Migrant Warning: Crossing the Coffee-Cup Barrier

When you get a cup of coffee from a vending machine, are you getting a soupćon of ink in your drink? This study looks into that question:

Determination the Set-Off Migration of Ink in Cardboard-Cups Used in Coffee Vending Machines,” Esther Asensio, Teresa Peiro, and Cristina Nerín, Food and Chemical Toxicology, epub 2019. The authors, at the University of Zaragoza, Spain, explain:

Food and beverages may interact strongly with the materials that they touch and this is specially important in vending machines, where often the contact is at high temperature. These interactions may result in migration of substances from the food contact materials to the beverages, affecting both the odour, quality of food as well as the health of consumers….

The aim of this study was the determination of the migration of compounds coming from different types of cardboard-cups used in coffee vending machines. The volatile compounds present in cardboard-cups were studied and specific migration studies were carried out by solid phase microextraction with headspace coupled to gas chromatography (HS-SPME-GC-MS). The migration of compounds from the cardboard-cups manufacturing material, plastic coating (LDPE) and printing inks were identified and quantified….

it is important to highlight the presence of compounds from both the material of the cardboard-cups (wood pulp) and the plastic coating (LDPE). Several compounds classified as Class II and Class III according to the Cramer rules, stand out the importance of the study and the required control of them, while their analysis suggests that this food contact material is unlikely to contribute significantly to dietary Cramer-threshold exceedance….

Some of the compounds found are not authorized for building food packaging materials. Even though they are coming from printing inks, the contact layer in the cups is LDPE, what makes this structure as a multilayer and then, included in the regulation 10/2011/EU. It is well known that diffusion of low polar organic molecules in LDPE is very fast and consequently the sorpted compounds in direct contact with LDPE can be easily transferred to the food.