Performance Evaluation of PVC-Free Metal Caps from the Point of View of Suitability for Food Contact and Tightness of the Packaging

In recent years, caps with PVC-free gasket have been developed and produced in the preserved food sector and they have been gradually replacing PVC-based ones. This type of choice was dictated by the need to produce sustainable packaging from a health and environmental point of view, even in the case of this type of closure. The study dealt with two type of caps, coded “A” and “B”, with two type of PVC-free gaskets, which differ in composition and application technology. In particular, the objective of this work was to study the behaviour of these new gaskets applied to metal caps intended for packaging preserved food, both in terms of suitability for food contact and from a technological standpoint. The gaskets were primarily characterized from a chemical–physical and mechanical point of view; overall migration and ad hoc methods for the determination of the specific migration of the substances present in their formulation were set up. In parallel, the technological suitability, related to the sealing parameters of the caps applied to the glass jars and the tightness of the packs, were evaluated. About food contact compliance, both caps, comply with the Union guidelines on Regulation (UE) n. 10/2011 on overall and specific migration. From the technological point of view, for gasket coded “A”, critical issues, the vacuum seal and, therefore, the tightness of the packages were highlighted.