Investigation of Aegilops umbellulata for stripe rust resistance,heading date,and the contents of iron,zinc,and gluten protein

Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and the contents of iron(Fe),zinc(Zn),and seed gluten proteins.Forty-two of the accessions were classified as resistant to stripe rust,while the other four accessions were classified as susceptible to stripe rust in four environments.The average HD of Ae.umbellulata was significantly longer than that of three common wheat cultivars(180.9 d vs.137.0 d),with the exception of PI226500(138.9 d).The Ae.umbellulata accessions also showed high variability in Fe(69.74-348.09 mg kg^(-1))and Zn(49.83-101.65 mg kg^(-1))contents.Three accessions(viz.,PI542362,PI542363,and PI554399)showed relatively higher Fe(230.96-348.09 mg kg^(-1))and Zn(92.46-101.65 mg kg^(-1))contents than the others.The Fe content of Ae.umbellulata was similar to those of Ae.comosa and Ae.markgrafii but higher than those of Ae.tauschii and common wheat.Aegilops umbellulata showed a higher Zn content than Ae.tauschii,Ae.comosa,and common wheat,but a lower content than Ae.markgrafii.Furthermore,Ae.umbellulata had the highest proportion of γ-gliadin among all the species investigated(Ae.umbellulata vs.other species=mean 72.11%vs.49.37%;range:55.33-86.99%vs.29.60-67.91%).These results demonstrated that Ae.umbellulata exhibits great diversity in the investigated traits,so it can provide a potential gene pool for the genetic improvement of these traits in wheat.

Effects of Dietary Corn Gluten Meal on Growth Performance and Protein Metabolism in Relation to IGF-I and TOR Gene Expression of Juvenile Cobia (Rachycentron canadum)

A growth experiment was conducted on cobia(Rachycentron canadum,initial weight 108.2 g ± 3.0 g) to investigate the effects of dietary corn gluten meal(CGM) levels on the fish growth,whole body composition and protein metabolism in relation to specific gene expression.Five isonitrogenous(crude protein 45%) and isoenergetic(gross energy 20 kJ g 1) practical diets were formulated by replacing 0%(the control),17.5%,35.0%,52.5%,and 70.0% of fish meal(FM) protein with CGM protein.No significant differences were observed in the survival,feed intake(FI),specific growth rate(SGR),feed efficiency(FE) and protein productive value(PPV) among fish fed diets with 0%,17.5%,35.0%,and 52.5% of CGM protein.However,these indices were significantly lower in fish fed the diet with 70.0% of CGM protein than those in fish fed the control diet(P < 0.05).The whole-body crude protein and lipid contents were significantly lower while the whole-body moisture content was significantly higher in fish fed the diet with 70.0% of CGM protein compared with the control group(P < 0.05).When 70.0% of FM protein was replaced by CGM,plasma total protein and cholesterol contents were significantly lower than those in the control group(P < 0.05).Fish fed the diet with 70.0% of CGM protein had significantly lower hepatic insulin-like growth factor I(IGF-I) expression levels than those in the control group(P < 0.05).However,no significant differences were observed in hepatic target of rapamycin(TOR),dorsal muscle IGF-I and TOR expression levels among dietary treatments.Results of the present study indicated that 52.5% of FM protein could be replaced by CGM in the diets without significant influences on the growth,feed utilization and protein metabolism of juvenile cobia.The present results might be useful for developing cost effective and sustainable cobia dietary formulations.

Involvement of heat shock proteins in gluten-sensitive enteropathy

Gluten-sensitive enteropathy,also known as coeliac disease(CD),is an autoimmune disorder occurring in genetically susceptible individuals that damages the small intestine and interferes with the absorption of other nutrients.As it is triggered by dietary gluten and related prolamins present in wheat,rye and barley,the accepted treatment for CD is a strict gluten-free diet.However,a complete exclusion of gluten-containing cereals from the diet is often difficult,and new therapeutic strategies are urgently needed.A class of proteins that have already emerged as drug targets for other autoimmune diseases are the heat shock proteins(HSPs),which are highly conserved stress-induced chaperones that protect cells against harmful extracellular factors.HSPs are expressed in several tissues,including the gastrointestinal tract,and their levels are significantly increased under stress circumstances.HSPs exert immunomodulatory effects,and also play a crucial role in the maintenance of epithelial cell structure and function,as they are responsible for adequate protein folding,influence the degradation of proteins and cell repair processes after damage,and modulate cell signalling,cell proliferation and apoptosis.The present review discusses the involvement of HSPs in the pathophysiology of CD.Furthermore,HSPs may represent a useful therapeutic target for the treatment of CD due to the cytoprotective,immunomodulatory,and anti-apoptotic effects in the intestinal mucosal barrier.

Wheat gluten protein and its impacts on wheat processing quality

Before the advent of the wheat genomic era, a wide range of studies were conducted to understand the chemistry and functions of the wheat storage proteins,which are the major determinants of wheat flour the suitability of wheat flour for various end products, such as bread, noodles and cakes.Wheat grain protein is divided into gluten and non-gluten fractions and the wheat processing quality mainly depends on the gluten fractions.Gluten provides the unique extensibility and elasticity of dough that are essential for various wheat end products.Disulfide bonds are formed between cysteine residues,which is the chemical bases for the physical properties of dough.Based on the SDS-extractability, grain protein is divided into SDS-unextractable polymeric protein(UPP)and SDS-extractable polymeric protein.The percentage of UPP is positively related to the formation of disulfide bonds in the dough matrix.In the wheat genomic era, new glutenins with long repetitive central domains that contain a high number of consensus hexapeptide and nonapeptide motifs as well as high content of cysteine and glutamine residues should be targeted.

加工方式对面筋蛋白结构及性质影响的研究进展

面筋蛋白是面类食品中重要的组成成分。常见的面类食品加工方法,如加热、冷冻、机械处理及发酵工艺会破坏面筋蛋白的二级结构,面筋蛋白的疏水性、二硫键发生变化,面筋蛋白会发生变性、聚集等复杂的物理化学变化,进而影响面制品的质构与风味。文章主要介绍了加热、冷冻、粉碎、揉面、挤压及发酵工艺等加工方式对面筋蛋白的结构、性质影响的研究现状,并展望了面筋蛋白未来的研究方向。

小麦面筋蛋白遗传特性综合评价

本研究对44个小麦品种的19个面筋蛋白性状进行分析,运用主成分分析、相关性分析、隶属函数法和逐步回归等方法对面筋蛋白品质进行综合评价。结果表明:二硫键含量变幅为3.28~6.78μmol/g,巯基含量的变幅为13.30~16.66μmol/g。面筋蛋白性状变异范围在4.74%~89.46%,其中稳定时间、粉质质量指数等变异系数较大,表明蛋白质量性状的变异潜力较丰富。主成分分析将19个蛋白性状转换为3个综合因子,贡献率分别为40.80%、19.86%和15.88%,累计贡献率达到76.54%,可以很好地将面筋蛋白归为质量性状、聚集性状和数量性状3类。利用隶属函数法计算面筋蛋白综合评价值(D值),主成分因子中载荷较大的12个性状的平均值与D值均呈显著正相关。通过逐步回归建立了7个性状(二硫键含量、麦谷蛋白大聚体含量、蛋白质含量、干面筋含量、面筋指数、拉伸面积和最大峰值时间)作为自变量的回归方程。面包品质评价指标与D值之间具有较好的线性关系,决定系数R2在0.5614~0.7713之间,验证了D值的准确性和可行性。结论:不同筋力小麦面筋蛋白存在较丰富的变异潜力;采用多元统计分析方法综合评价面筋蛋白品质具有可行性;面筋蛋白的量与质以及面筋网络中二硫键的含量可作为小麦品质评价和改良的关键指标。

外源氨基酸添加对春卷皮面浆体系的影响

氨基酸作为良好的营养、风味增强剂,其在春卷皮面浆体系的研究鲜有报道,该研究选取四类八种氨基酸[碱性氨基酸:精氨酸(Arginine,Arg),赖氨酸(Lysine,Lys);酸性氨基酸:谷氨酸(Glutamic Acid,Glu)、天冬氨酸(Aspartic Acid,Asp);中性氨基酸:苏氨酸(Threonine,Thr)、甘氨酸(Glycine,Gly);非极性氨基酸:色氨酸(Tryptophan,Trp)、蛋氨酸(Methionine,Met)]来探究其对制备春卷皮面浆体系流变学与热力学特性、微观结构以及面筋蛋白二级结构的影响。发现碱性和酸性氨基酸的添加增加了面浆粘度,降低了面浆析水率,致使体系中游离水含量减少,面筋蛋白网络结构强度增加,进而面浆体系连接更紧密;其中,碱性氨基酸中的Arg降低了面浆中淀粉糊化所需能量焓值(1.68至1.24 J/g);此外,加入酸性氨基酸后,面浆淀粉糊化所需能量增大,面筋蛋白二级结构中β-折叠含量减少、α-螺旋和无规卷曲含量增加。中性和非极性氨基酸的加入降低了面浆粘度,提高了面浆析水率,对面浆体系热力学特性影响较小,同时增加了面筋蛋白二级结构中β-折叠和β-转角的含量。该研究以期为氨基酸在面制品中的应用提供相关理论基础。

阿拉伯木聚糖对面团及面制品品质影响的研究进展

阿拉伯木聚糖(arabinoxylan,AX)作为一种膳食纤维,在面团加工过程中会与其主要组分发生相互作用,从而影响面团特性和面制品品质。文章分析了AX与面团中面筋蛋白和小麦淀粉间的相互作用,总结归纳了其对面团持水性、流变性和发酵特性等方面的影响规律,概述了近年来国内外关于AX在应用于蒸煮类、焙烤类、油炸类面制品等方面所取得的研究成果,指出了目前在AX的精细结构、链构象特征、量效关系等方面需要解决的一些重要问题,并针对这些问题提出了今后的研究建议,以期推动AX在面制品行业中的理论研究和实际应用。

施氮量对两个强筋小麦品种品质的影响

为了探究施氮量对强筋小麦品质特性的影响,以强筋小麦品种‘郑麦366’和‘郑农46’为试验材料,分别设置0、120、240和360 kg/hm^(2)的施氮量,研究不同氮水平对小麦面筋蛋白组成及二级结构、淀粉的粒度分布和粘度特性、面团流变学特性的影响。结果表明,‘郑麦366’和‘郑农46’分别在N_(1)(120 kg/hm^(2))和N_(2)(240 kg/hm^(2))水平下流变学特性达到最佳,这可能是因为两个小麦品种分别在N_(1)和N_(2)下蛋白质含量较高、总淀粉含量较低、B型淀粉相对含量较高;相比于N_(0)(0 kg/hm^(2)),N_(3)(360 kg/hm^(2))条件下的面团流变学特性显著降低,可能是由于过量施氮分别影响了‘郑麦366’的蛋白含量和‘郑农46’的B型淀粉含量。综上,相比于其他品质性状,蛋白含量对‘郑麦366’品质的影响更大,而B型淀粉含量的变化在‘郑农46’品质形成中起主导作用。本研究为强筋小麦‘郑麦366’和‘郑农46’的氮素施用提供理论依据。

小麦加工前中后路粉面筋蛋白特性差异性分析

以同一生产线不同出粉点的小麦粉制备的面筋蛋白为原料,在测定面筋蛋白基本理化组分性质基础上再分别测定其游离巯基含量、表面疏水性、麦谷蛋白大聚体(glutenin macropolymer,GMP)含量与流变学特性,探讨前中后路粉面筋蛋白理化性质以及流变学特性差异。实验发现,前路粉面筋蛋白的灰分、蛋白质含量、游离巯基含量、表面疏水性低于后路粉面筋蛋白(P≤0.05),而吸水率、面筋指数与GMP含量高于后路粉面筋蛋白(P≤0.05),流变学实验结果表明前路粉面筋蛋白中的储能模量、损失模量均大于后路粉面筋蛋白,后路粉面筋蛋白更容易发生形变且最大形变量显著高于前路粉面筋蛋白。

酶解联合美拉德反应处理对面筋蛋白特性的影响

为了更好地修饰和利用面筋蛋白,采用酶解联合美拉德反应对面筋蛋白进行改性,并对其理化、结构和加工性能进行了研究。结果表明:与面筋蛋白相比,当反应温度为100℃时,酶解产物的美拉德反应产物的最大发泡能力为19.17%,溶解度和接枝度分别提高到(40.27±0.32)%和(24.75±1.47)%,乳化活性提升了1.2倍,同时游离巯基含量为0.86μmol/g,表明酶解可以有效减少二硫键的生成;随着反应温度的升高,面筋蛋白及其酶解产物的美拉德反应产物的荧光强度降低,增强了色氨酸和酪氨酸残基的荧光猝灭作用,而荧光中间产物的含量增加;酶解促进了美拉德反应的发生和糖基化终末产物前体物质的生成;由于酶解和反应温度的影响,面筋蛋白及其酶解产物的美拉德反应产物在性质和结构上存在显著差异。研究结果为修饰面筋蛋白的结构和改善其加工性能提供了一种可行的方法。

不同筋力小麦面筋聚集特性及结构特性分析

通过分析面团质构特性、面筋蛋白聚集特性、面筋蛋白含量、分子量分布、二级结构以及微观结构,研究“郑麦103”、“郑麦136”、“新麦26”3种不同筋力小麦面筋蛋白聚集特性及结构特性并探讨其差异。结果表明:随着小麦筋力的增强,面团的硬度、弹性、内聚性、胶着性、咀嚼性和回复性升高,黏性降低。相比于“郑麦103”和“郑麦136”,“新麦26”的峰值形成时间较长、峰值扭矩较大且面筋蛋白聚集能较高,面筋蛋白含量更高。随着小麦筋力的增强,面筋蛋白各亚基含量及种类增多。与“郑麦103”和“郑麦136”相比,“新麦26”面筋蛋白的二级结构中β-折叠和β-转角含量增多,α-螺旋含量降低,无规则卷曲含量先减少再增加。小麦筋力越强,面筋蛋白网络结构连续性越好,包裹淀粉能力越强。综上所述,相比于“郑麦103”和“郑麦136”,“新麦26”面筋蛋白含量较高,面筋蛋白亚基种类较多,可促进面筋蛋白的聚集,面筋蛋白中增多的β-折叠结构促进面筋蛋白结构的稳定性,面筋网络结构的连续性增强,进而提高面团的强度和弹性。

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、可溶性与不可溶性谷蛋白含量间均呈显著正相关(P<0.01)。因此,通过远缘杂交能有效地将野生二粒小麦高蛋白含量特性转移到普通小麦中,并能提高普通小麦的所有贮藏蛋白组分含量,对丰富小麦蛋白含量的遗传多样性具有重要意义。

外源蛋白改良剂对米面团热力学性能及面包品质的影响

以小麦面包为对照,探究大豆分离蛋白、豌豆分离蛋白、玉米醇溶蛋白、乳清浓缩蛋白和蛋清蛋白5种外源植物和动物蛋白质对米面团及面包的混合特性、糊化特性、流变学特性、比容和感官分析的影响。结果表明,加入外源蛋白可以降低米面团的回生值到最小为211 cP,使面包的比容增加至1.810 mL/g,硬度下降约55.3%,胶着性降低至2 710.12 g。其中植物蛋白中添加量为12%的大豆蛋白组面包气孔数量最多,质地细腻且颜色均匀,持水性及感官品质最好。动物蛋白中9%的乳清浓缩蛋白组面包硬度显著下降,约2 032.9 g(P<0.05),此时面团硬度最接近于小麦面团,弹性为0.82%,口感较软,对米面包质构特性改善效果最佳。结论:在植物蛋白中大豆蛋白添加量为12%、动物蛋白中乳清浓缩蛋白添加量为9%的条件下可以改善米面包品质。

谷朊粉对豌豆植物蛋白肉产品特性的影响

以豌豆蛋白为原料,添加不同比例的谷朊粉,在相同条件下采用高水分(60%~80%)挤压技术制备植物蛋白肉,研究不同谷朊粉含量对产品理化性质和结构特性的影响。结果表明,随着谷朊粉含量的增加,植物蛋白肉的硬度和咀嚼度先升高后降低,弹性显著升高(P<0.05),颜色逐渐变浅,溶液的黏度增加。植物蛋白肉的复水率随着谷朊粉的增加先升高后降低,内部孔隙数量明显增加且分布变得均匀。谷朊粉的加入使植物蛋白肉的二级结构含量发生变化,无规则卷曲向β-折叠进行转化,有序结构的含量先增加后减少。综上,谷朊粉的加入能够显著改善植物蛋白肉的理化性质和结构特性,改善拉丝效果及纤维结构,提高与真肉的类似度。

Foliar applications of various nitrogen(N)forms to winter wheat affect grain protein accumulation and quality via N metabolism and remobilization

Foliar nitrogen(N)application is an effective strategy to improve protein content and quality in wheat kernels,but the specific effects of N forms remain unclear.In a two-year field study,foliar application of various N forms(NO_(3)^(-),urea,NH_(4)^(+))at anthesis was performed to measure their effects on wheat grain protein accumulation,quality formation,and the underlying mechanisms.Foliar application of three N forms showed varying effects in improving grain gluten proteins and quality traits.Under NH_(4)^(+) application,there was more post-anthesis N uptake for grain filling,with relatively strong increase in enzyme activities and gene expression associated with N metabolism in flag leaves at 8–20 days after anthesis(DAA),whereas its promotion of grain N metabolism became weaker after 20 DAA than those under NO_(3)^(-) and urea treatments.More N was remobilized from source organs to grain under treatment with foliar NO_(3)^(-) and urea.Genes controlling the synthesis of gluten protein and disulfide bonds were upregulated by NO_(3)^(-) and urea at 20–28 DAA,contributing to increased grain protein content and quality.Overall,foliar applications of NO_(3)^(-) and urea were more effective than those of NH_(4)^(+) in increasing grain N filling.These findings show that manipulating the source–sink relationship by reinforcing grain N metabolism and N remobilization is critical for optimizing grain protein accumulation and quality formation.

冷冻面制品品质改良研究进展

冷冻面制品具有方便快捷、保质期长、便于储藏运输、生产效率高、易实现产品质量标准化等优点,其产业规模发展迅速。但在其生产和冷冻过程中,由不稳定的环境条件所引起的产品品质劣变不容忽视,仍需对其品质改良方法进行探究。本文从引起冷冻面制品品质劣变的影响因素为切入点,从生产工艺优化和添加剂使用2个方面对目前冷冻面制品改良方法的研究进展进行了综述,包括生产方式、加工条件、冷冻解冻方式、辅助冷冻技术以及各类食品添加剂的使用情况,对冷冻面制品品质改良的未来研究前景进行了展望,旨在为其创新性发展和研究提供借鉴。

小麦面筋蛋白与风味化合物相互作用机制研究

采用GC-MS分析小麦面筋蛋白与风味化合物(正己醛、2-戊基呋喃、1-辛烯-3-醇)的相互作用,并结合荧光、红外、紫外光谱等技术分析蛋白质结构的变化。结果表明:当风味化合物加入后,蛋白质结构展开,蛋白质α-螺旋含量降低,β-折叠和β-转角含量上升;当风味化合物与蛋白质结合后,蛋白质的疏水性降低,说明风味化合物诱导了蛋白质构象变化;键中断剂的加入降低了蛋白质与风味化合物的结合率,表明非共价键在蛋白质与风味化合物的结合中发挥了重要作用。

施氮量对强筋小麦光合、产量、蛋白质含量和加工品质的影响

为探究冀东地区强筋小麦适宜施氮量,以强筋小麦石优20号和中麦998为材料,通过大田试验设置0 kg·hm^(-2)(N_(0))、180 kg·hm^(-2)(N 180)、210 kg·hm^(-2)(N 210)和240 kg·hm^(-2)(N 240)4个施氮水平,分析了施氮量对强筋小麦光合、产量、蛋白质含量和加工品质的影响。结果表明,与N_(0)处理相比,施氮后石优20号和中麦998的产量均在N 240处理下增加显著,增幅分别为3.20%和13.95%。随施氮量的增加,小麦旗叶叶绿素含量和光合参数均呈先升后降趋势,且在花后15 d达到最大值。施氮对F v/F m影响较小,对ΦPSⅡ影响较明显。旗叶、籽粒内硝酸还原酶和谷氨酰胺合成酶均随施氮量的增加呈先升后降趋势。增施氮肥后籽粒蛋白组分中清蛋白、球蛋白比例下降,醇溶蛋白、谷蛋白比例上升,各组分含量在N 210处理下均最高。面筋含量、沉降值、形成时间和稳定时间均随施氮量的增加先升后降。这说明增施氮肥可改善強筋小麦植株的光合特性,进而提高产量,同时增加植株体内氮代谢相关酶活性和籽粒蛋白质含量并改变蛋白质组分所占比例,有效改善加工品质。本试验条件下,210 kg·hm^(-2)施氮量下,小麦产量和品质较优,该施氮量可作为冀东平原强筋小麦栽培的最佳施氮量。

牡丹花蕊蛋白对面团和面筋蛋白特性的影响

为实现牡丹花蕊资源化利用,以大豆分离蛋白为参照,研究牡丹花蕊蛋白对面团和面筋蛋白质构、动态流变学特性、二硫键、表面微观结构和二级结构的影响。结果表明,牡丹花蕊蛋白能够明显提高面团的硬度、黏着性和咀嚼性,添加量低于6%时效果优于大豆分离蛋白。添加花蕊蛋白提高了面团的储能模量与损耗模量,使得面团黏弹性增加。牡丹花蕊蛋白对面筋蛋白网络结构形成的影响与大豆分离蛋白基本一致,添加量为6%时,扫描电镜显示面筋蛋白气孔数量多且孔洞深,网络结构致密;面筋蛋白二级结构中,相对稳定的α-螺旋+β-折叠占比达到最大值59.32%,与空白组相比二硫键含量提高了89%。牡丹花蕊蛋白能够有效促进面筋蛋白网络结构的形成,提高面团的品质,可用于对黏弹性要求较高的面制品生产。