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

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.     

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.     

不同品种核桃的氨基酸营养价值评价

选取新疆、云南等6个核桃主产区共29个核桃品种,对其蛋白质组成进行测定。应用模糊识别法计算核桃蛋白与模式蛋白的贴近度,并结合氨基酸比值系数法对核桃蛋白营养价值进行评价。依据核桃蛋白与模式蛋白的贴近度及氨基酸比值系数分,采用系统聚类分析法对29个品种核桃进行分类。结果表明:核桃蛋白总氨基酸含量在343.22~985.99 mg/g pro之间,必需氨基酸占氨基酸总量30%~41%,氨基酸比值系数分在67.02~87.98之间,核桃蛋白的第一限制性氨基酸为Lys。氨基酸营养价值最高的6个核桃品种分别为温185、和田小核桃、新早丰、辽核1号、西林2号和西林3号。对分类结果进行了显著性分析,显著性水平大于0.05,系统聚类结果合理。     

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。     

谷氨酸棒杆菌的氨基酸输送系统的存在、功能及其在氨基酸生产上的重要性

主要介绍了谷氨酸棒杆菌(Corynebacteriumglutamicum)中各种氨基酸输送系统及其基因、底物、特性和在氨基酸生产上的应用.     

新疆巴旦姆种仁高级脂肪酸与氨基酸营养评价

以新疆巴旦姆28个品种为试验材料,采用超临界CO2萃取法萃取其种仁油脂。用气相色谱法测定脂肪酸的含量及组分;采用自动定氮法和连续累进提取法测定粗蛋白和分离蛋白,并对蛋白质和氨基酸进行了营养的分析。结果表明,巴旦姆种仁油脂含量高(平均为54.68%),油脂以不饱和脂肪酸为主要成分,平均占脂肪酸总量的92.3%(其中单不饱和脂肪酸平均占脂肪酸总量的72.19%),饱和脂肪酸含量较低。巴旦姆种仁粗蛋白质含量平均为22.55%,以清蛋白为主,平均占蛋白质总量的48.86%以上,其次为球蛋白,而醇溶蛋白和谷蛋白含量较低。其蛋白质均含18种氨酸酸,属完全蛋白质。氨基酸含量丰富,每百克蛋白质中18种氨基酸平均含量为92.5%,且富含人体所需的8种必需氨基酸,含量达27.5%～35.1%。谷氨酸含量最高(平均为21.0%),含硫氨基酸(Met Cys)和赖氨酸(Lys)为其限制氨基酸。     

杨桃的氨基酸组成及其营养价值评价

对5个不同品种杨桃果肉中的氨基酸组成、营养成分测定分析。结果表明,杨桃鲜果中富含7种人体必需氨基酸（EAA）,特别是赖氨酸含量平均占EAA总量的29%。微量元素中钾和磷的含量较高,在5个品种中的范围分别为1249—1374mg/kg和259—291mg/kg。台湾软枝杨桃和泰国杨桃VC和尼克酸的含量较高,分别为24.6、26.3 mg/kg和19、17.6mg/kg。本研究得出杨桃是一种具有较高营养价值和保健功能的水果。     

6 种市售工厂化栽培金针菇的氨基酸组成及蛋白质营养评价

为分析工厂化栽培金针菇的蛋白质营养,本研究测定6?种来自不同生产企业的市售金针菇样品中粗蛋白含量及氨基酸组成,分析其中呈味氨基酸的含量,并通过计算蛋白质的氨基酸评分、化学评分、氨基酸比值系数分和必需氨基酸指数,以及预测蛋白质校正氨基酸计分等非生物学指标,评价金针菇的蛋白质营养价值。结果表明,6?种金针菇样品均含有18?种水解氨基酸,其中呈味氨基酸含量比例为56.28%～57.37%。必需氨基酸含量接近WHO/FAO模式,其中蛋氨酸、赖氨酸含量丰富,限制氨基酸为缬氨酸和异亮氨酸。6?种市售金针菇的氨基酸比值系数分为72.61～82.07,必需氨基酸指数均高于90,与卵清蛋白接近。上述结果表明工厂化栽培的金针菇中呈味氨基酸含量丰富,含有利于人体吸收的优质蛋白,具有较大的风味食品开发潜力,适合与谷物、肉类等进行膳食搭配以促进人体对氨基酸的平衡摄取。     

婴儿配方乳粉中蛋白质的营养评价及氨基酸分析研究进展

本文对婴儿配方乳粉中的蛋白质从质和量两个方面进行了综合评价,尤其对其营养评价方法进行了深入研究。以蛋白质营养评价的生物学法为参考,分析了5 种氨基酸分析评价法与生物学法的相关性,进而得出等权灰色关联度分析法是各方法中与生物学法相关性最高的一种;在进行食物中各种氨基酸与参考模式对应氨基酸比较时,氨基酸比值系数较氨基酸比值更加科学。本文用等权灰色关联度分析法对配方乳粉中氨基酸组成与母乳模式进行了相似度评价,并对配方乳粉中提供蛋白质的主要原料进行了氨基酸比较及互补性分析,为设计开发蛋白质质、量兼优的婴儿配方乳粉提供系统的分析方法。     

翅果油树种仁蛋白氨基酸组成分析及营养价值评价

以翅果油树种仁为原料,采用Osborne分级法制备得到4 种可溶性蛋白,在对其氨基酸组成及含量分析的基础上,采用氨基酸比值系数法和模糊识别法对翅果油树种仁蛋白的营养价值进行评价,并考察味觉氨基酸及药用氨基酸的含量分布。结果表明：翅果油树种仁4 种蛋白质中均含有17 种氨基酸,其中7 种为必需氨基酸,种类齐全,必需氨基酸占氨基酸总量的25.9%～30.0%。4 种翅果油树种仁蛋白中,水溶蛋白的氨基酸比值系数分最高（83.51）,其次是醇溶蛋白（75.45）、盐溶蛋白（69.09）,碱溶蛋白最低（66.44）,且4 种翅果油树种仁蛋白的贴近度都大于0.7,接近于全鸡蛋蛋白的营养价值,属于优质植物蛋白。水溶蛋白的第1限制氨基酸为苏氨酸,盐溶蛋白、醇溶蛋白和碱溶蛋白的第1限制氨基酸为蛋氨酸＋半胱氨酸。翅果油树种仁蛋白中味觉氨基酸和药用氨基酸的含量丰富,在风味产品开发及药用膳食搭配方面具有较大的开发潜力。     

3个不同产地的松露氨基酸组成及营养价值评价

该试验测定了四川会东县、四川攀枝花以及云南永仁县松露中蛋白质、脂肪和氨基酸的含量,并对其蛋白质的营养价值进行系统评价。结果表明,3个产地的蛋白质量分数在15.19%~19.91%之间,脂肪含量在2.12%~2.53%之间。不同产地松露的总氨基酸含量存在差异,介于14.82%~17.25%之间,17种游离氨基酸中谷氨酸和天门冬氨酸含量较高,鲜味氨基酸和甜味氨基酸分别占游离氨基酸总量的37.37%和32.55%;EAA/TAA在32.10%~34.12%之间,EAA/NEAA在47.29%~51.84%之间。氨基酸比值系数分(SRC)均值为90.83,酪氨酸+苯丙氨酸的氨基酸比值系数(RC)最小,为第一限制性氨基酸。     

不同产地藜麦籽氨基酸组成及其营养价值评价

采用氨基酸自动分析仪测定青海、云南、秘鲁、河北、玻利维亚等地产的15种藜麦籽的氨基酸组成,并对其氨基酸营养价值进行评价。结果表明:不同产地藜麦籽的总氨基酸含量为9.81%~12.68%,EAA/TAA的范围为34.5%~36.0%,EAA/NEAA范围为52.0%~56.0%,其中沽源县白色藜麦籽(Q13)EAA/TAA为36.0%,EAA/NEAA为56.0%,品质最佳,可作为藜麦籽蛋白产品开发与利用的理想资源。藜麦籽氨基酸比值系数分(SRC)均值为88.9,含硫氨基酸(甲硫氨酸、半胱氨酸)的氨基酸比值系数(RC)最小,为第一限制性氨基酸,与甲硫氨酸和胱氨酸含量较高的食品一起食用,可以提高食用价值。     

胶辊胶圈的存储及其与纺纱质量的关系分析

针对胶辊胶圈品种、型号繁多给其储存与管理带来不便的问题,阐述了胶辊胶圈存储环境、存储时间、存储温湿度等与其成纱质量的关系,说明这些因素是胶辊胶圈产生缠绕、变形、破裂、龟裂、脱落、损伤和损坏的主要原因之一,也是造成纺纱厂生产车间管理差异、棉纱质量差异和生产成本差异的关键;指出胶辊胶圈存储时间与纺纱厂生产车间温湿度环境相适应是保持其质量稳定一致的重要因素,也是延长其使用寿命的主要因素。     

牡蛎酶解工艺参数优化及其产物分析与评价

采用Protemax复合蛋白酶水解牡蛎肉,以水解度为指标,优化酶解时间、加酶量和酶解温度等酶解工艺参数,通过氮溶解指数(nitrogen solubility index,NSI)、三氯乙酸(trichloroacetic acid,TCA)-NSI、氨基酸评分、化学评分、必需氨基酸指数评价酶解产物的溶解性能及营养品质。最优酶解工艺参数为加酶量30 AU/kg、酶解温度55℃、酶解时间4 h,水解度达到27.28%。酶解液中18种氨基酸种类齐全,鲜味氨基酸含量丰富,Glu含量最高,必需氨基酸含量占总氨基酸含量的39.5%,必需氨基酸含量丰富,营养价值高。pH值为4.0~7.0时,酶解液的NSI达到83%以上,且TCA-NSI高达88.64%,酶解液具有高溶解性能。     

Changes in Germination and Malting Quality During Storage of Barley

To increase brewing yield and efficiency, malts with high extract values, high enzymic activities and good modification are essential. To produce malt that meets these requirements, the barley employed must have minimal post‐harvest dormancy and be able to germinate vigorously. The aims of this study were to determine the extent to which some Australian barley varieties changed during post‐harvest storage, how these changes influenced germination characteristics, enzyme production and malt quality, and, of the germination tests examined, which gave the best indication of a barley's malting potential. Four commercially grown barley samples were obtained, one from Tasmania and three from Victoria. Each sample was stored at room temperature for one year. At monthly intervals, samples were taken and placed at ?18°C. The germinative energy (GE) and germinative index (GI) of these samples were measured. Samples were also micro‐malted and the quality of the malt was assessed using standard EBC methodology. Storage at room temperature positively influenced the germination characteristics of all samples, with concomitant improvements in hydrolytic enzyme production during malting and in a number of malt quality parameters. It was found that, of the germination tests examined, the GI consistently correlated with enzyme activities during malting and with various malt quality parameters thus indicating that the GI is a good indicator of malting potential.     

Barley and Malt Proteins and Proteinases: I. Highly Degradable Barley Protein Fraction (HDBPF), a Suitable Substrate for Malt Endoprotease Assay

Barley grain proteins were extracted and fractionated, based on their solubility, to investigate their proteolytic digestibility and suitability to be used as a substrate for the assay of malt proteinases. The fraction extracted with alkaline buffer (Tris‐HCl or Tris‐glycine pH 8.8–9.5), at the end of the sequence, exhibited remarkably high degradability by malt proteases compared to other fractions or any known protein substrate. Gel filtration chromatographic analysis of this fraction revealed that it is composed of three different molecular weight components. Further investigation, after proteolytic treatment, demonstrated that the third and the low molecular weight component is the highly degradable protein(s) (HDP). We designated the whole fraction, the mixture of the three components, as the highly degradable barley protein fraction (HDBPF) and used it (and recommend it) as the substrate for the assay of malt endoproteases activity.     

Dormancy in Malting Barley: Quantifying the Effect of Storage Temperature on Different Varieties and the Response to Sudden Cooling

The rates of break of dormancy of the varieties Blenheim and Pipkin were examined during storage at temperatures of 8, 18, 26 and 33°C. The results were fitted to an established probit model of dormancy and compared with the previously fitted equations for Triumph. Triumph was shown to be the variety with the slowest recovery rate and this was consistent with the observations of other researchers. A similarity between varieties in the change of recovery rate with temperature suggested a consistency in the controlling reaction. A second experiment examined whether the sudden cooling of warm barley could induce ‘secondary dormancy’. The variety Triumph was stored at 12% moisture content and 33°C. Samples were then transferred to 8 or 15°C at different times. This procedure did not bring about any significant reduction in germinative energy. The only effect of a sudden temperature drop was a reduction in the rate of emergence from dormancy. ‘Secondary dormancy’ was not induced. The work is introduced and the results discussed in the context of the development of a thermally based integrated control strategy for malting barley. The strategy was designed to minimise the use of chemicals.     

抗坏血酸处理对李果实贮藏冷害及营养品质的影响

为探索减轻李果实冷害的新途径,本文以串红李子为试材,研究不同浓度的抗坏血酸处理对低温下贮藏的李果实冷害及营养成分的影响。结果表明,对照果在冷藏12 d后,可滴定酸、VC含量都呈现快速下降的趋势,还原糖、可溶性蛋白、总糖含量异常上升,冷害指数逐渐增加,说明此时冷害已经发生。而经过抗坏血酸处理的果实,蛋白质、还原糖、总糖含量都呈现上升幅度较大、下降幅度较小的趋势,可滴定酸、VC含量呈现缓慢下降的趋势,外观与内部冷害指数均明显降低,说明抗坏血酸处理明显地抑制了李果实冷害的发生,而且低浓度的抗坏血酸抑制李果实冷害的效果更好,保持了李果实较好的营养品质。