scholarly journals Comportamento reológico de iogurte de cajá comercializado em Campina Grande, Paraíba

2015 ◽  
Vol 10 (2) ◽  
pp. 257-260
Author(s):  
Flávio Farias Gurjão ◽  
Gilmara Gurjão Carneiro ◽  
Taciano Pessoa ◽  
Débora Rafaelly Soares Silva ◽  
Patricia Rodrigues Pê
Keyword(s):  
Molecular Structure ◽  
Rheological Behavior ◽  
Correlation Coefficients ◽  
Effect Of Temperature ◽  
Rheological Models ◽  
Rheological Study ◽  
Rheological Data ◽  
Different Temperatures ◽  
Hog Plum ◽  
Fluid Characteristics

O estudo reológico contribui para o conhecimento da estrutura molecular, no controle de qualidade e aceitação de um determinado produto, auxilia no controle do processo industrial e em projetos de equipamentos no processamento dos materiais. Objetivou-se avaliar o comportamento reológico de iogurte de cajá e a adequação dos dados reológicos aos modelos de Ostwald-de-Waele, Herschel-Bulkley e Mizrahi-Berk e ainda o efeito da temperatura sobre o comportamento reológico. Os dados reológicos foram obtidos através de um viscosímetro Brookfield DV-II+Pro. Os ensaios foram realizados nas temperaturas 20, 30 e 40 °C e os resultados experimentais foram ajustados pelos modelos de Ostwalde-de-Waelle, Casson, Hershel Bulkey e Mizrahi-Berk, com auxílio do software STATISTICA, versão 7.0. O iogurte analisado neste experimento apresentou comportamento de fluido não newtoniano com características pseudoplástica. Os modelos reológicos de Hershel Bulkey e Mizrahi-Berk representaram satisfatoriamente o comportamento reológico do iogurte de cajá nas diferentes temperaturas estudadas, apresentando coeficientes de correlação (R²), acima de 0,99. Rheological properties of yogurt cajá marketed in Campina Grande, state ParaíbaAbstract: The rheological study contributes to the knowledge of the molecular structure, the quality control and acceptance of a particular product, helps to control the manufacturing process and equipment designs in the processing of materials. This study aimed to evaluate the rheological behavior of yogurt cajá and the adequacy of the rheological data to models of Ostwald-de-Waele, Herschel-Bulkley and Mizrahi-Berk still the effect of temperature on the rheological behavior. The rheological data were obtained using a Brookfield DV-II + Pro. Assays were carried out at temperatures 20, 30 and 40 °C and the experimental results were adjusted by the model-to-Ostwalde Waelle, Casson and Herschel Bulkey Mizrahi-Berk, using the STATISTICA software, version 7.0. The yogurt analyzed in this experiment showed behavior of pseudoplastic non-Newtonian fluid characteristics. The rheological models Hershel Bulkey and Mizrahi-Berk satisfactorily represented the rheological behavior of the hog plum yogurt at different temperatures studied, with correlation coefficients (R²) above 0.99.

scholarly journals Comportamento reológico e perfil de textura de iogurte integral com polpa de achachairu (Garcinia humilis)

2019 ◽  
Vol 1 (47) ◽  
pp. 145
Author(s):  
Sâmela Leal Barros ◽  
Newton Carlos Santos ◽  
Renata Duarte Almeida ◽  
Virgínia Mirtes de Alcântara Silva ◽  
Raphael Lucas Jacinto Almeida ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Chi Square ◽  
Rheological Models ◽  
Texture Profile ◽  
Fluid Behavior ◽  
Texture Parameters ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Best Fit ◽  
Instrumental Texture

<p>One of the parameters that most influence the sensorial acceptance of yogurt is the texture presented. By determining the rheological behavior, we enable the sizing of the equipment. The aim of the present study is to determine the rheological behavior and the texture of whole yoghurts with different concentrations of achachairu pulp submitted to different temperatures. In addition to that we aim to adjust the data to the rheological models studied and to evaluate the influence of pulp and temperature on the instrumental texture profile. The rheological study was performed and the rheological models were adjusted to the experimental data. The Herschel-Bulkley rheological model presented the best fit for all formulations and temperatures with determination coefficients (R2 ) greater than 0.99 and low chi-square values (X2 ). Yogurt firmness decreased due to the increase of pulp concentration, however when submitted to 9 °C temperature they presented more firmness. On the other hand, yogurt showed non-Newtonian fluid behavior, in the specific case of pseudoplastic and instrumental texture parameters, they tended to decrease with increasing temperature. </p>

scholarly journals Colloidal and rheological behavior of aqueous dispersions of buriti tree (mauritia flexuosa) gum

2017 ◽  
pp. 716
Author(s):  
Diego Aires Da Silva ◽  
Pedro Henrique Santos ◽  
Rosinelson da Silva Pena
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Rheological Behavior ◽  
Aqueous Dispersion ◽  
Aqueous Dispersions ◽  
Rheological Data ◽  
Fluid Behavior ◽  
Mauritia Flexuosa ◽  
Different Temperatures

The temperature, concentration and pH variables influence the aqueous dispersion of the gum properties. In this context, the aims of this research were to characterize the gum obtained from the buriti tree (Mauritia Flexuosa) trunk exudate, as well as to evaluate the colloidal and rheological behavior of the aqueous dispersions of this gum. Thus, the centesimal composition, absolute zeta (ζ) potential as a function of pH (1.2 to 4.0), particle size distribution, as well as the rheological properties of the gum at different temperatures (15, 20, 25, 30, and 40 °C) and concentrations (4, 5, 8, and 10% (m/v)) were studied. In addition, the Newton, Power Law, and Herschel-Bulkley models were fitted to the rheological data. Buriti tree gum (BG) was found to have 10.43% moisture, 5.05% ashes, 0.68% lipids, 3.09% proteins, and 80.76% carbohydrate. The aqueous dispersion of the gum (1%) had a ζ value of -17.1 mV with a tendency for greater stability at pH < 4 and polydisperse particle size distribution (45 nm to 648.1 nm diameter) with PDI (polydispersity index) of 1. The aqueous dispersion with 4 and 5% gum had typical Newtonian fluid behavior and became pseudoplastic at concentrations of 8 and 10%. The Herschel-Bulkley model had the best fit to the rheological data (r2 > 0.99). Gum dispersion viscosity decreased with higher temperature and lower concentration. The activation energy (Ea) value for gum dispersion ranged from 9.07 to 17.35 kJ/mol.

Effect of temperature on the rheological behavior of sugary cassava

2020 ◽  
pp. 125
Author(s):  
Leiliane do Socorro Sodré Souza ◽  
Tatiane Pereira de Souza ◽  
Rafael Lopes e Oliveira ◽  
Sérgio Duvoisin Junior ◽  
Ari de Freitas Hidalgo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Food Production ◽  
Arrhenius Equation ◽  
Effect Of Temperature ◽  
Rheological Models ◽  
Rate Range ◽  
Fermented Beverages ◽  
Three Samples

The rheological behavior of the juice extracted from sugary cassava roots, a type of cassava that stored the largest amount of sugars and the starch as it was, at various temperatures (9-65ºC) and in concentrations of 5ºBrix, 10.5ºBrix, and 18.5ºBrix. The experiments were performed on a Brookfield viscometer in a shear rate range of 0.01-237.6 s-1. The rheological models of Newton, Bingham, and Ostwald-De-Waele were fitted to the experimental results. The Newton model describes well the rheological behavior of the three samples evaluated. The effect of temperature on viscosity was evaluated using an Arrhenius equation; the viscosity value is influenced by the same temperature. The activation energy values ​​for the concentrations of 5ºBrix, 10.5ºBrix and 18.5ºBrix correspond to 3.14 kcal mol-1, 3.53 kcal mol-1 and 3.71 kcal mol-1. This type of cassava can be used in the production of ethanol, fermented beverages and syrups. It is also an important alternative for food production, as the cultivation of cassava can be classified as less aggressive to the environment, in comparison with sugarcane.

Modelling of Rheological Behaviour of Pulps and Purées from Fresh and Frozen-Thawed Murta (Ugni molinae Turcz) Berries

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Kong S. Ah-Hen ◽  
Antonio Vega-Gálvez ◽  
Nelson O. Moraga ◽  
Roberto Lemus-Mondaca
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Rapid Change ◽  
Correlation Coefficients ◽  
Rheological Behaviour ◽  
Type Equation ◽  
Effect Of Temperature ◽  
Rheological Models ◽  
Temperature Activation ◽  
Ugni Molinae

Abstract The rheological behaviour of purées and pulps from fresh and frozen-thawed murta (Ugni molinae Turcz) berries was studied at 30, 45, 60 and 75 °C. The Mitschka method was shown to be applicable to the murta berries, with its products showing non-Newtonian pseudoplastic behaviour. Rheological models as Ostwald-de Waele, Herschel-Bulkley, Bingham, Casson and Mizrahi-Berk fitted the experimental data with high values for correlation coefficients. Effect of temperature was evaluated using an Arrhenius-type equation. Compared to the murta pulp, the fresh or frozen-thawed murta purées had higher apparent viscosity at any shear rate and would undergo a more rapid change in viscosity with temperature. Activation energy for fresh and frozen-thawed purées were 22.335 kJ mol-1 (R2 = 0.9225), and 16.478 kJ mol-1 (R2 = 0.9654) respectively, while for fresh and frozen-thawed pulp Ea values of 8.967 kJ mol-1 (R2 = 0.9618) and 6.943 kJ mol-1 (R2 = 0.9773) were determined respectively.

scholarly journals Rheological behavior of mixed drink of annona and milk

2012 ◽  
Vol 32 (2) ◽  
pp. 333-341
Author(s):  
Maria E. M. Duarte ◽  
Deyzi S. Gouveia ◽  
Mario E. R. M. C. Mata ◽  
Alexandre J. de M. Queiroz
Keyword(s):  
Power Law ◽  
Rheological Behavior ◽  
Physicochemical Parameters ◽  
Soluble Solids ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
Annona Squamosa ◽  
Concentric Cylinder ◽  
Different Temperatures ◽  
Behavior Index

In this study the rheological behavior in different temperatures (0; 6; 18 e 24 ºC) and physicochemical parameters of integral annona (Annona squamosa) pulp and the annona pulp with milk in different percentages pulp/milk (75g of annona pulp/25g of milk, 50g of annona pulp/50g of milk, 25g of annona pulp/75g of milk) have been availed, in order to verify the effect of temperature and pulp concentration in the rheological behavior of these beverages. To obtain the rheological parameters a concentric cylinder rheometer has been used and the rheograms were analyzed using the Ostwald-de-Wael (power Law) and Herschel-Bulkley models. The physicochemical parameters (sugars, pH, ash, acidity and soluble solids) were determined in order to establish correlations with the rheological behavior. Finally, the best results had been obtained using the Herschel-Bulkley model; the low values for the behavior index (n <1) obtained confirm the pseudoplastic behavior of all samples.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals Effect of temperature, CO2 and O2 on motility and mobility of Anisakidae larvae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël
Keyword(s):  
Enzymatic Digestion ◽  
Infected Fish ◽  
Effect Of Temperature ◽  
Video Recordings ◽  
Different Temperatures ◽  
Semi Solid ◽  
Zoonotic Parasites ◽  
The Impact ◽  
Phosphate Buffered Saline

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.

scholarly journals Effect of Temperature during Drying and Storage of Dried Figs on Growth, Gene Expression and Aflatoxin Production

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 134
Author(s):  
Ana Isabel Galván ◽  
Alicia Rodríguez ◽  
Alberto Martín ◽  
Manuel Joaquín Serradilla ◽  
Ana Martínez-Dorado ◽  
...  
Keyword(s):  
Gene Expression ◽  
Aflatoxin Production ◽  
Effect Of Temperature ◽  
Mycotoxin Production ◽  
Industrial Processing ◽  
Factors Associated ◽  
Different Temperatures ◽  
Major Producer ◽  
Main Factors ◽  
And Storage

Dried fig is susceptible to infection by Aspergillus flavus, the major producer of the carcinogenic mycotoxins. This fruit may be contaminated by the fungus throughout the entire chain production, especially during natural sun-drying, post-harvest, industrial processing, storage, and fruit retailing. Correct management of such critical stages is necessary to prevent mould growth and mycotoxin accumulation, with temperature being one of the main factors associated with these problems. The effect of different temperatures (5, 16, 25, 30, and 37 °C) related to dried-fig processing on growth, one of the regulatory genes of aflatoxin pathway (aflR) and mycotoxin production by A. flavus, was assessed. Firstly, growth and aflatoxin production of 11 A. flavus strains were checked before selecting two strains (M30 and M144) for in-depth studies. Findings showed that there were enormous differences in aflatoxin amounts and related-gene expression between the two selected strains. Based on the results, mild temperatures, and changes in temperature during drying and storage of dried figs should be avoided. Drying should be conducted at temperatures >30 °C and close to 37 °C, while industry processing, storage, and retailing of dried figs are advisable to perform at refrigeration temperatures (<10 °C) to avoid mycotoxin production.

scholarly journals Corrosion Behaviour of 316L Stainless Steel in CNTs–Water Nanofluid: Effect of Temperature

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 119
Author(s):  
Dana H. Abdeen ◽  
Muataz A. Atieh ◽  
Belabbes Merzougui
Keyword(s):  
Stainless Steel ◽  
316L Stainless Steel ◽  
Corrosion Behaviour ◽  
Gum Arabic ◽  
Steel Sample ◽  
Open Circuit ◽  
Deionized Water ◽  
Effect Of Temperature ◽  
Different Temperatures ◽  
In Series

The inhibition behavior of carbon nanotubes (CNTs) and Gum Arabic (GA) on the corrosion of 316L stainless steel in CNTs–water nanofluid under the effect of different temperatures was investigated by electrochemical methods and surface analysis techniques. Thereby, 316L stainless steel samples were exposed to CNTs–water nanofluid under temperatures of 22, 40, 60 and 80 °C. Two concentrations of the CNTs (0.1 and 1.0 wt.% CNTs) were homogenously dispersed in deionized water using the surfactant GA and tested using three corrosion tests conducted in series: open circuit test, polarization resistance test, and potentiodynamic scans. These tests were also conducted on the same steel but in solutions of GA-deionized water only. Tests revealed that corrosion increases with temperature and concentration of the CNTs–water nanofluids, having the highest corrosion rate of 32.66 milli-mpy (milli-mil per year) for the 1.0 wt.% CNT nanofluid at 80 °C. In addition, SEM observations showed pits formation around areas of accumulated CNTs that added extra roughness to the steel sample. The activation energy analysis and optical surface observations have revealed that CNTs can desorb at higher temperatures, which makes the surface more vulnerable to corrosion attack.

Effect of temperature on composite films made with activated carbon, graphite, or graphene oxide (GO) in a gelatin matrix

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 77-95
Author(s):  
Siqiao Yang ◽  
Haichao Li
Keyword(s):  
Contact Angle ◽  
Activated Carbon ◽  
Water Absorption ◽  
Composite Films ◽  
Effect Of Temperature ◽  
Gelatin Matrix ◽  
Vapour Permeability ◽  
Blending Method ◽  
The Matrix ◽  
Different Temperatures

Activated carbon, graphite, and GO/gelatin composite films were prepared by the blending method. The properties of composites were characterized by tensile strength (TS), elongation at break (EB), water vapour permeability (WVP), water-absorption ability, contact angle, scanning electron microscopy (SEM), and moisture at different temperatures. The properties of GO/gelatin composite films were better when each of three kinds of carbon materials were used as reinforcement phases and added into the matrix gelatin. The results showed that EB and TS of GO/gelatin composite films were both excellent. The moisture of GO/gelatin composite films was greater than the others. SEM micrographs showed that GO had better compatibility and dispersibility with gelatin than activated carbon and graphite. The water absorption of GO/gelatin composite films were low, at 15 °C and 25 °C, and the WVP was low at 35 °C. The WVP of GO/gelatin composite films was lower than the others at different temperatures. The contact angle of GO/gelatin composite films was larger than the others.

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