Marta Izydorczyk

Roller Milling of Canadian Hull-less Barley: Optimization of Roller Milling Conditions and Composition of Mill Streams

ABSTRACT Roller milling of hull-less barley generates mill streams with highly variable β-glucan and arabinoxylan (AX) content. For high β-glucan cultivars, yields >20% (whole barley basis) of a fiber-rich fraction (FRF) with β-glucan contents >15% can be readily obtained with a simple short mill flow. Hull-less barley cultivars with high β-glucan content require higher power consumption during roller milling than normal β-glucan barley. Recovery of flour from high β-glucan cultivars was greatly expedited by impact passages after grinding, particularly after reduction roll passages. Pearling before roller milling reduces flour yield and FRF yield on a whole unpearled barley basis, but flour brightness is improved and concentration of β-glucan in fiber-rich fractions increases. Pearling by-products are rich in AX. Pearling to 15–20% is the best compromise between flour and FRF yield and flour brightness and pearling by-products AX content. Increasing conditioning moisture from 12.5 to 14.5% strongly improv...

Quality characteristics of yellow alkaline noodles enriched with hull-less barley flour

ABSTRACT Roller milled flours from eight genotypes of hull-less barley (HB) with normal, waxy, zero amylose waxy (ZAW), and high amylose (HA) starch were incorporated at 20 and 40% (w/w) with a 60% extraction Canada Prairie Spring White (CPSW, cv. AC Vista) wheat flour to evaluate their suitability as a blend for yellow alkaline noodles (YAN). The barley flour supplemented noodles were prepared using conventional equipment. Noodles containing 40% HB flour required less work input than the corresponding 20% blend noodles due to a higher water absorption at the elevated level of HB flour addition, which probably caused them to soften. The addition of any HB flour at either level to the CPSW flour resulted in significantly decreased brightness (L*) and yellowness (b*), elevated redness (a*), concomitant with a significantly greater number of specks per unit area of noodle sheet compared with the control flour. The addition of 40% HB flour to YAN decreased cook time and cooking losses. Noodle firmness, as det...

Distribution and Structural Variation of Nonstarch Polysaccharides in Milling Fractions of Hull-less Barley with Variable Amylose Content

ABSTRACT Three hull-less barley genotypes containing starches with variable amylose content (23.8% normal, 4.3% waxy, 41.8% high-amylose barley) were pearled to 10% and then roller-milled to produce pearling by-products (PBP), flour, and fiber-rich fractions (FRF). PBP were enriched in arabinoxylans, protein, and ash and contained small amounts of starch and β-glucans. FRF were considerably enriched in β-glucans and arabinoxylans. The solubility of β-glucans was higher in PBP than in FRF. The solubility of arabinoxylans was higher in FRF than in PBP. Small amounts of arabinogalactans detected in barley were concentrated in the outer portion of the barley kernel. The content and solubility of nonstarch polysaccharides (NSP) in various milling fractions was also dependent on the type of barley. To obtain more detailed information about the content and molecular structure of NSP, each milling fraction was sequentially extracted with water, alkaline [Ba(OH)2], again with water, and finally with NaOH. These ex...

Quality Characteristics of Fresh and Dried White Salted Noodles Enriched with Flour from Hull-less Barley Genotypes of Diverse Amylose Content

ABSTRACT Fresh and dried white salted noodles (WSN) were prepared by incorporating up to 40% flour from hull-less barley (HB) genotypes with normal amylose, waxy, zero amylose waxy (ZAW), and high amylose (HA) starch into a 60% extraction Canada Prairie Spring White (cv. AC Vista) wheat flour. The HB flours, depending on genotype, contained four to six times the concentration of β-glucan of the wheat flour, offering potential health benefits. The HB-enriched noodles were made with conventional equipment without difficulty. Noodles containing 40% HB flour required less work input during sheeting, probably due to higher optimum water absorption and weakening of the dough due to dilution of wheat gluten. The addition of HB flour had a negative impact on WSN color and appearance, as evident from decreased brightness, increased redness, and more visible specking. The impact of HB flour on cooked WSN texture varied by starch type. Enrichment with HA or normal starch HB flour produced WSN with bite and chewiness...

Separation and Characterization of Barley Starch Polymers by a Flow Field-Flow Fractionation Technique in Combination with Multiangle Light Scattering and Differential Refractive Index Detection

ABSTRACT Flow field-flow fractionation (flow FFF) with frit inlet and frit outlet mode (FIFO) was coupled online to multiangle light scattering (MALS) and refractive index (RI) detectors to investigate the molecular characteristics of normal and zero amylose barley starch polymers. Application of two different cross-flows, 0.35 mL/min followed by 0.1 mL/min, and constant channel and frit flows of 0.1 and 1.0 mL/min, respectively, permitted a complete separation of amylose and amylopectin. The improved signals from the detectors due to application of the FIFO mode enabled the proper characterization of the small molecular weight species, as well as significantly enhanced the reproducibility of the measurements. The weight-average molecular weight (Mw) and zaverage root-mean-square (RMS) radii of gyration (Rg) values for amylose and amylopectin in the normal starch samples were 2.3 × 106 and 280 × 106, and 107 and 260 nm, respectively. The Mw and Rg of amylopectin in the zero amylose starch samples were 360...

Effects of Pearling, Grinding Conditions, and Roller Mill Flow on the Yield and Composition of Milled Products from Hull-less Barley

ABSTRACT Two hull-less barley cultivars, one with waxy starch and the other with high-amylose starch, were roller-milled unpearled and after 15% pearling. Flows of varying length, with diverse roll settings and roll surfaces were used to determine effects on the yield, composition, and properties of milled products. Similar trends were noted for the two cultivars. When using a short flow comprising four break passages and a sizing passage, power consumption during grinding was reduced by 10% when roll flute orientation was changed from dull-to-dull (D/D) to sharp-to-sharp (S/S). Flute orientation had minimal effects on the yield and brightness of flour, but SS grinding gave a higher yield of a fiber-rich fraction (FRF). FRF yield and composition are of particular interest because FRF has potential as a functional food ingredient due to elevated levels of β-glucans (BG) and arabinoxylans (AX). When using smooth frosted rolls (SM) for the sizing passage, power consumption increased by several times over usi...

Variations in Content and Molecular Structure of Barley Nonstarch Polysaccharides Associated with Genotypic and Cellular Origin

ABSTRACT Barley cell walls are an excellent source of soluble and insoluble dietary fiber. Despite variations due to genetic and environmental factors within cereal grains, generally the content of total dietary fiber in whole barley grain (17.3%) is higher than in other cereal grains. Arabinoxylans and mixed linkage (1→3)(1→4)-β-d-glucans are the major nonstarch polysaccharides present in various tissues of barley, but other polysaccharides such as cellulose, glucomannans, and arabinogalactans also occur, although in much smaller amounts. Depending on the genotypic or cellular origin, both polymers exhibit variations in molecular features. The molecular structures of β-glucans and arabinoxylans are important determinants of physicochemical properties and may affect physiological functionality in the gastrointestinal tract. Barley β-glucans have been associated with lowering plasma cholesterol, reducing glycemic index, and reducing the risk of colon cancer. Furthermore, arabinoxylans offer nutritional ben...

Milling of Canadian oats and barley for functional food ingredients: Oat bran and barley fibre-rich fractions

Izydorczyk, M. S., McMillan, T., Bazin, S., Kletke, J., Dushnicky, L., Dexter, J., Chepurna, A. and Rossnagel, B. 2014. Milling of Canadian oats and barley for functional food ingredients: Oat bran and barley fibre-rich fractions. Can. J. Plant Sci. 94: 573-586. Oats and barley are recognized for their valuable fibre constituents having protective and therapeutic effects against the development of diet-related disorders. Mixed linkage (1-3), (1-4)-β-D-glucans, the major dietary fibre constituents in oats and barley, have been linked to blood cholesterol lowering properties of these grains. The objective of this study was to compare oat bran and barley fibre-rich fractions (FRF) as two products with elevated levels of β-glucans and obtained by similar roller milling processes. The content of β-glucan in oat brans prepared from three different cultivars (AC Morgan, HiFi, and CDC ProFi) ranged from 7.90 to 9.50%, whereas the content of β-glucans in FRF prepared from three barley cultivars (CDC McGwire, CDC Fibar, and CDC Hilose) ranged from 9.31 to 18.19% (dwb). The yields of oat brans ranged from 44 to 49% and the yields of barley FRF from 39-49%. Both preparations contained higher amounts of arabinoxylans, proteins, and ash compared with the original grains. The oat brans were made up mainly of fragments containing the outer grain layers with a substantial portion of the subaleurone starchy endosperm attached to them, whereas the barley FRF consisted primarily of fragments containing the endosperm cell walls, with a smaller proportion of the outer grain tissues. The barley FRF contained smaller particles with broader distribution of particle size than the oat brans. The oat bran particles had higher bulk density and lower porosity than the barley FRF. Both preparations showed pronounced viscosity-building properties when dispersed in water at 45°C, but exhibited different viscosity profiles and differences in the attainable viscosity values.

Canadian buckwheat: A unique, useful and under-utilized crop

Izydorczyk, M. S., McMillan, T., Bazin, S., Kletke, J., Dushnicky, L. and Dexter, J. 2014. Canadian buckwheat: A unique, useful and under-utilized crop. Can. J. Plant Sci. 94: 509-524. Buckwheat is a broad-leafed herbaceous annual plant, belonging to the genus Fagopyrum of the family Polygonaceae, the “smartweed” family, also called the buckwheat, rhubarb, or sorrel family. Although not a cereal, buckwheat on the whole resembles cereal grains; it is handled and processed like other cereals and officially listed among the 20 grains inspected and graded by the Canadian Grain Commission. In addition to starch (65-75% dwb) and proteins (13-14% dwb), buckwheat is a source of flavonoids (with rutin being the most distinctive), a group of polyphenolic compounds with a potential to inhibit lipoprotein oxidation and to reduce risk of cardiovascular diseases, and fagopyritols, another group of unique bioactive compounds first identified in buckwheat and associated with reduction of symptoms on non-insulin-dependent diabetes. Buckwheat proteins do not contain gluten, and buckwheat is regarded as an excellent alternative source of protein for individuals with celiac disease. Buckwheat is a particularly good dietary source of Zn, Cu, Mn and Mg. Buckwheat starch and dietary fibre constituents exhibit some distinctive physicochemical and functional properties. Despite the availability of several high-yielding, high-quality Canadian buckwheat cultivars and the well-established production of buckwheat on the Canadian prairies, buckwheat is found in relatively few food products manufactured in North America, and Canada remains largely an exporter of buckwheat rather than its processor. Buckwheat can be roller milled into various types of flours with variable composition and properties. Buckwheat milling fractions can be relatively easily incorporated in a variety of food products to improve their nutritional qualities and potential health benefits, but much more attention should be paid to the development and improvement of modern food processing techniques to improve the palatability and acceptability of buckwheat products.

Whole-Grain Fiber Composition Influences Site of Nutrient Digestion, Standardized Ileal Digestibility of Amino Acids, and Whole-Body Energy Utilization in Grower Pigs

BACKGROUND Variant chemical composition and physical structure of whole grains may change the site of energy digestion from the small to the large intestine. OBJECTIVE We determined the site of nutrient digestion, standardized ileal digestibility (SID) of amino acids (AAs), and net energy (NE) value of barley cultivars that vary in nutrient composition compared with wheat. METHODS Ileal-cannulated barrows (27.7 kg initial body weight) were fed diets containing 800 g whole grains/kg alongside a basal and nitrogen-free diet for calculations in a 6 (period) × 7 (diet) Youden square. Diets included 1 of 5 whole grains-1) high-fermentable, high-β-glucan, hull-less barley (HFB); 2) high-fermentable, high-amylose, hull-less barley (HFA); 3) moderate-fermentable, hull-less barley (MFB); 4) low-fermentable, hulled barley (LFB); and 5) low-fermentable, hard red spring wheat (LFW). Intestine nutrient flow and whole-body energy utilization were tested and explained by using whole-grain and digesta confocal laser scanning. RESULTS Starch apparent ileal digestibility was 14-29% lower (P < 0.05) in HFB and HFA than in MFB, LFB, and LFW due to the unique embedding of starch within the protein-fiber matrix of HFB and the high amylose content in HFA. Starch hindgut fermentation was 50-130% higher (P < 0.05) in HFB and HFA than in MFB, LFB, and LFW. The SID of indispensable AAs was lower (P < 0.05) in HFB and HFA than in MFB, LFB, and LFW. NE value was 18% higher (P < 0.05) for HFB than for HFA and was not different from MFB, LFB, and LFW. CONCLUSIONS Whole grains high in fermentable carbohydrates shifted digestion from the small intestine to the hindgut. NE value depended on the concentration of fermentable fiber and starch and digestible protein, ranging from 2.12-1.76 Mcal/kg in barley to 1.94 Mcal/kg in wheat. High-fiber whole grains may be used as energy substrates for pigs; however, the reduced SID of AAs requires titration of indispensable AAs to maintain growth.