Chapter 21 Food Contact Materials

Poly(ethylene terephthalate), Poly(butylene terephthalate), and Polystyrene Oligomers: Occurrence and Analysis in Food Contact Materials and Food

Polyesters (PES) and polystyrene (PS) are among the most used plastics in the production of food contact materials (FCM). The existence of compounds that could migrate from these materials into food requires a constant analytical control to ensure the safety of consumers due to consumption. It also implies a significant research challenge for their identification and quantification. One of the most important groups of known FCM migrants are the substances known as oligomers. PES and PS oligomers have long been suspected to possess some toxicological effects. The International Agency for Research on Cancer and the European Food Safety Authority alerted recently to the potential carcinogenicity of styrene, with its oligomers consequently being also in the spotlight. At the same time, PES cyclic oligomers are categorized as having Cramer III toxicity. Many recent works on the occurrence of poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), and PS oligomers in FCM and food have been published. The oligomeric chemical analysis requires the use of demanding analytical strategies to address their different physicochemical characteristics (melting points, octanol/water partition coefficients, and solubility properties). Chromatographic methods are normally preferred due to the intrinsic complexity of the target matrices, but the reduced amount of reliable analytical standards still hinders the widespread screening analysis of oligomers in food. This work presents the most relevant recent studies and analytical methodologies used in the analysis of PET, PBT, and PS oligomers in food and FCM, as well as current and future challenges.

Migration study of chemical additives from low density polyethylene (LDPE) into dahi

Dahi is widely used fermented milk product in India. Low Density Polyethylene (LDPE) is the most extensively used packaging material for Dahi in India. The present study was conducted to develop the analytical methods for extraction and migration of chemical additives from LDPE into dahi. Characterization of dahi packaging materials collected from five different firms was done by Fourier Transform Infrared Spectroscopy. Focused ultrasound solid liquid extraction method was observed to be better as compared to solid liquid extraction method as the former extracted maximum additives from the LDPE. Out of total 76 chemical additives extracted from LDPE, only eight (10.52%) matched with the existing positive list of polyolefins prescribed by Bureau of Indian Standads (BIS). The overall migration of chemical additives from all the LDPE samples was below their maximum limit as given by BIS standards. Chemical additives which migrated into the simulants included the antioxidants, fatty acids and their derivatives, unreacted hydrocarbons, plasticizers, lubricants and surfactant etc.

Food packaging's materials: A food safety perspective

Food packaging serves purposes of food product safety and easy handling and transport by preventing chemical contamination and enhancing shelf life, which provides convenience for consumers. Various types of materials, including plastics, glass, metals, and papers and their composites, have been used for food packaging. However, owing to consumers' increased health awareness, the significance of transferring harmful materials from packaging materials into foods is of greater concern. This review highlights the interactions of food with packaging materials and elaborates the mechanism, types, and contributing factors of migration of chemical substances from the packaging to foods. Also, various types of chemical migrants from different packaging materials with their possible impacts on food safety and human health are discussed. We conclude with a future outlook based on legislative considerations and ongoing technical contributions to optimization of food-package interactions.

Migration Studies of Two Common Components of UV-curing Inks into Food Simulants

The Rapid Alert System for Food and Feed (RASFF) has reported many cases of different UV curing inks components in foodstuffs during the last few years. These contaminants reach foodstuffs mainly by set-off, their principal migration mechanism from the package. Under this premise, this work has tried to characterize the process of migration of two common UV ink components: a photoinitiator (4-Methylbenzophenone) and a coinitiator (Ethyl-4-(dimethylamino) benzoate), from the most common plastic material used in food packaging low-density polyethylene (LDPE) into six different food simulants. The migration kinetics tests were performed at four different common storage temperatures, obtaining the key migration parameters for both molecules: the coefficients of diffusion and partition. The migration process was highly dependent on the storage conditions, the photoinitiator properties and the pH of the foodstuff.

Influence of pre-heating of food contact polypropylene cups on its physical structure and on the migration of additives

Laboratories unexpectedly carried out pre-heating of polypropylene beverage cups prior to performing a migration test in a proficiency test. Principal component analysis of the data collected showed that the preheating temperature of the cups contributed to an increased variance of the data and distinguishing pre-heating and non-pre-heating groups. This triggered to study the effect of applying such pre-heating on the physical structure of the material and on the migration of additives to food simulant D1 (ethanol 50% v/v). Several cups were pre-heated at selected temperatures and either analyzed with differential scanning calorimetry to establish the degree of crystallinity or used for the migration test. Six target additives from Regulation (EU) No 10/2011 were quantified in the food simulant using HPLC-FLD and LC-MS. Results show that pre-heating of the beverage cups led to a significant change in the degree of crystallinity, resulting in a change of analyte migration in comparison to the migration results from non-pre-heated cups.