Scientists estimate chemical leakage from food packaging through improved models

19 Jul 2023 --- Researchers have developed a method to estimate the amount of chemicals that can leach from food packaging and processing equipment into food. New innovative models could help regulators and the industry assess food contact materials’ safety more efficiently and accurately.

Food contact chemicals (FCCs) are substances added to food packaging materials or processing equipment. They can migrate into food under certain conditions, such as high temperature, fat content or acidity. 

Some FCCs may pose health risks to consumers as they might be carcinogenic and toxic to reproduction and development, according to the researchers.

The study was conducted by researchers of the Kaohsiung Medical University and National Health Research Institutes, Kaohsiung, Taiwan and published in the journal Food and Chemical Toxicology.

Estimating FCC’s dangers
To evaluate the exposure and risk of FCCs, it is necessary to estimate their migration potential, that is, the ratio of the concentration of a chemical in food to its concentration in the packaging material or equipment. 

The estimation can be done by conducting experimental tests or using mathematical models. 

Experimental tests are costly, time-consuming and require large amounts of samples and chemicals. Mathematical models are faster, cheaper and more environmentally friendly.Experimental tests are costly, time-consuming and require large amounts of samples and chemicals. Mathematical models are faster, cheaper and more environmentally friendly, but need to be accurate and reliable, explain the researchers.

The Taiwanese researchers opted for a mathematical nonlinear prediction model. 

New modeling approaches
Previous studies proposed new modeling approaches for predicting FCC migration. 

The authors used data from these previous studies and molecular descriptors to train and validate their model. They found that it performed better than existing linear models, which do not account for the complex interactions between different factors that affect migration.

The researchers applied their model to 47 carcinogenic FCCs and 12 FCCs toxic to reproduction or development. They found that some of these “chemicals of concern,” such as diethyl sulfate, methanol and ethylene oxide, had high migration potential into various food simulants. 

The scientist suggested that their model could be used to prioritize FCCs of concern and accelerate their risk assessment.

Estimating BPA release
Another study, published in the Journal of Food Engineering, proposed two approaches for modeling the migration of specific additives and elements from plastic packaging and steel processing equipment. 

The authors focused on searching for bisphenol A (BPA). The widely used plastic additive is known to have endocrine-disrupting effects.

They developed two models based on mass transfer equations and experimental data. One model estimated the release of BPA and iron from packaging and equipment into the water as a function of time, temperature and surface area.

The other model estimated the release of BPA and iron from packaging and equipment into different food simulants as a function of time, temperature, surface area and food properties.In the sandwich experiment, scientists discovered that the plastic chemical exceeded its safety limit after ten days in the fridge.

Ensuring food safety
In the Journal of Food Engineering study scientists tested two scenarios: one where a sandwich wrapped in plastic gets contaminated by a chemical over time in the fridge and another where metal ions leach from a steel piece into an acidic solution. The researchers used different software tools to create the models based on the materials’ shape, size and properties. 

They also checked their models against real experiments and found good matches and discovered that the plastic chemical exceeded its safety limit after ten days in the fridge.

“After this time span, the food acquires a migrant concentration above the limit imposed by the regulations. The obtained results are in good agreement with both the shelf life of refrigerator-stored sandwiches and the values reported by European regulations,” they found. 

In the case of the steel piece, the study “gave results spanning 30 min” as “imposed by regulations.” 

Such models could help regulators and industry to ensure the safety of food contact materials and protect consumers’ health, highlight the scientists.

Meanwhile, Zero Waste Europe recently urged policymakers to take advantage of fresh delays to EU regulation to address growing concerns around human exposure to hazardous chemicals through food packaging. 

By Marc Cervera