Speaking at this year's Expo in Chicago, Jodi Engelson, a senior research scientist at Cargill said: "There is clearly a market opportunity for gluten-free foods. For the patients who suffer, the diagnosis rate is increasing. In response to this, we have witnessed over a 100 per cent increase in gluten-free products over the last seven years." According to market analyst Mintel the overall 'free-from' market has already enjoyed sales growth of over 300 per cent since 2000. The growing demand has opened up a new lucrative sector that many food makers are keen to exploit. The free-from market was worth €90 million ($123 million) in 2005, and Mintel said that the gluten and wheat-free sector has benefited in particular from the nation's increasing interest in healthy eating. Sales of products such as wheat-free breads and cakes have grown by almost 120 per cent over the last three years alone, to reach €48 million ($65 million). However, while the market for such products is booming, according to the experts at IFT, researchers have yet to fully solve their greatest challenge - making products taste good. Replacement of wheat in baked goods, like bread and cookies, poses technical problems since gluten impacts significantly on the texture and taste of the final product. "That's the real challenge for a product development person," said Engelson. Ranjit Kadan, a researcher with the U.S. Department of Agriculture, said the gluten-free market is projected to be €1.25 billion ($1.7 billion) by 2010. "Until recently, we thought [celiac disease] was a rare disease," said Kadan, "But that's not so. In 2003, we found that one out of 133 in the US had it." Coeliac disease is caused by an intolerance to gluten - the protein found in wheat, rye and barley - and currently affects an average of one in 300 people in Europe. In Germany the figure is higher at one in 200, while the UK reports a figure of one in 100. In the US, Congress mandated the Food and Drug Administration (FDA) to define gluten-free products by 2008. For the moment no standards exist, and products may claim food is gluten-free if it has no gluten, if it has a limited amount of gluten, or if it never had gluten. "So far, we've received over 700 comments to the proposed rule," said Geraldine June, an FDA official.