Rheological behaviors of doughs reconstituted from wheat gluten and starch

Modulation in Techno-Functional, Textural Properties, In Vitro Starch Digestibility and Macromolecular-Structural Interactions of Pasta with Potato (Solanum tuberosum L.)

The replacement of semolina with potato flour (PF) and potato mash (PM) at different levels was assessed for its effects on pasta quality. The results showed that the addition of PF and PM increased the pasting viscosity of the blends; in addition, PF enhanced the functional properties, while PM reduced them. The minimum cooking time decreased with PF and PM, while the PF pasta exhibited a higher cooking loss (5.02 to 10.44%) than the PM pasta, which exhibited a lower cooking loss. The pasta with PF and PM showed an increase in the total phenolic and flavonoid content, with reduced in vitro digestibility as confirmed by Fourier transform infrared spectroscopy. The PF pasta exhibited lower lightness and higher yellowness than the PM pasta, and its firmness and toughness also modulated owing to the complex interaction between potato starches and the gluten protein matrix, as evident from scanning electron microscopy. Sensory data revealed that pasta containing 30% PF and 16% PM was highly acceptable.

Rheological, microstructure and mixing behaviors of frozen dough reconstituted by wheat starch and gluten

The effects of starch and gluten on the physicochemical properties of frozen dough were studied using reconstituted flour. The profiles of frozen dough were studied by Mixolab, rheometer, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Results revealed that starch, rather than gluten, played a decisive role in mixing properties. The breakdown and aggregation of the gluten network structure as well as the formation of β-turns and β-sheets in the frozen dough would be aggravated by the freezing of wheat starch. Smaller wheat starch granules (B-Type granules) affected the secondary structure of gluten network more than larger granules (A-Type granules), resulting in greater rheological property changes. The viscoelastic properties and freezable water content of frozen dough were more influenced by the freezing of gluten.

Gluten-starch interface characteristics and wheat dough rheology-Insights from hybrid artificial systems

Referring to the total surface existing in wheat dough, gluten-starch interfaces are a major component. However, their impact on dough rheology is largely unclear. Common viewpoints, based on starch surface modifications or reconstitution experiments, failed to show unambiguous relations of interface characteristics and dough rheology. Observing hybrid artificial dough systems with defined particle surface functionalization gives a new perspective. Since surface functionalization standardizes particle-polymer interfaces, the impact on rheology becomes clearly transferable and thus, contributes to a better understanding of gluten-starch interfaces. Based on this perspective, the effect of particle/starch surface functionality is discussed in relation to the rheological properties of natural wheat dough and modified gluten-starch systems. A competitive relation of starch and gluten for intermolecular interactions with the network-forming polymer becomes apparent during network development by adsorption phenomena. This gluten-starch adhesiveness delays the beginning of non-linearity under large deformations, thus contributing to a high deformability of dough. Consequently, starch surface functionality affects the mechanical properties, starting from network formation and ending with the thermal fixation of structure.

An extensive review: How starch and gluten impact dough machinability and resultant bread qualities

Wheat flour can form dough with a three-dimensional viscoelastic structure that is responsible for gas holding during fermentation and oven-rise, creating a typical fixed, open-cell foam structure of bread after baking. As the major components of dough, the continuous reticular skeleton formed by gluten proteins and the concentrated starch granules entrapped in gluten matrix predominantly determine dough rheological behaviors and bread qualities. This review surveys the latest literatures and draws out a conclusion from a plethora of information related to the filling effects of starch granules on gluten matrix and the cross-linking mechanisms between gluten proteins and starch granules, which is of great significance to provide sufficient scientific knowledge for development of bread with satisfactory attributes and quality control of end products.

Interaction between A-type/B-type starch granules and gluten in dough during mixing

To explore the interaction between A/B starch and gluten, the rheological and structural properties of starch-gluten dough with varied A/B starch ratios during mixing were investigated. The G' and G″ values of under- and overdeveloped dough with an A/B starch ratio of 5:5 were higher than those of dough with other ratios and decreased as the A/B starch ratio increased in optimized dough. B starch enhanced extension resistance and dough firmness. Small B starch granules promoted continuous gluten network formation, while large A starch granules readily separate from the gluten network. B starch promoted GMP polymerization. Covalent bonds were the main force involved in A starch-gluten interactions. Hydrophobic interactions were the main force in the under- to optimum-mixing stages, whereas hydrogen and covalent bonds were involved in B starch-gluten interactions from the optimum- to over-mixing stages. A model describing the interactions between gluten and starch components was proposed.

Pasting, thermo, and Mixolab thermomechanical properties of potato starch-wheat gluten composite systems

This research investigated the viscosity, thermal, thermomechanical, and microstructural properties of potato starch-wheat gluten composite systems with different starch/gluten ratios under mechanical shear and heating conditions. Results showed that the peak, trough, and final viscosities increased with the increase in potato starch fraction. The breakdown and setback values of samples decreased with increasing gluten content, and the endothermic enthalpy showed a similar variation trend. The gelatinization temperature of the samples increased significantly as the gluten proportion increased. Morphological observation showed that the gluten protein was wrapped around potato starch granules and the starch granules have a diluting effect on gluten network. Moreover, gluten formed a water diffusion barrier out of the starch granules, this barrier effect and the competitive hydration between starch and gluten could primarily explain the delayed gelatinization temperatures.

A highly sensitive and selective spectrofluorimetric method for the determination of cerium at pico-trace levels in some real, environmental, biological, soil, food and bone samples using 2-(α-pyridyl)-thioquinaldinamide

A very simple, ultra-sensitive and highly selective non-extractive new spectrofluorimetric method is presented for the determination of cerium at pico-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA). PTQA has been proposed as a new analytical reagent for the direct non-extractive spectrofluorimetric determination of cerium(iv). This novel fluorimetric reagent, PTQA becomes oxidized in a slightly acidic (0.0005-0.0015 M H2SO4) solution with cerium(iv) in absolute ethanol to produce a highly fluorescent oxidized product (λ ex = 303 nm; λ em = 370 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.0005-0.0015 M H2SO4) for the period between 5 min and 24 h. Linear calibration graphs were obtained for 0.001-600 μg L-1 of Ce, having a detection limit of 0.1 ng L-1; the quantification limit of the reaction system was found to be 1 ng L-1 and the RSD was 0-2%. A large excess of over 60 cations, anions and complexing agents (like, chloride, phosphate, azide, tartrate, oxalate, SCN- etc.) do not interfere in the determination. The developed method was successfully used in the determination of cerium in several certified reference materials (alloys, steels, noodles, ores and sediments) as well as in some environmental waters (potable and polluted), biological fluids (human blood, urine and milk), soil samples, food samples (vegetable, rice, corn and wheat), bone samples (human, cow, bull, fish, hen, goat, sheep), solutions containing both cerium(iii) and cerium(iv) and complex. The results of the proposed method for assessing biological, food and vegetables samples were comparable with ICP-OES and were found to be in excellent agreement.

Rheological properties and bread quality of frozen sweet dough with added xanthan and different freezing rate

In this paper the effects of frozen storage time, xanthan gum and rate of freezing on frozen sweet dough properties and unfermented bread quality was investigated. Results revealed that the water holding capacity, WHC, K₁ (stress decay rate) and K₂ (residual stress at the end of the stress relaxation experiment) values of frozen dough decreased with increasing frozen storage time and decreasing freezing rate; while the lowest values for these parameters were obtained for samples without xanthan gum. The amount of unfreezable water increased and freezable water decreased with addition of xanthan gum. Glass transition temperature for fresh or frozen sweet were around -37 and -39 °C, respectively. Addition of xanthan gum increased the glass transition temperature of fresh and fozen sweet dough. Firmness and gumminess of sweet bread increased during frozen storage which led to lower specific volume of frozen sweet bread. Increasing freezing rate and addition of xanthan gum to dough formulation improved the texture and specific volume of the final bread.

Suitability of spring wheat varieties for the production of best quality pizza

The selection of appropriate wheat cultivars is an imperative issue in product development and realization. The nutritional profiling of plants and their cultivars along with their suitability for development of specific products is of considerable interests for multi-national food chains. In this project, Pizza-Hut Pakistan provided funds for the selection of suitable newly developed Pakistani spring variety for pizza production. In this regard, the recent varieties were selected and evaluated for nutritional and functional properties for pizza production. Additionally, emphasis has been paid to assess all varieties for their physico-chemical attributes, rheological parameters and mineral content. Furthermore, pizza prepared from respective flour samples were further evaluated for sensory attributes Results showed that Anmool, Abadgar, Imdad, SKD-1, Shafaq and Moomal have higher values for protein, gluten content, pelshenke value and SDS sedimentation and these were relatively better in studied parameters as compared to other varieties although which were considered best for good quality pizza production. TD-1 got significantly highest score for flavor of pizza and lowest score was observed from wheat variety Kiran. Moreover, it is concluded from current study that all wheat varieties except TJ-83 and Kiran exhibited better results for flavor.