Bacterial contribution to salted anchovy (Engraulis anchoita Hubbs & Marinni, 1935) ripening process

The bacterial populations of the salted anchovy ripening process and its potential role on the development of the typical sensory characteristics of this product were studied. Salted anchovy samples were taken during the ripening process and submitted to microbiological analyses in order to monitor the evolution of bacterial groups. According to the results obtained, the ripening process would be dominated by moderate halophilic bacteria. Moreover, many of the isolated strains showed proteolytic, lipolytic and TMAO reductase activities. All this activities would contribute to the development of typical flavour of this product and to the increase of total volatile basis observed during ripening.Fil: Czerner, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; ArgentinaFil: Yeannes, Maria Isabel. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentin

Gamma radiation effect on quality changes in vacuum-packed squid (Illex argentinus) mantle rings during refrigerated (4-5°C) storage

The effect of gamma radiation (0, 1.8, 3.3 and 5.8kGy) on microbiological, chemical and colour characteristics of vacuum-packed squid (Illex argentinus) mantle rings was studied. Total viable counts; psychrotrophic bacteria counts, Escherichia Coli, Staphylococcus aureus and Clostridium perfringens; total volatile basic nitrogen (TVBN) and colour difference were analysed during 29days of storage at 4-5°C. Higher doses of gamma radiation significantly reduced Total Viable, phychrotrophic counts and TVBN production (P<0.05) in a dose-dependent way, delaying squid spoilage. Colour difference of non-irradiated samples with respect to first day significantly increased while it was constant in radiated samples during 22days (P<0.05). Independently from the dose, radiation avoided colour changes of squid rings. Gamma irradiation was effective in delaying deterioration reactions, improving microbiological, chemical and colour quality of vacuum-packed squid rings stored at 4-5°C.Fil: Tomac, Alejandra. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Yeannes, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; Argentin

La revalorización del espacio público a partir de las condiciones de accesibilidad peatonal : Un estudio sobre las barreras arquitectónicas en la ciudad de Mar del Plata

La accesibilidad peatonal constituye una de las condiciones físico-ambientales determinantes para la funcionalidad del espacio público y el mejoramiento de la calidad de nuestras ciudades. En la ciudad de Mar del Plata, el paisaje urbano ha estado sujeto a importantes transformaciones en los espacios públicos. Estas intervenciones involucran de manera directa su accesibilidad peatonal y las necesidades de sus usuarios, que no siempre se ven correctamente atendidas. Con el bbjetivo de producir avances en el conocimiento de estas condiciones se elabora un diagnóstico general para identificar el o los paseos peatonales más afectados; posteriormente se construye un diagnóstico específico, estableciendo a partir de un instrumento de relevamiento, la identificación puntual de las barreras y trampas urbanas en los itinerarios seleccionados. Los resultados permiten diagnosticar y categorizar los problemas de accesibilidad, conocimiento esencial en aquellos programas vigentes, base instrumental en la construcción de planes y proyectos a futuro.Pedestrian accessibility constitutes one of the determinant physical-environmental conditions for public space function and improvement on the quality of our cities. In Mar del Plata, the urban landscape has been subject to important modifications in public spaces. These interventions directly involve its pedestrian accessibility and its user's needs which are not always satisfied. Aiming to improve such conditions, a general analysis is carried out in order to identify the most affected pedestrian areas. Afterwards, a report method on specific assessment is undertaken to establish the exact identification of urban barriers and traps in the selected areas. Results allows the analysis and categorization of access problems which are essential knowledge for those current, and future programs.Pedestrian accessibility constitutes one of the determinant physical-environmental conditions for public space function and improvement on the quality of our cities. In Mar del Plata, the urban landscape has been subject to important modifications in public spaces. These interventions directly involve its pedestrian accessibility and its user's needs which are not always satisfied. Aiming to improve such conditions, a general analysis is carried out in order to identify the most affected pedestrian areas. Afterwards, a report method on specific assessment is undertaken to establish the exact identification of urban barriers and traps in the selected areas. Results allows the analysis and categorization of access problems which are essential knowledge for those current, and future programs.El presente trabajo corresponde a un resumen del capítulo 3 de la tesis de maestría titulada «El cero urbano. La accesibilidad peatonal en los espacios públicos de la ciudad de Mar del Plata" presentada en el Centro de Investigaciones Ambientales (CIAM) de la Universidad Nacional de Mar del Plata.Facultad de Arquitectura y Urbanism

Effect of Frozen Storage on Biochemical Changes and Fatty Acid Composition of Mackerel (Scomber japonicus) Muscle

The aim of the present work was to analyze the effect of frozen storage on biochemical characteristics in mackerel (Scomber japonicus). Fresh mackerel captured from Southwest Atlantic Ocean was frozen and then stored at -19 ± 1 ºC for one year. Biochemical analyses were done at established sampling times: total volatile basic nitrogen (TVB-N), fatty acid profile, thiobarbituric acid values (TBA-RS) and colour determinations. After twelve months TVB-N increase correlated (R2 : 0.888) with storage time indicating the effect of enzymatic activity. Lipid content presented high degree of unsaturation, EPA (eicosapentaenoic acid; C20:5 -3) and DHA (docosahexaenoic acid; C22:6 -3) acids prevail among total -3 acids. During frozen storage, polyunsaturated fatty acids, -3 and Polyene Index (EPA + DHA ⁄ C16) contents decreased. Frozen storage of whole mackerel caused important changes in fatty acid composition simultaneously with an increase in lipid oxidation in fillets, measured as TBA-RS. Dark muscle was more sensitive to lipid oxidation than the light muscle. Color analysis showed that L* value was the parameter which presented more changes during frozen storage indicating loss of lightness in the dorsal and ventral fish fillet areas. The increase in b* value on the ventral zone indicated the presence of yellow pigments as result of lipid oxidation. Although the frozen storage technique represents important changes in mackerel samples, the high values of PUFA in muscle are still high over other fish species making mackerel an important nutritional resource.Fil: Agustinelli, Silvina Paola. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Yeannes, Maria Isabel. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

La revalorización del espacio público a partir de las condiciones de accesibilidad peatonal. Un estudio sobre barreras arquitectónicas en la ciudad de Mar del Plata

La accesibilidad peatonal constituye una de las condiciones físico-ambientales determinantes para la funcionalidad del espacio público y el mejoramiento de la calidad de nuestras ciudades. En la ciudad de Mar del Plata, el paisaje urbano ha estado sujeto a importantes transformaciones en los espacios públicos. Estas intervenciones involucran de manera directa su accesibilidad peatonal y las necesidades de sus usuarios, que no siempre se ven correctamente atendidas. Con el bbjetivo de producir avances en el conocimiento de estas condiciones se elabora un diagnóstico general para identificar el o los paseos peatonales más   afectados; posteriormente se construye un diagnóstico específico, estableciendo a partir de un instrumento de relevamiento, la identificación puntual de las barreras y trampas urbanas en los itinerarios seleccionados. Los resultados permiten diagnosticar y categorizar los problemas de accesibilidad, conocimiento esencial en aquellos programas vigentes, base instrumental en la construcción de planes y proyectos a futuro

Psychophysical estimation of acid intensity and determination of sweet-acid interaction in a fish paste containing glycerol

In a fish paste made with cooked Brazilian flathead (Percophis brasiliensis), glycerol (17%), sodium chloride (1.5%) and potassium sorbate (0.1%) the following acid percentages: 0.2; 0.4; 0.6; 0.8, 1 and 1.5% w/w were incorporated to determine the relationship between added acetic acid and the sensorially perceived intensity, and the effects of the combination of sweet-acid tastes. Tests for paired comparison, ranking and structured verbal scales for sweet and acid attributes and psychophysical test were carried out. There was a perceptible difference among samples for differences of 0.4 units of acid concentration. Samples indicated as sweeter by 89.47% of the judges were those containing a lesser acid concentration. A reduction in glycerol sweetness when increasing acid levels was observed. Acetic acid reduced the sweetness of glycerol and inversely glycerol reduced the acidity of acetic acid. The data obtained with the magnitude estimation test agree with Steven’s law.Foram incorporados glicerol (17%), cloreto de sódio (1,5%) e sorbato de potássio (0.1%) nas seguintes porcentagens de ácido: 0,2; 0,4; 0,6; 0,8; 1 e 1,5% p/p, em um patê elaborado a partir de congro-real (Percophis brasiliensis) cozido, com o intuito de determinar a relação entre o ácido acético adicionado e a intensidade sensorialmente percebida, assim como o efeito da combinação dos gostos doce e ácido. Foram realizados testes de comparação pareada, de classificação e também estruturada uma escala verbal para os atributos ácido e doce, e testes psicofísicos. Foi percebida diferença entre as amostras com diferença de 0,4 unidades de concentração de ácido. As amostras indicadas como as mais doces por 89,47% dos julgadores foram as que continham menor concentração de ácido. Foi observada a redução da doçura do glicerol quando aumentaram os níveis de ácido. O ácido acético reduziu a doçura do glicerol e, inversamente, o glicerol reduziu a acidez do ácido acético. Os dados obtidos com o teste de estimação de magnitude concordaram com a lei de Steven

Osmotic dehydration of mackerel (Scomber japonicus) fillets by means of binary and ternary solutions

Osmotic dehydration of mackerel fillets was achieved by immersing them in binary and ternary solutions (NaCl/water or NaCl/sucrose/water). The kinetics of water loss and NaCl and sucrose gains were studied, as well as the accuracy of empirical models to explain these experimental behaviours. The results show how the presence of both solutes can enhance water loss and also interfere in each other’s diffusion. Among the three empirical models analyzed, Peleg’s equation proves to be the most suitable (R2 >0.836) to describe all the mass transfer process. A modified Peleg’s model was also obtained with a high performance to describe the relationship between water content of mackerel fillets and sucrose and NaCl concentration in binary and ternary solutions.Fil: Agustinelli, Silvina Paola. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salvadori, Viviana Olga. 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: 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; Argentin

Cold smoking of Lebranche mullet (Mugil liza): Physicochemical, sensory, and microbiological evaluation

The suitability of Mugil liza for cold smoking was evaluated and the effect of four different salting treatments on physicochemical, microbiological, and sensory characteristics was assessed. The addition of sucrose (3%) and acetic acid (0.5%) to the brine lead to fillet dehydration with lower NaCl penetration, combined with higher reduction of pH. Brining at refrigerated temperature (5 ± 1 ℃) instead of room temperature (16 ± 2 ℃) was more effective in preventing microbial growth. Loads of bacterial groups assessed in all smoked samples were below 100 CFU/g and the aw, moisture, NaCl, and pH values achieved were within the typical stability range of smoked fish products. The obtained products were characterized by the smoked aroma and salty taste, differing in 7 of the 21 evaluated descriptors. The use of acetic acid in brine formulation showed an effect over color and texture descriptors. The affective test indicated the overall acceptability of products, being preferred the samples treated in the lowest NaCl concentration (5%).Fil: Jiménez Lugo, Rolando Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; ArgentinaFil: Agustinelli, Silvina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; 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. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Preservación y Calidad de Alimentos; ArgentinaFil: Czerner, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; 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 & 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