Water vapor and oxygen barrier estimation in designing a single-serve package of powdered infant formula for required shelf life

摘要

Protection from the ingress of moisture and oxygen from the outside environment is required for the quality preservation of powdered infant formula. Water vapor and gas barriers for a small single-serve package were assessed to ensure proper protection for the required shelf life of the powdered infant formula in the package. The water vapor barrier was calculated as the ability to suppress the product moisture increase from monolayer moisture to critical moisture, which causes physical transformation from amorphous to crystalline state releasing moisture, during the shelf life period. The oxygen barrier was based on the amount of oxygen absorption for a certain level of oxidation, measured in terms of peroxide content. A shelf life longer than 0.5 year was found to demand very low permeability against both water vapor and oxygen, which can be achieved by aluminum-laminated plastic films, composite cans, or metal cans.