Effect of sucrose fatty acid esters on pasting, rheological properties and freeze–thaw stability of rice flour

Effect of compositions and physical properties on 3D printability of gels from selected commercial edible insects: Role of protein and chitin

Compositions and rheological properties of alternative protein sources, including honey bee pupa, grasshopper, cricket, earthworm, and scorpion, and their relationships with 3D printing behaviors were investigated. Protein was found to be the major composition in all insects, while chitin exhibited the most variation. At optimal moisture contents, honey bee pupa and earthworm gels displayed sufficient fluidity but resulted in unstable printed structures, as observed visually and microstructurally. Grasshopper and scorpion gels possessed weak fluidity but produced more stable printed structures. Cricket gel exhibited the most balanced flow behavior and self-supportability. Protein-to-chitin mass ratio proved to be a main factor affecting the 3D printing behavior of the gels. Possible mechanisms on how compositions and properties affected the printing behavior of the gels were proposed. Suggestions for improving the 3D printability of insect and invertebrate resembling insect gels were provided based on these proposed mechanisms.

Impact of Guar Gum and Locust Bean Gum Addition on the Pasting, Rheological Properties, and Freeze-Thaw Stability of Rice Starch Gel

Improving the gel texture and stability of rice starch (RS) by natural hydrocolloids is important for the development of gluten-free starch-based products. In this paper, the effects of guar gum and locust bean gum on the pasting, rheological properties, and freeze−thaw stability of rice starch were investigated by using a rapid visco analyzer, rheometer, and texture analyzer. Both gums can modify the pasting properties, revealed by an increment in the peak, trough, and final viscosities, and prevent the short-term retrogradation tendency of RS. Dynamic viscoelasticity measurements also indicated that the starch−gum system exhibits superior viscoelastic properties compared with starch alone, as revealed by its higher storage modulus (G′). Compared with the control, the hysteresis loop area of the guar gum-containing system and locust bean gum-containing system was reduced by 37.7% and 24.2%, respectively, indicating that the addition of gums could enhance shear resistance and structure recovery properties. The thermodynamic properties indicated that both gums retard short-term retrogradation as well as long-term retrogradation of the RS gels. Interestingly, the textural properties and freeze−thaw stability of the RS gel were significantly improved by the addition of galactomannans (p < 0.05), and guar gum was more effective than locust bean gum, which may be due to the different mannose to galactose ratio. The results provide alternatives for gluten-free recipes with improved texture properties and freeze−thaw stability.

Physicochemical and Structural Characterization of Potato Starch with Different Degrees of Gelatinization

Starch gelatinization has been widely studied previously, but there is still a lack of systematical research on the relationship between the degree of starch gelatinization (DSG) and its physicochemical and structural properties. In this study, potato starch samples with DSG ranging from 39.41% to 90.56% were obtained by hydrothermal treatment. The thermal, rheological, and structural properties, as well as the water-binding capacity of samples were investigated. A starch solution with a DSG of 39.41% was partially sedimented at room temperature, while starch with a DSG of 56.11% can form a stable paste with a fine shear-thinning property, as well as samples with a DSG larger than 56.11%. The endothermic enthalpy, gelatinization range, and short-range ordered structure of starch were negatively correlated with DSG, whereas onset gelatinization temperature, apparent viscosity, and water-binding capacity were positively correlated. The viscoelasticity of starch gels was negatively correlated with the DSG after full gelatinization (DSG > 39.41%). Starch granules gradually lose their typical shape and less birefringence can be observed with increasing DSG. Hydrothermal treatment has a more significant effect on the amount of exposed hydroxyl groups than the ordered and amorphous structures of partially gelatinized starch. This study built linear correlations between starch physicochemical properties and the DSG and provided comprehensive insight into the characteristics of partially gelatinized potato starch.

Effects of concentrations, temperature, pH and co-solutes on the rheological properties of mucilage from Dioscorea opposita Thunb. and its antioxidant activity

The mucilage from Dioscorea opposita (DOM) dispersions presented shear-thinning behaviour that well fitted to the Power Law model. The effects of different concentrations (2%-10% w/v), temperatures (25-80 °C), pH (3.0-9.0), freeze-thaw conditions (thawed at 25 °C and 4 °C), co-salts (KCl and CaCl₂) and co-sugars (sucrose, fructose and mannose) on the rheological properties were investigated. Generally, higher concentrations, neutral pH, Ca²⁺ and sugars increased the viscosity of DOM, while increasing temperature (25-65 °C) had opposite effects. The results suggested that cross-linked networks exist in DOM, and viscosity changes may be related to the ionisation of carboxyl groups, structural changes and enhancement/reduction of molecular interactions. Particularly, Ca²⁺ could interact with uronic acids of two or more polysaccharide molecules, modify the network-structure through cross-linking with carboxyl groups, and enhance the stronger carboxylate-cation²⁺-carboxylate interactions. Therefore, DOM is suitable for food applications as thickening or gelling agents in aqueous solutions.

The effect of additives combination on rheological properties of dough and quality of bread with Agaricus bisporus powder

The bread with Agaricus bisporus powder has the defects of poor texture and taste, so it is necessary to optimize the appropriate additives in order to improve its quality. The purpose of this study was to evaluate improvement of the combination of vital wheat gluten, sucrose fatty acid esters and cellulase on the improved Agaricus bisporus powder bread (IABPB), with wheat bread (WB) and bread with Agaricus bisporus powder (ABPB) as control. The results of rheological properties indicated the dough samples improved with three improvers had higher solid-like behaviour than the control sample. The results of nutritional quality analysis showed that the protein and dietary fiber content of IABPB was higher than those of WB and ABPB, but the fat content was relatively low. In addition, the additives combination could effectively improve the baking quality of ABPB. Compared with ABPB without additives, the specific volume increased by 21.22%, the brightness of bread crumb increased by 8.75%, but the crumb hardness decreased by 32.57%. Furthermore, the study on texture property and water migration during the storage showed that the addition of three improvers could delay the aging of bread. Therefore, it was feasible to use additives combination as a special quality improver for ABPB, which could effectively improve its quality.

Starch Retrogradation in Rice Cake: Influences of Sucrose Stearate and Glycerol

Retrogradation properties and kinetics of rice cakes with the addition of glycerol (GLY) and sucrose fatty acid ester (SE) were investigated. In hardness, both rice cakes with glycerol (RGLY) and rice cakes with sucrose fatty acid ester (RSE) showed lower initial hardening compared with the control for up to 5 days. X-ray diffraction (XRD) pattern of RSE showed a B+V-type pattern, and the relative crystallinity showed that GLY and SE lowered the initial and final crystallization of rice cake. Both GLY and SE affected the retrogradation enthalpy, glass transition temperature, and ice melting enthalpy in differential scanning calorimeter (DSC). However, ¹H NMR relaxation time (T₂) of rice cake decreased regardless of additives. From these results, the addition of glycerol and sucrose stearate inhibits the retrogradation process of rice cakes, which will solve industrial problems. Applying the Avrami equation for retrogradation kinetics of rice cake was suitable in XRD and DSC with high coefficient of determination (0.9 < R²). Meanwhile, the other retrogradation index improved the R² when the exponential rise to maximum equation was used. This suggests that there is an alternative of Avrami equation to predict the retrogradation.

Effects of sucrose on pasting, thermal, rheological and textural properties of native and alcohol-alkali-treated waxy rice starch

In this work, the physicochemical properties of native waxy rice starch (WRS) and alcohol-alkali-treated waxy rice starch (AAT-WRS) were studied in the presence of sucrose. The results indicated that the addition of sucrose improved the transparency and freeze-thaw stability of WRS pastes and AAT-WRS pastes. Differential scanning calorimetry showed that the gelatinization temperatures of WRS increased with increased sucrose concentration, but the gelatinization enthalpy increased at low concentration of sucrose and decreased at high concentration. Rheological measurements indicated that sucrose addition had no significant effect on the pseudoplastic shear-thinning behaviors of WRS pastes and AAT-WRS pastes, but changed the apparent viscosity. Dynamic moduli (G' and G″) values of WRS pastes and AAT-WRS pastes with or without sucrose showed frequency dependency and sucrose addition dependency. The elastic behavior was dominant over viscous in the WRS-sucrose mixed pastes, while the AAT-WRS-sucrose mixed pastes was the opposite. The textural paraments of WRS and AAT-WRS before or after retrogradation increased with the increasing concentration of sucrose. These results suggested that sucrose potentially changed the physicochemical properties of WRS and AAT-WRS.

A Novel Simple Approach to Material Parameters from Commonly Accessible Rheometer Data

When characterizing the viscoelastic properties of polymers, shear rheological measurements are commonly the method of choice. These properties are known to affect extrusion and nozzle-based processes such as fiber melt spinning, cast film extrusion and 3D-printing. However, an adequate characterization of shear thinning polymers can be challenging and still insufficient to not only describe but predict process relevant influences. Furthermore, the evaluation of rheological model systems in literature is mostly based on stress–relaxation experiments, which are rarely available for various polymeric materials. Therefore, a simple approach is presented, that can be used to evaluate and benchmark a wide range of rheological model systems based on commonly accessible frequency sweep data. The approach is validated by analyzing alginate PH176 solutions of various concentrations, a thermoplastic poly-urethane (TPU) Elastollan 1180A melt, the liquid silicon rubber Elastosil 7670 and a polycaprolactone (PCL) fiber-alginate composite system. The used rheological model systems, consisting of simple springs and dashpots, are suitable for the description of complex, viscoelastic material properties that can be observed for polymer solutions and gel-like systems. After revealing a suitable model system for describing those material properties, the determination and evaluation of relevant model parameters can take place. We present a detailed guideline for the systematic parameter revelation using alginate solutions of different concentrations as example. Furthermore, a starting point for future correlations of strut spreading in 3D-bioprinting and model parameters is revealed. This work establishes the basis for a better understanding and potential predictability of key parameters for various fabrication techniques.

Effect of curdlan and xanthan polysaccharides on the pasting, rheological and thermal properties of rice starch

The effects of microbial polysaccharides xanthan and curdlan on the pasting, viscoelastic properties and retrogradation of rice starch were studied. The additions of xanthan and curdlan increased the peak viscosities and decreased the final viscosities. The breakdown viscosities were increased by the curdlan addition, but were decreased by the xanthan addition. The dynamic viscoelastic results showed that the addition of xanthan in rice starch significantly increased storage modulus and loss modulus. The rice starch gel with xanthan addition exhibited higher resistances to the stress and produced a stronger microstructure network. The creep recovery data were well fitted by a 4-element Burger's model. Differential scanning calorimetry showed that the addition of curdlan and xanthan decreased the melting enthalpy values and retarded the retrogradation of the rice starch gel during storage at 4 °C for 12 days. The pasting and thermal results demonstrated that the addition of xanthan could significantly inhibited the retrogradation of rice starch. It was concluded that the addition of curdlan and xanthan modified the rheology of rice starch gel in different ways and interacted under different models based on their molecular structures.

Effect of sucrose fatty acid esters with different hydrophilic-lipophilic balance values on pasting and rheological properties of waxy rice flour

Effects of sucrose fatty acid esters (SEs) with hydrophilic-lipophilic balance (HLB) values of 5 (S-570), 9 (S-970), and 15 (S-1570) on the pasting and rheological properties of waxy rice flour (WRF) were investigated. Rapid Visco Analyzer (RVA) showed that addition of SEs affected the pasting properties of WRF. Rheological experiment includes the steady shear flow characteristics, and dynamic viscoelastic properties were also determined using a controlled-stress rheometer. The steady shear tests demonstrated that the viscosity data fitted well with the power law model (R ²≥0.976) and all WRF pastes exhibited typical pseudoplastic and shear-thinning properties. Dynamic rheological measurements revealed that the addition of S-970 and S-1570 significantly increased the values of G' and G″ of samples, whereas the addition of S-570 decreased these values. The addition of S-1570 reduced the value of tanδ, whereas S-570 and S-970 increased it.

Effects of Sucrose Stearate Addition on the Quality Improvement of Ready-To-Eat Samgyetang During Storage at 25℃

The effects of sucrose stearate at various concentrations (0.1%, 0.2%, and 0.3%, w/v) on the physico-chemical characteristics of ready-to-eat (RTE) Samgyetang were investigated during storage at 25℃ for 12 mon. Over the storage duration, the addition of sucrose stearate had no significant effects on the proximate composition of Samgyetang, including meat, broth, and porridge, or the hardness and spreadability of the porridge, although it resulted in significantly higher CIE L* values for the porridge. The CIE L* values of Samgyetang porridge with added sucrose stearate increased until 9 mon, while the control decreased until 6 mon, and the values for both changed insignificantly thereafter. The breast meat of Samgyetang treated with sucrose stearate showed higher percentages of polyunsaturated fatty acid after 3 mon and lower percentages of monounsaturated fatty acid after 6 mon compared to the control (p<0.05), while no significant differences were observed with the different sucrose stearate concentrations (p>0.05). The overall sensory acceptability scores were higher at sucrose stearate concentrations of 0.2% or 0.3% after 6 mon and at 0.1% after 9 mon compared to those of the control.