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首页> 外文学位 >Solvent Effects on the Molecular Structures of Crude Gliadins as Revealed by Density and Ultrasound Velocity Measurements.
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Solvent Effects on the Molecular Structures of Crude Gliadins as Revealed by Density and Ultrasound Velocity Measurements.

机译：溶剂对粗麦醇溶蛋白分子结构的影响，如密度和超声速度测量所揭示。

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摘要

Gliadin is associated with some of the functional properties of dough and the breadmaking suitability of flours. This study was undertaken to characterize the effects of solvents on the molecular structure of crude gliadins in terms of the physical properties of these proteins as assessed by ultrasound velocity and density measurements.;For the solvent analyses, crude gliadins were extracted from Canada Western Red Spring (CWRS) wheat flour with 70% (v/v) aqueous ethanol solutions and then lyophilized. Lyophilized crude gliadins were dissolved in 70% (v/v) aqueous ethanol (EtOH) or 4 mM acetic acid (HAc) and the density and ultrasound properties were measured at 20°C. Good linear relationships of density, ultrasound velocity and ultrasound attenuation with solution concentrations were found. Solvent and sonication effects on the crude gliadins were discussed in terms of the values of the partial specific volume, nu o, and the partial specific adiabatic compressibility coefficient, boS&d1; , for crude gliadins. The ethanol soluble crude gliadins had a larger partial specific volume, nuo (0.747 mL·g-1), and larger partial specific adiabatic compressibility coefficient, boS&d1; (10.27 x 10-6 bar-1) than those for acidic soluble crude gliadins (nu o = 0.736 mL·g-1; boS&d1; 3.72 x 10-6 bar-1). These large values for the physical properties of ethanol soluble crude gliadins were thought to be evidence for the existence of complexes formed by some proteins (ethanol soluble LMW-glutenins and gliadins) and lipids in ethanol solutions and it was also found that the protein-lipid complexes were not destroyed by sonication treatment.;In the flour analyses, crude gliadins were extracted from wheat flours of different classes (Canada Western Red Spring, Canada Western Extra Strong and Soft White Spring) with 70% (v/v) aqueous ethanol solutions and freezed dried material was subsequently dissolved in 4 mM HAc. The density and ultrasound velocity and ultrasound attenuation were measured at 20°C. Good linearity of density and ultrasound properties with solution concentration was found for the crude gliadins from the three different flours. There was no evidence showing that gliadins change with different wheat flours and cause different volume and compressibility properties of crude gliadins. However, the volume and compressibility properties were found to be related to the protein contents of the crude gliadin solutions, as well as the protein contents of the flours, and proteins had positive contributions to the volume and compressibility properties of acidic soluble crude gliadins and non-protein components had negative contributions.;In the preliminary experiments, crude gliadins were extracted using modified Osborne fractionation from flours from four wheat cultivars (Glenlea, Katepwa, AC Reed and Genesis) and the ultrasound velocities of the crude gliadin serial dilutions were measured at 20°C. The ultrasound velocity values of the crude gliadins in alcoholic solutions exhibited non-linearity with solution concentrations. Thus, fresh 70% (v/v) aqueous ethanol solutions made of 95% (v/v) ethanol and water were selected for further experiments to extract the crude gliadins from wheat flours.
机译：麦醇溶蛋白与面团的某些功能特性和面粉的面包制作适用性有关。本研究旨在通过超声速度和密度测量评估溶剂对粗麦醇溶蛋白分子结构的影响，以这些蛋白的物理性质为特征;为了进行溶剂分析，从加拿大西部红泉中提取粗麦醇溶蛋白。 （CWRS）小麦粉和70％（v / v）乙醇水溶液，然后冻干。将冻干的麦醇溶蛋白粗品溶解在70％（v / v）的乙醇水溶液（EtOH）或4 mM乙酸（HAc）中，并在20°C下测量密度和超声性能。发现密度，超声速度和超声衰减与溶液浓度之间具有良好的线性关系。根据部分比容nu o和部分比绝热压缩系数boS＆d1讨论了对粗麦醇溶蛋白的溶剂和声处理作用。 ，用于粗麦醇溶蛋白。溶于乙醇的粗麦醇溶蛋白的部分比容较大，为nuo（0.747 mL·g-1），部分绝热绝热压缩系数为boS＆d1。 （10.27 x 10-6 bar-1）比酸性可溶性粗麦醇溶蛋白（nu o = 0.736 mL·g-1; boS＆d1; 3.72 x 10-6 bar-1）高。认为乙醇溶性粗麦醇溶蛋白的物理性能具有如此高的值，是乙醇溶液中某些蛋白质（乙醇溶性LMW-谷蛋白和麦醇溶蛋白）和脂质形成的复合物存在的证据，并且还发现该蛋白-脂质复合物未通过超声处理破坏。在面粉分析中，从含70％（v / v）乙醇水溶液的不同类别（加拿大西部红春，加拿大西部特强和软白春）的小麦粉中提取了粗麦醇溶蛋白。然后将冷冻干燥的物质溶解在4mM HAc中。在20℃下测量密度，超声速度和超声衰减。发现来自三种不同面粉的粗麦醇溶蛋白的密度和超声性能与溶液浓度具有良好的线性关系。没有证据表明麦醇溶蛋白随小麦粉的变化而变化，并导致粗麦醇溶蛋白的体积和压缩特性不同。但是，发现其体积和可压缩性与粗麦醇溶蛋白溶液中的蛋白质含量以及面粉中的蛋白质含量有关，并且蛋白质对酸性可溶性粗麦醇溶蛋白和非水溶性麦醇溶蛋白的体积和可压缩性具有积极的作用。 -蛋白质组分具有负作用。；在初步实验中，使用改良的奥斯本分级分离法从四个小麦品种（Glenlea，Katepwa，AC Reed和Genesis）的面粉中提取粗麦醇溶蛋白，并在60℃下测量了粗麦醇溶蛋白系列稀释液的超声速度。 20℃。酒精溶液中粗麦醇溶蛋白的超声速度值与溶液浓度呈非线性关系。因此，选择了由95％（v / v）乙醇和水制成的新鲜70％（v / v）乙醇水溶液，用于进一步的实验，以从小麦粉中提取粗制麦醇溶蛋白。

著录项

  • 作者

    Zhang, Zhuo.;

  • 作者单位

    University of Manitoba (Canada).;

  • 授予单位 University of Manitoba (Canada).;
  • 学科 Agriculture Food Science and Technology.
  • 学位 M.Sc.
  • 年度 2010
  • 页码 160 p.
  • 总页数 160
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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