Abstract

The influence of heat-moisture treatment (HMT) and flour hydration (DY) on the restoration of dough viscoelasticity of wheat/non-wheat binary matrices was investigated by applying fundamental and empirical rheological procedures, and the protein structural reorganization was monitored by measuring residual protein solubility in different media, and by assessing the accessibility of thiol groups inside the protein network. Single chestnut (CN), chickpea (CP), millet (MI), and teff (T) flour samples submitted to HMT (15% moisture content, 1 h and 120 °C) were blended with wheat flour at 10% (CN, CP) and 30% (MI, T) of replacement, and binary matrices hydrated at low (L), medium (M), and high (H) DY. Structuring ability of HMT was mainly observed in cereal flour blends (T, MI), where higher elastic moduli and lower loss tangent together with solid-like elastic structure over higher shear stress were observed as compared with treated non-cereal flour blends (CN, CP). Increased flour hydration significantly weakened blends structure, inducing a stepped decrease in dynamic moduli values particularly noticed in cereal blends at highest level of flour hydration, and a shift from elastic-like to viscous-like structure at lower shear stress in non-wheat cereal matrices. The formation of a protein network with reinforced compact structure associated to the presence or formation of intramolecular (CN, CP, T) and intermolecular disulphide bonds (CN, CP, MI, T), water-soluble (CN, MI) and water-insoluble aggregates (CP, T) is feasible to achieve with proteins of non-wheat flours submitted to HMT, particularly in high DY doughs. The lower the amount of free thiols in high molecular weight proteins encompassing high degree of crosslinking, corresponded to thermally treated samples (T, MI) blended at L and M hydration levels. For thermally treated samples, the lower the amount of free thiols in high molecular weight proteins encompassing high degree of crosslinking, corresponded to T and MI binary matrices blended at L and M hydration levels. These samples exhibited a solid-like elastic structure over higher shear stress and showed increased tolerance to stress/strain before losing the structure.

中文翻译：

---

构建稀释的小麦基质：湿热处理对水合复合面粉蛋白质聚集和粘弹性的影响

摘要

运用基本和经验的流变方法，研究了热湿处理和面粉水合对小麦/非小麦二元基质面团粘弹性恢复的影响，并通过测量残留量来监测蛋白质的结构重组。蛋白质在不同介质中的溶解度，以及通过评估蛋白质网络内部巯基的可及性。将提交给HMT（含水量15％，在1 h和120°C下）的栗子（CN），鹰嘴豆（CP），小米（MI）和teff（T）面粉样品与10％（CN， CP）和30％（MI，T）的替代品，二元矩阵在低（L），中（M）和高（H）DY下水合。HMT的结构能力主要在谷物粉混合物（T，MI）中观察到，与经处理的非谷物面粉混合物（CN，CP）相比，在较高的剪切应力下观察到较高的弹性模量和较低的损耗角正切以及类似固体的弹性结构。面粉水化程度的增加会显着削弱混合物结构，导致动态模量值逐步降低，尤其是在面粉水化度最高的谷物混合物中，尤其是在非小麦谷物基质中，在较低的剪切应力下，其弹性模量会转变为粘稠状。 。形成具有紧密结构的增强蛋白网络，该结构与分子内（CN，CP，T）和分子间二硫键（CN，CP，MI，T），水溶性（CN，MI）和水-不溶性聚集体（CP，T）是可行的，适用于HMT的非小麦面粉的蛋白质，尤其是在高DY面团中。包含高度交联度的高分子量蛋白质中的游离硫醇含量较低，对应于在L和M水合水平下混合的热处理样品（T，MI）。对于热处理样品，包含高交联度的高分子量蛋白质中游离硫醇的含量较低，对应于在L和M水合水平下混合的T和MI二元基质。这些样品在较高的剪切应力下表现出固态的弹性结构，并且在失去结构之前显示出对应力/应变的增加的耐受性。包含高交联度的高分子量蛋白质中游离硫醇的含量越低，对应于在L和M水合水平下混合的T和MI二元基质。这些样品在较高的剪切应力下表现出固体状的弹性结构，并且在失去结构之前显示出对应力/应变的增加的耐受性。包含高交联度的高分子量蛋白质中游离硫醇的含量越低，对应于在L和M水合水平下混合的T和MI二元基质。这些样品在较高的剪切应力下表现出固态的弹性结构，并且在失去结构之前显示出对应力/应变的增加的耐受性。