Putting tomato skins to good use

Demand for sustainable production and the safeguarding of consumer health is on the rise in all sectors, including the food canning industry. These demands must be met while ensuring competitive growth as well as waste reduction and reuse.

The EU-funded BIOCOPAC (Development of bio-based coating from tomato processing wastes intended for metal packaging) initiative looked to tomato by-products to satisfy some of these needs. The goal was to develop a natural lacquer liner for tins that is made from discarded tomato skins. The coating will be applied to internal and external surfaces of food tins to ensure consumer health and safety.

Researchers first characterised tomato peels of different origins and identified the best method to extract the required substance, known as cutin. Results showed that there were no major differences in peel composition from different areas, and no dangerous substances were present.

They conducted a range of tests and selected the best method for cutin extraction in terms of yield, reproducibility and feasibility. After developing the method in a laboratory, BIOCOPAC successfully tested this method in a pilot plant.

The next step was to develop the bioresin, and the biolacquer, from the cutin raw material. Scientists came up with two different formulas, one specifically designed for tinplate and a generic one for all types of metal can. BIOCOPAC produced several canned goods using these lacquers, demonstrating that the lacquer performs as well as current products.

Once realised, these results will allow tomato farmers and producers to add value to their own processing wastes and promote eco-friendly packaging. In addition, packaging producers will be able to supply an innovative and easily recyclable container.