Breeding of Fukumi Fiber, a new six-rowed waxy hull-less barley cultivar containing high levels of β-glucan with a proanthocyanidin-free gene

A new, two-rowed, waxy, hull-less barley cultivar, Kirari-mochi, was bred by the pedigree breeding method, and derived from a three-way cross (Shikoku-hadaka 103/Daikei HL107 (ant28.494)) F1/Shikoku-hadaka 97 (wax). Kirari-mochi is both proanthocyanidin-free (ant28.494) and amylose-free (wax), and boiled pearled barley of Kirari-mochi showed lower levels of discoloration after incubation at high temperatures than Ichibanboshi (a standard cultivar of hull-less barley). The polyphenol content of pearled Kirari-mochi is roughly half that of Ichibanboshi and the β-glucan content of Kirari-mochi pearled barley is about 1.5-times higher than that of Ichibanboshi. The broken kernel ratio of Kirari-mochi is lower than that of Ichibanboshi. Although the grain yield of Kirari-mochi is approximately 85% of that of Ichibanboshi, its tolerance to pre-harvest sprouting is lower than that of Ichibanboshi. Kirari-mochi is resistant to both barley yellow mosaic virus and powdery mildew, and is moderately resistant to scab. Kirari-mochi is well adapted to cultivation in the plains of central and western Japan, and it was released in 2010. Kirari-mochi is suitable for pearling and boiling, and has good eating quality.

Five different hull-less barley cultivars of Korea, including normal and low amylose content, were examined both from a chemical and physical perspective. The barley cultivars showed a large variation in whiteness (28.8–39.2), fat (0.69–1.28%), ash (0.77–1.12%), protein (10.1–12.1%), β-glucan (5.2–8.4%), starch (59.9–68.9%), and amylose (5.3–22.7%) contents. Amylose content was positively correlated with starch content (r=0.723) and negatively correlated with β-glucan (r= −0.959), ash (r= −0.796), and fat (r= −0.682) content. Among the chemical components of barley, amylose and β-glucan contents are the most important factors influencing physical properties. Amylose content was related with hardness (r=0.855), adhesiveness (r= −0.642), initial pasting temperature (r=0.924), and setback viscosity (r=0.835). β-Glucan content was related with water absorption (r=0.581), hardness (r= −0.767), initial pasting temperature (r= −0.947), and final viscosity (r= −0.909). Hardness was highly correlated with setback (r=0.925) and adhesiveness was correlated with final viscosity (r=0.866). The results obtained in this study indicate that there are interesting correlations between chemical composition and physical characteristics of barley cultivars and could be used to predict the physicochemical properties of barley based food products.

Six hulless barley (Hordeum Vulgare L.) cultivar, including 3 normal, 2 waxy, and 1 colored-waxy, was used to substitute 20% of wheat flour for pan-bread making. Replacing 20% barley flour significantly increased β-glucan content, which ranged in 0.98-1.36% for normal, 1.65-1.67% for waxy, and 1.50% for colored-waxy barley, which are all higher than wheat flour (0.14%). Pasting viscosity of barley flour blends varied by barley type and cultivar, presenting that barley cv. Dapung (DP) had the highest peak viscosity of 170.1 RVU, whereas the lowest value was 80.2 RVU in “Jasujeongchal (JSJC)”. Substitution of barley flour decreased the Hm and H’m value during dough fermentation and estimated a reduction of bread qualities compared to wheat bread. Bread loaf volume varied by barley type and cultivar, showing a slight decrease in loaf volume, but increase in crumb firmness compared to wheat bread. Among barley cultivars, DP barley showed high bread loaf volume (691.7 cm3 /g) with lower firmness (11.8 N). In contrast, bread made from JSJC barley flour had the lowest bread-making qualities probably due to bran layer inclusion. It appeared that barley type influenced more than barley cultivars although the mean values of all quality parameters slightly varied by barley cultivar. Results indicated that the inclusion of barley flour for bread-making could provide an elevated intake of β-glucan, which had health benefits by increasing dietary fiber content.

The influence of the carbohydrate (CHO) composition of cereal cultivars on microbial ecophysiology was studied using an in vitro model of the porcine gastrointestinal tract. Ten hull-less barley cultivars, six barley cultivars with hulls, six oat cultivars, and six oat groats that differed in beta-glucan, nonstarch polysaccharide (NSP), and starch contents and starch type were hydrolyzed enzymatically and incubated for 72 h with pig feces. Fermentation kinetics were modeled, and microbial compositions and short-chain fatty acid (SCFA) profiles were analyzed using terminal restriction fragment length polymorphism and gas chromatography. Cluster analysis and canonical ordination revealed different effects on fermentation and microbial ecology depending on the type of CHO and cultivar. First, in cultivars of barley with hulls and oats, the cellulose and insoluble NSP contents (i) increased Ruminococcus flavefaciens-like and Clostridium xylanolyticum-like phylotypes, (ii) increased acetate production, and (iii) decreased fermentation activity. Second, in hull-less barley cultivars the beta-glucan, amylose, amylopectin, crude protein, and soluble NSP contents determined the microbial community composition and activity as follows: (i) the amylose contents of the hull-less barley varieties increased the butyrate production and the abundance of Clostridium butyricum-like phylotypes, (ii) the beta-glucan content determined the total amounts of SCFA, and (iii) the amylopectin and starch contents affected the abundance of Clostridium ramosum-like phylotypes, members of Clostridium cluster XIVa, and Bacteroides-like bacteria. Finally, the effect of CHO on proliferation of Salmonella enterica in the model was determined. Salmonella cell counts were not affected, but the relative proportion of Salmonella decreased with hull-less barley cultivars and increased with oat cultivars as revealed by quantitative PCR. Our results shed light on the complex interactions of cereal CHO with intestinal bacterial ecophysiology and the possible impact on host health.

Barley (Hordium vulgare L.) grain is an important food ingredient due to the presence of essential compounds like β-glucans, proteins, resistant starch, phenolic compounds etc. β-glucans are able to lower cholesterol level in blood plasma and the glycaemic index, to enhance lipid metabolism and to reduce the risk of colon cancer. Hulless barley cultivars are more suitable to the human diet, because the hulls can be easily removed, as well as minimal grain processing in food production contributes to the full benefit of the whole grain. Several studies show that hulless grains have a higher digestible energy, and they have higher protein content compared to hulled grains. Different cultivars have unique composition and physical properties. The hulless barley cultivars are less studied than hulled barley and oats. The aim of this study was to evaluate the fermentation characteristics of flakes of different hulless barley cultivars in vitro and to analyse the fermentation pattern of β-glucans and proteins. Samples of six hulless barley cultivar flakes with different β-glucan (4.17–6.59%), soluble dietary fibre (18.1–32.0%) and resistant starch (0.74–10.65%) content were boiled in water 10 min, and the obtained porridge samples were treated under in vitro fementation conditions. The concentration of fermented porridge solids as well as β-glucans and proteins was measured. The concentration of undigested solids varied from 38.3 to 61.0% depending on barley cultivar. The concentration of protein was not significantly changed, but β-glucan concentration was significantly decreased after in vitro digestion comparing to indigestible samples.

Characterizing the molecular structure features of newly developed hulless barley cultivars with altered carbohydrate traits (Hordeum vulgare L.) by globar-sourced infrared spectroscopy in relation to nutrient utilization and availability

The objective of this study was to compare three new Canadian hull-less barley cultivars with altered starch characteristics (zero-amylose waxy, CDC Fibar; waxy, CDC Rattan; and high-amylose, HB08302) with conventional normal starch hull-less barley (HB) cultivar (CDC McGwire) in terms of ruminant feed value. The study revealed that altered starch HB cultivars possessed several desirable feed characteristics, distinct from conventional normal starch HB, although they were similar in some respects: (1) basic chemical and carbohydrate subfraction profiles varied; (2) starch degradation kinetics showed altered starch HB containing higher soluble starch, rumen undegraded starch, lower degradable starch, and slower degradation rate; (3) all altered starch HB cultivars had similar soluble and degradable starch, different from that of conventional normal starch HB; (4) two waxy HB cultivars were lower, whereas the high-amylose cultivar was similar in effective degradability of the starch as compared to conventional normal starch HB; (5) zero-amylose waxy HB had the greater effective degradability of protein among HB cultivars; and (6) amylopectin in HB had a positive relationship with protein supply (increasing amylopectin was correlated with increased effective degradability of protein). Overall, these results demonstrate that the alteration of starch structure in granule affects not only starch fermentation and utilization but also protein value in hull-less barley. In summary, the HB cultivars with modified starch might be a better feed grain for ruminants than the normal starch HB.

Effect of Feeding Corn, Hull-Less or Hulled Barley on Fermentation by Mixed Cultures of Ruminal Microorganisms

Predicted truly absorbed protein supply to dairy cattle from hulless barley (Hordeum vulgare L.) with altered carbohydrate traits with multi-year samples

Analysis of β-glucan content in barley cultivars from different locations of China

The grain and agronomic characteristics of Korean barley cultivars were investigated with respect to ethanol yield. Test weight, grain yield, and starch yield showed noticeable variation among the cultivars. Grain yields were higher in covered barley and non-waxy barley. Starch yield was higher in non-waxy barley than waxy barley. Protein, β-glucan, and starch content of tested cultivars ranged in 10.0-12.9%, 4.4-7.5% and 49.7-65.3%, respectively. Naked barley cultivar had higher starch content than covered barley cultivar. However, covered barley had high starch yield because it has higher grain yield than naked barley. Covered barley cultivar had higher husk content, ranging 7.6-14.0%, than that of naked barley cultivar, ranging 5.3-8.0%. Starch content was positively correlated with amylose content, test weight, ethanol yield and negatively correlated with protein, husk, β-glucan content. Ethanol yield per ton was positively correlated with starch content, but negatively correlated with husk content. Ethanol yield per hectare was positively correlated with starch yield, grain yield, grain weight and negatively correlated with protein, test weight. From this research, the important characteristics of barley cultivar as a bioethanol producing material were starch content and grain yield. Optimum barley genotype was non-waxy naked barley that had low protein, β-glucan, husk content, and high starch content and grain yield.

Hydrothermal and β-glucanase effects on the nutritional and physical properties of starch in normal and waxy hull-less barley

Wholegrain cereals are an important source of folates. In this study, total folate was analysed in pearled fractions of barley and wheat cultivars employing AOAC Official Method 2004.05. In particular, the distribution of folate in the kernels was evaluated in three barley cultivars (two hulled types and a hulless one as well as two- and six-row types) and in a common and a durum wheat cultivar. A noticeable variation in the folate content was observed between the barley [653-1033 ng g(-1) dry matter (DM)] and wheat cultivars (1024-1119 ng g(-1) DM). The highest folate content was detected in the hulless barley cultivar (1033 ng g(-1) DM). A significant reduction in total folate, from 63% to 86%, was observed in all cultivars from the outermost to the innermost pearled fractions. Results proved that folates are mainly present in the germ and in the outer layers of the kernel. This is the first study reporting the folate distribution in kernels of both common and durum wheat and in a hulless barley cultivar. Results suggest that the pearling process could be useful for the selection of intermediate fractions that could be used in order to develop folate-enhanced ingredients and products.

Effect of altered carbohydrate traits in hulless barley (Hordeum vulgare L.) on nutrient profiles and availability and nitrogen to energy synchronization

Cultivar and Environmental Effects on (1→3,1→4)-β-D-Glucan and Protein Content in Malting Barley