Accurate quantification of small and large starch granules in barley and malt

The proportion of small and large starch granules in barley and malt is often neglected, leading to underestimation of their importance in processes in which they are used. This study aimed to accurately determine the volume and number based percentages of small and large starch granules for three barley varieties, their micro-malted malts and three commercial malts. Quantitative starch isolation was performed and starch granule proportions were estimated using microscopic and image analysis, taking the non-sphericity of the large starch granules into account. Results show that barley starch consists of 32-39 volume% of small starch granules. Upon malting, this percentage is reduced to 17-27 volume%, showing that small granules are hydrolyzed faster than large granules during this process. The analyzed commercial malt samples have a small starch granule content of 22-25 volume%. Malt hence still contains a substantial amount of small starch granules, which can be expected to impact processing.status: publishe

Study of the role of bran water binding and the steric hindrance by bran in straight dough bread making

This study investigates the effect of the physical presence and water binding of wheat bran during bread making, and the possible mechanisms behind this effect. Regular bran, pericarp-enriched bran and synthetic bran-like particles with different water binding capacities and particle sizes were used. Incorporation of regular and pericarp-enriched bran in dough (15% dm) led to a lower oven rise than the control dough. Bread volumes decreased with 11% and 30%, respectively. Dough with synthetic bran, having a low water binding capacity, displayed a near to normal leavening and oven rise and resulted in a bread volume decrease of only 5% compared to the control. Particle size reduction of regular bran and synthetic bran to an average size of 200 µm did not affect final bread quality. Results indicate that water binding by bran affects bread quality the most, whereas steric hindrance by physical presence of bran particles is less determinative.status: publishe