小麦籽粒硬度与胚乳显微结构关系研究

本文选用了8个籽粒角质率不同的小麦品种(系)进行籽粒硬度和胚乳横断面显微结构关系的研究。结果表明籽粒硬度不同的小麦品种其胚乳结构存在差异：硬度值较大的硬质品种胚乳蛋白质较多。淀粉粒与蛋白质结合紧密；而硬度值较小的软质小麦品种胚乳蛋白质较少。淀粉粒与蛋白质结合松散。     

文献导读

正小麦籽粒淀粉与面粉的理化特性差异面制食品的品质与籽粒淀粉理化特性关系密切,糯质和非糯质小麦籽粒淀粉组分有明显差别。本研究比较了糯小麦(宁糯麦1号、扬糯麦1号)和非糯小麦(扬麦16、中国春)的淀粉与面粉的黏度特性、热力学特性、膨胀势、溶解度等参数,旨在阐明小麦籽粒淀粉与面粉的理化特性差异。4个品种籽粒淀粉粒均以C型淀粉粒(粒径2μm)为主,占96.14%~97.36%,糯小麦C型淀粉粒的比例高于非     

烟台地区小麦硬度指数调查分析

<正>采用硬度指数法对烟台地区2015年种植收获的鲁麦21、烟农24、烟农999、烟农5158、济麦22、胶州22六个主要品种的小麦进行小麦籽粒硬度测定,为2015年度入库小麦品质判定和质量控制提供参考,也为小麦种植品种选择提供部分数据参考。小麦硬度即小麦胚乳质地,是指小麦籽粒抵抗外力作用下发生变形和破碎的能力,即破碎小麦籽粒时所需要的力。小麦硬度受遗传控制,不同品种的小麦胚乳细胞中蛋白质基质和     

Friabilin蛋白与籽粒硬度和面团流变学特性关系研究

籽粒硬度是决定普通小麦(Triticum aestivum L.)最终用途和市场分级的重要性状之一,而水洗淀粉表面的friabilin蛋白及其两个主要组分puroindoline a (PINA)和puroindoline b (PINB)蛋白是决定这一性状的分子遗传基础.本试验采用改进的SDS-PAGE和A-PAGE方法分离了90份小麦单籽粒friabilin和puroindoline蛋白,进一步把电泳谱带的相对表达量与籽粒硬度、面团流变学参数进行相关性分析.结果表明,三个蛋白的谱带相对表达量与籽粒硬度呈显著负相关,相关系数为-0.78、-0.77、-0.79,均达到1%显著水平;蛋白表达量与面团吸水率、稳定时间、评价值、延伸度、最大拉伸比等流变学特性呈显著相关,部分相关达到1%显著水平.     

小麦籽粒硬度和小麦销售加工及育种关系的探讨

简要论述了我国小麦籽粒硬度分类及测定方法，就籽粒硬度与加工及小麦育种的关系进行了探讨。     

软质小麦与硬质小麦的籽粒结构比较研究

用扫描电镜观察三个小麦品种（２软质１硬质）的籽粒结构结果表明，硬质小麦淀粉粒较小，胚乳中淀粉与蛋白质基质密结，导致磨粉时破损淀粉粒较多，胚乳也易于与麸皮分离，出粉率高，麸星较少。而软质麦淀粉粒较大，淀粉粒与基质蛋白质结合不牢固，磨粉时易于分离，淀粉粒破碎少，且麸星较多，总出粉率低。     

小麦胚乳A、B型淀粉粒的形成与生长特征及氮素调节

为研究小麦胚乳淀粉粒形成与生长特征,以优质小麦品种藁城8901为材料,在缺氮(对照)和施氮条件下,对籽粒发育过程中淀粉粒的产生、体积与数目分布及粒径变化进行比较。结果表明,花后4 d,小麦胚乳已出现A型淀粉粒,其中施氮处理粒径显著高于对照,说明氮素有利于早期淀粉粒的产生。花后10 d,又产生了一个新的小淀粉粒群体,即B型淀粉粒。花后10~12 d,施氮处理的粒径显著低于对照,可能是这个阶段施氮能促进小麦产生了更多的小(B型)淀粉粒,说明这个时期淀粉粒的生长以数目增长为主。花后14~17d,施氮处理淀粉粒粒径显著高于对照,说明这个时期淀粉粒生长以个体体积增大为主。花后24 d,0.8μm淀粉粒数目急剧增加,表明此期又产生了一个小淀粉粒群体。花后28 d,施氮处理0.8μm淀粉粒数目仍不断增加,表明施氮能促进灌浆后期籽粒产生更多的小淀粉粒。通过透射电镜观察发现,小淀粉粒是由大淀粉粒分裂而来的,单个存在。小麦胚乳A型淀粉粒形成和发育时期基本在花后14 d之前,而B型淀粉粒在成熟前,其体积和数目一直在增加。施氮有利于胚乳A、B型淀粉粒个体的增大和数目的增多。     

彩色小麦的理化特性及麸皮粉的品质评价

目的研究彩色小麦和普通小麦的理化特性、营养组成及小麦皮层和胚乳中淀粉粒的结构形态和类型,为进一步了解彩色小麦的特性提供理论依据,为彩色小麦的营养加工奠定良好的基础。方法采用国标方法,对彩色小麦的理化指标和营养组成进行综合分析;采用扫描电子显微镜方法观察分析彩色小麦的皮层和胚乳中淀粉粒的结构形态和类型。结果彩色小麦在千粒重、容重等物理特性方面低于普通小麦,且彩色小麦籽粒的长宽比大,没有普通小麦籽粒饱满。在营养组分方面,绿麦3104、紫麦3202、黑麦3201的蛋白质含量分别比普麦烟农19高29.5%、24.4%、21.3%;湿面筋含量分别比普麦烟农19高29.6%、19.0%、17.0%;粗脂肪含量分别比普麦烟农19高31%、10.4%、22.2%。通过扫描电镜对小麦皮层结构分析发现彩色小麦糊粉层中含有大量的糊粉颗粒,集中了小麦籽粒大部分的营养物质。干法制备的麸皮粉,随着碾磨道数的增加,其灰分含量呈升高趋势,出粉率和白度呈降低趋势。结论彩色小麦在营养组成方面与普通小麦相比有很大优势,麸皮粉的品质特性与普通小麦相似,但彩色小麦的胚乳淀粉粒的形态和类型与普通小麦存在很大差异。     

甘肃环县商品小麦的配麦配粉效应分析

以甘肃环县的5种商品小麦为材料．系统分析和比较了商品小麦的籽粒品质、蛋白质品质、磨粉品质、粉质参数和蒸煮品质，并对甘肃环县商品小麦与陕253的配麦配粉效应进行了研究。结果表明：甘肃环县商品小麦的容重、籽粒硬度较高，蛋白含量、湿面筋含量、沉淀值和面团稳定时间较低，筋力较弱。不同品种小麦以相同比例与陕253搭配。其品质也有较大差别。陕253的搭配比例在40％以上时，搭配效果较为理想。     

科技文摘

本文测定了用室温裁培和田间生长的小麦中蛋白组分和硬度.收获室温培育成熟的籽粒,按照麦种分出麦穗.用粒度分析仪测定每个籽粒的硬度,并抽提麦醇溶蛋白,用     

In situ examination of starch granule-soy protein and wheat protein interactions

The objective of this study was to evaluate the association between heat and pressure-treated soy proteins and wheat prime starch relative to the level of granule surface proteins present. Soy isolates were manufactured from defatted soy flour and from two types of textured soy flour. Conditions for binding between wheat starch and soy fractions were established by altering pH, protein and sucrose concentrations. Conformations of exogenous proteins bound to the wheat starch granule surface were evaluated using an amyloglucosidase assay. Proteins present on the granule surface were removed and soy protein binding was reevaluated. Thermal and pressure processing of soy protein significantly influenced binding kinetics. Textured soy proteins exhibited increased wheat starch granule adsorption characteristics compared to untreated soy protein. Removal of native wheat starch granule surface proteins decreased the binding of added proteins. This suggests that native granule proteins may mediate the binding of exogenous protein.     

Wheat (Triticum aestivum L. and T. turgidum L. ssp. durum) Kernel Hardness: I. Current View on the Role of Puroindolines and Polar Lipids

Wheat hardness has major consequences for the entire wheat supply chain from breeders and millers over manufacturers to, finally, consumers of wheat‐based products. Indeed, differences in hardness among Triticum aestivum L. or between T. aestivum L. and T. turgidum L. ssp. durum wheat cultivars determine not only their milling properties, but also the properties of flour or semolina endosperm particles, their preferential use in cereal‐based applications, and the quality of the latter. Although the mechanism causing differences in wheat hardness has been subject of research more than once, it is still not completely understood. It is widely accepted that differences in wheat hardness originate from differences in the interaction between the starch granules and the endosperm protein matrix in the kernel. This interaction seems impacted by the presence of either puroindoline a and/or b, polar lipids on the starch granule surface, or by a combination of both. We focus here on wheat hardness and its relation to the presence of puroindolines and polar lipids. More in particular, the structure, properties, and genetics of puroindolines and their interactions with polar lipids are critically discussed as is their possible role in wheat hardness. We also address future research needs as well as the presence of puroindoline‐type proteins in other cereals.     

PHYSICAL PROPERTIES OF SUGAR-SNAP COOKIES USING GRANULE SURFACE DEPROTEINATED WHEAT STARCH

The physical properties of soft wheat starch granule surface proteins and soy flours or isolates, which contribute to the texture of sugar‐snap cookies was studied. Soft wheat flour was deproteinated and cookies were produced containing 0, 10, 20 or 30% soy flour, or one of two types of ground, textured soy flour. Color, fracture force and spread ratio of cookies were determined. Cookies formulated with wheat starch stripped of the starch granule surface proteins exhibited significant alterations in diameter, fracture force, thickness and surface cracking. Cookies containing ground, textured soy flour and protein‐stripped starch granule wheat flour were larger, thinner and had more surface cracking than those produced with nontextured soy flour. Wheat starch granule surface proteins appear to partially mediate the interaction of proteins and starch in a sugar‐snap cookie system.     

Comparison of Endosperm Starch Granule Development and Physicochemical Properties of Starches from Waxy and Non-Waxy Wheat

Starch granule development and physicochemical properties of starches in waxy wheat and non-waxy wheat were investigated in this article. Starch granules in waxy wheat endosperm showed an early developmental process. Compared with non-waxy wheat starch granules (round-shaped), waxy wheat starch granules (ellipse-shaped) were larger and contained more B-type granules. According to the granule size, starch granules were divided into two groups in waxy wheat, but were divided into three groups in non-waxy wheat. Compared with non-waxy wheat starch, waxy wheat starch had higher swelling power, gelatinization temperatures (To, Tp, Tc), and relative degree of crystallinity. They showed similar ordered structures on external regions of starch granules. Additionally, waxy wheat starch had a higher proportion of double-helical components and a lower proportion of single-helical components than non-waxy wheat starch. Based on the previous results, it was concluded: (1) waxy wheat and non-waxy wheat not only differed in starch granule development, but also in physicochemical properties of starches; (2) waxy wheat had more potential value for producing traditional products than non-waxy wheat.     

Partial Leaching of Granule‐Associated Proteins from Rice Starch during Alkaline Extraction and Subsequent Gelatinization

Starch granule‐associated proteins, including granule‐bound starch synthase (GBSS), were found to be partially lost during alkaline extraction of rice starch. Variability in amount of loss of GBSS and other granule proteins was found among different rice lines. Also, part of the GBSS and other granule proteins leached out during gelatinization of the alkali‐extracted rice starch. Confocal laser scanning microscopy revealed that some protein still existed in gelatinized starch granules prepared from starch isolated using alkaline extraction. The starch that retained more GBSS and other granule proteins after alkaline extraction tended to have more protein in the isolated gelatinized starch granules, indicating that proteins resistant to alkaline extraction also tended to resist leaching during gelatinization. The study suggests that leaching of granule‐associated proteins may contribute to variations in paste properties of alkali‐extracted starches.     

Effects of Soy Protein on Physical and Rheological Properties of Wheat Starch

It is necessary to understand the interaction phenomena between proteins and polysaccharides for the development of starch‐based products with better physical and sensory properties. A simplified model system was chosen to study the influence of soy protein on physical and rheological properties of wheat starch and the possible interactions between them. Thermal and pasting behaviors of the slurries and texture properties, water retention capacity and ultra structure of soy protein‐wheat starch gels were analyzed. While soy protein isolate increased the viscosity of starch suspension during and after heating, gels with soy protein presented a weaker structure than wheat starch gels. Results suggested association between leached out material and swollen granule surface of starch with soy protein. Scanning electron microscopy reflected these changes in the gel ultrastructure.     

Effect of proteins on the formation of starch–lipid complexes during extrusion cooking of wheat flour with the addition of oleic acid

The formation of starch–lipid complexes plays an important role in extruded products. The effect of gluten proteins on thermal conditions at which the starch–lipid complexes formed during extrusion cooking of wheat flour with the addition of oleic acid was evaluated, considering wheat starch as a reference. The presence of gluten proteins in wheat flour extrudates brought about a reduction of the formation of starch–lipid complexes compared to blend of wheat starch and oleic acid extruded at the same operating conditions (melting enthalpy: 0.4 vs. 1.6 kJ kg^?1). Moreover, the lubricant effect of oleic acid observed during extrusion of wheat starch (low values of specific mechanical energy and residence time) was not found during extrusion of wheat flour with addition of oleic acid because of the interaction between gluten proteins and oleic acid. This research points out the importance of proteins on biopolymer modifications and their effect on extrudate quality.     

调质对小麦粉粒度及组分的影响

调质是小麦研磨前不可缺少的工序之一,可有效改善制粉效果和小麦粉品质。本文通过改变调质水分（14.5%、15.5%、16.5%）、调质温度（25、35、45 ℃）及调质方式（真空调质、常规调质）,探究调质对小麦粉粒度及其组分的影响。结果表明,随着调质水分增加,小麦粉颗粒度先变细后变粗,出粉率、灰分、总蛋白、麦谷蛋白和破损淀粉呈降低趋势,L*与醇溶蛋白增大,总淀粉先降低后升高。提高调质温度后小麦粉颗粒度、总淀粉与支链淀粉逐渐增大,总蛋白、麦谷蛋白和破损淀粉逐渐减小。与常规调质相比,真空调质后小麦粉整体粒径较大,醇溶蛋白和破损淀粉含量较低,麦谷蛋白和支链淀粉含量较高。不同调质条件对小麦制粉品质有显著差异,在调质水分为15.5%、调质温度25 ℃时,小麦粉最细、出粉率较高、灰分较低,小麦制粉品质较好。     

脂类和颗粒结合蛋白对小麦A、B淀粉理化性质的影响

淀粉颗粒中的脂类和颗粒结合蛋白对其理化和结构性质存在一定影响,研究了小麦A、B淀粉经脱脂、脱蛋白处理后其化学组成、颗粒形态、糊特性等性质。结果表明:脱脂处理对小麦A、B淀粉的晶体类型、溶解度、膨胀度、起始温度、峰值温度、终值温度、热焓值、峰值黏度、谷黏度、衰减值、最终黏度、峰值时间、成糊温度均无显著性影响,相对结晶度降低。脱蛋白处理使小麦淀粉溶解度和膨胀度随温度的增长趋势显著增加,相对结晶度、起始温度、峰值温度、终值温度、峰值黏度、衰减值、回生值显著增大,谷黏度和峰值时间显著降低,对晶体类型、热焓值无显著影响。脱蛋白处理对小麦A、B淀粉理化性质的影响显著高于脱脂处理。     

Model system analysis of wheat starch-soy protein interaction kinetics using polystyrene microspheres

The objective of this study was to identify the interaction of puroindoline and starch lipids with soy proteins when coupled to polystyrene microspheres. Manipulation and removal of wheat starch granule surface proteins and lipids may damage granule integrity and hinder studies of ungelatinized starch systems. Therefore, 5 μm polystyrene microspheres were used to evaluate the role of starch granule surface components on exogenous protein binding. Puroindoline, phospholipid, glycolipid and triglyceride were passively adsorbed to the surface of polystyrene microspheres. Binding assays using soy protein indicated that puroindoline-lipid coated microspheres adsorbed soy protein to a greater extent than did those coated with puroindoline alone. Phospholipids increased binding more than glycolipids and triglycerides.