Testing 13 commercial ketchup sources – organic and different coloured varieties – scientists at the US department of agriculture revealed that the organic versions excelled, with one brand containing 183 micrograms of lycopene per gram of ketchup, about five times as much per weight as a tomato, reports the New Scientist.

“The lycopene content ranged from 59.42 to 183.36 microg, and total carotenoids were as high as 216.6 microg/g fresh weight, respectively,” say the researchers, presenting their findings in the December issue of the Journal of Agricultural and Food Chemistry.

Opportunities for food makers working with tomato-based ingredients continue to open up on the back of mounting science suggesting the health benefits of lycopene, the pigment that makes tomatoes red.

And as the functional food trend continues to soar, food and beverage manufacturers are increasingly on the hunt for natural colours – fuelling growth in the colouring foodstuffs market and outstripping the base line growth of the European colours market in general valued at €195 million in 2001.

In addition to the influence of the functional food trend, the shift from synthetic colours to natural equivalents is underpinned by consumer suspicions that all E-numbers are unhealthy.

"Colouring foodstuffs include fruit and vegetable juices, concentrates and dried, powdered extracts. They do not contain any carriers or additives, and may be listed as ingredients, rather than as food additives," comments Frost and Sullivan analyst Lyndsey Greig.

A carotenoid, lycopene has attracted significant attention in recent years, linked in some research to reduced risk for cancers, especially prostate cancer. New findings also suggest that it could have a protective effect on heart disease, the cause of more deaths among women than any other disease.

The lycopene market is expanding significantly, with growth rates forecast at over 100 per cent in a recent report on the carotenoids market from Frost & Sullivan. The report values the ingredient at $34 million (€27.6m) in 2003, and with growing demand, new sources of the nutrient will attempt to lift this figure further.

Betty Ishida and Mary Chapman at the Agricultural Research Service California, US set out to identify if the different colourings in ketchup varieties on sale might have an impact on lycopene levels.

Their results showed little difference in lycopene levels between green, purple and red ketchups.

Non-organic brands averaged 100 micrograms per gram, with one fast-food sample containing just 60 micrograms per gram.

“If you want high lycopene levels, the rule of thumb is to pick the darkest red ketchup” says Ishida, cites the New Scientists.

Full findings for the ARS research are published in Journal of Agricultural and Food Chemistry (DOI: 10.1021/jf0401540).