scholarly journals Effect of grasshopper (Sphenarium purpurascens Charpentier) paste addition on rheological behavior of Mole Poblano

Author(s):  
Eliza Guadalupe Arcos-Estrada ◽  
Mayra Díaz-Ramírez ◽  
Judith Jiménez-Guzmán ◽  
Erika Berenice León-Espinosa ◽  
Mariano García-Garibay ◽  
...  

Objective: Analyze the effect of grasshopper (Sphenarium purpurascens Charpentier) paste addition on the rheological behavior of Mole Poblano (MP) and its relation with the technological properties of the grasshopper paste. Design/methodology/approach: The addition of grasshopper paste was done at different proportions as follows: T0= 0% of grasshopper paste (GP) and 100% of mole Poblano (MP); T10=10% GP and 90% MP; T15=15% GP and 85% MP, T20=20% GP and 80% MP, T25=25% GP and 75 % MP, T30=30% GP and 70% MP. Water retention and emulsifying capacity of grasshopper paste were evaluated. Density, kinematic and apparent viscosity, and rheological behavior were analyzed at 25ºC; rheological parameters (consistency index (k) and flow behavior index (n)) were calculated by performing a regression analysis to adjust the graphs to a power-law model. Findings/conclusion: Grasshopper paste had higher emulsifying capability than water retention capability.  Apparent viscosity of all formulations decreased as shear rate increased, so all mixtures of GP and MP demonstrated No-Newtonian behavior and pseudoplastic performance. Index consistency increased as GP content increased, these results are related with protein content because GP had a good emulsifying capability. Limitations on study/implications: More studies about the characterization of the proteins of GP and their interaction with other components are required.

Author(s):  
Charles Windson Isidoro Haminiuk ◽  
Maria-Rita Sierakowski ◽  
Giselle Maria Maciel ◽  
José Raniere Mazile Bezerra Vidal ◽  
Ivanise Guilherme Branco ◽  
...  

Rheological parameters of Butia pulp were determined at different temperatures using a concentric cylinder Haake Rotovisco rheometer, model RV-20, with measurement system ZA-30. Butia pulp was found to exhibit non-Newtonian, pseudoplastic behavior at all temperatures and the rheological parameters were adequately described by the Herschel-Bulkley model. Yield stress, flow behavior index, and consistency coefficient were significantly affected by temperature. The yield stress decreased exponentially with process temperature and ranged between 36.60 and 21.70 Pa. Apparent viscosity calculated through the Herschel-Bulkley model decreased with an increase in temperature. The Arrhenius model gave a good description of temperature effect on apparent viscosity of the pulp.


2020 ◽  
Vol 50 (6) ◽  
Author(s):  
Stella Regina Arcanjo Medeiros ◽  
Victor Alves de Oliveira ◽  
Amanda Mazza Cruz de Oliveira ◽  
Marjory Lima Holanda Araujo ◽  
Judith Pessoa de Andrade Feitosa ◽  
...  

ABSTRACT: Dairy desserts containing Caesalpinia pulcherrima seed galactomannan were evaluated to determine their static and dynamic rheological behaviors. Variations in consistency index (k), flow behavior (n), yield stress and thixotropy of the desserts indicated that the galactomannan caused an increase in the shear stress and apparent viscosity of the system. All samples exhibited shear-thinning behavior with flow behavior index values (n) between 0.06 and 0.37. Dynamic rheological behavior was evaluated for MD (high solid levels) and MD/2 (half the amount of solids) groups, and both G’ and G’’ moduli were depended on the frequency. The MD and MD/2 groups showed variations in the elastic modulus (G’) throughout the temperature range (mainly at 50 °C), showing greater sensitivity at high temperatures. C. pulcherrima galactomannan was able to promote synergism with starch, milk protein and sucrose and to improve the development of stronger and more resistant gels.


2017 ◽  
Vol 882 ◽  
pp. 119-123
Author(s):  
Mahfuzah Zainudin ◽  
Muhammad Hussain Ismail

The characterization of CIM feedstock consisting 58, 59, 60vol% of YSZ powder with binder system comprising a palm stearin (PS) and low density polyethylene (LDPE) were studied. The effects of powder loading and temperature (°C) on the rheological behavior of the YSZ were investigated by using Rosand RH2000 Capillary Rheometer. The results showed all the feedstock achieved desirable injection moulding characteristics such as pseudoplastic behavior, flow behavior index (n) less than 1 and low activation energy (E). The rectangular parts were successfully injected moulded at optimum temperature of 170°C with the highest green strength was 12.7 N, obtained from 60 vol% powder loading which correspond to greater density and low porosity of the samples.


2008 ◽  
Vol 18 (3) ◽  
pp. 34482-1-34482-11 ◽  
Author(s):  
Vassilios C. Kelessidis ◽  
Roberto Maglione

AbstractA methodology is presented to invert the flow equation of a Herschel-Bulkley fluid in Couette concentric cylinder geometry, thus enabling simultaneous computation of the true shear rates, γ̇HB, and of the three Herschel-Bulkley rheological parameters. The errors made when these rheological parameters are computed using Newtonian shear rates, γ̇N, as it is normal practice by research and industry personnel, can then be estimated. Quantification of these errors has been performed using narrow gap viscometer data from literature, with most of them taken with oil-field rheometers. The results indicate that significant differences exist between the yield stress and the flow behavior index computed using γ̇HB versus the parameters obtained using γ̇N and this is an outcome of the higher γ̇HB values. Predicted true shear rates and rheological parameters are in very good agreement with results reported by other investigators, who have followed different approaches to invert the flow equation, both for yield-pseudoplastic and power-law fluids.


Author(s):  
ROSANE DA SILVA RODRIGUES ◽  
ÂNGELA MARIA GOZZO ◽  
ROBERTO HERMÍNIO MORETTI

Estudou-se o comportamento reológico de extratos elaborados com grãos, farinha integral e isolado protéico de soja. Extratos com 3% de proteína foram obtidos de grãos de soja (em equipamento conhecido como “vaca mecânica”), de farinha integral e de isolado protéico (por dissolução em água) e pasteurizados a 74±2°C por 15 seg. Os parâmetros reológicos estudados foram o coeficiente de consistência, o índice de comportamento do fluxo e a viscosidade aparente. Foram determinados, também, sólidos totais, proteínas, lipídios, cinzas, fibra bruta, carboidratos e índice de sedimentação (AOAC, 1995). Verificou-se que a viscosidade aparente, a 4 e 25°C, do extrato obtido de grãos de soja (fluido nãonewtoniano com comportamento pseudoplástico) foi maior que a do extrato da farinha (fluido não-newtoniano com comportamento pseudoplástico a 4°C e dilatante a 25°C) e do isolado (fluido newtoniano). O maior índice de sedimentação constatado no extrato de farinha integral e o baixo teor de sólidos solúveis no isolado protéico foram determinantes, entre outros fatores, no comportamento reológico verificado. AbstractRHEOLOGICAL BEHAVIOR OF SOYMILK, WHOLE SOY FLOUR AND SOY ISOLATED PROTEIN The rheological properties of extracts elaborated with soybeans, whole soy flour and isolated protein were studied. Extracts with 3% of protein were obtained from soybeans (in a equipment called “mechanic cow”), whole soy flour and isolated soy protein (by dissolution in water) and pasteurized at 74±2°C for 15 seg. The rheological parameters studied were the flow behavior index, consistency coefficient and apparent viscosity. Total solid, proteins, lipids, ashes, brute fiber, carbohydrates and sedimentation index (AOAC, 1995) was also determined. The apparent viscosity, at 4 and 25°C, of the extract obtained from soybeans (non-newtonian fluid with pseudoplastic behavior), was greater than the one of whole soy flour extract (nonnewtonian fluid with pseudoplastic behavior at 4°C and dilatant at 25°C) and of the isolated soy protein extract (Newtonian fluid). The highest sedimentation index verified in the whole soy flour extract and the low content of soluble solids in the extract of isolated soy protein defined, among others factors, the rheological behavior verified.


2012 ◽  
Vol 430-432 ◽  
pp. 301-305
Author(s):  
Li Wen Tan ◽  
Dong Mei Xu ◽  
Quan Ji ◽  
Bing Bing Wang ◽  
Yan Zhi Xia

Rheological properties of blend spinning solution of sodium alginate and TiO2 nanoparticles (SA/nano-TiO2) were investigated. The rheological parameters, structural viscosity index (Δη) and flow activation energy (Eη) of spinning solutions were calculated. The results reported that the blend spinning solutions were non-newtonian fluids. The apparent viscosity, consistency index (k) and Eη increased with increasing nano-TiO2 content in SA spinning solution, but the degradation degree of apparent viscosity decreased, flow behavior index (n) only slightly decreased and the Δη had no significantly change. The apparent viscosity (ηa) of spinning solutions could be regulated by changing temperature under 50oC. Blend spinning solution had good stability and practical applicability.


Author(s):  
Pedro Esteves Duarte Augusto ◽  
Marcelo Cristianini ◽  
Albert Ibarz

The rheological characterization of food is important for efficient product and process design. Although its importance in semi-arid regions, there are only a few studies regarding the rheological properties of cactus pear products in the literature. The present work has used the Mitschka-Briggs-Steffe method for evaluation of the rheological behavior of cactus pear concentrated pulps. The pulps have shown pseudoplastic behavior. The flow behavior index (n) shows a constant value in the evaluated conditions, and its average value was considered in the evaluated temperature and concentration range. The consistency index (k) has shown dependency of concentration and temperature, being well modeled by a modified Arrhenius equation. Thus, the rheological parameters of cactus pear concentrated pulps can be obtained using a single equation, related with temperature, concentration and shear rate. The obtained data are potentially useful for future studies on product development, food properties and process design.


Author(s):  
Jana Andertova´ ◽  
Frantisˇek Rieger

The rheological behavior of ceramic suspensions affects significantly wet ceramic processing. On the base of knowledge of rheological parameters the technological parameters of various processes (mixing, batching, spray drying, slip casting, of rheological parameters the selection of proper geometry and sensors must be done. From the data measured the flow curves must be designed and parameters of appropriate rheological models must be calculated. The power-law is the simplest model mostly used for description of rheological behavior of non-Newtonian fluids. Using this model, the dependence of shear stress on shear rate can be expressed. The aim of this paper is to show how the flow curves necessary for parameters of rheological model evaluation can be obtained from primary experimental data received from measurements on rotational viscometer. The two arrangements of rotational viscometer method were used in rheological measurements. The procedure of experimental data to obtain parameters K (coefficient of consistency) and n (flow behavior index) is presented.


2015 ◽  
Vol 76 (6) ◽  
Author(s):  
Mohammad Dahar Kamal Bahrin ◽  
Nor ‘Aini Wahab ◽  
Nor Amalina Nordin ◽  
Muhammad Hussain Ismail ◽  
Ismail Nasiruddin Ahmad

The characterization of MIM feedstock consisting of 63 vol% of copper powder with a binder system consisting of palm stearin (PS) and low density polyethylene (LDPE) was studied. To achieve porous structure, sodium chloride (NaCl) was added as a space holder. The effect of shear rate (s-1), temperature (oC) and viscosity (Pa.s) on the rheological behavior of solid and porous copper feedstocks were investigated by using the Rosand RH2000 Capillary Rheometer at temperatures of 160, 170 and 180oC. The feedstocks achieved desirable injection molding characteristics such as pseudo-plastic behaviour, stable flow, flow behavior index less than 1 (n<1) and low activation energy (E). It can be concluded from the analysis that both feedstocks showed a good pseudo-plastic behavior within acceptable ranges in MIM. 


2019 ◽  
Vol 70 (2) ◽  
pp. 382-386
Author(s):  
Andra Tamas ◽  
Sabina Nitu

The paper presents the study of the rheological and superficial behavior (foaming power and wetting capacity) of some aqueous solutions with polyethoxylated fatty alcohols content. The influence of fatty alcohols concentration and their degree of ethoxylation as well as that of temperature on the rheological behavior was determined from the dependences between the shear stress t and the shear rate. The results demonstrate that all the studied solutions have non-Newtonian behavior, with flow behavior index smaller than 1.


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