Structure and physicochemical properties of defatted and pin‐milled oat bran concentrate fractions separated by air‐classification⁴

Abstract

Oat bran concentrate (OBC) was defatted by supercritical carbon dioxide, pin-milled and air-classified into five fractions (<15, 15-18, 18-24, 24-30 and > 30 lm). b-glucan content (% dry weight) of defatted OBC, its subsequent pin-milling and the air-classified fractions in ascending particle size was 14.3, 17.0, 4.3, 5.8, 12.6, 14.7 and 22.4, respectively. High-performance size-exclusion chromatography equipped with multiangle laser-light scattering and refractive index detectors showed that amylopectin was the predominant molecule present in all OBC powders but was present in greater concentration in fractions collected that were < 24 lm. Fractions >24 lm, which had the highest b-glucan contents had higher starch gelatinisation temperatures (measured using differential scanning calorimeter), and had substantially higher peak, breakdown, final and setback paste viscosity (measured using Rapid Visco Analyser, Foss North America, Eden Prairie, MN, USA) compared with the other lower-b-glucan containing fractions. No differences in water retention of 25% (w ⁄ w) oat powders in water (measured using thermogravimetric analyser) were observed among defatted OBC, its subsequent pin-milling and the five fractions separated by airclassification. In particular, differences in pasting properties show that defatted, pin-milled OBC that is fractionated by air-classification will have different food applications depending on particle size collected.

Effect of particle size reduction on physicochemical properties of ashgourd (Benincasa hispida) and radish (Raphanus sativus) fibres

“…The increase in particle size resulted in an increased fibre content. Similar results have been reported during the pin-milling and air-classification of oat bran concentrate (<15 mm for the finest fraction, >30 mm for the coarsest fraction), where b-glucan (SDF) content varied from 4.3% for the <15 mm fraction to 22.4% dry weight in the case of the coarser fraction (Stevenson et al 2008). In general, the total DF was high in ashgourd samples, ranging from 58.67% to 66.08%, compared with that of radish samples, which ranged from 35.7% to 53.15% for the respective mesh sizes ranging from 100 to 30.…”

The Study of Particle Size Distribution of Micronized Oat Bran Layer

“…Taking into account the revolution of classifier the lowest value of this parameter were usually found for middle speed of classifier (965, 1450 and 1930 rpm). Relatively high content of fat in oat bran can cause a grinding and separation problem problems (Sibakov et al 2011, Stevenson et al, 2008, particles are more plastic and can combine into agglomerates. This could be a reason why an increase in the speed of disc had relatively low influence on particle size distribution of micronized oat bran.…”

Health Benefits of High Protein and Dietary Fiber Dry-Fractioned Brewery Spent Grain Fines

“…These food applications have generated greater interest in whole grain products and the manufacture of bran fractions. 20 Cereal fractionation can be classified into two processes: wet and dry. Wet fractionation is the most popular practice used, but due to its high demand for energy and water, the development of alternative processes based on dry fractionation has been sought.…”

“…There is a growing interest in incorporating dry and ground BSG with flour mixtures into food products such as bread, cookies, and meat products due to a high demand for nutritious, healthy, and functional foods for the population. These food applications have generated greater interest in whole grain products and the manufacture of bran fractions …”