According to scientists at the US Department of Agriculture's Agricultural Research Service (USDA ARS), the rice-sweet potato pancakes had a similar texture to a wheat pancake control.
Published this week on the ARS website, the findings claim to provide an acceptable gluten-free pancake formula, which could appeal to sufferers of celiac disease. This is characterized by an intolerance to gluten, a protein found in wheat, rye and barley that contributes to the viscosity of baked products.
The gluten-free pancakes were prepared using rice flour and sweet potato flour substituted for wheat flour in traditional pancakes on an equal weight basis. Of the total flour in the mixture, rice flour was replaced with 0, 10, 20 and 40 percent of sweet potato flour. To a mixture of dry ingredients, including flour (97.7g), salt (2g), sugar (19.7g), baking powder (4.2g) and nonfat dried milk (15.0g), were added water (108.4g) and Egg Beaters (39.1g) to make a batter slurry.
The ideal formula was found to contain 20 to 40 percent sweet potato flour, said the ARS.
The findings, which were first published last year in the Journal of Food Quality, revealed that textural properties of the rice-potato pancakes, such as hardness, chewiness and cohesiveness were improved and became comparable with those of the wheat pancake control. Protein content, dietary fiber, total carbohydrate and calories differed very little for all pancakes.
Indeed, although both rice flour and potato flour are not new ingredients to the industry, their combination as a complete substitute for wheat flour could provide manufacturers of baked goods with new avenues of exploration. Although awareness of celiac disease is increasing, technical challenges remain a major barrier to the development of successful gluten-free products.
Currently, around three million Americans, a little less than 1 percent of the population, suffer from gluten intolerance, although estimates suggest that 97 percent of celiac sufferers remain undiagnosed and go untreated.
Indeed, it is estimated that the number of known sufferers of celiac disease will increase worldwide by a factor of 10 during the next few years, findings that present an opportunity for the development and marketing of gluten-free foods, according to a report published by Packaged Facts last year.
Most gluten-free products are alternatives to traditional grain-based goods, including bakery products, pasta and cereals. These are made with alternative grains and flours, such as rice, corn, amaranth and quinoa.
In 2001, the market for gluten-free products was valued at $210m, and has grown at a compound annual growth rate of 27 percent since then, to reach $696.4m in 2006. The market is estimated to continue to grow at 25 percent per year until 2010.
But despite the strong performance of this sector, and the opportunities it entails, major food marketers have largely not entered the market as yet. According to Packaged Facts, this is because they are reluctant to invest in research and product development until fixed regulations for gluten-free are in place.
According to ARS chemists Fred Shih and Kim Daigle, their rice- and sweet potato-based pancakes are not limited to those suffering from celiac disease and wheat allergies, as they could also be marketed for their antioxidant levels. Due to the sweet potato content in the products, they have been found to contain 56 percent more beta carotene than traditional wheat-based pancakes. The body uses beta carotene to make vitamin A, an important immune booster and possible cancer preventer.
According to Daigle, developing a successful recipe was "not at all hard to do".
"It's just a challenge to get the texture right, as you have to compensate for the amount of water, since rice flour doesn't pick up as much water as wheat," she told FoodNavigator-USA.com, adding that possibly the largest challenge would be securing enough supply of sweet potato flour.
The rice-sweet potato flour mix could also serve as a base for development of other gluten-free bakery goods, she said.