Researchers develop biodegradable tomato-based varnish for food packaging


Researchers from the Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-CSIC-UMA) in Malaga and the Instituto de Ciencia de los Materiales de Sevilla (ICMS-CSIC-US) have found a sustainable and environmentally friendly way to coat the inner surface of metal food packaging. In a recent study published in the Journal of Cleaner Production, the researchers proposed using tomato bagasse, a by-product from tomato processing, to create a biodegradable alternative to the commonly used epoxy resin.

Protecting Food Without Harmful Chemicals

When steel and aluminum are in contact with food, they can corrode and contaminate the food, making it unsafe for consumption. To prevent this, the inner surface of metal containers is coated with a protective layer of epoxy resin. However, epoxy is made from bisphenol A (BPA), an industrial chemical compound that can cause damage to human health. In contrast, the tomato bagasse varnish repels water, adheres firmly to metal surfaces, and has anti-corrosive properties that make it a safe and sustainable alternative to epoxy.

Reuse of tomato bagasse

Tomato bagasse is typically disposed of as solid waste, burned, or used in animal feed due to its low nutritional value. However, the researchers have found a way to reuse this waste product by creating a biodegradable alternative to epoxy resin. This solution reduces waste generation and minimizes the extraction of fossil resources for manufacturing containers, making it a more sustainable solution. Additionally, the researchers found that the manufacture of the tomato pomace resin produces less carbon dioxide than the manufacture of BPA resin.

The researchers found that tomato pomace resin repels water, has a high adhesion rate to metal surfaces, and has a high anti-corrosive capacity against salt and any liquid. Furthermore, the resin does not pass into the food. The tomato pomace resin acts as a protective barrier between food and metal, reducing the risk of contamination even if the container is dropped or impacted during transportation. Overall, the use of tomato pomace resin as an alternative to epoxy resin is a more sustainable and environm