Estabilidad y vida útil de caballa (<i>Scomber japonicus</i>) preservada mediante combinación de barreras

El objetivo de la presente tesis fue estudiar la estabilidad y la vida útil de caballa (Scomber japonicus) preservada mediante combinación de barreras de stress microbiano (cocción, disminución de aw, envasado al vacío, pasteurización a baja temperatura y refrigeración). Se desarrolló el proceso de elaboración de los lomitos de caballa de humedad intermedia y se realizó una caracterización sensorial y fisicoquímica del producto terminado. Se estudió la difusión de los solutos (glicerol y sal) y del agua durante la deshidratación osmótica utilizando los modelos de Crank, Peleg, Zugarramurdi & Lupín, Weibull y Azuara. Se analizó el comportamiento de los microorganismos presentes en la preserva (flora nativa) durante el almacenamiento y se realizó un estudio de reto microbiano con el fin de validar experimentalmente la etapa de pasteurización. Por último, se estimó la vida útil sensorial de la preserva almacenada en refrigeración mediante un estudio de vida útil acelerado utilizando tres temperaturas: 15, 25 y 35ºC. Se logró desarrollar un producto a partir de caballa preservado mediante la tecnología de obstáculos comprobando que las barreras aplicadas fueron efectivas para reducir la flora bacteriana inicial y mantener sin desarrollo microbiológico durante al menos 12 meses de almacenamiento.Facultad de Ingenierí

Mass Transfer During Osmotic Dehydration of Chub Mackerel Cylinders in Ternary Solution

In the analysis, design and optimization of an osmotic dehydration process is important to know the kinetic of water loss and solutes gain. In this study, the mass transfer during osmotic dehydration of chub mackerel (Scomber japonicus) cylinders in ternary solution glycerol/salt/water was analyzed. The models of Zugarramurdi &amp; Lupín and Azuara were used to describe mass transfer and to estimate equilibrium values. The radial effective diffusion coefficient was estimated using the analytical solution of Fick's second law. Diffusion coefficients were determined for a finite cylinder, for an infinite cylinder considering only the first term of the series and considering higher order terms of the series. The profiles of water and solutes during the osmotic dehydration were calculated by using the estimated water and solutes diffusivities. According to the results obtained, using three terms in the analytical solution of the Fick's second law is appropriate to determine the diffusion coefficients. The diffusion coefficient for infinite cylinder were 2.63×10-6, 4.11×10-6 and 4.25×10-6 cm2/s for water loss, salt and glycerol gain respectively. For a finite cylinder these values were 2.30×10-6, 3.67×10-6 and 3.78×10-6 cm2/s respectively. All the models proposed were in agreement with experimental data for solutes gain ((0.967&lt;R2adj&lt;0.986); (0.0016&lt;RMSE&lt;0.039) and (4.17&lt;P&lt;10.0)). The model based on the solution of Fick’s Law for an infinite cylinder with higher order terms was the best fit for water loss and solutes gain. The equilibrium values estimated with Azuara model agree with the experimental (0&lt;relative error&lt;9.8). Water and solute distributions as a function of time and location in the radial direction were plottedCentro de Investigación y Desarrollo en Criotecnología de AlimentosConsejo Nacional de Investigaciones Científicas y Técnica

Mass Transfer During Osmotic Dehydration of Chub Mackerel Cylinders in Ternary Solution

In the analysis, design and optimization of an osmotic dehydration process is important to know the kinetic of water loss and solutes gain. In this study, the mass transfer during osmotic dehydration of chub mackerel (Scomber japonicus) cylinders in ternary solution glycerol/salt/water was analyzed. The models of Zugarramurdi & Lupín and Azuara were used to describe mass transfer and to estimate equilibrium values. The radial effective diffusion coefficient was estimated using the analytical solution of Fick's second law. Diffusion coefficients were determined for a finite cylinder, for an infinite cylinder considering only the first term of the series and considering higher order terms of the series. The profiles of water and solutes during the osmotic dehydration were calculated by using the estimated water and solutes diffusivities. According to the results obtained, using three terms in the analytical solution of the Fick's second law is appropriate to determine the diffusion coefficients. The diffusion coefficient for infinite cylinder were 2.63×10-6, 4.11×10-6 and 4.25×10-6 cm2/s for water loss, salt and glycerol gain respectively. For a finite cylinder these values were 2.30×10-6, 3.67×10-6 and 3.78×10-6 cm2/s respectively. All the models proposed were in agreement with experimental data for solutes gain ((0.967<R2adj<0.986); (0.0016<RMSE<0.039) and (4.17<P<10.0)). The model based on the solution of Fick’s Law for an infinite cylinder with higher order terms was the best fit for water loss and solutes gain. The equilibrium values estimated with Azuara model agree with the experimental (0<relative error<9.8). Water and solute distributions as a function of time and location in the radial direction were plottedFil: Checmarev, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; ArgentinaFil: Yeannes, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; ArgentinaFil: Bevilacqua, Alicia Eva. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Casales, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; Argentin

Mass Transfer During Osmotic Dehydration of Chub Mackerel Cylinders in Ternary Solution

In the analysis, design and optimization of an osmotic dehydration process is important to know the kinetic of water loss and solutes gain. In this study, the mass transfer during osmotic dehydration of chub mackerel (Scomber japonicus) cylinders in ternary solution glycerol/salt/water was analyzed. The models of Zugarramurdi &amp; Lupín and Azuara were used to describe mass transfer and to estimate equilibrium values. The radial effective diffusion coefficient was estimated using the analytical solution of Fick's second law. Diffusion coefficients were determined for a finite cylinder, for an infinite cylinder considering only the first term of the series and considering higher order terms of the series. The profiles of water and solutes during the osmotic dehydration were calculated by using the estimated water and solutes diffusivities. According to the results obtained, using three terms in the analytical solution of the Fick's second law is appropriate to determine the diffusion coefficients. The diffusion coefficient for infinite cylinder were 2.63×10-6, 4.11×10-6 and 4.25×10-6 cm2/s for water loss, salt and glycerol gain respectively. For a finite cylinder these values were 2.30×10-6, 3.67×10-6 and 3.78×10-6 cm2/s respectively. All the models proposed were in agreement with experimental data for solutes gain ((0.967&lt;R2adj&lt;0.986); (0.0016&lt;RMSE&lt;0.039) and (4.17&lt;P&lt;10.0)). The model based on the solution of Fick’s Law for an infinite cylinder with higher order terms was the best fit for water loss and solutes gain. The equilibrium values estimated with Azuara model agree with the experimental (0&lt;relative error&lt;9.8). Water and solute distributions as a function of time and location in the radial direction were plottedCentro de Investigación y Desarrollo en Criotecnología de AlimentosConsejo Nacional de Investigaciones Científicas y Técnica

Lomitos de caballa preservados mediante tecnología de obstáculos

El objetivo de este trabajo fue diseñar una preserva de caballa de humedad intermedia mediante combinación de barreras de estrés microbiano. Las barreras utilizadas fueron: disminución de la carga bacteriana e inactivación enzimática por cocción al vapor disminución de la actividad de agua, envasado al vacío en películas impermeables al O2, tratamiento térmico moderado y almacenamiento en refrigeración. Los troncos de caballa se cocinaron al vapor durante 20 minutos, se dejaron orear en refrigeración y se eliminó la piel, espinas y músculo rojo. Los lomitos se deshidrataron osmóticamente en una solución de glicerol y sal (aw=0,64) durante 19 hs en refrigeración, se envasaron al vacío en bolsas termosellables de polietileno de baja densidad y poliamida y se pasteurizaron a 60 °C durante 50 minutos (con Staphylococcus aureus como microorganismo de control). Luego de la pasteurización se enfriaron y se almacenaron en refrigeración (5 °C). La preserva tuvo una aw de 0,89, un pH de 5,5 y un contenido de agua de 49,70 %. Los lomitos se analizaron el día de su preparación, semanalmente durante el primer mes y mensualmente durante 11 meses. Se realizaron análisis fisicoquímicos (aw y contenido de agua), análisis microbiológicos (recuento total de microorganismos psicrótrofos, mesófilos, clostridios sulfito reductores y Staphylococcus spp) y análisis sensoriales (color y aroma rancio). No se detectó crecimiento microbiano y los parámetros sensoriales y fisicoquímicos se mantuvieron sin variación durante todo el tiempo de almacenamiento. Se diseño satisfactoriamente una preserva de caballa mediante el uso de la tecnología de obstáculos.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Criotecnología de Alimento

Kinetics of color change of osmotically dehydrated chub mackerel (Scomber japonicus) during storage at different temperatures

Abstract The aim of this study was to determine the effect of storage temperature on the kinetics of color change of chub mackerel dehydrated in a ternary solution (water, glycerol and salt) and vacuum packaged in films. The color of processed fish can change because of lipids and protein oxidation during storage. Samples were stored at 7, 25 and 35 °C for seven months and kinetic models of 0, 1 and 2 order were applied to describe the color changes. It was observed that an increase in the storage temperature improved the changes in the CIE color values (L*, a* and b*). First-order reaction had the best statistical parameters for a* at the three temperatures tested. The temperature dependence of parameter a* indicated an Arrhenius relationship and the activation energy (Ea) was 44.33 kJ/mol. The parameter b* fitted to the proposed models only in samples stored at 35 °C. The L* value decreased during storage at 25 and 35 °C (pale to dark). Storage at refrigeration temperature (7 °C) minimized the color changes

Analysis of applicability of Peleg model to the cooking-infusion of mackerel (Scomber japonicus) slices

Mass transfer kinetics in osmotic dehydration is usually modeled by Fick's law, empirical models and probabilistic models. The aim of this study was to determine the applicability of Peleg model to investigate the mass transfer during osmotic dehydration of mackerel (Scomber japonicus) slices at different temperatures. Osmotic dehydration was performed on mackerel slices by cooking-infusion in solutions with glycerol and salt (a w = 0.64) at different temperatures: 50, 70, and 90 ºC. Peleg rate constant (K1) (h(g/gdm)-1) varied with temperature variation from 0.761 to 0.396 for water loss, from 5.260 to 2.947 for salt gain, and from 0.854 to 0.566 for glycerol intake. In all cases, it followed the Arrhenius relationship (R²&gt;0.86). The Ea (kJ / mol) values obtained were 16.14; 14.21, and 10.12 for water, salt, and glycerol, respectively. The statistical parameters that qualify the goodness of fit (R²&gt;0.91 and RMSE<0.086) indicate promising applicability of Peleg model