Health benefits of tomatoes linked to colour

High levels of specific antioxidants are linked to particular tomato colours, meaning each tomato has its own health benefits, researchers have found.

Tomatoes are a great source of antioxidants and contribute significantly to human health because of their anti-inflammatory, antiallergenic and antithrombotic properties. However, Laura Pérez-Flores from the Universidad Autónoma Metropolitana in Mexico said, “... little is known about their contents and regulation in genotypes of different colours, shapes and sizes.”

A team of researchers, led by Pérez-Flores, clarified differing antioxidant levels by focusing on four native and four hybrid tomato genotypes with different-coloured fruit. They evaluated the variation in carotenoid, polyphenol and tocopherol content among tomato lines as well as assays for antioxidant capacity of the fruit. They also determined the expression of isoprenoid metabolism-related genes and two pigmentation-related transcription factors.

“The association of greater levels of specific antioxidants with particular colourations of tomato fruit suggests a ‘balance’ between these compounds,” Pérez-Flores explained.

The research revealed: red fruit genotypes were associated with greater lycopene, which can help heart health and certain cancers; orange fruit genotypes had high concentrations of tocopherols, known as Vitamin E, which help to neutralise free radicals (linked to skin problems and chronic inflammation); and yellow fruit genotype was high in polyphenols, which are antioxidants that can reduce the risk of diabetes, heart disease and cancer.

According to the researchers, the results “support either the direct commercialisation of tomatoes with different colour fruit or use of their genotypes in breeding programs to increase antioxidant levels among existing cultivars”.

The study was conducted in Mexico, and all genotypes used were part of the Mexican Network of Plant Genetic Resources.

The findings are published in the Journal of the American Society for Horticultural Science.

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