Small and large strain rheology of gluten and gluten-starch doughs containing wheat bran dietary fiber

Cereal dietary fiber regulates the quality of whole grain products: Interaction between composition, modification and processing adaptability

The coarse texture and difficulty in processing dietary fiber (DF) in cereal bran have become limiting factors for the development of the whole cereal grain (WCG) food industry. To promote the development of the WCG industry, this review comprehensively summarizes the various forms and structures of cereal DF, including key features such as molecular weight, chain structure, and substitution groups. Different modification methods for changing the chemical structure of DF and their effects on the modification methods on physicochemical properties and biological activities of DF are discussed systematically. Furthermore, the review focusses on exploring the interactions between DF and dough components and discusses the effects on the gluten network structure, starch gelatinization and retrogradation, fermentation, glass transition, gelation, and rheological and crystalline characteristics of dough. Additionally, opportunities and challenges regarding the further development of DF for the flour products are also reviewed. The objective of this review is to establish a comprehensive foundation for the precise modification of cereal DF, particularly focusing on its application in dough-related products, and to advance the development and production of WCG products.

Interaction of wheat bran dietary fiber-gluten protein affects dough product: A critical review

Wheat bran dietary fiber (WBDF) is an emerging food additive used for improving the nutritional value of dough products, albeit its adverse effects cannot be ignored. The dilution effect, mechanical shear effect, competitive water absorption, and steric hindrance of WBDF, as well as the non-covalent binding between WBDF and gluten protein, are considered the key mechanisms underlying the WBDF-gluten protein interaction. However, current studies on the interaction are mostly limited to the impact of the interaction on gluten protein and are rarely focused on the quality of products. Therefore, the effects of the interaction on the structural characteristics and aggregation behavior of gluten protein and multiple involved mechanisms are discussed in this review. On this basis, these changes are systematically related to the gluten network structure, dough properties, and product quality. Mitigation measures corresponding to negative impacts also need to be elaborated to guide and standardize the production and development of dough products containing WBDF.

Cauliflower by-products as functional ingredient in bakery foods: Fortification of pizza with glucosinolates, carotenoids and phytosterols

Industrial cauliflower by-products still represent a no-value food waste, even though they are rich in bioactive compounds. With the aim of valorizing them, optimized special flours rich in glucobrassicin, lutein, β-carotene, and β-sitosterol obtained from leaves, orange and violet stalks were used at 10 and 30% w/w in the formulation of functional leavened bakery. For the first time, the effect of bioactive compounds enrichment in pizza products as well as the rheological properties were evaluated. As results, pizza making process affected the recovery of the bioactive compounds. The recovery of glucobrassicin and carotenoids in pizza depended on the aerial part of cauliflower. Pizza with violet stalks was the richest in glucobrassicin, providing 8.4 mg per portion (200 g). Pizza with leaves showed the highest carotenoid content with a 90% of recovery rate while pizza with orange stalks provided up to 5.8% of the phytosterols health claim requirement. All 10% enriched pizzas revealed viscoelastic and springiness properties similar to the control, contrary to 30% fortification level. Therefore, the use of 10% special flour in pizza should meet both technological industrial processing and consumer acceptance. Orange stalks are the most promising ingredients for high levels of fortification in pizzas.

Impact of Fermented Wheat Bran Dietary Fiber Addition on Dough Rheological Properties and Noodle Quality

This study aimed to evaluate the effect of fermented wheat bran dietary fiber (FWBDF) on the rheological properties of the dough and the quality of noodles and to compare it with the effect of the unfermented WBDF (UWBDF). WBDF was fermented with Auricularia polytricha. The results showed that adding UWBDF/FWBDF increased the storage modulus G' and loss modulus G” of the dough, converted α-helices and β-turns into β-sheets and random coils, respectively, inhibited water flow, increased cooking loss, and decreased the maximum resistance in the noodles. The formed gluten network had a more random and rigid structure, resulting in the deterioration of the quality of noodles. Furthermore, the number of α-helices and the peak proportions of weakly bound water A₂₂ increased but the number of β-sheets and cooking loss decreased in the FWBDF group compared with the UWBDF group. FWBDF (≤4%) improved the hardness of noodles, while UWBDF decreased it. These changes indicated that fermentation could reduce the destructive effects of WBDF on the quality of noodles, providing a new perspective on balancing dietary fiber-rich and high-quality foods.

Effect of stearic acid on the microstructural, rheological and 3D printing characteristics of rice starch

The aim of this study was to investigate the changes of the microstructural, rheological and printing properties of rice starch-stearic acid (SA) paste during the hot-extrusion 3D printing (HE-3DP). The results showed that starch chains could complex with SA to form V-type crystalline structure and its molecular kinematic behaviors were changed under shear force, and crystalline structure were then embedded and rearranged to constitute an ordered sea-island structure, thus improving the rigidity and dynamic storage modulus of network structure, leading to the increased layer number. Interestingly, with the increase of SA addition, the network structure became weakened and the viscosity decreased which might due to the destroyed continuity and the breaking of entanglement and hydrogen bonding between starch chains, and finally impairing the printing accuracy of objects. Overall, this study provided important information for the application of lipid in the preparation of starch-based food by HE-3DP.

Effects of moisture content and tillage methods on creep properties of paddy soil

The rheological properties parameters of paddy soil affect the interaction between the tillage tools and soil, thus influencing the operation quality and power consumption. In order to study the effects of tillage methods and moisture content on the rheological properties parameters of paddy soil in the middle and lower reaches of the Yangtze River, uniaxial compression creep tests of paddy soils with four moisture contents under no tillage (moisture contents: 26.71%, 24.52%, 23.26%, 21.28%) and plough tillage (moisture contents: 26.77%, 25.55%, 23.40%, 20.56%) were carried out using a TMS-PRO texture analyzer. The creep properties curves obtained from the tests, and the rheological constitutive equation of paddy soil under compression was established by Burgers viscoelastic model. Respectively, the quantitative change rules of creep properties of paddy soil with different moisture contents under different tillage methods and the correlation between these parameters were explored. The results showed that the moisture content under the three-year plough tillage and no tillage methods had significant influence on the rheological properties parameters of paddy soil (P < 0.05). The instantaneous elastic modulus, delay elastic modulus, and viscosity coefficient of the two paddy soils (no tillage and plough tillage soils) decreased with the increase of moisture content. However, the variation rules of relaxation time and delay viscosity coefficient with moisture content differed between these two paddy soils. Specifically, the strain rate of the two paddy soils decreased as moisture content decreased, where the total strain combines elastic strain, viscous strain, and viscoelastic strain. The initial strain rate and steady strain rate of the plough tillage paddy soils were lower than that of the no tillage paddy soils. The established creep model equation could be used to obtain viscoelastic rheological parameters of paddy soil in a wide range. The fitting equations between rheological parameters and moisture content were introduced into Burgers model, and the coupling equations between creep deformation and moisture content and time were derived, which could be used to predict the creep properties and deformation behavior of paddy soil in a certain range of no tillage and ploughed field. Overall, this study has a certain theoretical significance for the development and improvement of paddy soil rheology theory, and can also provide theoretical basis and technical support for the research of agricultural machinery design optimization, field water, soil conservation, soil tillage and compaction related simulation analysis in the middle and lower reaches of the Yangtze River.

Wheat bran, as the resource of dietary fiber: a review

Wheat bran is a major by-product of white flour milling and had been produced in large quantities around the world; it is rich in dietary fiber and had already been used in many products such as whole grain baking or high dietary fiber addition. It has been confirmed that a sufficient intake of dietary fiber in wheat bran with appropriate physiological functions is beneficial to human health. Wheat bran had been considered as the addition with a large potential for improving the nutritional condition of the human body based on the dietary fiber supplement. The present review summarized the available information on wheat bran related to its dietary fiber functions, which may be helpful for further development of wheat bran as dietary fiber resource.

Carboxymethylcellulose-induced changes in rheological properties and microstructure of wheat gluten proteins under different pH conditions

ABSRACT

The interaction between gluten and hydrocolloid additive, as well as the pH condition during dough formation is very important in making flour products. In this study, the influence of different pH conditions on the interactions between gluten proteins (including glutenin and gliadin) and carboxymethylcellulose (CMC), and on the rheological and microstructure changes of gluten proteins was investigated. The dynamic frequency sweep indicated CMC-gluten displayed more solid-like behavior under alkaline conditions than that under acidic conditions. The creep-recovery experiment suggested acidic conditions were not conducive to maintain the elasticity of CMC-gluten. Microstructural changes of various glutens with CMC showed that a higher ratio of β-sheets was observed in the CMC-gluten and CMC-glutenin under alkaline conditions. Total free sulfhydryl contents and changes in tryptophan microenvironment showed glutenin played a key role in the G polymerization with the addition of CMC. Lower surface hydrophobicity of CMC-gluten was displayed under acidic conditions. Scanning electron microscopy images showed that neutral and alkaline conditions were conducive to the network structure formation of CMC-gluten and CMC-glutenin.

PRACTICAL APPLICATION

This study investigated the interaction of CMC with gluten, gluten, and gliadin under different pH conditions, providing a basis for expanding dough quality improvement, and extending the in-depth application of CMC in the food industry.