The EU TOM(ato) project suggests that tomato waste could be used as a natural food additive. Researchers have looked into ways to help treat tomato leftovers in a cleaner and cheaper way, without using chemicals to extract valuable nutrients, and reducing the overall amount of waste. Final results of the project are due in April next year.
"We have for a long time known the nutritional benefits of eating tomatoes," said European research commissioner Philippe Busquin. "Now, with the TOM project we are set to maximise the potential of this juicy fruit."
Around 8.5 million tonnes of tomatoes are cultivated every year in Europe. Nearly 18 per cent - 1.5 million tonnes - is sold directly to consumers and the rest is processed into foods, such as ketchup, pasta sauce and canned goods. However, during processing, up to 40 per cent of the raw material ends up as residue, mainly skin and seeds.
Of the waste products, the oils, in particular, are highly valued for their unsaturated fat content, according to the Spanish research centre AZTI, which is participating in TOM along with ten other partners from the Netherlands, Germany, Ireland and Portugal.
Scientists working on the project have now found ways of removing impurities from the tomato sludge left after initial processing. Solvents have commonly been used for this, but they tend to be less effective and leave chemical traces.
Using a two-fold cleaning process, TOM's researchers expect to be able to produce a much purer compound extract. First, they obtain a crude extract using the conventional but environmentally clean method of washing the tomato residue with water and supercritical CO2. Next, they use 'affinity chromatography' to raise the quality of the extract to a level of 98 per cent purity.
"Every year millions of tons of tomatoes are destroyed, and large amounts of tomato by-products in manufacturing are treated as waste. Instead of simply discarding this material, it will be possible to benefit all European citizens with a wide range of alternative uses. This is an example of how technology can help enhance European citizens' quality of life and turn sustainable development into reality."