EQA - Artigos Publicados em Periódicos
URI permanente para esta coleçãohttps://rihomolog.furg.br/handle/1/1611
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- ItemCaracterização da secagem convectiva de tomate (Lycopersicon Esculentum Mill) em camada delgada(EDGRAF, 2011) Coelho, Karen Dias; Pinto, Luiz Antonio de AlmeidaO trabalho teve como objetivo a caracterização da cinética de secagem do tomate (Lycopersicon esculentum Mill) em camada delgada, e a determinação da reidratação e do teor de licopeno do produto final. O estudo foi realizado em um secador de bandejas com escoamento paralelo do ar, onde as variáveis estudadas foram temperatura do ar de secagem (60, 70 e 80°C) e espessura das amostras (3, 5 e 7 mm). As isotermas de equilíbrio foram determinadas pelo método gravimétrico usando soluções ácidas, e os dados experimentais foram ajustados através da equação de GAB. Nos experimentos de secagem, foi usada a equação de Henderson e Pabis para a obtenção da constante de secagem (K), e os valores de da difusividade efetiva de umidade (DEF) apresentaram-se entre 1,56 a 2,67×10-10 m2 s -1 e entre 4,21 a 8,35×10-11 m 2 s -1, sendo os valores da energia de ativação de 16,99 e 30,64 kJ mol-1, respectivamente, para o primeiro e o segundo períodos de taxa decrescente de secagem. Para a reidratação, verificou-se que com menores temperaturas do ar obteve-se uma maior reidratação do produto num menor tempo, e o teor de licopeno também foi maior nessas condições.
- ItemMoisture sorption characteristics of microalgae Spirulina platensis(2009) Oliveira, Elisangela Gonçalves de; Rosa, Gabriela da Silveira; Moraes, Mariana Agostini de; Pinto, Luiz Antonio de AlmeidaIn recent times, the microalgae Spirulina platensis has been used as a functional ingredient in several food applications; its process involving drying and storage steps. Moisture equilibrium data for adsorption isotherms of microalgae Spirulina were investigated at 10, 20 and 30°C and for desorption, at 40, 50 and 60°C, using the gravimetric static method. The experimental data were analyzed by GAB and BET models. The GAB equation showed the best fitting to the experimental data with R² ≈ 99% and MRE < 10%. The water surface area values calculated by GAB and BET models were very similar. The isosteric heats were determined by application of Clausius-Clapeyron equation to sorption isotherms obtained from the best-fitting equation. The isosteric heat and the entropy of desorption isotherm presented similar behavior, with a sharp change in an equilibrium moisture content of 10%. The enthalpy-entropy compensation theory was applied to the isotherms, indicating that they are enthalpy-controlled.
- ItemPolyunsaturated fatty acid concentrates of carp oil: chemical hydrolysis and urea complexation(Springer, 2012) Crexi, Valéria Terra; Monte, Mauricio Legemann; Monte, Maurício Legemann; Pinto, Luiz Antonio de AlmeidaThe aims of this study were to compare three treatments in the chemical hydrolysis reaction of bleached oil from carp (Cyprinus carpio) heads and to obtain polyunsaturated fatty acid concentrates by urea complexation. The three treatments were carried out with different oil:ethanol molar ratios. In the treatment with a 1:39 molar ratio, a higher yield of free fatty acids was found. These fatty acids were submitted to urea complexation (−10 °C for 20 h, and urea–fatty acid ratio of 4.5–1). There was a 31.4% increase in monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) content and a 75% decrease in saturated fatty acids (SAF) content. An increase of 85.4% in the EPA + DHA content was found. The non-urea complexing fraction can be considered a rich source of MUFA and PUFA with a total amount of 88.9%.
- ItemKinetics and mechanism of the food dye FD&C Red 40 adsorption onto chitosan(ACS, 2011) Piccin, Jeferson Steffanello; Dotto, Guilherme Luiz; Vieira, Mery Luiza Garcia; Pinto, Luiz Antonio de AlmeidaThe kinetics and mechanism of the food dye disodium 6-hydroxy-5-((2-methoxy-5-methyl-4-sulfophenyl)azo)-2-naphthalenesulfonate (FD&C Red 40) adsorption onto chitosan were studied. The effects of pH (5.7 to 7.4), chitosan dosage [(250 to 500) mg 3 L 1], deacetylation degree (42 % to 84 %), and particle size [(0.10 to 0.26)mm] were investigated. The adsorption reaction models were used to evaluate the kinetic behavior. Infrared analysis and models based on mass transfer phenomena were used to investigate the adsorption mechanism. The maximum adsorption capacity (300 mg 3 g 1 ) was found at a pH 5.7, chitosan dosage of 250 mg 3 L 1 , deacetylation degree of 84 %, and particle size of 0.10 mm. Pseudosecond-order and Elovich models were the most appropriate to fit the experimental data of adsorption kinetics. The adsorption process was controlled by intraparticle diffusion, film diffusion, or convection according to the experimental conditions. Infrared analysis showed the chemical interaction between chitosan and food dye FD&C Red 40.
- ItemCarp (Cyprinus carpio) oils obtained by fishmeal and ensilage processes: characteristics and lipid profiles(Wiley Online Library, 2009) Crexi, Valéria Terra; Soares, Leonor Almeida de Souza; Pinto, Luiz Antonio de AlmeidaFish oil is an important source of long-chain ω-3 polyunsaturated fatty acid. The common carp (Cyprinus carp) is a major fish species in world aquaculture production. This study aimed towards obtaining carp viscera oil by ensilage and fishmeal processes. Characteristics of crude oils obtained were also compared with oil extracted by Bligh and Dyer methods. Crude oils obtained by the three processes resulted in significant difference (P < 0.05) for free fatty acids, peroxide, thiobarbituric acid and Lovibond colour values; however, iodine and saponification values were not significantly affected (P > 0.05). Recovery yield of crude oils was approximately 85% in relation to carp viscera oil. Carp crude oils obtained by the ensilage and fishmeal processes resulted in high unsaturated and polyunsaturated fatty acid contents (67.4%), and ω3/ω6 ratios around 1.15. These oils are applicable in fish diets; however, crude oils require refinement for human consumption.
- ItemMoisture sorption isotherms and thermodynamic properties of apple Fuji and garlic(Wiley Online Library, 2008) Moraes, Mariana Agostini de; Rosa, Gabriela Silveira da; Pinto, Luiz Antonio de AlmeidaThe moisture equilibrium isotherms of garlic and apple were determined at 50, 60 and 70 °C using the gravimetric static method. The experimental data were analysed using GAB, BET, Henderson–Thompson and Oswin equations. The isosteric heat and the differential entropy of desorption were determined by applying Clausius–Clapeyron and Gibbs–Helmholtz equations, respectively. The GAB equation showed the best fitting to the experimental data (R2 > 99% and E% < 10%). The monolayer moisture content values for apple were higher than those for garlic at the studied temperatures; the values varied from 0.050 to 0.056 and from 0.107 to 0.168 for garlic and apple, respectively. The isosteric heat and the differential entropy of desorption were estimated in function of the moisture content. The values of these thermodynamic properties were higher for apple (in range 48–100 kJ mol−1 and 14–150 J mol−1 K−1) than for garlic (in range 43–68 kJ mol−1 and 0–66 J mol−1 K−1). The water surface area values decreased with increasing temperature. The Kelvin and the Halsey equations were used to calculate the pore size distribution.
- ItemReduction of drying and ripening times during the iItalian type salami production(2006) Fonseca, Gustavo Graciano; Porto, Paulo Sérgio da Silva; Pinto, Luiz Antonio de AlmeidaSalami is a product which preparation time varies notably in function of some parameters, especially its size. This study carried out in a company to verify in industrial scale the possibility of the reduction of the days of process. Drying curves were done for salami with 60 mm diameter and 240 and 260 mm lengths, corresponding to masses of 776 and 852 g, respectively. In the current conditions, the process time was of 38 days. It was concluded that the maintenance of the 7 days of pre-ripening, a reduction in the period of the first ripening from 13 to 7 days and in the second ripening from 18 to 17, totaling 31 days, reached the desired humidity, occurring no alterations in the final product characteristics. Through non-linear regression analysis it was verified that the obtained parameters of the drying curves, had presented excellent adjustment of correlation (R2 > 99%).
- ItemPhycocyanin content os spirulina platensis dried in spouted bed and thin layer(Wiley Online Library, 2008) Oliveira, Elizangela Gonçalves de; Rosa, Gabriela Silveira de; Moraes, Mariana Agostini de; Pinto, Luiz Antonio de Almeidahe aim of this work was to study the drying of Spirulina platensis, evaluating the final product characteristics about its phycocyanin content and its protein solubility in water. Two drying techniques were used: the spouted bed and the thin layer. For drying in a spouted bed, the cone-cylindrical geometry was chosen, namely type conventional spouted bed (CSB) and jetspouted bed, with a paste concentration of 5%. The thin-layer drying was performed at temperatures of 50 and 60C, with a load of material of 4 kg/m2 in the tray. The spouted bed dryer type CSB demonstrated good functionality, not presenting a collapse during the experiments. The solubility in aqueous mean was similar in all the drying techniques used, being the values found around 37%. The largest phycocyanin values were found in the thin-layer temperature of 50C and in the spouted bed type CSB; however, the thin layer was excluded so as not to reach the commercial moisture content.
- ItemDeodorisation process variables for croaker (M. furnieri) oil(Elsevier, 2009) Crexi, Valéria Terra; Grunennvaldt, Fernanda Lourdes; Soares, Leonor Almeida de Souza; Pinto, Luiz Antonio de AlmeidaFish oil is the major food source of the long-chain omega-3 polyunsaturated fatty acids. Deodorisation represents a critical step of the refining process since it involves high temperature that could induce degradation reactions which affect oil integrity and quality. The present study evaluated the effect of the deodorisation variables (temperature, time and steam) on the croaker (Micropogonias furnieri) oil refining process. The evaluated parameters were Lovibond color (LC), free fatty acids (FFA), peroxide (PV), Iodine (IV) and Saponification (SV) values. The best deodorisation conditions were at 220 °C, 60 min and 5% of steam (based in oil mass), resulting in oil with LC of 0.4 red and 30 yellow, FFA of 0.09%, PV of 0.53 meq/kg. IV and SV were not significantly affected. The obtained fish oil presented high quality and oxidative stability, as well as EPA and DHA contents of approximately 12% of total fatty acids.
- ItemCharacterization of thin layer drying of Spirulina platensis utilizing perpendicular air flow(Elsevier, 2009) Oliveira, Elisangela Gonçalves de; Rosa, Gabriela Silveira da; Moraes, Mariana Agostini de; Pinto, Luiz Antonio de AlmeidaSpirulina is the most extensively used microalgae for animal and human nutrition mostly because of its high protein content, 60–65% on a dry weight basis. The drying is the most expensive operation. The aim of the study was to characterize drying of Spirulina platensis in thin layer. A Statistical model was applied to analyze the effects of independent variables (air temperature and loads of solids in the tray) on the response of solubility in acid medium. The analysis of phycocyanin content was determined at the best drying condition. The Spirulina isotherm data were adjusted through Guggenheim, Anderson and de Boer (GAB) and Brunauer, Emmett and Teller (BET) correlations. The nonlinear regression analysis of isotherms data showed that the GAB equation more effective adjusted the experimental data (R2 > 99% and E% < 10%). Drying curves of Spirulina showed only a decreasing rate-drying period. The material load and the interaction between the air temperature and material load were significant effects (P 6 0.05), and the best results of solubility in acid medium (79%) occurred at 60 C and 4 kg/m2. In under theseconditions the phycocyanin content was determined to be 12.6% of dried Spirulina.