) in poly (propylene) cups lidded with a nylon-6-based film. Cups were filled, sealed, packaged, stacked, and exposed to a simulated 3-day cross-country shipment. Cups were sampled with or without simulated shipment after 0, 7, 14, or 28 days at 20.6°C. Epsilon-caprolactam was determined using a gas chromatograph (GC) equipped with flame ionization detector and Restek Rtx 1301 megabore column. Results of the study indicated release of ε-caprolactam into containers at the time of sealing with significantly higher levels (4.42 ppm average) occurring in 12 % ethanol versus water (0.01 ppm average). After the cups were sealed, neither simulated cross-country shipment nor storage increased levels of ε-caprolactam in either solvent. It is not understood how the alcohol, whether as liquid or vapor, interacted with the lidding material to increase ε-caprolactam release at the time of sealing. No delamination of the poly (propylene) layer of the lidding material was observed when cups were sealed. Future research needs to be conducted to study the effects of alcohol, alcohol vapor, sealing time, and temperature on potential ε-caprolactam release.
