Protein-rich flours offer potential for gluten-free foods
rice flour may find potential in the rapidly growing gluten-free
market, suggests new research.
Writing in the Journal of Food Engineering, researchers report that protein isolates a significant improved the water absorption of the composite blends, as well as favourably modifying the mechanical and surface related textural properties. "Scanning electron micrographs of the composite blends showed that the usage of soybean, pea protein isolates and transglutaminase would be a promising approach to produce protein enriched blends for making fermented gluten free products," wrote Cristina Marco and Cristina Rosell from the Cereal Group, Institute of Agrochemistry and Food Technology (IATA-CSIC), Valencia. 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. The new research looked at the potential of composite protein-enriched flours for use in gluten-free products. Marco and Rosell formulated rice flours (Harinera Belenguer SA, Valencia, Spain) and enriched them with pea and soybean protein isolates (Trades SA, Barcelona, Spain), with and without additional transglutaminase (Activa TG, Apliena, SA, Barcelona, Spain), an enzyme with cross-linking activity. The researchers report that addition of transglutaminase reinforced the network structure, although the high amount of protein isolates masked the effects. They state that the protein isolates were associated with a significant increase in the water absorption of the composite blends, while also having synergistic effects on increasing parameters linked to storage and viscosity. Moreover, the isolates modified the textural properties with soybean showing the most "significant effect on the functional properties, rheometer and surface related textural responses," wrote Marco and Rosell. The work was funded by the Comision Interministerial de Ciencia y Tecnologia and Consejo Superior de Investigaciones Científicas (CSIC). Ranjit Kadan, a researcher with the U.S. Department of Agriculture, said at last year's IFT that the gluten-free market is projected to be €1.25 billion ($1.7 billion) by 2010. 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. Source: Journal of Food Engineering Published online ahead of print, doi: 10.1016/j.jfoodeng.2008.01.018 "Functional and rheological properties of protein enriched gluten free composite flours" Authors: C. Marco, C.M. Rosell
