The Agricultural Research Service (ARS) has launched a database on the web for phytonutrients known as 'proanthocyanidins' - a subclass of flavonoids - in 206 selected foods.
Phytonutrients - the most common being vitamin E, carotenoids, flavonoids, isoflavones and phytosterols - are beneficial compounds found in plant-based foods and are widely studied by the scientific community because of purported health benefits.
Proanthocyanidins are abundant in certain fruits, nuts, beverages (such as red wine and purple grape juice) and even some chocolates. Those in cranberries, for example, may help protect against urinary tract infections. Other health associations of these powerful antioxidants include a reduced risk of cardiovascular diseases, cancer and blood clotting.
Scientists with ARS' Beltsville Human Nutrition Research Center released the food-composition resource this month on the web. Collaborators include scientists at the ARS-funded Arkansas Children's Nutrition Center (ACNC), Mars, and cranberry supplier Ocean Spray Cranberries.
ARS researchers, led by chemist Ronald Prior at ACNC, adapted an earlier method for analysing proanthocyanidins in foods. They used it to analyse them in nationally representative food samples procured by the NDL. "The new compilation is based on acceptable data extracted from reviews of existing scientific literature, as well as data analysed by researchers at ACNC," said the scientists in a statement this week.
The new database complements several other databases, including a flavonoids database developed earlier by the NDL, and will impact previous estimates of the total flavonoids in foods. For example, the range of proanthocyanidins (PAC) in various small apples is between 70 and 140 milligrams each, but the sum of other known subclasses of flavonoids in the same samples is only about 5 to 13 mg.
PACs, or condensed tannins, have been identified as the active component responsible for inhibiting the adhesion of certain bacteria to cell walls. This has been postulated as the mechanism behind the cranberry fruits's ability to fight urinary tract infections. These are caused by bacteria in the stool and foods that alter the properties of the fecal bacterial flora may be able to reduce the risk of the disease.
A 2002 report from market analysts Frost & Sullivan pitched the growing European phytonutrient market at $94 million (€106m) in 2000, rising to be worth $144 million (€162.89) by 2008. In volume terms, over the same period, the market is forecast to more than double, from 276 tonnes to a staggering 570 tonnes.
"We forecast that the demand for these products in Europe will rise dramatically. If we look at what is happening in the US where isoflavones and flavonoids are currently used extensively in functional foods, we would expect to see this pattern mirrored in Europe," said Anna Ibbotson, Frost & Sullivan food analyst.
Price erosion is forecast to be the strongest restraint on revenue growth in the phytonutrient market despite the higher sales volumes. Increased competition and improved extraction techniques in the phytonutrients market mean that prices have been in steady decline for some time, and Frost's report suggests that many Asian producers are prepared to sell their products as loss leaders - i.e. below cost price - in order to gain European market share.