野生二粒小麦和普通小麦及其渐渗系全麦与脱麸面粉蛋白分析

为了解野生二粒小麦籽粒蛋白特性对普通小麦全麦面粉和脱麸面粉的改良价值,以高产弱筋小麦品种川农16(CN16)为母本,分别与籽粒蛋白含量存在显著差异的四倍体野生二粒小麦D1和D97进行远缘杂交,按高产性状定向选择并连续自交获得稳定高世代渐渗系共61份,本研究对61份渐渗系、7份野生二粒小麦和6份普通小麦进行了全麦和脱麸面粉粗蛋白质含量及其各蛋白组分含量分析、比较。结果显示,野生二粒小麦的籽粒粗蛋白(GPC)及其清蛋白、球蛋白、醇溶蛋白、谷蛋白含量均较普通小麦具有更丰富的遗传多样性,各蛋白组分含量均显著高于普通小麦。61份渐渗系中,分别有54.10%和52.46%的材料全麦面粉和脱麸面粉的粗蛋白含量显著高于母本CN16,全麦和脱麸面粉蛋白质含量最高达17.77%和17.62%,较CN16分别提高了5.05和5.33个百分点;全麦和脱麸面粉的清蛋白、球蛋白、醇溶蛋白、谷蛋白分别有18.03%和32.79%、50.82%和62.30%、67.21%和77.05%、37.70%和81.97%的株系高于母本CN16。全麦和脱麸面粉的粗蛋白含量与醇溶蛋白和谷蛋白含量间、贮藏蛋白的各组分间、可溶性与不...     

辣木籽渣组分蛋白的理化与功能性质研究

辣木籽渣是辣木籽提取油之后的副产物,为了提高其综合利用价值,本文以辣木籽渣为原料,通过奥斯本(Osborne)四步法提取清蛋白、球蛋白、谷蛋白和醇溶蛋白,分析比较了4种组分蛋白的理化性质及功能特性.结果表明:清蛋白、球蛋白、谷蛋白和醇溶蛋白的提取率分别为10.34％、0.69％、3.40％和3.65％,纯度均在82％以...     

不同品质类型小麦籽粒游离氨基酸、蛋白质及其组分的动态变化

为了解小麦氮素营养代谢的动态变化规律,给优质专用小麦品种选育与应用提供科学依据,选用不同品质类型的四个小麦品种(系)济南17、PH82-2-2、PH97-4、PH97-5,在两种施氮水平和两种追肥时期下研究了籽粒游离氨基酸、蛋白质及其组分的动态变化.结果表明,籽粒发育初期游离氨基酸含量高,随籽粒发育其含量逐渐下降;蛋白质含量积累呈现"高-低-高"的变化趋势,品种之间差异显著,成熟期蛋白质含量高的品种一般有较高的游离氨基酸和蛋白质积累水平.不同品质类型小麦籽粒蛋白质组分含量变化动态基本一致,灌浆初期清蛋白含量较高,随籽粒发育逐渐下降,灌浆中后期下降趋缓;球蛋白总体含量水平较低,随籽粒发育缓慢下降,灌浆末期略有上升.醇溶蛋白在籽粒发育前期积累较少,花后14 d快速积累;谷蛋白在花后7 d已有一定的积累,随后其含量逐渐上升,强筋高蛋白品种有较高的醇溶蛋白和谷蛋白积累水平,在成熟籽粒蛋白质中谷蛋白和醇溶蛋白所占比例也高,弱筋低蛋白品种有相对较低的醇溶蛋白和谷蛋白积累,醇溶蛋白和谷蛋白所占比例也低.     

玉米种子清蛋白和球蛋白PAGE比较分析

利用改进的聚丙烯酰胺凝胶电泳(PAGE),对玉米种子清蛋白和球蛋白进行研究.结果用含有NaCl的球蛋白提取液Ⅰ提取5次蛋白质后,清蛋白和球蛋白几乎全部被提取;而用不含NaCl的清蛋白提取液Ⅱ提取4次蛋白质后,再用提取液Ⅰ提取,可得到球蛋白组分,而且在清蛋白中也有相同迁移位置的谱带存在.表明对球蛋白进行提取操作时,总有清蛋白相伴随,而对清蛋白进行提取分析时一般不会有球蛋白的存在;球蛋白的遗传组分较清蛋白少,并在清蛋白中一般都有相同分子量的组分存在。     

提取方法对脱脂松仁粕蛋白性质的影响

以脱脂松仁粕为原料,比较提取方法对蛋白性质的影响。采用Osboren分级提取各组分蛋白,并与碱法提取的蛋白进行理化性质与功能性质的比较。研究不同蛋白的等电点、热变性温度、氨基酸组成、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gelelectrophoresis,SDS-PAGE)及不同蛋白的溶解性、起泡性和起泡稳定性、乳化性和乳化稳定性。结果表明:Osboren提取的清蛋白、球蛋白、谷蛋白的蛋白质含量分别为77.87%、68.23%、79.05%,碱法提取的蛋白含量为83.50%;四种蛋白的等电点为3.4、3.8、3.6、4.0,热变性温度为94℃、81℃、95℃、112℃;四种蛋白的必需氨基酸组成基本合理,主要含有谷氨酸与精氨酸;SDS-PAGE分析得出四种蛋白的条带有差别但主要集中在9.31~41.32ku;除乳化性和乳化稳定性以碱法提取的蛋白最好外,其余加工性质清蛋白均为最好。由此可见不同的提取方法对SDS-PAGE、热变性温度及加工性质均有不同的影响。     

醋制对黑豆蛋白含量及多肽ACE抑制活性的影响

为考察醋制对黑豆蛋白含量及多肽ACE抑制活性的影响,为对黑豆醋浸过程中蛋白组分及含量变化进行分析,并对相应ACE抑制肽活性进行测定。黑豆经醋浸不同时间后,采用顺序抽提法提取清蛋白、球蛋白、醇溶蛋白和谷蛋白,并采用凯氏定氮法及SDS-PAGE电泳进行定量和定性分析;各蛋白组分经胃蛋白酶水解,经超滤(截留分子量3 k D)后收集滤液,获得多肽组分,RP-HPLC法进行ACE抑制活性评价。结果表明:经醋浸14 d后,黑豆总蛋白含量变化幅度小于±0.5%;清蛋白含量由55.13%(0 d)降低至9.61%(14 d);球蛋白由7.04%(0 d)增加到20.34%(14 d);醇溶蛋白由0.81%(0 d)增加到1.72(14 d);谷蛋白由21.11%(0 d)增加到59.45%(14 d),含量最高。醋浸处理降低了清蛋白源多肽的ACE抑制活性,但提高了球蛋白、醇溶蛋白及谷蛋白多肽的ACE抑制活性,其中,谷蛋白多肽抑制率由18.18%(0 d)增加至37.58%(14 d),抑制活性升高。醋浸可改变黑豆各蛋白组分的含量和对应多肽的ACE抑制活性,其中,谷蛋白含量及其多肽ACE抑制活性均有增加。研究结果表明可进一步采用分离纯化技术从谷蛋白多肽中获得高活性降压肽。     

南方和黄淮海地区大豆地方品种贮存蛋白组分含量遗传变异的初步分析

我国南方和黄淮海地区的７２个大豆地方品种的贮存蛋白组分含量分析结果表明，大豆种子贮存蛋白各组分平均含量为球蛋白．２４．３９、清蛋白５．７７、醇溶蛋白１．７４、谷蛋白５．２７（ｇ／１００ｇ），其遗传变异丰富。南方与黄淮海地区品种间的４种贮存蛋白组分含量平均数及方差均无显著差异。     

氮肥运筹对啤酒大麦籽粒品质及产量的影响

为了揭示氮肥运筹对啤酒大麦籽粒品质和产量的调节效应,以啤酒大麦花30为材料,在施纯氮总量225kg.hm-2条件下,研究了不同氮肥运筹对千粒重、β-淀粉酶活性、蛋白质组分含量动态变化和产量及其构成因子的影响。结果表明:(1)随花后天数的增加,大麦籽粒千粒重、β-淀粉酶活性、醇溶蛋白和谷蛋白含量呈现由低到高的变化,而清蛋白和球蛋白含量先急剧上升,后略微下降;(2)增加拔节肥比例能显著增加β-淀粉酶活性、醇溶蛋白和谷蛋白含量,而对清蛋白和球蛋白含量影响较小;(3)千粒重、β-淀粉酶活性及蛋白质组分含量的相关性均达极显著水平;(4)随着氮肥用量后移,有效穗数、产量呈上升趋势,千粒重呈下降趋势。综合考虑各项指标,建议在类似本试验条件下的啤酒大麦生产区,基肥、苗肥、拔节肥比例以6∶3∶1为宜。     

小麦贮藏蛋白分析的改良SDS-PAGE法

本文提出了一种单向一步SDS-PAGE(聚丙烯酰胺凝胶电泳)分析小麦贮藏蛋白(谷蛋白和醇溶蛋白)的方法,利用SDS-PAGE重新评价普通小麦品种间染色体代换系醇溶谷蛋白的组成.从小麦品种Cheyenne和Wichita的第1和第6组染色体的轮回代换系中提取谷蛋白和醇溶蛋白,估计每个品种特有蛋白质的分子量,第1组染色件编码的蛋白质,特别是醇溶蛋白和低分子谷蛋白亚基比第6组染色体编码的蛋白质变异大,高分子和低分子谷蛋白亚基都微溶于乙醇溶液.和四交品种相比,Cheyenne和Wichita的染色体代换系的醇溶谷蛋白多肽链都产生了变化.因而,只有在分析了两种醇溶谷蛋白组分后,才能确定品质改变(和代换染色体有关)和贮藏蛋白之间的相关性.     

我国江浙地区粳稻品种间的植酸与蛋白质组分差异及其相关性

选用我国江浙地区近期育成的晚粳稻品种（系）29个,对它们在浙江杭州相同栽培条件下籽粒中的植酸、蛋白质含量与其组分差异及其相关性进行了分析。供试29个品种(系)植酸含量的平均值为0.868%,变化幅度为0.699%~1034%,其中秀水系列品种的植酸含量一般较低,而武育粳系列和淮字系列品种（系）的植酸含量则相对较高;供试29个品种材料总蛋白质含量的平均值为8.722%,其含量大致呈正态分布。在4种蛋白质组分中,谷蛋白、球蛋白和清蛋白在品种间的变异系数较大,而醇溶蛋白则相对较小,且在分布频率上也表现出品种类型间的差异特征;除谷蛋白与总蛋白质之间存在着极显著的正相关外,供试29个品种(系)的植酸含量与蛋白质含量及4种蛋白质组分含量间并无密切的关系。     

pH、离子强度等因素对椰子分离蛋白溶解性和乳化性的影响

分析椰子分离蛋白(CPI)溶解性、乳化性、乳化稳定性及pH、离子强度和温度对这些功能特性的影响。结果表明,与大豆分离蛋白和棉籽分离蛋白相比,椰子分离蛋白具有较好的溶解性、乳化性、吸油性和吸水性;而pH、离子强度和温度等因素对椰子分离蛋白的溶解性、乳化性和乳化稳定性有显著影响。在等电点附近,椰子分离蛋白表现出最低的溶解性与乳化性;低离子强度可提高椰子分离蛋白的溶解性和乳化性,而高离子强度降低了其溶解性和乳化性;CPI在60℃时有较好的溶解性和乳化性。     

Characterisation and functional properties of Australian rice protein isolates

Albumin, globulin, glutelin and prolamin fractions were isolated from an Australian rice variety (cv. Langi) and characterised by yield, protein content and molecular weight profile using both capillary electrophoresis (SDS-CE) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The influence of pre-extraction enzymatic hydrolysis of starch and heating to 70 °C was also investigated, as was the extraction of the glutelin fraction without prior removal of the albumin and globulin fractions. Pre-extraction treatment affected mainly the albumin fraction, increasing dry matter yield but reducing protein content. SDS-CE was able to separate the protein fractions over a wider molecular weight range than SDS-PAGE, and the peaks from SDS-CE showed slightly higher molecular weight compared to equivalent bands from SDS-PAGE. The glutelin fraction extracted without prior removal of albumin and globulin fractions had different characteristics compared to those obtained by conventional extraction methods. Pre-extraction hydrolysis of starch did not significantly affect the emulsifying, foaming and gelling properties of extracted protein. Although rice glutelin had poor solubility, emulsifying and foaming properties in aqueous systems, it had good gelling properties which could be important for food applications.     

Functionality of Succinylated Brazil Nut (<Emphasis Type="Italic">Bertholletia excelsa HBK</Emphasis>) Kernel Globulin

One of the possible ways to improve the utilisation of defatted Brazil nut kernel flour, a by-product of oil extraction industries, is to improve its functional properties by chemical modification as it possesses very modest functional characteristics. Succinylated Brazil nut kernel globulin at 55.8%, 62.4% and 72.0% level showed a positive effect on functionality. The solubility of acylated globulin was improved above pH 4.0 butwas reduced in the pH range of 3.0-4.0. Water absorption (1.96-4.00, 4.12, and 4.21 ml/g protein), oil absorption capacity (1.44-2.72, 2.80 and 2.94 ml/g protein) and apparent viscosity of the succinylated globulin increased with increase in the level of succinylation. The extent of modi-fication also influenced emulsifying capacity, which showed a decrease at pH 3.0, but was increased at pH 5.0, 7.0 and 9.0. Highest emulsion activity (approximately 63.0%) was observed at pH 3.0, followed by pH 9.0 and pH 7.0 and, least (about 11.8%) at pH 5.0. Emulsion stability also followed similar behaviour as that of emulsion activity. The improved functional properties of succinylated Brazil nut kernel globulin could be explored in a variety of food formulations such as high protein drinks, soups, bakery and meat products as well as in salad dressings and mayonnaise as an emulsifier.     

Amino acid compositions of different protein fractions in developing grains of NP 113 barley and its high lysine Notch-2 mutant

The percent distributions of protein fractions namely albumin + globulin, prolamine and glutelin were studied in developing grains of NP 113 barley and its high lysine mutant Notch-2. During development the percentage of albumin + globulin fraction decreased in NP 113, while those of prolamine and glutelin remained unchanged. The increase in prolamine was substantial from 24 to 31DAA. In Notch-2 the trend followed by albumin + globulin and prolamine was like that in NP 113, while the glutelin fraction showed an increase as compared to 10 DAA. The percent of albumin + globulin was slightly higher in Notch-2 as compared to NP 113. The absolute amount (mg/grain) of all the protein fractions increased during development in both NP 113 and its mutant Notch-2. During the grain development the prolamine content was substantially lower in the mutant than in the parent NP 113. The albumin + globulin content per endosperm was in general also higher in NP 113 than Notch-2. Amino acid analysis of the protein fractions did not reveal significant changes in lysine between NP 113 and Notch-2. Thus, the improvement in lysine in the mutant is primarily due to reduced synthesis of the prolamine fraction and not due to an increase in lysine in the mutant hordein fraction. Part of the improvemenht in lysine may also be due to increase in the percentage of albumin + globulin fractions which is lysine rich.Part of the Ph.D thesis submitted by S. Joshi to P.G. School, IARI, New Delhi.     

双氧水脱色对油茶粕蛋白结构和功能特性的影响

为了除去油茶粕蛋白的色素,添加体积分数为4%的双氧水在40℃下作用蛋白提取液1h可取得较好的脱色效果,但双氧水脱色对油茶粕蛋白结构和功能的影响需要进一步研究。本文通过测定变性温度、表面疏水性和巯基的含量,分析红外光谱、X射线衍射峰、微观形貌等研究脱色前后油茶粕蛋白结构和功能的变化。结果显示:双氧水脱色使油茶粕蛋白的表面疏水性上升,巯基含量下降,二硫键含量基本不变;通过红外光谱分析,双氧水脱色减弱了油茶粕蛋白化学键强度,但没有影响油茶粕蛋白基本骨架,微观结构基本相似,油茶粕蛋白的X射线衍射峰的位置和强度基本一致,热变性温度升高,双氧水没有改变油茶粕蛋白的等电点,但油茶粕蛋白的溶解度、乳化性、乳化稳定性、起泡能力和泡沫稳定性均下降,持油性和持水性上升。本研究结果表明双氧水脱色未明显改变油茶粕蛋白的结构,但其功能性质受到一定影响。     

Transglutaminase polymerisation of buckwheat (Fagopyrum esculentum Moench) proteins

Recently, screening of transglutaminase (TGase) treatment on several gluten-free cereals revealed significant improvements on the baking performances of buckwheat flour by promoting protein networks. In this study, the impact of TGase on the protein fractions of buckwheat flour was investigated in order to better understand the activity and specificity of the enzyme. Albumin, globulin, prolamin and glutelin fractions were extracted from the flour and incubated with TGase. Capillary electrophoresis, two dimensional (2D) gel electrophoresis and size exclusion chromatography (SEC) were performed on each fraction. Capillary electrophoresis and 2D gel electrophoresis revealed that buckwheat main storage proteins, i.e. 2S albumin, 13S and 8S globulin, were cross-linked after TGase treatment. SEC showed the presence of high molecular weight (HMW) protein polymers in the TGase-treated albumin and globulin fraction. Analysis of the amino acid composition of the fractions revealed high amounts of glutamine and lysine residues in all fractions. In conclusion, the increase in the average molecular weight of buckwheat proteins and the formation of HMW protein polymers after TGase treatment are responsible for the improved functionality of buckwheat flour in terms of breadmaking potential. The enzyme was revealed to be not fraction specific as all fractions were TGase-reactive.     

Transglutaminase polymerisation of buckwheat (Fagopyrum esculentum Moench) proteins

Recently, screening of transglutaminase (TGase) treatment on several gluten-free cereals revealed significant improvements on the baking performances of buckwheat flour by promoting protein networks. In this study, the impact of TGase on the protein fractions of buckwheat flour was investigated in order to better understand the activity and specificity of the enzyme. Albumin, globulin, prolamin and glutelin fractions were extracted from the flour and incubated with TGase. Capillary electrophoresis, two dimensional (2D) gel electrophoresis and size exclusion chromatography (SEC) were performed on each fraction. Capillary electrophoresis and 2D gel electrophoresis revealed that buckwheat main storage proteins, i.e. 2S albumin, 13S and 8S globulin, were cross-linked after TGase treatment. SEC showed the presence of high molecular weight (HMW) protein polymers in the TGase-treated albumin and globulin fraction. Analysis of the amino acid composition of the fractions revealed high amounts of glutamine and lysine residues in all fractions. In conclusion, the increase in the average molecular weight of buckwheat proteins and the formation of HMW protein polymers after TGase treatment are responsible for the improved functionality of buckwheat flour in terms of breadmaking potential. The enzyme was revealed to be not fraction specific as all fractions were TGase-reactive.     

Functional properties of protein from Lesquerella fendleri seed and press cake from oil processing

This investigation determined the functional properties of protein in Lesquerella fendleri seed and press cake from oil processing. L. fendleri seeds were heat-treated at 82 °C (180 °F) during 120 min residence time in the seed conditioner, and then screw-pressed to extract the oil. Unprocessed ground, defatted lesquerella seeds and press cakes were analyzed for proximate composition and protein functional properties. Protein from unprocessed lesquerella seed showed the greatest solubility (≥60%) at pH 2 and 10 and was least soluble (25%) at pH 5.5–7. Unprocessed lesquerella protein also had high surface hydrophobicity index (S_o), as well as, excellent foaming capacity and stability, emulsifying properties, and water-holding capacity (WHC) at pH 7. Protein solubility profile of the press cake showed up to 50% reduction in soluble proteins at nearly all pH levels, indicating heat denaturation during cooking and screw-pressing. Foaming capacity of the press cake protein decreased slightly, but foam stability was completely lost. Press cake protein also had markedly reduced values for S_o, emulsifying properties and WHC, further confirming lesquerella protein’s sensitivity to heat treatment.     

不同基质配比对酸柚苗生长的影响

通过设置不同基质配比处理,筛选出较适合酸柚苗的基质配方,为无籽蜜柚优质砧木繁育提供理论依据。以椰糠、表土、甘蔗灰和菜籽饼为原料,按不同体积比配制9种栽培基质进行容器育苗,并测定各基质理化性质及苗木生长生理指标。结果表明:不同基质配比处理对酸柚苗的苗高、径粗、叶片增加数、总生物量及叶绿素含量方面影响显著,其中T5(1/3椰糠、1/3表土、1/3菜籽饼)综合表现最好,其次为T2(2/3椰糠、1/6表土、1/6菜籽饼)和T9(2/3表土、1/6甘蔗灰、1/6菜籽饼),表现较差的为T1(2/3椰糠、1/6表土、1/6甘蔗灰)、T4(1/3椰糠、1/3表土、1/3甘蔗灰)和T7(1/6椰糠、2/3表土、1/6甘蔗灰)。结合苗木生长状况及基质成本,认为体积比为1/3椰糠、1/3表土、1/3菜籽饼的栽培基质较适合酸柚苗生长。