Ovomucin-Complex (OVM) is responsible for providing the natural gel-like properties of egg white, especially in alkali-induced egg white gels. In this study, OVM was modified by alkaline to produce ...gel-type materials. The structure, physicochemical and viscoelastic properties of OVMs under different pH (7–12) were probed using FTIR, HPLC, SEM, CLSM and rheometer. The results of rheological measurements in linear viscoelastic region revealed that alkaline modified OVMs exhibited a soft viscoelastic gel in alkaline conditions, with the transition occurring near pH 8, compared with a viscoelastic solution at neutral pH. In addition to the pH-dependent gelation behavior of OVMs, further rheological studies under nonlinear deformations reveal shear thinning and an apparent yield stress, which were also highly affected by pH. The results from HPLC and molecular interactions suggest that the alkaline modification led to the depolymerization of OVMs in alkaline conditions, enhancing the formation of intermolecular disulfide bonds, electrostatic force and hydrophobic interactions. The differences in these mechanical properties were also reflected in the OVM structure. The SEM and CLSM images demonstrated that the arrangement of gel pores under pH 10 conditions is denser and well-distributed than those under other conditions. The FTIR results verified that alkaline modification leads to the decreased content of β-sheet. Nevertheless, prolonged exposure to pH 12.0 resulted in a gradual liquefaction of the gel due to increased electrostatic repulsion and surface hydrophobicity, as well as the reduced disulfide bond and an increase in the disordered structure. These findings provide a novel insight for the development of mucin gel foods.
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•Alkaline pH significantly improved the gel properties of OVM-Complex.•Disulfide bonds are the decisive interacting forces to alter the gel properties.•The dissociation of OVM chains was promoted under alkaline pH conditions.
Excessive intake of saturated fatty acids poses a serious health risk, necessitating the urgent development of healthier plant-based fat replacers. Despite the emulsifying properties of chitosan ...(CS), it remains a significant challenge to create CS emulsions with minimal CS content and superior rheological properties as fat replacers. In this study, a supramolecular interaction system was constructed with inner hydrophilicity and outer hydrophobicity, enabling tunable rheological properties. This system was utilized to assemble hydrophobically modified CS with sodium alginate through appropriate treatment. As the oil phase fraction in the emulsion of stabilized flaxseed oil in the supramolecular system increases, the viscosity, storage modulus (G′), and loss modulus (G″) of the emulsion also increase. The emulsion transitions to a semi-solid state when the oil phase fraction ≥60 wt%. The supramolecular system (1 mg/g) can stabilize flaxseed oil emulsion with 80 wt% oil phase fraction. There were no significant changes in the morphology and rheological properties of the emulsions following a 60-day storage period at room temperature. In addition, emulsions can be used in several scenarios as fat replacers in food processing due to their tunable rheological properties.
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•An inner hydrophilic and outer hydrophobic supramolecular system was constructed.•The supramolecular system (1 mg/g) can stabilize emulsion with 80% oil fraction.•Hydrophobicity of chitosan and rheological properties of emulsions are tunable.•Emulsions can be used in several scenarios as fat replacers in food processing.
Water activation as a way to improve the quality of bakery products has been used recently. In this study, we investigated the effect of dough mixing with plasma-activated water (PAW) for 1, 2, and ...3 min on the rheological characteristics of dough and the pan bread's quality and stability during storage at room temperature (25±2 °C). The PAW pH was decreased (from 6.2 to 3.5), and oxidation reduction potential (ORP) increased (from 223.7 to 564.4 mV). Results showed that the addition of PAW to the dough caused an increase in dough stability, elasticity, and extensibility, as well as a decrease in dough development, arrival time, and degree of softness compared with control.
Using PAW in pan bread preparation increased its specific volume, porosity, and crumb and crust colour parameters. Using PAW in pan bread preparation reduced hardness, gumminess, cohesiveness, and chewiness, while springiness increased. Also, the results of the storage experiment showed that PAW addition enhanced pan bread freshness and shelf life, as well as reducing its fungal count. Generally, using PAW in pan bread preparation enhances the dough's rheological characteristics as well as its quality and stability during storage. In addition, water activated for 3 min was the most effective.
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•Plasma activated water enhance dough rheological properties.•Plasma activated water enhance pan bread specific volume and porosity.•Plasma activated water enhance colour and texture properties of pan bread.•Using plasma activated water in pan bread preparation reduce bread staling rate.•Water activated for 3 min by cold atmospheric plasma was most suitable for pan bread quality improvement.
The rheology is an effective tool to characterize workability, consistency, flowability, and predict stability, pumpability, shootability, pressure of formwork, multi-layer casting. This paper ...presents a critical review on the rheological properties of fresh concrete in recent publications. The applicable rheological models for the flow of concrete are revealed. The effects of constituents of fresh concrete, including cement, supplementary cementitious materials (fly ash, ground blast furnace slag, and silica fume), limestone powder, coarse and fine aggregates, and chemical admixtures (superplasticizer, viscosity modifying agent and air-entraining agent) on the rheological properties are discussed in detail. The applications of rheograph and workability box in mixture proportioning and quality control are also illustrated.
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