Hull-less Barley Varieties: Storage Proteins and Amino Acid Distribution in Relation to Nutritional Quality

Abstract

Barley (Hordeum vulgare L.) has had an important impact on human nutrition. Hull-less barley is a genetically improved type that has been widely used in recent years. Six Brazilian hull-less barley varieties (IAC-IBON 214-82; IAC 8612-421; IAC 8501-31; IAC 8501-12; IAPAR 39-ACUMAI; IAC 8501-22) were analyzed for storage protein constituents, amino acid contents, and similarity among the hull-less barley varieties. Albumins, globulins, prolamins I and II, and glutelins were extracted and separated by SDS-PAGE. The total protein amino acid contents of the flour were also determined for each variety by TLC and HPLC. Variations in intensity and appearance and disappearance of protein bands were observed among the varieties suggesting genetic variability. However, the amino acid profile did not indicate any major variations in the amino acid concentrations. The high lysine and threonine total concentrations detected in the seeds of the hull-less barley varieties encouraged an investigation into the regulation of amino acid metabolism and storage protein synthesis.     

Hull-less barley for swine: ileal and faecal digestibility of proximate nutrients,amino acids and non-starch polysaccharides

The nutritive value of three hull-less barley cultivars (Condor, Falcon and CDC Buck) were evaluated. The samples were analysed for proximate composition, amino acids and non-starch polysaccharides (NSP). Wheat and normal barley were used for comparison. Apparent digestibilities were determined with eight cannulated pigs. The diets were formulated to have all energy and protein supplied by the cereals. Compared to normal barley, hull-less barley has higher contents of protein and amino-acids, and lower levels of fibre components. The levels of several essential amino acids in hull-less barley are higher than in wheat. No obvious differences in NSP composition were observed, but the hull-less barley contained considerably higher levels of β-glucan compared to hulled barley and wheat. In digestion trials the piglets did not accept the diet in which conventional barley was formulated as the only energy and protein source, whereas hull-less barleys were well consumed. The results showed that, in the order of Condor, Falcon, CDC Buck and wheat, the overall tract digestibilities of intake energy were 83·1, 80·3, 83·2 and 82·9%, and of protein were 72·6, 69·5, 76·5 and 77·6%, respectively. The averages of apparent ileal amino acid digestibility were 56·5, 58·4, 65·3 and 65·4%, respectively. Hull-less barleys showed 20–37% ileal digestibility of total NSP. This study provides digestibility coefficients of hull-less barleys, and it is concluded that the digestibility of hull-less barley is comparable to wheat and superior to hulled barley in terms of nutrient composition and acceptability. © 1998 SCI.     

Effects of feeding hull-less barley on production performance,milk fatty acid composition,and nutrient digestibility of lactating dairy cows

The objectives of this study were to evaluate production performance, milk fatty acid composition, and nutrient digestibility in high-producing dairy cows consuming diets containing corn and hull-less barley (cultivar Amaze 10) in different proportions as the grain source. Eight primiparous and 16 multiparous Holstein cows were assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design with 21-d periods. Cows were fed once daily (1200 h) by means of a Calan gate system (American Calan Inc., Northwood, NH). All diets contained ～20% grain (dry matter basis). Treatments consisted of 100% corn (0B), 67% corn and 33% hull-less barley (33B), 33% corn and 67% hull-less barley (67B), and 100% hull-less barley (100B) as the grain sources. Total-tract nutrient digestibility was estimated using lanthanum chloride (LaCl₃) as an external marker. Dry matter intake differed quadratically among treatments, being lowest for 67B and highest for 0B and 100B. Feeding hull-less barley did not affect milk yield, and milk fat concentration differed cubically among treatments. The cubic response was attributed to the higher milk fat concentration observed for the diet containing 67B. Neither the concentrations in milk of protein and lactose nor the yields of protein and lactose differed among treatments. The proportion of de novo synthesized fatty acids in milk did not differ among treatments. The apparent total-tract digestibility of dry matter, crude protein, and neutral detergent fiber did not differ among treatments. Although a quadratic effect was observed, starch digestibility was minimally affected by treatments. In conclusion, this study indicates that hull-less barley grain is as good as corn grain as an energy source when formulating diets for high-producing dairy cows.     

我国29种青稞的营养及功能组分分析

为了解我国不同青稞品种的营养及功能组分,对29种青稞的成分进行分析,包括碳水化合物、蛋白质、脂肪、氨基酸、灰分、水分及β-葡聚糖、总黄酮。研究结果表明:29种青稞中蛋白质含量变化范围为8.74%~13.16%,脂肪含量变化范围2.44%~4.48%,总氨基酸含量变化范围7.48%~11.86%,β-葡聚糖含量变化范围2.89%~6.11%,总黄酮含量变化范围0.11%~0.28%,灰分变化范围1.66%~2.95%,不同品种之间存在显著性差异;碳水合物和水分的变化范围分别为73.82%~78.30%和7.69%~9.68%,显著性差异不明显。29种青稞中均含有17种氨基酸,包括人体所需的8种必需氨基酸。其中,青稞XZDM00025的蛋白质、总氨基酸和总黄酮含量最高,青稞XZDM00027的β-葡聚糖含量最高,青稞XZDM00074脂肪含量最低。通过对比WHO/FAO理想蛋白质氨基酸模式,青稞的第1限制性氨基酸是甲硫氨酸,第2限制性氨基酸是赖氨酸,第3限制性氨基酸是异亮氨酸。采用聚类分析(组间连接-平方欧式距离)法将29种青稞分为7类,前4类都仅包括1个品种,第Ⅴ类包括6个品种,第Ⅵ类包括2个品种,第Ⅶ类包括17个品种,且各大类间营养和功能含量组分存在显著性差异。     

Effects of genotype and environment on β-glucan and dietary fiber contents of hull-less barleys grown in Turkey

In this study, the effects of cultivar and environment on β-glucan and total dietary fibre (TDF) contents and various quality characteristics of hull-less barley samples grown in Turkey were investigated. There were significant differences among the barley genotypes and different locations in terms of β-glucan and TDF content (p < 0.05). Significant correlations were found between β-glucan content and some quality criteria (sieve analysis and 1000 kernel weight). The correlations between TDF and grain yield, hectolitre weight, 1000 kernel weight and protein content were also generally significant. These results indicated that environmental and genetic factors are involved in the total β-glucan content of barley.     

Effect of feeding corn, hull-less or hulled barley on fermentation by mixed cultures of ruminal microorganisms

Increased demands for corn grain warrant the evaluation of alternative grain types for ruminant production systems. This study was conducted to determine the effects of hulled and hull-less barley (Hordeum vulgare L.) cultivars compared with corn (Zea mays L.) as an alternative grain type on fermentation in cultures of mixed ruminal microorganisms. Three continuous fermentors were fed 14 g of dry feed per day (divided equally between 2 feedings) consisting of alfalfa (Medicago sativa L.) hay pellets (40% of dry matter) and 1) ground corn, 2) hulled barley, or 3) hull-less barley concentrate (60% of dry matter) in each fermentor. Following an adaptation period of 5 d, culture samples were taken at 2 h after the morning feeding on d 6, 7, and 8 of each period for analysis. A second run of the fermentors followed the same treatment sequence to provide replication. Culture pH was reduced with corn (5.55) and did not differ between barley cultivars (average pH 5.89). Total volatile fatty acid concentration and acetate to propionate ratio were not different across grain type or barley cultivar with the exception of greater total volatile fatty acid concentrations with hull-less barley. Corn produced less methane (14.6 mmol/d) and ammonia-N (7.3 mg/100 mL) compared with barley (33.1 mmol/d and 22 mg/100 mL, respectively); methane was greater with hull-less barley but ammonia-N concentration was similar between the 2 barley cultivars. Hull-less barley had greater digestibility compared with hulled barley, and corn had reduced digestibility compared with barley. Concentrations of C18:0 were greater and those of C18:1 and C18:2 lesser in cultures fed hulled and hull-less barley compared with corn. Our data indicate that grain type and barley cultivar have an impact on ruminal fermentation. The lesser starch concentration of barley minimized the drop in culture pH and improved digestibility.     

Chemical composition and microstructure of milled barley fractions

Wholegrain barley and peeled and pearled barley were roller milled in a Bühler mill, each producing three fractions: endosperm, middlings and bran. These fractions were compared and contrasted with one another and also with milled wheat fractions. Barley endosperm had the highest total starch content in both wholegrain and peeled and pearled barley. Amylose-to-amylopectin ratios (Am:Ap) were higher in barley flours than in wheat flours (P < 0.001). Peeled and pearled barley grain had lower soluble and insoluble fibre contents in all fractions, with wholegrain barley bran in particular having significantly more fibre than that of peeled and pearled barley bran (P < 0.001). The protein contents of the fractions of both barley types did not differ significantly. The endosperm had the lowest protein content, with the bran and middling fractions having double the protein content of the endosperm fraction. The total amino acid concentrations of the fractions followed a similar pattern, the total amino acid concentrations being lower in the endosperm fractions than in the bran and in the middlings fractions. These findings suggest that both types of barley fractions differed essentially from those of wheat. Pearling has a greater effect on the middlings and bran fractions than on the endosperm. The majority of these differences may not be significant enough to impact on the baking qualities of breads made using these fractions.     

Chemical characterisation and ruminal nutrient degradability of hulled and hull-less oats

The objectives of this study were to determine the chemical and ruminal nutrient degradability characteristics of two hulled (Calibre and AC Mustang) and one hull-less (AC Belmont) oat varieties. Ruminal nutrient degradability characteristics of the oat varieties were determined relative to barley using one ruminally fistulated cow. Neutral (NDF) and acid (ADF) detergent fibre levels were higher (P < 0·05) in hulled than hull-less oats. Hulled AC Mustang had higher (P < 0·05) NDF and ADF content than hulled Calibre. Starch content was higher (P < 0·05) in AC Belmont (590 g kg⁻¹) than Calibre (457 g kg⁻¹) and was higher in Calibre than AC Mustang (415 g kg⁻¹). Crude protein was higher (P < 0·05) in hull-less than hulled oat. Both hulled varieties had similar CP content (average 124 g kg⁻¹). Estimated digestible energy value was highest (P < 0·05) for AC Belmont (16·94 MJ kg⁻¹), intermediate for Calibre (14·18 MJ kg⁻¹) and lowest for AC Mustang (13·34 MJ kg⁻¹). Ruminal dry matter and NDF degradability were higher (P < 0·05) in hull-less than barley and was higher in barley than hulled oats. Ruminal starch degradability exceeded 900 g kg⁻¹ for all tested feeds and had the order AC Belmont = barley > Calibre = AC Mustang. It was concluded that oat varieties used in this study varied considerably in their chemical composition and ruminal degradability. When compared with barley, hulled oats had lower while hull-less oats had higher ruminal degradability. © 1998 SCI.     

Proteins of Italian millet: Amino acid composition,solubility fractionation and electrophoresis of protein fractions

Determination of the protein contents of 14 varieties of Italian millet revealed considerable varietal differences. The total protein of the 14 varieties was fractionated into albumin-globulin, prolamin and glutelin fractions. The prolamin fraction constitutes the major storage protein of the grain. There is a positive correlation between protein content and the prolamin levels of the seeds and the increase in protein content is largely due to an increase in the prolamin content. The amino acid composition of each of 14 varieties of the millet and the individual protein fractions from three varieties were determined. The limiting amino acids are lysine followed by tryptophan and the sulphur containing amino acids, methionine and cystine. The lysine content of the grain decreases with increase in protein content. The total protein has a rather high content of leucine. SDS-polyacrylamide gel electrophoresis of the protein fractions indicated similarities in the prolamin fraction and differences in the albumin-globulin and glutelin fractions of the different varieties.     

Effects of grain source and enzyme additive on site and extent of nutrient digestion in dairy cows

Four lactating, cannulated Holstein cows were used in a 4 x 4 Latin square design to investigate the effects of grain source and fibrolytic enzyme supplementation on ruminal fermentation, nutrient digestion in the rumen and in the intestine, and milk production. A 2 x 2 factorial arrangement was used; two grains (barley and hull-less barley) were combined with and without enzyme. The enzyme supplement (Pro-Mote; Biovance Technologies Inc., Omaha, NE) contained primarily cellulase and xylanase activities and was applied daily to the total mixed diet. Dry matter intake was not affected by diet, but starch intake was greatest when hull-less barley was fed. Starch from hull-less barley was more digestible in the rumen and in the total tract than was starch from barley, but opposite results occurred for fiber digestion, indicating that hull-less barley depressed fiber digestion. As a result, cows fed the hull-less barley diets tended to produce more milk with a higher milk lactose content than did cows fed the barley diets. Enzyme supplementation had minimal effects on ruminal digestion but increased nutrient digestibility in the total tract and the proportion of microbial N in nonammonia N. Consequently, cows fed diets supplemented with enzyme had a higher milk protein content and tended to produce more 4% fat-corrected milk than did control cows. These results indicate that the use of hull-less barley rather than barley increased the digestible energy intake of dairy cows, resulting in higher milk production. The use of a fibrolytic enzyme mixture enhanced feed digestibility and milk production.     

7种云南产核桃中17种氨基酸含量测定与必需氨基酸模式分析

目的对7个云南地方核桃品种中17种氨基酸进行含量测定和比较分析。方法样品经酸水解法处理后,使用氨基酸自动分析仪对样品氨基酸含量进行测定,在氨基酸含量值基础上,计算7个核桃品种必需氨基酸占总氨基酸的质量分数、氨基酸比值、氨基酸比值系数和比值系数分,对照世界卫生组织/联合国粮农组织(World Health Organization/Food and Agriculture Organization of the United Nations,WHO/FAO)颁布的理想蛋白质必需氨基酸模式谱以及已报道的核桃氨基酸成分研究,对7个核桃品种氨基酸组成特征和营养品质进行分析。结果 7个云南地方核桃品种氨基酸总含量差异不大,最高和最低分别为漾濞大泡核桃(18.16 g/100 g)和娘青核桃(13.53 g/100 g),漾濞大泡核桃必需氨基酸比例则较低;17种氨基酸在7个品种中组成特征是:谷氨酸含量最高,蛋氨酸含量最低;7个品种苯丙氨酸+酪氨酸、亮氨酸含量均高于WHO/FAO模式谱,赖氨酸含量明显低于模式谱,蛋氨酸+半胱氨酸含量在其中5个品种只达模式谱一半;氨基酸比值系数显示,苯丙氨酸+酪氨酸、异亮氨酸在7个核桃品种中均为过剩,7个品种赖氨酸均表现为不足,除大姚三台核桃外,其余6个品种蛋氨酸+半胱氨酸含量不足;漾濞大泡核桃、华宁小紫瓤核桃、昌宁香茶核桃、永平核桃、娘青核桃5个核桃品种的第一限制氨基酸是蛋氨酸+半胱氨酸。综合比较后,昌宁大尖嘴核桃营养价值最高。结论 7个云南地方核桃品种口感优异,营养构成上具特色。     

Microbiological and technological characterization of sourdoughs destined for bread-making with barley flour

The aim of the present study was the microbiological and technological characterization of laboratory- made sourdoughs for use in barley-flour-based bread-making. A defined multi-strain starter culture consisting of selected lactic acid bacteria (LAB) and yeasts from wheat sourdoughs was inoculated into three flour–water mixtures, composed of: (i) 100% wheat flour (ii) 50% wheat flour and 50% hull-less barley flour (composite flour); (iii) 100% hull-less barley flour. After two months of continuous propagation, the chemical characteristics of the three sourdoughs were investigated by measuring: pH, total titratable acidity and concentrations of various microbial metabolites by HPLC (i.e. lactic, acetic, phenyllactic and butyric acids and diacetyl). The microbial traits were studied through viable counts, isolation and typing of LAB and yeasts and PCR-DGGE analyses. Only Saccharomyces cerevisiae and Lactobacillus plantarum were detectable in the sourdoughs together with other lactobacilli species which were different depending on the type of flour blend used. The molecular typing of the isolates highlighted that only a few strains among those initially inoculated prevailed. The volume increases of the three types of sourdough were also investigated and a correlation was seen between an increase in the barley flour content and a reduction in the dough volume.     

Genotypic and environmental variation in the total phenol and flavanol contents of barley grain

Flavanol and total phenol contents have been determined in samples of barley grown in Britain under a wide range of environmental conditions. An assessment has also been made of the genetic variation in flavanol and total phenol contents among exotic genotypes and current UK varieties. Total phenol content decreased in the first 3 months immediately after harvest but no indication was observed that prolonged storage significantly reduced the levels of flavanols and, after the initial decline, no systematic decreases were found in total phenol content. Significant differences were found between trial sites for both constituents but these could not be related to geographical locations. An examination of inter-varietal variation revealed significant differences among both the current UK varieties (flavanols 0.11–0.17%, total phenols 0.43–0.53%) and 85 diverse genotypes (flavanols 0.08–0.15%, total phenols 0.37–0.54%). The levels of both constituents appeared to be independent of grain size, malting quality, oil content and protein content and no significant differences were found between either two and six-rowed varieties or husked and naked grain types.     

青稞品种对青稞发酵酒营养与感官品质的影响

本研究以7种西藏特有的青稞品种及相应发酵青稞酒为对象,基于理化性质、营养、风味和感官等指标,采用典范对应分析（canonical correspondence analysis,CCA）和主成分分析（principal component analysis,PCA）等探究青稞品种与其发酵酒品质的关系。研究表明,与青稞原粮相比,青稞酒体氨基酸中必需氨基酸占比增加,可能是酿造过程中非必需氨基酸转化形成了必需氨基酸。CCA结果显示不同品种青稞原粮在总氨基酸、γ-氨基丁酸、β-葡聚糖和总多酚含量等方面具有一定相似性,但其营养结构的差异经微生物生物化学转化得以放大,为筛选青稞酒的优质品种提供了可能。通过青稞原粮及相应青稞酒中的蛋白质、氨基酸、γ-氨基丁酸和总多酚水平等营养指标分析初步优选出‘藏青2000’为酿酒青稞品种,其次是‘隆子黑’‘芶芝黑’‘藏青25’。结合青稞酒营养、风味和感官等多维度指标,最终确定‘藏青2000’为最佳酿酒青稞品种,其次为各具特色风味的‘芶芝黑’‘隆子黑’‘藏青25’。本研究可为我国青稞酒领域的发展提供参考。     

Protein quality and identification of the storage protein subunits of tofu and null soybean genotypes,using amino acid analysis,one- and two-dimensional gel electrophoresis,and tandem mass spectrometry

The protein quality of 11 null and 2 tofu soybean genotypes were determined from their total protein content, their amino acid composition, and their glycinin and β-conglycinin contents. There were highly significant differences (P < 0.001) in their total storage proteins, and amino acid contents. Total protein among these genotypes ranged from 33 to 37%, with arginine being the third highest amino acid (7.4–10.9 g/100 g protein) followed by glutamic and aspartic acids. Methionine accounted for only 1.6–2.4 g/ 100 g of protein. All genotypes contained a good balance of essential amino acids (EAA₉), ranging from 43.5 to 47.3% of the total protein, limited only in methionine and possibly threonine and valine. Two-dimensional gel electrophoretic (2-DE) reference maps, using narrow range immobilized pH gradient (IPG) strips, revealed unique differences in the proteome, and subunit expression of glycinin and β-conglycinin, among these null genotypes, which can then be correlated with their protein quality. Out of a total of 111 basic (pH 6–11), and 223 acidic (pH 4–7) protein spots separated by 2-DE, 41 soybean storage protein spots were excised, and identified by liquid chromatography on-line with electro spray LCQ DecaXP tandem quadrupole time-of-flight mass spectrometry (LC/MS/MS). These methods will enable accurate evaluation of protein quality in soybeans, based on their protein digestibility-corrected amino acid score, assessment of the genetic variability of soybean genotypes, and serve as very effective tools for assisting plant breeders in their selection of high quality soybean varieties.     

The chemical components in malt associated with haze formation in beer

In bright beer, haze formation is a serious quality problem, which reduces beer storage and shelf life. In this study, haze‐active proteins, alcohol chill haze formation ability, α‐amylase activity, the contents of total polyphenol, protein and its fractions and amino acids were analysed using 23 barley accessions to investigate the relationship between the quality components in the malt and the haze character in beer. The results showed that there were largely genotypic variations for all examined traits among the 23 barley accessions. However, there was no significant correlation between the haze character and α‐amylase activity. All haze characteristics were significantly and positively correlated with total protein content, albumin, globulin and the hordein content, as well as the glutamic acid (glutamine), proline and phenylalanine content, and were not correlated with total polyphenols. A model describing the relationship between the chill haze in the beer and the protein content in the malt was developed. Copyright © 2016 The Institute of Brewing & Distilling     

湖南石门县地方品种鸡肉氨基酸组成分析及蛋白质营养价值评价

目的 探究湖南省石门当地7个品种鸡肉中的基本营养成分及氨基酸组成差异,并对其进行蛋白质营养价值评价。方法 采用相关国家标准测定7个品种鸡肉中水分、粗灰分、粗脂肪、粗蛋白含量,并利用高效液相色谱仪对鸡肉氨基酸含量进行测定,基于联合国粮食及农业组织和世界卫生组织(Foodand Agriculture Organization/World Health Organization, FAO/WHO)标准模式谱对不同品种鸡胸肉和腿肉蛋白质分别进行营养学评价。结果 7个品种鸡胸肉、腿肉中水分含量分别为71.20～74.97 g/100 g、72.65～76.22 g/100 g,粗灰分含量分别为0.90～1.38 g/100 g、0.91～1.28 g/100 g,粗脂肪含量分别为0.15～0.64 g/100 g、2.30～7.74 g/100 g,粗蛋白质含量分别为22.29～24.61 g/100 g、19.00～21.80 g/100 g,不同品种、部位间存在差异。7个品种鸡肉均检测出17种氨基酸,均以谷氨酸含量为最高;胸肉氨基酸含量高于腿肉(除壶瓶山鸡),其中青脚鸡胸肉和壶瓶山鸡腿肉的...     

Relationship between wheat proteins

Recent evidence including amino acid analyses, immunological tests and fingerprinting suggests that the gliadins of wheat varieties have evolved from a common ancestral protein by a series of mutations. No evidence to support a relationship of this nature between the gliadin, albumin and globulin classes was found. Confirmation of the genetic link between wheat and barley is provided by the close structural affinity between purothionin and its barley counterpart. There are some similarities in amino acid composition between a barley trypsin inhibitor and a wheat albumin. Available evidence, though scanty, is significant enough to justify the generalisation that storage proteins of identical mobility in different wheat varieties have closely similar primary and tertiary structures. Although the individual gliadins within a given variety are mutationally linked, their tertiary structures as judged by immunological tests show characteristic differences.     

Nutritional Quality of Sorghum Seeds: Storage Proteins and Amino Acids

One sorghum commercial genotype (MASSA 03) and nine ICRISAT high-lysine genotypes from India were analyzed for storage protein content, distribution profile, and soluble amino acid concentrations. Storage proteins fraction were extracted and separated by SDS-PAGE. Soluble amino acids contents were determined by HPLC. Variations in intensity and appearance and disappearance of protein bands were observed among the sorghum genotypes suggesting genetic variability. Amino acid profile also indicated large variations in the amino acid concentrations. The high lysine and threonine soluble concentrations observed in the seeds of the sorghum genotypes encouraged the use of these genotypes as potential food source due to the better balanced amino acids profile.     

Protein and amino acids contents of Libyan dates at three stages of development

The protein and amino acid contents of three Libyan date varieties (Taasfirt, Bikrari and Khadhrai) at different stages of fruit development were determined. The protein concentration in all three varieties was highest at the green stage. Seventeen amino acids were detected and quantified; their concentrations (dry weight basis) were higher in Khadhrai and Bikrari than in Taasfirt. At the green stage the concentrations of glutamic acid, aspartic acid, lysine, leucine, alanine and serine were highest. At the yellow and ripe stages, glutamic acid, aspartic acid, lysine, leucine, proline and glycine were present in high concentrations. For most amino acids the concentrations were higher at the yellow stage than at the ripe stage. Copyright © 2004 Society of Chemical Industry