Food packaging, color migration

Miscellaneous Uses. Inks used by inspectors to stamp the grade or quaUty on meat must, bylaw, be made from food-grade colors. Dyes used in packaging materials that come in direct contact with a food must also be food-grade or, if not, it must be estabUshed that no part of the colorant used migrates into the food product. Pet foods, too, if colored, must contain only those colorants recognized by the FDA as suitable for the purpose. 

BPA can occur due to an incomplete polymerization, followed by migration into the food or environment [200], Furthermore, BPA monomer is used as color developer in thermal paper and is consequently also present in recycled paper and paperboard which can be used as food packaging material [201]. Human exposure to BPA is believed to occur mainly through contaminated food, although recently dermal exposure and absorption have gained attention [202-204]. 

Antimicrobial agent, preservative, flavoring agent, for baked goods, beverages, food colors, milk, wine, antimycotic migrating from food package... 

Plasticizers, antioxidants, and colorants are all potential contaminants of foods that are contained in plastics made with these chemicals. Control of potential migration of plastic components requires testing the containers with food simulants selected to yield information relevant to the intended type of food to be packaged (DeKruyf et al. 1983 Bieber etal. 1984). 

Sorption, such as flavor scalping, is the uptake of product components, such as flavor, aroma, or colorant compounds (called sorbates) by the package. European literature sometimes calls this negative migration, but the use of this term is unfortunate since it may lead to confusion. Many studies of sorption of food components have been reported in the literature. 

The solubility diffusion of food pigments is the phenomena responsible for this coloration. It is important to highlight that in the opposite direction, from the packaging to food, substances from the material, of approximately the same size of P-carotene or smaller, can also migrate provided that they are not covalently bonded to the polymer matrix. This contamination of food is usually invisible, without being smelled or tasted, but occurs insidiously. 

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