Effects of nitrogen,phosphorus and potassium on amino acid composition and on relationships between nitrogen and amino acids in wheat and oat grain

During two seasons, pot experiments in which increasing applications of nitrogen, phosphorus and potassium were given to wheat and oats produced grain with widely varying N contents. The total amino acid composition of the grain was mainly dependent on N content of grain. Phosphorus and potassium affected the amino acid composition of wheat and oat grain only indirectly through their effects on nitrogen concentration. In wheat increasing grain N% was accompanied by a decrease in the amount (as g per 16 g N) of lysine, threonine, methionine, cystine and an increase in glutamic acid, proline, phenylalanine, and serine contents. Lysine, methionine, and cystine in oats decreased with increasing grain N content, but arginine, aspartic acid, glutamic acid and phenylalanine increased. Changes were less pronounced with oats than with wheat, and concentrations of most essential amino acids were higher in oats. When expressed as % dry matter all amino acids increased with increasing N concentration. Linear regression equations were calculated and significant correlations were found in both crops between concentrations of most amino acids and N content in grain. Some correlations between amino acids in the grain are also given. Correlations between amino acids and nitrogen within a variety were similar despite widely differing yields.     

不同品种桑葚与桑叶中氨基酸含量差异研究

目的比较不同品种果桑中游离氨基酸总量、必需氨基酸及药用氨基酸含量差异。方法以6个品种果桑(中葚1号、红果3号、831A、四季果桑、大白葚、江米果桑)的桑葚果实和桑叶为检测样品,利用全自动氨基酸分析仪分别测定成熟期桑葚和桑叶中游离氨基酸含量。结果 6个供试品种桑葚和桑叶均含有19种游离氨基酸,桑叶中氨基酸含量明显高于桑葚中氨基酸含量,紫色果实品种的叶片中氨基酸总量高于白色果实品种,紫色果实品种果实中的氨基酸总量又都低于白色果实品种,两者呈相反趋势。结论不同品种桑葚与桑叶中氨基酸存在较大差异。     

Semolina supplementation with processed lupin and pigeon pea flours improve protein quality of pasta

The objective of this work was to study the effect of processing (alcoholic extraction, fermentation and germination) on protein quality of lupin (Lupinus angustifolius L. var. Troll and Emir) and pigeon pea (Cajanus cajan L. var. Aroito) flours. Second, the effect of semolina supplementation with the processed legume flours on protein quality of pasta was also evaluated. For protein quality evaluation amino acid composition and chemical score (CS) were determined in raw and processed legume flours as well as cooked semolina pasta supplemented and non-supplemented with processed legumes. Alcoholic extraction did not cause important changes in the amino acid profile of lupin seeds. Certainly, sulphur amino acid content of ethanol extracted lupin flours was reduced but levels remained similar to those usually found in other legumes. However, fermentation and germination of pigeon pea seeds improved some essential amino acids and slight changes in CS indexes were observed. Moreover, semolina supplementation with processed lupin and pigeon pea flours improved protein quality of pasta as a result of higher CS and EAA levels compared to the control cooked semolina pasta. Therefore, ethanol extracted lupin, as well as fermented and germinated pigeon pea seeds are suitable protein sources for formulating new pasta products.     

The role of a low molecular weight glutenin fraction in the cooking quality of durum wheat pasta

Durum wheat glutenin fractions, composed of two low molecular weight proteins DSG-1 and DSG-2 (durum wheat (Triticum durum Desf) sulphurrich glutenin fractions) were extracted from semolina samples using a low concentration of Na tetradecanoate after extracting albumins, globulins and gliadins. DSG proteins have a high? SH plus S? S content. A highly significant correlation was found between the ? SH plus S? S content of this DSG-rich fraction and the cooking quality of pasta (0.63, P <0.01 with firmness and 0.86, P <0.001 with the state of the surface of the cooked pasta) and this seems to be a functional relationship. The use of acetic acid at various molarities showed the presence of high molecular weight glutenin fractions with differing solubility properties. In this respect, differences were found between varieties which are placed in the same group according to the classification of durum wheats based upon the composition of high molecular weight glutenin subunits.     

阿克陶引种栽培的5个果桑品种桑葚氨基酸分析与评价

对新疆阿克陶县玉麦乡引种栽植的5个果桑品种的成熟桑葚的氨基酸含量进行了检测,分析了不同品种间的氨基酸组成、总氨基酸、必需氨基酸、鲜味氨基酸、药用氨基酸及支链氨基酸含量的差异,采用RAA、RC、SRC等氨基酸评价指标进行了营养评价。结果表明:5个果桑品种的成熟桑葚中均含有16种氨基酸,总含量为0.802~1.323 g/100 g,其中谷氨酸含量最高,色氨酸和蛋氨酸含量最低,不同品种之间EAA/TAA差异不显著(P>0.05);8632的总氨基酸、必需氨基酸、鲜味氨基酸、药用氨基酸和支链氨基酸的含量均显著高于其它品种,红果2号次之;与FAO/WHO氨基酸模式谱比较得出,除蛋氨酸+胱氨酸之外,其它必需氨基酸接近或符合FAO/WHO氨基酸模式要求;氨基酸比值系数法评定可知第一限制氨基酸为蛋氨酸+胱氨酸,不同品种的SRC评分依次为红果2号>8632>台果>大10>果选2号,红果2号和8632的SRC分别为84.863和82.859。说明5个果桑品种中8632和红果2号的氨基酸营养价值高,作为新疆地区推广的果桑品种具有明显的优势。     

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.     

市售颗粒小麦粉溶剂保持能力及制作挂面的品质分析

选取市售8种颗粒小麦粉样品和1种普通小麦粉，测试评价二者的颗粒特性、理化品质、溶剂保持能力的区别，制作挂面以评价颗粒小麦粉的加工品质特性。结果表明，颗粒小麦粉的粒径分布与普通小麦粉之间差异显著（P<0.05），普通小麦粉中粒径（D50）为60.32μm，颗粒小麦粉中粒径（D50）均大于77.43μm。与普通小麦粉相比，颗粒小麦粉灰分和损伤淀粉含量低，面筋指数高、面筋质量好。除乳酸保持能力外，颗粒小麦粉的其余三种溶剂保持能力均显著低于普通小麦粉（P<0.05）。颗粒小麦粉挂面拥有良好的柔韧性和耐煮性，干物质吸水率和蒸煮损失率显著高于普通小麦粉挂面（P<0.05）。颗粒小麦粉挂面煮后的硬度、粘附性较低，延伸性较好，表现出较好的质地及爽滑不易断的特征。     

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。     

小麦品种对库德里阿兹威氏毕赤酵母风味代谢特性影响的研究

研究不同小麦品种对库德里阿兹威氏毕赤酵母（Pichia kudriavzevii）MT-Y01风味代谢特性的影响,并对小麦中的游离氨基酸与酵母代谢产生的挥发性风味物质进行典型关联分析（CCA）。结果表明,8种小麦的基本理化指标存在差异,游离氨基酸组成相似,但含量差异较大。小麦品种对酵母MT-Y01代谢产生挥发性风味物质有重要的影响,主要为高级醇和酯类物质（占比80%以上）。酵母MT-Y01以小麦品种鄂麦596为基质时代谢产生的挥发性风味物质总含量最高（568.5 mg/L）;以郑麦1769为基质时代谢产生的挥发性风味物质总含量最低（96.8 mg/L）;以百农201、淮麦32、徐麦35为基质时代谢产生的最高含量风味物质分别为3-甲硫基丙醇、己酸乙酯及苯甲醛。小麦品种对酵母发酵风味的影响与氨基酸关联,3-甲基丁醇、苯乙醇分别与缬氨酸、苯丙氨酸相关性强,3-甲基丁酸与天冬氨酸和天冬酰胺相关性强,苯乙醛受精氨酸影响大,丙酸乙酯、乙酸异戊酯、乙酸-2-苯乙酯受亮氨酸、半胱氨酸和赖氨酸影响大。     

Biochemical studies of some non conventional sources of protein. Part 4. The proteins of mango waste stone kernels

The gross chemical composition, protein content and amino acid composition of mango stone kernels of four Egyptian varieties (Ewsi, Hendi, Fonso and Timour) were investigated. Carbohydrates are the main components of the seed. The protein content varies between 5.0 and 7.2% and the ether extract ranged from 10.8% to 13.6%. High glutamic acid, aspartic acid and leucine content and low concentration of sulfur-containing amino acids are characteristic for the proteins of mango kernels. Lysine level is also low, the concentration of other essential amino acids is acceptable. Sulfur-containing amino acids are the first limiting ones followed by lysine and threonine.     

Protein composition of some Croatian and German wheat varieties and their influence on the loaf volume

Ten Croatian and five German wheat varieties were tested. Wheat protein composition was analysed according to a modified Osborne fractionation. They were extracted in four fractions: NaCl fraction, ethanol fraction, acetic acid fraction and insoluble fraction. The influence of protein and protein composition on the loaf volume was investigated. In protein composition a difference between the Croatian and German wheat varieties were found. Protein content, glutenin content and insoluble glutenin content showed influences on the loaf volume.     

Chemical composition of Egyptian sweet potatoes

Two Egyptian sweet potato varieties were studied. The study showed considerable differences in chemical composition between the two varieties. The mineral found in the highest concentration was calcium, followed by magnesium, iron, copper, zinc and manganese.The chemical composition of sweet potato protein isolates indicated that the pulp had high protein content. The maximum solubility of nitrogen was at pH 12 and 17 amino acids were separated from the protein isolate of both peel and pulp of the Giza 69 variety and from the pulp of the Abees variety. The protein isolate of the Abees variety had only 16 amino acids.     

鲜食大豆食味品质的评价指标研究

鲜食大豆的品质指标包括外观品质、营养品质、食味品质、卫生品质。衡量食味的主要品质指标有甜味、质地、香味和鲜味等。研究表明鲜食大豆的甜味与其籽粒的蔗糖含量呈显著正相关；可用籽粒的硬度表示质地；鲜食大豆的鲜味品质主要是由鲜食大豆的游离氨基酸含量决定的，可用天冬氨酸和谷氨酸的含量作为评价的客观指标。研究还表明了鲜食大豆的营养与食味品质问存在着一定的矛盾，大豆蛋白质的含量与其籽粒硬度呈显著正相关。     

15种坚果果仁氨基酸组成及含量差异分析

目的分析15种市售坚果中氨基酸组成,比较不同品种坚果间必需氨基酸、非必需氨基酸含量的差异。方法使用氨基酸分析仪对样品中氨基酸的组成及含量进行分析,用最小显著性差异法(least-significant difference,LSD)进行多重比较。结果纸皮核桃中的必需氨基酸含量最高,为6.264 g/100 g,花生中总氨基酸含量最高,为22.622 g/100 g。使用模糊辨识法对贴近度进行计算得出,FAO/WHO模式蛋白质贴近度为0.840-0.933。结论坚果中必需氨基酸和总氨基酸含量的差异显著。限制氨基酸均为蛋氨酸和胱氨酸。东北松子的FAO/WHO模式蛋白质贴近度最高,最贴近人体所需蛋白质的模式。     

7个不同品种藜麦营养成分比较分析

以陇藜1号、香格里拉白藜、香格里拉红藜、香格里拉黑藜、太旗白藜、太旗红藜、太旗黑藜为材料,对不同品种藜麦的营养成分、氨基酸和矿质元素进行了含量测定和分析比较。结果表明,7个不同品种藜麦的营养成分存在差异,其中太旗黑藜蛋白质含量高达16.52 g/100 g、脂肪含量为3.38 g/100 g,总膳食纤维含量11.07 g/100 g,其高蛋白质、低脂肪、高总膳食纤维特性尤为突出,更适合有减肥需求或素食主义群体。藜麦富含氨基酸,主要以谷氨酸、精氨酸和天冬氨酸为主,酪氨酸、组氨酸和蛋氨酸则含量较低。其中陇藜1号和香格里拉红藜主要氨基酸(谷氨酸、精氨酸和天冬氨酸)均高于其他品种,且其必需氨基酸(EAA)含量也明显较高。对必需氨基酸进行评分的结果表明,太旗白藜和香格里拉红藜必需氨基酸含量评分最优,更适合婴幼儿群体。另外,藜麦含有丰富的矿质元素,7个品种藜麦中K、Ca、Cu、Mg的含量都高于小麦、水稻和小米,尤其是香格里拉黑藜K含量高达12037 mg/kg,而Na含量在检出限以下,具有高钾低钠的良好营养特性,更适合中老年群体。本文为开发特定群体的藜麦功能食品的品种选择提供了依据。     

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。     

辽宁省主栽品种马铃薯块茎和马铃薯全粉的品质分析

以辽宁省主栽的11个品种马铃薯块茎为原料,采用捣碎制泥工艺生产马铃薯颗粒全粉,测定其原料品质指标(总淀粉、蛋白质、还原糖、脂肪、粗纤维和氨基酸)和颗粒全粉功能性指标(碘蓝值、透光率、冻融稳定性、持水和持油性)。结果表明:11个马铃薯品种的淀粉含量为67.9%~73.4%,其中大西洋、919淀粉含量高,早大白和克23淀粉含量低;蛋白质含量差异较大,其中富金、尤金蛋白质含量高,中5蛋白质含量最低;还原糖含量差异也较大,BQ25和大西洋含量较低,克23还原糖含量较高;脂肪含量差异不大;大西洋粗纤维含量较低,克23粗纤维含量较高。异亮氨基酸、苯丙氨基酸+酪氨酸含量11个品种均高于世界卫生组织(WHO)的“必需氨基酸模式标准”,相对其他氨基酸,33、大西洋、夏波蒂和中5的氨基酸含量较高。11种马铃薯全粉的游离淀粉率差异不大。但是透光率差异很大,919的透光率最大,BQ25和大西洋的透光率较小。富金、克23和33的析水率较高,BQ25和大西洋析水率低。11种马铃薯全粉的持水能力为7.3~8.1 g/mL,持油能力为7.6~8.6 g/mL。     

Effect of variety and crude protein content on nutrients and certain antinutrients in field peas (Pisum sativum)

Protein content was used as an indicator of environmental conditions for a study on varietal and environmental variation in proximate composition, minerals, amino acids and certain antinutrients of field peas. Four field pea varieties, each with three levels of protein content, were selected. Crude protein content overall ranged from 20.2 to 26.7%. Analysis of variance showed that both variety and environmental conditions had a significant effect on starch, acid detergent fibre (ADF), neutral detergent fibre (NDF) and fat content, but ash content was only affected by variety. Significant varietal and environmental differences in potassium (K), manganese (Mn) and phosphorus (P) were noted. Calcium (Ca) and copper (Cu) showed significant varietal differences, while iron (Fe), magnesium (Mg) and zinc (Zn) had significant environmental differences. Environmental conditions showed significant effects on alanine, glycine, isoleucine, lysine and threonine content. Variety had a significant effect on sucrose, raffinose and phytic acid content, whereas environmental conditions had an influence on trypsin inhibitor activity (TIA). The major pea components protein and starch were inversely correlated. ADF, NDF, Fe, Mg, Zn and the amino acid arginine were positively correlated with protein content. The amino acids glycine, histidine, isoleucine, lysine and threonine were negatively correlated with protein content. It was found that tryptophan was the most deficient amino acid and the sulphur‐containing amino acids were the second limiting amino acids in peas. Raffinose was positively correlated with sucrose but negatively correlated with verbascose. There were significant correlations between mineral contents and some of the proximate components. Copyright © 2004 Society of Chemical Industry     

Nitrogen-to-protein conversion factors for some cereal products in Japan

ABSTRACT:  To evaluate a practical method of determining more accurately conversion factors for calculating the protein contents of foods from the total nitrogen content, 19 cereal products found in Japan were analyzed for total nitrogen, amino acid nitrogen, and amide nitrogen, and then the nitrogen-to-protein conversion factors were calculated. The average conversion factors were 5.75 for rice, 5.81 for wheat, and 5.95 for others. These values, corresponding to the proportion of the amino acid residue to amino acid nitrogen recovered from 20 amino acids, were lower than the currently applied factors to these foods, except for wheat flour and amaranth. The use of this factor for estimating the protein content results in a considerable difference from the estimate based on amino acid residue concentrations, due to the wide variations in amino acid composition and to the presence of a significant level of nonprotein nitrogen. The distribution of the protein nitrogen recovered from the amino acids to total nitrogen averaged 93%. Adjusted conversion factors corresponding to the proportion of the amino acid residue to total nitrogen averaged 5.26 for rice, 5.47 for wheat, and 5.54 for other cereal products. Protein contents estimated using these factors are in good agreement with the contents defined as amino acid residues.     

Characterization of the Bread Made with Durum Wheat Semolina Rendered Gluten Free by Sourdough Biotechnology in Comparison with Commercial Gluten‐Free Products

Durum wheat semolina was fermented with sourdough lactic acid bacteria and fungal proteases aiming at a complete gluten hydrolysis. The gluten‐free (GF) semolina, added with naturally GF ingredients and structuring agents, was used to produce bread (rendered GF bread; rGFB) at industrial level. An integrated approach including the characterization of the main chemical, nutritional, structural, and sensory features was used to compare rGFB to a gluten‐containing bread and to 5 commercial naturally GF breads. High‐performance liquid chromatography was used for free amino acids (FAAs), organic acids, and ethanol analysis. A methanolic extract was used for determining total phenols and antioxidant activity. The bread characterization also included the analysis of dietary fibers, mycotoxins, vitamins, and heavy metals. Beyond chemical analysis, nutritional profile was evaluated considering the in vitro protein digestibility and the predicted glycemic index, while the instrumental texture profile analysis was performed to investigate the structure and the physical/mechanical properties of the baked goods. Beyond the huge potential of market expansion, the main advantages of durum wheat semolina rendered GF can be resumed in the high availability of FAAs, the high protein digestibility, the low starch hydrolysis index, and the better technological properties of bread compared to the commercial GF products currently present on the market. Vitamins, minerals, and dietary fiber profiles are comparable to those of gluten‐containing wheat bread. Also the sensory profile, determined by a panel test, can be considered the most similar to those of conventional baked goods, showing all the sourdough bread classic attributes.