Finding better ways to mill Canadian food barley into flour may open opportunities for its commercial use as a healthy ingredient.
Preliminary work done several years ago at Cigi (Canadian International Grains Institute) revealed that milling performance of food barley is improved when it is blended with wheat, producing flour with enhanced nutritional properties. During that time a commercial bakery asked Cigi to try blending 15 per cent barley with wheat to mill flour for pan bread and results indicated there was no adverse effect on the milling process.
Cigi recently completed a year-long project intended to determine the specific blends that would provide optimum milling performance and nutritional quality. The results showed that up to 40 per cent hulless food barley can be milled with wheat to produce a quality flour with suitable levels of beta-glucan. This work will help Cigi develop guidelines for milling hulless barley for the milling industry.
Funded by Alberta Innovates BioSolutions with food barley varieties supplied by the Alberta Barley Commission (ABC), the project was carried out by Cigi’s milling and analytical services areas. Work focused on developing milling techniques and other information that would improve the competitiveness of flour produced from Canadian food barley and wheat in health food and ingredient markets.
Food barley has a number of beneficial health properties — consumption can reduce the risk of coronary heart disease, regulate blood glucose levels and possibly offset certain cancers. The benefits are attributed to beta-glucan, phytonutrients, antioxidants, and vitamins contained in barley. In 2012, Health Canada approved a health claim for foods containing 1.0 gram of barley beta-glucan per serving as a way to lower cholesterol.
Hulless barley is easier to work with since there isn’t a requirement to remove the hulls prior to milling, says Elaine Sopiwnyk, Cigi’s director of grain quality. “However, hulless food barley varieties, especially those that are characterized as “waxy,” are also sticky when milling. Waxy starch properties are associated with higher levels of beta-glucan as well as lower levels of amylose, a component of the starch, which contributes to the stickiness. This can pose a problem for millers but blending the barley with wheat appears to resolve this issue.”
Wheat is coarser and more granular which helps with sifting and prevents the barley flour from clogging the sifter screen perforations during the milling process, explains adviser in Cigi Technology and project leader Ashok Sarkar. The project used hulless barley with three different starch characteristics — normal, partial waxy, and fully waxy — blended with wheat at 20 per cent, 30 per cent, and 40 per cent. Throughput, or milling capacity, was maintained at the same rate for all millings.
Commercial millers aim to manage throughput and extraction levels to meet a required particle size to control their costs, Sarkar says. The current project showed only a slight drop in flour extraction rate without changes made to throughput.
Baking trials using flours from milling 40 per cent CDC Rattan (partial waxy) barley with CWRS wheat required only small changes in formulation and processing to produce pan breads with acceptable handling properties and end-product quality.
The inclusion of 40 per cent hulless barley produces enough beta-glucan to meet the U.S. health claim of 0.75 grams of soluble beta-glucan per serving but proved to be more difficult to reach the 1.0 gram per serving required for a health claim in Canada, adds Sopiwnyk. “We plan to further examine the potential of additional blends in order to produce a flour that has the required functionality and beta-glucan levels.”
Ellen Goodman is a communications specialist with the Canadian International Grains Institute in Winnipeg.