Papers by JEFFERSON LUIZ GOMES CORREA
The aim of this study was to evaluate the parameters of mass transfer in the dehydration of yacon... more The aim of this study was to evaluate the parameters of mass transfer in the dehydration of yacon slices with different polyols as osmotic agents. The samples were immersed on hypertonic solutions (40 °Brix) of xylitol, maltitol, erythritol, isomalt and sorbitol at 25 °C. The kinetics of solid gain (SG), water loss (WL) and water activity (aw) of the yacon slices were evaluated over 120 minutes of osmotic dehydration. The effective diffusion coefficients of water and solids were calculated by the diffusive model of Fick. The results showed that the SG was greater in samples treated with solutions of erythritol and lower in isomalt and maltitol solutions. Samples immersed in solutions of sorbitol and xylitol showed intermediate SG. The samples treated in solutions of sorbitol, xylitol and erythritol presented higher water diffusion coefficients and were more effective at reducing parameters of WL and aw than the other polyols. The model of Fick represented well the differences between the kinetics of WL and SG for the tested polyols.
Acta Scientiarum-technology, Apr 28, 2023
Tomato is one of the most cultivated vegetables, playing important role in the human feed. Due to... more Tomato is one of the most cultivated vegetables, playing important role in the human feed. Due to its characteristics and composition, tomatoes present reduced shelf life, and preservative techniques are required. In this study, response surface methodology was used to optimize process conditions during the osmotic dehydration (OD) of tomato slices, through the desirability function. Optimization factors were absolute pressure (21-89 kPa), vacuum application period (7-15 min), and osmotic solution water activity (0.893-0.943), while investigated responses were sodium incorporation (NaI), water loss (WL), solid gain (SG), weight reduction (WR), and osmodehydrated product water activity (ODaw). The optimized conditions were achieved, and a further hot-air drying (HAD) was conducted at different temperatures and air velocities. During the OD, lower absolute pressure, and osmotic solution water activity led to lower NaI and higher WL and WR. Shorter drying time and higher diffusivity were obtained at higher temperature and air velocity, during the HAD. The dried tomato slices with sodium incorporation reduction were evaluated with regard to the final water activity, rehydration and color, in which no significant differences (p > 0.05) were observed between the treatments.
Os autores agradecem ao CNPq, Fapemig e Capes, pelo apoio financeiro.
The convective drying is a slow operation. Several techniques has been studied to increase the ki... more The convective drying is a slow operation. Several techniques has been studied to increase the kinetics of process such as the pretreatments in liquids or the application of high intensity ultrasound during both, pretreatment or convective drying. In this work, the influence of the pretreatment (with distilled water (20 and 40 min at 25 °C) on convective drying (40 °C, 1 m s-1) of pineapple slices (2.0 cm diameter, 0.5 cm thickness) was studied. The application of ultrasound during pretreatment (55.5 W/L, 40 kHz) or during convective drying (31 kW m −3 ; 21.8 kHz) was also addressed. The results showed that the application of ultrasound during the pretreatment and during drying increased water transport and reduced the drying time. The use of ultrasound in the pretreatment or in the convective drying could improve drying processes.
Journal of Food Science
This study aimed to evaluate coconut sugar (CS) as an alternative osmotic agent to sucrose for th... more This study aimed to evaluate coconut sugar (CS) as an alternative osmotic agent to sucrose for the osmotic dehydration (OD) of strawberries. OD was performed by immersing strawberries cut into 13.6 ± 0.4 mm edge cubes in osmotic solutions of CS or sucrose, at two different concentrations (40% and 60%, w/w), with and without application of vacuum (AV) in the first 20 min of the process. The total OD time was 300 min. Evaluations of the kinetics of solid gain (SG), water loss (WL), and weight reduction (WR) were performed at 30, 60, 120, 180, 240, and 300 min. SG, WL, and WR increased over the OD time and showed values of up to 7.94%, 63.40%, and 55.94%, respectively. AV increased WL, WR, shrinkage, pH, and total color difference and decreased anthocyanin, ascorbic acid (AA), phenolic, and antioxidant contents. The higher concentration led to higher SG, WL, WR, shrinkage, hardness, and lower moisture content, water activity, anthocyanin, AA, phenolic, and antioxidant contents. The use...
Anais do Congresso Brasileiro de Sistemas Particulados
Anais do Congresso Brasileiro de Sistemas Particulados
Anais do Congresso Brasileiro de Sistemas Particulados
Anais do Congresso Brasileiro de Sistemas Particulados
Journal of Food Processing and Preservation
Journal of Food Processing and Preservation
Brazilian Journal of Development, 2020
Predição de escoamento de ar em um secador tipo túnel: Avaliação do uso de placas de direcionamen... more Predição de escoamento de ar em um secador tipo túnel: Avaliação do uso de placas de direcionamento de fluxo e de modelos de turbulência Prediction of air flow in a tunnel type dryer: Evaluation of the use of plates direction of flow and turbulence models
A pasteurizacao constitui o metodo mais empregado na industria para conservacao dos alimentos pel... more A pasteurizacao constitui o metodo mais empregado na industria para conservacao dos alimentos pela inativacao de microrganismos, porem este metodo pode alterar as caracteristicas nutricionais e sensoriais de alimentos relativamente sensiveis como e o caso das polpas de frutas. Novas tecnologias estao sendo empregadas com o objetivo de promover seguranca microbiologica, com efeitos minimos na qualidade nutricional e sensorial dos alimentos. O uso do ultrassom e um processo alternativo ao metodo convencional, que vem sendo estudado como uma forma de conservar o alimento fornecendo um alimento seguro sem causar reacoes indesejaveis. Diante disso, este trabalho tem como objetivo avaliar a qualidade fisico-quimica, microbiologica e sensorial das polpas de goiaba e maracuja, submetidas aos tratamentos de pasteurizacao, convencional e por aplicacao de ultrassom. Primeiramente, foram elaboradas as polpas das frutas, e posteriormente submetidas a pasteurizacao convencional, e por aplicacao...
Food and Bioprocess Technology, 2021
Convective drying of strawberries was performed with or without ethanol pre-treatment (ET) in the... more Convective drying of strawberries was performed with or without ethanol pre-treatment (ET) in their fresh state or enriched with isomaltulose osmotic dehydration (OD) or by pulsed vacuum osmotic dehydration (PVOD). Both osmotic processes were executed by the immersion of 10 mm strawberry cubes in the osmotic solution for 300 min. The PVOD was done at reduced pressure (160 mbar) during the first 20 min. The ET was conducted by immersion of the samples in 95% ethanol for 2 min. Convective drying (60 °C and 1 m s−1) was performed until a final moisture content of 11.50%w.b.. The convective drying required from 195 to 300 min. The non-osmotically dehydrated dried sample required a shorter drying time and produced samples with lower water activity, hardness and color change, and higher total anthocyanin content (TAC), total phenolic content (TPC), and antioxidant capacity (AC). In addition to promoting enrichment with isomaltulose, both osmotic processes reduced shrinkage and hygroscopicity compared to non-osmotically dehydrated dried samples. ET reduced drying time by up to 30%, reduced hygroscopicity, and contributed to TAC, TPC, and AC preservation, showing as an interesting procedure to be applied in the convective drying of strawberries. However, the ET increased the shrinkage of the samples.
Research, Society and Development, 2020
Among all stages in the coffee production (Coffea arabica L.), post-harvest can significantly imp... more Among all stages in the coffee production (Coffea arabica L.), post-harvest can significantly impact the final cost and product quality. Among the stages of this phase, drying is one’s that requires most care. The search for new technologies to optimize this process has been growing exponentially, a example is the use of enzymes and yeasts, which can guarantee a safer drying and even improve the quality of the bevarege. The objective of the study was to evaluate the drying behavior of coffee without changing the temperature, air flow, only changing the processing (natural and pulped natural) of the beans using the enzyme Pectinex® Ultra SPL and the yeast CA11 to observe the occurrence of some change in the drying kinetics after processing and modeling the drying kinetics, analyzing which model can more accurately predict the coffee drying. The VALCAM model was the best model to describe drying kinetics, with the highest value of determination coefficient (R2> 99.73%), lowest mean...
Food and Bioprocess Technology, 2018
Pulsed vacuum osmotic dehydration (PVOD) is a widely used technique for reducing moisture content... more Pulsed vacuum osmotic dehydration (PVOD) is a widely used technique for reducing moisture content and water activity in biological products. This study aimed to analyze the effect of vacuum application (VA) on PVOD of beetroot, carrot, and eggplant slices, with respect to chemical (moisture, water activity, specific pigments, polyphenols, and sodium content), optical (color), mechanical (shrinkage, maximum stress, and elasticity), and structural (microstructure) properties. PVOD was conducted at three different vacuum pressures (0, 40, and 80 kPa, for 10 min), during a total process time of 300 min. Osmotic processing was performed at 35°C by using a ternary osmotic solution [40% sucrose + 10% sodium chloride (w/w)]. Eggplant and carrot samples were more sensitive to VA, compared to beetroot. This was related to their porous and less compact structure. In general, VA reduced the moisture content and water activity and preserved the carotenoid content. VA caused loss of betalain and phenolic acid, favored sodium uptake, and induced significant changes in the optical, mechanical, and structural properties, compared to the osmotic processing conducted at atmospheric pressure.
LWT - Food Science and Technology, 2016
Abstract Semi-dehydrated food is obtained via osmotic dehydration (OD). The influence of the osmo... more Abstract Semi-dehydrated food is obtained via osmotic dehydration (OD). The influence of the osmotic agent (27.5% sucrose or maltodextrin combined with 10.0% of NaCl, 40 °C) with/without the application of a vacuum pulse (VP) (100 mbar, 20 min) on the NaCl incorporation and on the kinetics of water loss (WL), solid gain (SG), and water activity (a w ) were studied in the OD of sliced tomatoes. The kinetics of the WL and SG were evaluated and fitted with diffusive and hydrodynamic models. The NaCl incorporation was 25% lower in the maltodextrin-NaCl solution (MN) compared to the sucrose-NaCl solution (SN). The MN reduced that incorporation compared to the SN. Moreover, the salt incorporation was significantly reduced (by approximately 50%) by using a VP in the osmotic process, which was independent of the ternary solution. The variable effective diffusivity improved the fitness of the OD kinetics with respect to the constant diffusivity or the modelling of the hydrodynamic mechanism. The large reduction of NaCl incorporation obtained in the present work, which was mainly due to the use of a VP, suggests that more attention is necessary in studies of OD with vacuum pulse involving the immersion of food in a ternary.
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
RESUMO-O objetivo deste trabalho foi otimizar a PVOD de fatias de yacon com relação à temperatura... more RESUMO-O objetivo deste trabalho foi otimizar a PVOD de fatias de yacon com relação à temperatura (T, 24 a 44 °C), pressão do pulso de vácuo (PV, 49,4 a 220,6 mmHg) e concentração da solução osmótica de sorbitol (CS, 22 a 60,8 °Brix) através de um delineamento composto central rotacional com relação às variáveis resposta perda de água (PA), perda de peso (PP), ganho de sólidos (GS), atividade de água (a w), cor e teor de frutanos. Após 300 minutos de DO, a PA foi de até 73,03 % e a retenção de frutanos de 28,13 a 82,03 %. Maiores CS e T levaram a maiores PP, PA e GS. O aumento da CS e da PV acarretou menor a w e o aumento de T, maior escurecimento. Estabeleceu-se, como ponto ótimo, a PVOD com T igual a 35 °C, CS, 38 °Brix e aplicação de 74 mmHg de PV nos 10 primeiros min.
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Papers by JEFFERSON LUIZ GOMES CORREA