scholarly journals DETERMINATION OF VOLUMETRIC CONTRACTION AND DRYING KINETICS OF THE DRYED BANANA

2019 ◽  
Vol 3 (1) ◽  
pp. 20-30
Author(s):  
Lucas Fernandes De Souza ◽  
Ednilton Tavares De Andrade ◽  
Paula De Almeida Rios
Keyword(s):  
Mathematical Models ◽  
Exponential Model ◽  
Drying Kinetics ◽  
Moisture Ratio ◽  
Nonlinear Regression Analysis ◽  
Before And After ◽  
Kinetics Of ◽  
Wood Model ◽  
Best Fit

Banana (Musa spp.) is one of the most nutritious and consumed fruits, especially in tropical countries. The drying of the fruit is an alternative against the injuries suffered, mainly during the post-harvest process. Thus, the knowledge of the physical properties of the product that is intended to be processed has a big importance for the dimensioning of equipment. Therefore, the objective of this work was to study the drying kinetics of the banana, transforming it into dried banana, besides evaluating the volumetric contraction suffered during drying. The bananas were dried in an oven at temperatures of 70, 60 and 50 ºC. The volumetric measurements were carried out before and after drying to determine the volumetric contraction during the process. After drying, the experimental data were modeled by nonlinear regression analysis by the Quase-Newton method, to adjust 4 mathematical models of moisture ratio and 5 mathematical models of volumetric contraction. Among the models tested, the best fit for the prediction of the Moisture Ratio was the exponential model, and for the Volumetric Contraction was the modified BALA and WOOD model.

scholarly journals Drying Kinetics of Noni Seeds

2019 ◽  
Vol 11 (5) ◽  
pp. 250 ◽  
Author(s):  
Wellytton Darci Quequeto ◽  
Osvaldo Resende ◽  
Patrícia Cardoso Silva ◽  
Fábio Adriano Santos e Silva ◽  
Lígia Campos de Moura Silva
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Moisture Content ◽  
Mathematical Models ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Information Criterion ◽  
Drying Kinetics ◽  
Kinetics Of

Noni seeds have been used for years as an important medicinal source, with wide use in the pharmaceutical and food industry. Drying is a fundamental process in the post-harvest stages, where it enables the safe storage of the product. Therefore, the present study aimed to fit different mathematical models to experimental data of drying kinetics of noni seeds, determine the effective diffusion coefficient and obtain the activation energy for the process during drying under different conditions of air temperature. The experiment used noni seeds with initial moisture content of 0.46 (decimal, d.b.) and dehydrated up to equilibrium moisture content. Drying was conducted under different controlled conditions of temperature, 40; 50; 60; 70 and 80 ºC and relative humidity, 24.4; 16.0; 9.9; 5.7 and 3.3%, respectively. Eleven mathematical models were fitted to the experimental data. The parameters to evaluate the fitting of the mathematical models were mean relative error (P), mean estimated error (SE), coefficient of determination (R2), Chi-square test (c2), Akaike Information Criterion (AIC) and Schwarz’s Bayesian Information Criterion (BIC). Considering the fitting criteria, the model Two Terms was selected to describe the drying kinetics of noni seeds. Effective diffusion coefficient ranged from 8.70 to 23.71 × 10-10 m2 s-1 and its relationship with drying temperature can be described by the Arrhenius equation. The activation energy for noni seeds drying was 24.20 kJ mol-1 for the studied temperature range.

scholarly journals Mathematical modeling of pequi pulp drying and effective diffusivity determination

2017 ◽  
Vol 21 (7) ◽  
pp. 493-498 ◽  
Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Air Speed ◽  
Drying Curves ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

Application of mathematical models to predict the drying kinetics of energy cane

2015 ◽  
Author(s):  
Laura Marcela Guiffo-Cardona ◽  
Melina Gesteira Souza ◽  
Kátia Tannous ◽  
Caio Glauco Sanchez
Keyword(s):  
Mathematical Models ◽  
Drying Kinetics ◽  
Energy Cane ◽  
Kinetics Of

scholarly journals CINÉTICA DE SECAGEM DOS RESÍDUOS DA AGROINDÚSTRIA PROCESSADORA DE POLPA DE FRUTAS

2019 ◽  
Vol 34 (01) ◽  
pp. 134-141
Author(s):  
Bruno Fonsêca Feitosa ◽  
Emanuel Neto Alves de Oliveira ◽  
Juvêncio Olegário de Oliveira Neto ◽  
Danielle Bezerra de Oliveira ◽  
Regilane Marques Feitosa
Keyword(s):  
Rio Grande ◽  
Drying Kinetics ◽  
Total Acidity ◽  
Processing Industry ◽  
Dry Extract ◽  
Physical Chemical ◽  
Randomized Design ◽  
Before And After ◽  
Pulp Processing ◽  
Kinetics Of

CINÉTICA DE SECAGEM DOS RESÍDUOS DA AGROINDÚSTRIA PROCESSADORA DE POLPA DE FRUTAS   BRUNO FONSÊCA FEITOSA1; EMANUEL NETO ALVES DE OLIVEIRA2; JUVÊNCIO OLEGÁRIO DE OLIVEIRA NETO3; DANIELLE BEZERRA DE OLIVEIRA4; REGILANE MARQUES FEITOSA5   1Tecnologia de Alimentos, Universidade Federal de Campina Grande (Rua Jairo Vieira Feitosa, n. 1770, Pereiros, 58840-000, Pombal, Paraíba, Brasil), [email protected] 2Tecnologia de Alimentos, Instituto Federal do Rio Grande do Norte (Rua Portugal, n. 260, Nações Unidas, Pau dos Ferros, Rio Grande do Norte, Brasil), [email protected] 3Tecnologia de Alimentos, Universidade Federal de Campina Grande (Rua Pe. Amâncio Leite, n. 313, Centro, 58840-000, Pombal, Paraíba, Brasil), [email protected] 4Tecnologia de Alimentos, Instituto Federal do Rio Grande do Norte (Ab. Independência, n. 808, Bela Vista, 59900-000, Pau dos Ferros, Rio Grande do Norte, Brasil), [email protected] 5Tecnologia de Alimentos, Universidade Federal de Campina Grande (Rua José de Alencar, n. 451, 63050-310, Juazeiro do Norte, Ceará, Brasil), [email protected]   RESUMO: O Brasil é um dos maiores produtores de frutas do mundo. No entanto, a agroindústria processadora de polpa de frutas gera diversos resíduos, como cascas, talos e sementes, que muitas vezes são desperdiçados, mas podem ser utilizados como ingredientes para o desenvolvimento de novos produtos alimentícios. Diante do exposto, objetivou-se com este trabalho avaliar a cinética de secagem e a qualidade físico-química dos resíduos da agroindústria processadora de polpa de frutas. Com isso, determinou-se a cinética de secagem de cinco resíduos agroindustriais (manga, abacaxi, acerola, goiaba e graviola), os quais foram submetidos as análises físico-químicas (umidade, extrato seco, cinzas, acidez total titulável, pH e atividade de água) antes e após a secagem em estufa com circulação forçada de ar, a 60 °C. Os resultados obtidos foram tratados, através de Delineamento Inteiramente Casualizado em esquema fatorial, aplicando Análise de Variância e comparação de médias pelo teste de Tukey a 5% de significância. Observou-se bons ajustes (R2>0,98) na cinética de secagem. Após a secagem, a maioria dos resíduos apresentaram redução nos parâmetros físico-químicos de umidade, atividade de água e pH, bem como aumento do extrato seco, cinzas e acidez total. Infere-se que o resíduo de graviola e goiaba indicaram melhores respostas às condições experimentais empregadas, requerendo ainda o estudo da variação de temperatura de secagem e avaliação da estabilidade física, química e microbiológica.   Palavras-chaves: desidratação, farinhas vegetais, qualidade físico-química   KINETICS OF DRYING WASTE FROM FRUIT PULP PROCESSING AGROINDUSTRY   ABSTRACT: The fruits pulp processing industry generates wastes as barks, stalks and seeds, which are often wasted, but can be used as ingredients for development of new food productsThe aim of this work was to evaluate the drying kinetics and the physicochemical quality of residues from the fruits pulp processing industry. The drying kinetics of five agroindustrial residues (mango, pineapple, acerola, guava and graviola) were determined, which were submitted to physical-chemical analyzes (moisture, dry extract, ash, total acidity, pH and activity of water) before and after oven drying with forced air circulation at 60°C. The results were evaluated using a completely randomized design in a factorial scheme, applying Analysis of Variance (ANOVA) and comparison of means by the Tukey test at 5% of significance. Good adjustments (R2>0.98) were observed for drying kinetics. After drying, most of the residues showed a reduction in the physical-chemical parameters of moisture, water activity and pH, as well as increase of dry extract, ashes and total acidity. It is inferred that graviola and guava residue indicated better responses to experimental imposed conditions, also requiring the rying temperature variation study and physical evaluation, chemical and microbiological stability. Keywords: dehydration, vegetable flours, physical-chemical quality

scholarly journals Drying kinetics of fermented grape pomace: Determination of moisture effective diffusivity

2016 ◽  
Vol 20 (8) ◽  
pp. 763-768 ◽  
Author(s):  
Kricelle M. Deamici ◽  
Lucas C. de Oliveira ◽  
Gabriela S. da Rosa ◽  
Elizangela G. de Oliveira
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Grape Pomace ◽  
Desorption Isotherms ◽  
Drying Curves ◽  
Gab Model ◽  
Kinetics Of ◽  
Moisture Effective Diffusivity

ABSTRACT The aim of this study was to obtain the equilibrium moisture content of grape (variety ‘Tannat’) pomace through desorption isotherms, to evaluate the drying kinetics, determine the coefficient of effective diffusivity and physico-chemically characterize the grape pomace and the product obtained after drying. The desorption isotherms were determined at 50, 60 and 70 ºC and the experimental data were fitted using the GAB model (Gugghenheim, Anderson and de Boer). Drying was evaluated using a 22 factorial experimental design with three center points and effective diffusivity was obtained through the diffusion model of Fick’s second law. The grape pomace was characterized regarding the contents of moisture, protein, carbohydrates, lipids, ash and dietary crude fiber. The obtained isotherms showed sigmoid shape and the experimental data fitted well to the GAB model. The drying curves showed only a decreasing rate period. The effective diffusivity values were within the range for organic materials. Dry grape pomace showed high contents of protein and fiber and can be used in the development of new products, in order to increase the nutritional content and add value to this byproduct.

Mass Transfer Parameters and Modeling of Hot Air Drying Kinetics of Dill Leaves

2016 ◽  
Vol 12 (2) ◽  
Author(s):  
Hosain Darvishi ◽  
Zanyar Farhudi ◽  
Nasser Behroozi-Khazaei
Keyword(s):  
Activation Energy ◽  
Mass Transfer ◽  
Moisture Content ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Transfer Model ◽  
Hot Air ◽  
Drying Behavior ◽  
Kinetics Of ◽  
Best Fit

Abstract Moisture diffusivity (Dem), mass transfer coefficient (hm), activation energy and drying kinetics of the dill leaves were studied and modeled as a function of temperature (40–70 °C) and moisture content (0.20–5.67 kg water/kg dry matter). Results showed that the Dem and hm significantly depend on the temperature and moisture content (p < 0.05). The average of Dem and hm varied between 4.02 × 10–9 to 9.65 × 10–9 m2/s, and 2.38 × 10–7 to 6.33 × 10–7 m/s, respectively. Activation energy showed a significant dependence on the moisture content and estimated as 16.84 kJ/mol for diffusion model and 28.70 kJ/mol for mass transfer model. Out of the six models considered, the logarithmic model showed the best fit to drying behavior of the dill leaves.

scholarly journals Determination of the velocity coefficients for polymerization processes III. Effect of environment on polymerization processes

1947 ◽  
Vol 189 (1019) ◽  
pp. 494-507 ◽  
Keyword(s):  
Ethyl Acetate ◽  
Monomer Concentration ◽  
Life Time ◽  
Gel Effect ◽  
Bulk Reaction ◽  
Before And After ◽  
Normal Hexane ◽  
Kinetics Of ◽  
Hexane Solution

The kinetics of the photopolymerization of vinyl acetate in ethyl acetate and n-hexane solutions were investigated with a view to studying the effect of environment on the course of the reaction. The ethyl acetate solutions allow the polymer to remain extended so that the course of the reaction is similar to that of the pure monomer. With n-hexane, precipitation of the polymer takes place with the result that a considerable ‘gel’ effect is observed. The reaction rate in both cases is proportional to the monomer concentration and to the square root of the light intensity. In ethyl acetate solutions the activation energy is 4.42 kcal./g.mol., which is virtually the same as for the bulk reaction, while in normal hexane the value found is —1.30 kcal./g.mol. Reasons for this have been suggested. The life time of the active polymer in n-hexane solution both before and after the inception of the gel stage has been measured using the sector technique, and the values of the coefficients for the propagation and termination reactions have been computed. It is found that the value of the former is little changed by the change in medium, while that of the termination step falls sharply—the fall being in agreement with the increase in rate. These results confirm present theories on the cause of the gel stage.

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