Paste Viscosity Research Articles

Rheology and hardened properties of eco-friendly ultra-high performance concrete paste: Role of waste stone powder fillers

Waste stone powder is the largest by-product generated during the production of manufactured sand, which causes environmental pollution and resource wastage due to its large accumulation and landfill disposal. In this study, the effectiveness of basalt powder (BP) was evaluated against that of limestone powder (LP) to verify its potential for use as a functional and environmentally-friendly filler in Ultra-High Performance Concrete (UHPC) compositions. The theories of wet packing density (WPD) and water film thickness (WFT) are introduced to investigate the effect of stone powder on hardened and rheological properties of UHPC. Results indicate that the WFT of the solid particle system (cement and stone powder) exhibits a direct correlation with the increase in stone powder content (up to 20 %). As the WFT increases, the shear resistance between particles is reduced, leading to a nonlinear decrease in the yield stress and plastic viscosity of the UHPC paste, thereby enhancing its flowability. More superplasticizer is adsorbed on the surface of BP, which weakens the gain effect of the superplasticizer in reducing the yield stress. Due to the increased WPD, a near-linear enhancement in the compressive strength of the paste is observed. Supplementary nucleation sites for C-S-H are provided by the surface of the stone powder, thus accelerating the early hydration kinetics of the UHPC paste and facilitating development of strength at an early age. When 20 % of cement is replaced by LP and BP, the carbon emission index of UHPC paste is reduced by 34.9 % and 21.7 %, respectively.

Effects of different fermentation processes on cooking and eating quality of brown rice noodles

While brown rice noodles are nutritionally dense, their subpar cooking and eating attributes render them unpalatable to consumers. Fermentation serves as a viable method to enhance food quality and taste. In our previous study, the quality of brown rice noodles was notably enhanced through solid-state fermentation of rice flour (SFRF) with Limosilactobacillus fermentum. In this study, we investigated the impact of SFRF, solid-state fermentation of rice grains (SFRG), and liquid-state fermentation of rice grains (LFRG) on the cooking attributes, sensory qualities, and processing characteristics of brown rice noodles (BRN). The findings indicated that the quality of brown rice noodles (BRN) could be notably enhanced through the application of these three fermentation techniques. In comparison to the BRN produced via SFRF and LFRG, the rice noodles processed using SFRG exhibited superior visual appeal, reduced cooking losses (4.87%), minimal breakage rates (4.00%), and enhanced taste profile. Following fermentation, the gelatinization temperature (Tp) and peak viscosity of rice flour decreased, with SFRG demonstrating the lowest gelatinization temperature. Pasting and rheological assessments revealed that solid-state fermentation of rice grains led to a reduction in the pasting viscosity of rice flour by hindering starch granule swelling and disintegration. In summary, noodles processed through SFRG exhibited enhanced cooking and sensory characteristics, luminosity (L*), and superior gel structure.

Improvement of pasting behavior and retrogradation inhibition of normal corn starch treated with phytic acid and malic acid

Phytic acid (PA) and malic acid (MA), as environmentally friendly, plant-based water-soluble acids, were applied to normal corn starch during dry heating at mildly acidic pH to improve its gelatinization and retrogradation behaviors. A significant increase in peak viscosity (5011–6338 mPa·s) was observed in starch treated with MA compared to native corn starch (1162 mPa·s). The treatment with PA and MA further increased the peak viscosity (8140–8621 mPa·s). The interactions of PA and MA with starch were analyzed using ICP-OES, FTIR, and 13C CP/MAS NMR. Swelling power and solubility increased in MA and PA + MA starches. After storage at 4 °C for 14 d, MA and PA + MA starches produced transparent and fluid gels without forming B-type crystals, which indicated inhibition of starch retrogradation by PA and MA treatments. In conclusion, dry heating with PA and MA produced starch with remarkably superior paste viscosity, swelling, and inhibition of retrogradation.

Effect of wet grinding carbonation of sintering red mud on the performance of carbon sequestered mortar

The use of alkaline solid waste to CO2 capture is a potential way to upgrade the recycling of solid waste and reduce CO2 emission. In previous work, we proposed a novel wet grinding carbonation technique to achieve rapid carbonation of sintering red mud (SRM). Herein, the effect of wet grinding carbonation of SRM (WGCS) replacement rate (0 %, 5 %, 10 %, 15 %, 20 % and 25 %) on the hydration and hardening of Portland cement was further explored, such as rheology, compressive strength, hydration products and water transfer properties. The plastic viscosity and yield stress of carbon sequestered paste rose together with the WGCS replacement rate, which was due to the decreased D50 of SRM after wet grinding carbonation. When the WGCS replacement rate was 15 %, the 56 d compressive strength of carbon sequestered mortar was increased by 14.1 %. The microscopic characterization showed that the nucleation of calcite crystals and the pozzolanic reaction of silica-rich gels clearly improved the microstructure compactness. The electric flux and porosity of cement mortar was decreased by 25.7 % and 11.4 %, respectively. In terms of environmental and economic benefits, the CO2 sequestration of carbon sequestered mortar reached as high as 24.7 kg/m3 and the CO2 emission was reduced by 30.9 %.

Crack-healing and rheological properties of high content fly ash/slag/silica fume green and sustainable cement-based materials incorporating crystalline admixture and calcium alginate biomass hydrogel

Cracking is an important factor affecting the durability of concrete. Rheological properties are important performance indicators of the workability of fresh concrete. Ion chelator (CA) is one kind of crystalline admixture, which can enhance crack-healing of concrete by promoting the formation of calcium carbonate in wet environment. Calcium alginate hydrogel (CaAlg) can maintain the humidity of cementitious matrix and promote the crystallization of inorganic minerals. Therefore, in this study, CaAlg bead was prepared to further improve the crack-healing of cementitious materials containing CA. Self-healing performance was evaluated by visual crack closure and water permeability test. Rheological property was measured by rotor rheometer. Healing mechanism of cementitious materials with CA and CaAlg was analyzed. Results showed that with the increase of CaAlg dosage, yield stress and plastic viscosity of paste decreased gradually. Meanwhile, fly ash and slag reduced viscosity of pastes, while silica fume increased the viscosity of pastes. CA could evidently improve the permeability and mechanical properties of mortar, especially for slag mortar. Self-healing performance test and characterization showed that CaAlg could further enhance crack-healing process of mortar with CA, especially for pure cement and slag mortar. Microscopic testing indicates that CaAlg could induce the formation of vaterite and calcite on its surface to further improve crack-healing efficiency.

Integrative experimental and computational analysis of the impact of KGM's polymerization degree on wheat starch's pasting and retrogradation characteristics

This study investigated the influence of Konjac Glucomannan (KGM) with varying degrees of polymerization (DKGMx) on the gelatinization and retrogradation characteristics of wheat starch, providing new insights into starch-polysaccharide interactions. This research uniquely focuses on the effects of DKGMx, utilizing multidisciplinary approaches including Rapid Visco Analysis (RVA), Differential Scanning Calorimetry (DSC), rheological testing, Low-Field Nuclear Magnetic Resonance (LF-NMR), and molecular simulations to assess the effects of DKGMx on gelatinization temperature, viscosity, structural changes post-retrogradation, and molecular interactions. Our findings revealed that higher degrees of polymerization (DP) of DKGMx significantly enhanced starch's pasting viscosity and stability, whereas lower DP reduced viscosity and interfered with retrogradation. High DP DKGMx promoted retrogradation by modifying moisture distribution. Molecular simulations revealed the interplay between low DP DKGMx and starch molecules. These interactions, characterized by increased hydrogen bonds and tighter binding to more starch chains, inhibited starch molecular rearrangement. Specifically, low DP DKGMx established a dense hydrogen bond network with starch, significantly restricting molecular mobility and rearrangement. This study provides new insights into the role of the DP of DKGMx in modulating wheat starch's properties, offering valuable implications for the functional improvement of starch-based foods and advancing starch science.

Phase transition and gel properties of chemically modified cassava starch in choline acetate and water mixtures

This work studied the phase transition and gel properties of cassava starch in aqueous choline acetate ([Ch][OAc]) solution at different [Ch][OAc]:water weight ratios. The paste viscosity and gel strength followed a similar pattern to the starch phase transition temperature, increasing at a 2:3 [Ch][OAc]:water ratio and then decreasing at 3:2 and 4:1 ratios. However, the mobility of free water in the starch gel decreased as the [Ch][OAc]:water ratio increased. At the same [Ch][OAc]:water ratios, acetylated cassava starch (ACS) underwent phase transition more easily than native cassava starch (NCS), leading to greater granule destruction. Nevertheless, ACS gels displayed more viscous-dominated rheological behavior, lower paste viscosity, viscoelasticity, and weaker water-holding capacity (WHC) than NCS gels. In contrast, cross-linked cassava starch (CCS) gels had higher paste viscosity, gel viscoelasticity, and WHC. However, at a 4:1 [Ch][OAc]:water ratio, the viscoelasticity of CCS gel was lower than NCS gel, and the differences in WHC were minimal, likely due to the incomplete phase transition of especially CCS under this condition. Our findings show that starch chemical modification significantly affects phase transition behavior and gel properties in [Ch][OAc]:water mixtures, with outcomes influenced by the viscosity of the aqueous [Ch][OAc] solution and the interaction between [Ch][OAc] and water.

Effect of Mild Alkali Treatment on the Structure and Physicochemical Properties of Normal and Waxy Rice Starches.

Mild alkali treatment can potentially be developed as a greener alternative to the traditional alkali treatment of starch, but the effect of mild alkali on starch is still understudied. Normal and waxy rice starches were subjected to mild alkali combined with hydrothermal treatment to investigate their changes in physicochemical properties. After mild alkali treatment, the protein content of normal and waxy rice starches decreased from 0.76% to 0.23% and from 0.89% to 0.23%, respectively. Mild alkali treatment decreased gelatinization temperature but increased the swelling power and solubility of both starches. Mild alkali treatment also increased the gelatinization enthalpy of waxy rice starch from 20.01 J/g to 25.04 J/g. Mild alkali treatment at room temperature increased the pasting viscosities of both normal and waxy rice starches, whereas at high temperature, it decreased pasting viscosities during hydrothermal treatment. Alkali treatment significantly changed the properties of normal and waxy rice starch by the ionization of hydroxyl groups and the removal of starch granule-associated proteins. Hydrothermal conditions promoted the effect of alkali. The combination of hydrothermal and alkali treatment led to greater changes in starch properties.

Rheological and sensory properties of chickpea and quinoa pastes and gels for plant-based product development.

The aim of this study was to investigate the modification of mechanical, rheological, and sensory properties of chickpea pastes and gels by incorporating other ingredients (olive oil or quinoa flour), to develop plant-based alternatives that meet consumer demands for healthy, natural, and enjoyable food products. The pastes and gels were made with different amounts of chickpea flour (9% and 12%, respectively). For each product, a first set of products with different oil content and a second set with quinoa flour (either added or replaced) were produced. The viscoelastic properties of the pastes and the mechanical properties of the gels were measured. Sensory evaluation and preference assessment were carried out with 100 participants using ranking tests. The study found remarkable differences in rheological, mechanical, and sensory properties of chickpea products upon the inclusion of oil and quinoa flour. The addition of oil increased the viscosity and decreased the elastic contribution to the viscoelasticity of the pastes, while it improved the firmness and plasticity in gels. It also increased the creaminess and preference of both pastes and gels. Replacing chickpea with quinoa flour resulted in less viscous pastes and gels with less firmness and more plasticity. In terms of sensory properties, the use of quinoa as a replacement ingredient resulted in less lumpiness in the chickpea paste and less consistency and more creaminess in both the pastes and gels, which had a positive effect on preference. The addition of quinoa increased the viscosity of pastes and the firmness and stiffness of gels. It increased the consistency and creaminess of both pastes and gels. Quinoa flour and/or olive oil are suitable ingredients in the formulation of chickpea-based products. They contribute to the structure of the system, providing different textural properties that improve acceptance.

Optimization of Awaze paste formulations: The effects of using spices through a mixture design approach

Previous studies have revealed the microbial quality of Awaze paste. However, limited reports describe the effect of individual spices on Awaze paste quality. A mixture design approach was used to determine the appropriate proportions, with 15 experimental points for independent variables including RP (60–90 %), GA (10–30 %), RO (5–20 %), and GI (5–10 %). The techno-functional properties, particle size, antioxidant activity (DDPH radical assay), proximate composition, iron (Fe), zinc (Zn) content, viscosity, hardness, and microbiological quality of Awaze paste were assessed. The prepared Awaze paste showed a range of characteristics, with antioxidant activity (DDPH radical assay) ranging from 11.86 % to 62.5 %, crude protein content from 6.18 % to 16.22 %, crude fat from 5.7 % to 12.6 %, crude fiber from 16.86 % to 29.06 %, total ash content from 6.32 % to 9.94 %, total carbohydrate from 41.79 % to 60.61 %, energy from 264.3 to 329.2 k cal. , iron (Fe) content from 35.59 to 108.82 mg/100g, zinc (Zn) content from 1.72 to 26.93 mg/100g, viscosity from 65.5 to 125.5 cps, hardness from 8.48 to 55.09 g, yeast and mold count from 0.83 to 2.04 log cfu/g, and total bacterial count from 1.53 to 2.61 log cfu/g. Significant differences (p < 0.05) were observed in proximate composition, techno-functional properties, particle size, antioxidant activity, physicochemical properties, and microbiological characteristics among the formulations of Awaze paste. The selected formula showed a statistically significant difference (p < 0.05) compared to the control sample. The formulation containing 74.79 % RP, 10 % GA, 10.2 % RO, and 5.0 % GI was determined to be the optimal formula with a desirability of 0.73, based on the evaluated parameters. This preferred Awaze paste had a porosity of 28.12 %, particle size of 16.49 μm, antioxidant activity of 63.63 %, crude protein content of 17.28 %, iron (Fe) content of 98.06 mg/100g, and zinc (Zn) content of 15.04 mg/100g. Therefore, this optimal blend of ingredients could be used to produce a consumer accepted Awaze paste.

Effect of chickpea thermal treatments on the starch digestibility of the fortified biscuits

Flour of roasted and heat-moisture treated chickpeas was used as a partial replacement of wheat flour, facilitating the development of biscuits with delayed digestion properties. The multiscale structural properties of starch and microstructural changes in chickpea flour and fortified biscuits were analyzed. Chickpea thermal treatment reduced the starch digestibility of fortified biscuits by 5.43%–7.33%, enhanced the resistant starch content of chickpea flour by 7.86%–12.28%. For thermal-treated chickpea fortified biscuits, the degree of relative crystallinity, short-range order, and double helix of starch was enhanced, the pasting viscosity was reduced, and the heat-moisture treatment showed a significant effect. Scanning electron microscope showed that fortified biscuits had a continuous and denser microstructure, reducing the accessibility of enzymes to hydrolyze starch molecules. The glycemic index values of fortified biscuits were reduced to below 66 in mice, as seen by their postprandial blood glucose response. Altogether, these results provide guidance for the development of delayed digestion meal replacement biscuits.

Synergistic influences of ground granulated blast-furnace slag and silica fume on the viscosity of extremely low W/B cement pastes

Particularly with a low water/binder ratio, the synergistic effects of supplemental cementitious materials (SCMs) have drawn a lot of interest in improving the characteristics of cement-based products. The effects of SCMs, such as silica fume (SF) and ground granulated blast furnace slag (GGBS) with varying fineness, on the setting time, saturation point, and viscosity of ultra-high performance cement pastes (UHPCP), are examined experimentally in this work. 56 mixes with various SF and BFS substitutions and exceptionally low water/binder ratios (0.16, 0.20) were used in the experiments. This work demonstrates the synergistic effects of SCMs from several angles, including the UHPCP fresh characteristics. It is shown that carefully regulating the water/binder ratio, the BFS fineness, and most significantly the addition of an ideal SF content will have a beneficial synergistic effect on the fresh qualities of UHPCP. However, utilizing high BFS replacement is discouraged as it may have a negative impact on viscosity.

Influence of SiO2@CaAl-LDH core-shell nanocomposite on rheology and hydration of cement

Nano-SiO2@ Layered double hydroxide (LDH) core-shell nanocomposite shows a promising application as high-efficiency chloride adsorbent in cement-based materials. However, its effect on rheology and hydration of cement is not yet known. In this study, the SiO2@CaAl- LDH core-shell nanocomposite by growing the LDH on nano-SiO2 surface was firstly created using in-situ co-precipitation method. The influence of as-synthesized nanocomposite on the rheology and hydration of cement was systematacially researched through contrasting experiments. Besides, microstructures of SiO2@LDH and its cement paste were characterized. The results show that the LDH with petal-like shape on the nano-SiO2 surface exhibits a higher specific area than pure nano-SiO2 and LDH alone. The addition of SiO2@CaAl-LDH core-shell material significantly shortens the initial and final setting time of cement and increases cement hydration heat generation rate and the total exothermic amount for 72 h. Contrary to the mixture of LDH, the additions of nano-SiO2 and SiO2@LDH increases the yield stress and plastic viscosity of cement paste. Compared to the additions of LDH and SiO2, the addition of SiO2@LDH more significantly enhances the strength of cement, of which the highest increasing level reaches 66 % at the early age of 1 d. In addition, SiO2@LDH exhibits the best refinement effect on the pore structure of cement because of the synergetic effect between the LDH and nano-SiO2.

Effects of protein-glutaminase on the properties of glutinous rice flour, paste, and gel food: Based on the interactions between the deamidated protein and starch

In the present study, protein-glutaminase (PG) from Chryseobacterium proteolyticum was applied to improve the processing properties of glutinous rice flour (GRF). After PG modification, the degree of deamidation of glutinous rice protein (GRP) reached 13.6% at 2.0 h, with smaller particle size and decreased zeta potential. The interaction of GRP with starch in PG-modified GRF (PM-GRF) was changed, exhibiting in protein aggregates decreasing and exposure of starch on the surface of GRF. Compared with unmodified GRF (UM-GRF), the solubility and turbidity of PM-GRF were both increased. The rheological properties reflected that the viscosity of PM-GRF paste was increased, and the freeze-thaw stability was also enhanced. Moreover, the textural characteristics showed that the hardness of PM-GRF balls remarkably reduced and the springiness increased. These results indicate that deamidation by PG could be an efficient method for improving characteristics of GRP and GRF.

Effect of Different Fertilizer Types on Quality of Foxtail Millet under Low Nitrogen Conditions.

In order to clarify the effect of different fertilizers on foxtail millet quality under low nitrogen conditions, we used JGNo.21 and LZGNo.2 as experimental materials and set up five treatments, including non-fertilization, nitrogen, phosphorus, compound, and organic fertilizers, to study the regulation of different fertilizer types on agronomic traits, nutrient fractions, and pasting characteristics of foxtail millet under low nitrogen conditions. Compared with the control, all of the fertilizers improved the agronomic traits of JGNo.21 to a certain extent. Nitrogen and compound fertilizer treatments reduced the starch content of JGNo.21; the starch content was reduced by 0.55% and 0.07% under nitrogen and compound fertilizers treatments. Phosphorus and organic fertilizers increased starch content, and starch content increased by 0.50% and 0.56% under phosphorus and organic fertilizer treatments. The effect of each fertilizer treatment on protein content was completely opposite to that of starch; different fertilizer treatments reduced the fat content of JGNo.21 and increased the fiber content. Among them, nitrogen and phosphorus fertilizers increased the yellow pigment content; the yellow pigment content increased by 1.21% and 2.64% under nitrogen and phosphorus fertilizer treatments. Organic and compound fertilizers reduced the content of yellow pigment; the yellow pigment content was reduced by 3.36% and 2.79% under organic and compound fertilizer treatments. Nitrogen and organic fertilizers increased the fat content of LZGNo.2; the fat content increased by 2.62% and 1.98% under nitrogen, organic fertilizer treatment. Compound and phosphorus fertilizer decreased the fat content; the fat content decreased by 2.16% and 2.90% under compound and phosphorus fertilizer treatment. Different fertilizer treatments reduced the cellulose and yellow pigment content of LZGNo.2. The content of essential, non-essential, and total amino acids of JGNo.21 was increased under compound and nitrogen fertilizer treatments and decreased under organic and phosphorus fertilizer treatments. The content of essential, non-essential, and total amino acids of LZGNo.2 was significantly higher under compound, nitrogen, and organic fertilizer treatments compared with control and significantly decreased under phosphorus fertilizer treatments. Nitrogen and compound fertilizer treatments significantly reduced the values of peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, and pasting time of each index of JGNo.21; phosphorus and organic fertilizer treatments improved the values of each index. In contrast, the pasting viscosity of LZGNo.2 increased under phosphorus fertilizer treatment and decreased under nitrogen fertilizer treatment. Reasonable fertilization can improve the quality of foxtail millet, which provides a scientific theoretical basis for improving the quality of foxtail millet.

Responses of rice qualities to temperature and light in three different ecological environments in karst regions

Rice cultivation in Karst regions shows significant variations in both yield and quality due to temperature and light. Herein, 241 varieties including 198 indica rice and 43 japonica rice were planted in three ecological regions to investigate responses of rice qualities to meteorological factors. Results showed that in regions with higher average temperature (25.43 °C) and less daily sunshine hour (2.53 h/day), the appearance qualities (chalkiness degree, chalkiness rate and size) and processing qualities (brown rice percentage, head rice and milled rice percentages) were significantly reduced (p < 0.05). A total of 723 samples in three ecological environments were grouped into 4 clusters, arranged in descending order of cluster scores. In high-scoring cluster, the processing quality, appearance quality, protein content, hot paste viscosity, consistence viscosity, and setback viscosity were negatively correlated with temperatures (average temperature, temperature difference, effective accumulated temperature, maximum and minimum temperatures) from heading to mature stages, but positively correlated with sunshine hours. Apparent amylose contents were negatively correlated with temperatures but not significantly correlated with sunshine hours. In low-scoring cluster, only the processing quality had significant correlations with meteorological factors. These findings revealed the interaction between temperature and light for the formation of rice quality.

Effects of adding proteins from different sources during heat-moisture treatment on corn starch structure, physicochemical and in vitro digestibility

Proteins impact starch digestion, but the specific mechanism under heat-moisture treatment remains unclear. This study examined how proteins from various sources—white kidney bean, soybean, casein, whey-altered corn starch's structure, physicochemical properties, and digestibility during heat-moisture treatment (HMT). HMT and protein addition could significantly reduce starch's digestibility. The kidney bean protein-starch complex under HMT had the highest resistant starch at 19.74 %. Most proteins effectively inhibit α-amylase, with kidney bean being the most significantly (IC50 = 1.712 ± 0.085 mg/mL). HMT makes starch obtain a more rigid structure, limits its swelling ability, and reduces paste viscosity and amylose leaching. At the same time, proteins also improve starch's short-range order, acting as a physical barrier to digestion. Rheological and low-field NMR analyses revealed that protein enhanced the complexes' shear stability and water-binding capacity. These findings enrich the understanding of how proteins from different sources affect starch digestion under HMT, aiding the creation of nutritious, hypoglycemic foods.

Understanding the cavitation effect of power ultrasound in cement paste

While power ultrasound (PUS) has been proven to accelerate cement hydration, it remains unclear whether cavitation occurs during this process. This study aimed to test the cavitation effect of a single bubble in cement paste through a KI oxidation experiment. An ultrasonic pressure field model was established using the linear Helmholtz equation, and the cavitation effect of a single bubble in cement paste was simulated based on the modified Keller–Miksis model. The results indicate that the conventional water-cement ratio (w/c ratio ≤1.0) does not produce transient cavitation but can produce stable cavitation. The efficiency of stable cavitation initially increases and then decreases as the bubble diameter increases. An optimum stable cavitation efficiency is achieved with a 50 μm bubble, but the bubble expansion rate remains consistently less than 40 %. Increasing the acoustic pressure to 5 atm or higher can cause the bubbles in cement paste with a water-to-cement ratio of 1.0 to expand more than tenfold. However, even when the acoustic pressure was further increased to 10 atm, no noticeable bubble expansion was observed in the cement paste with a w/c ratio of 0.30. The high viscosity of cement paste is the primary cause of the high transient cavitation threshold of bubbles.

Physicochemical, functional, pasting, and amino acid compositions of milled rice, and extrusion behavior of milled rice from basmati and nonbasmati varieties

AbstractBackground and ObjectivesThis study was carried out to evaluate the difference in physiochemical, functional, cooking, textural, and pasting properties along with amino acid profile of nine basmati and nine nonbasmati rice varieties. Principle component statistical analysis was done to analyse the relationships among different properties of these varieties. Some verities containing high amylose content and good amino acid profile were selected for further development of extruded products (rice extrudates).FindingsVariations were observed in the physicochemical and functional properties of basmati and nonbasmati varieties. Low amylose rice varieties had higher cooking time, firmness, pasting temperature, and lower pasting viscosity. Selected high amylose‐containing varieties were showed higher bulk density but lower expansion ratio and hardness of rice extrudates. Result of this study will help industry for selection of rice for development of gluten‐free rice‐based breakfast cereals, puffed rice snacks, and so forth.ConclusionsAmong all varieties, PR122, PR128, PB3, PB4, and PB1121 exhibited higher levels of ash content, amylose content and protein content. Consequently, these varieties demonstrated longer CT, greater GSL, higher cooked grain firmness, and higher pasting PT, although they exhibited lower PV. PB1637, PB1509, PB1121, and PB4 displayed higher levels of essential AAs and sweet taste attributing amino acids, such as serine, glycine, and alanine, when compared to the other varieties. The results showed that rice containing higher amylose had lower expansion ratio of the extrudates, while higher bulk density and hardness. PR126 and CSR30 had the highest expansion ratio among the varieties that have been evaluated. Based on these results, PR126 and CSR30 could be used to make gluten‐free rice‐based breakfast cereals, rice snacks, and instant products.Significance and NoveltyPhysiochemical, functional, cooking, texture, pasting properties as well as amino acid profile were evaluated of different basmati and non‐basmati Indian (Punjab) varieties. Principle component (Relationship) analysis between various properties and different rice varieties was carried out. Extrusion is the most versatile processing technology used in the food industry to develop the product having better functional and sensory characteristics. The findings highlight the necessity of taking amylose content and amino acid composition into account when selecting rice types for preparation of extruded rice food.

Effect of the paste spreadability on ultrasonic transducer fabricated by pressureless sintering of nano-Ag

Paste spreadability is critical to paste spread layer and thus the quality of final product in pressureless sintering of nano-Ag, but the metrics and the underlying mechanics have not yet been well acknowledged. In this work, various ultrasonic transducers are fabricated by pressureless sintering of various nano-Ag pastes. Particle dynamics mechanism during the paste spreading process and the relationship between paste viscosity and spreadability are clarified. The influences of paste spreadability on dynamic performances of transducer are analysed, and the underlying mechanisms are also investigated. The results show that the normalized mass of Ag NPs is basically positively correlated with the flatness of the coupling layer, and the flatness of the coupling layer is also positively correlated with the peak-to-peak voltage and SNR of the transducer. The attenuation in the far-field scattering process mainly depends on the porosity of the coupling layer.