Pilot scale air classification of flours from hulled and hull-less barley for the production of protein enriched ingredients

Abstract

This study explored pilot scale air classification of flours from two barley varieties: CDC Austenson (hulled) and CDC Valdres (hull-less) for the production of protein enriched food ingredients. The objective was to understand the effect of repeat milling and air classification cycles on the shift of proteins and other components including starch, β-glucan, fiber and ash. Protein enrichment was achieved for both varieties, with 2.13 and 1.75 times increase in protein content for CDC Austenson and CDC Valdres, respectively, after the first fractionation cycle. Repeat cycles led to further protein separation for both varieties, resulting in an effective protein separation efficiency of 47–52% w/w towards the fine fractions. The fine fractions were also enriched with fat and ash. Whereas, the coarse fractions were enriched in total, soluble and insoluble dietary fibers as well as β-glucan. Starch distribution varied between varieties, with CDC Austenson showing a shift towards coarse fractions, while towards fine fraction for CDC Valdres due to its smaller granule size. This study established a pilot scale process for fractionation of barley. The compositional data of these fractions will aid the development and use of barley as a food ingredient in foods including snacks (starch-rich) and meat alternatives (protein-rich).