[Total bacterial count in raw milk from the dairy farms that characterize the zone northwest of Santa Fe and south of Santiago del Estero]. / Recuento de bacterias totales en leche cruda de tambos que caracterizan la zona noroeste de Santa Fe y sur de Santiago del Estero.

A total of 6,998 raw milk samples of bulk tank, belonging to 55 dairy farms associated to the Cooperativa Tambera Nueva Alpina Ltda., were collected between the years 1993 and 2002. The Total Mesophilic Aerobic Microorganisms Count was analyzed, obtaining a medium value of 1.2 x 10(5) +/- 2.4 x 10(5) CFU/ml that characterizes the zone. The final year of experience, observed a 97% of dairy farms evaluated with averages < or = 1.0 x 10(5) CFU/ml. Only a 3% it surpasses this limit, not being found establishments with levels over 1.5 x 10(5) CFU/ml. Relating this indicators with compositionals parameters, the most significant correlation resulted for: Total Bacterial Count vs Acidity (r = 0.292; P < 0.001) and Total Bacterial Count vs Freezing Point (r = 0.157; P < 0.001. The microbiological quality in raw milk of dairy farms belonging to the northwest zone of Santa Fe and south of Santiago del Estero showed a significant improvement during this time.

Recuento de bacterias totales en leche cruda de tambos que caracterizan la zona noroeste de Santa Fe y sur de Santiago del Estero / Total bacterial count in raw milk of dairy farms that characterize the northwest zone of Santa Fe and south of Santiago del Estero

Un total de 6.998 muestras de leche cruda de pool de tanque, correspondientes a 55 establecimientos lecheros asociados a la Cooperativa Tambera Nueva Alpina Ltda., fueron recolectadas entre los años 1993 y 2002. Se realizó el Recuento de Microorganismos Aerobios Mesófilos Totales, obteniéndose como resultado un valor medio de 1,2 x 105± 2,4 x 105UFC/ml que caracteriza la zona. El año de finalización de la experiencia, se observó un 97% de los tambos evaluados con promedios £ 1,0 x 105UFC/ml. Solamente un 3% sobrepasa este límite, no encontrándose establecimientos con niveles superiores a 1,5 x 105UFC/ml. Al relacionar este indicador con parámetros composicionales, las correlaciones más significativas resultaron para: Recuento de Bacterias Totales vs Acidez (r = 0,292; P < 0,001) y Recuento de Bacterias Totales vs Descenso Crioscópico (r = 0,157; P < 0,001). La calidad microbiológica en leche cruda de tambos que pertenecen a la zona noroeste de Santa Fe y sur de Santiago del Estero, presentó un mejoramiento significativo.

A total of 6.998 raw milk samples of bulk tank, belonging to 55 dairy farms associated to the Cooperativa Tambera Nueva Alpina Ltda., were collected between the years 1993 and 2002. The Total Mesophilic Aerobic Microorganisms Count was analyzed, obtaining a medium value of 1.2 x 105± 2.4 x 105CFU/ml that characterizes the zone. The final year of experience, observed a 97% of dairy farms evaluated with averages £ 1,0 x 105CFU/ml. Only a 3% it surpasses this limit, not being found establishments with levels over 1.5 x 105CFU/ml. Relating this indicators with compositionals parameters, the most significant correlation resulted for: Total Bacterial Count vs Acidity (r = 0.292; P < 0.001) and Total Bacterial Count vs Freezing Point (r = 0.157; P < 0.001. The microbiological quality in raw milk of dairy farms belonging to the northwest zone of Santa Fe and south of Santiago del Estero showed a significant improvement during this time.

Recuento de bacterias totales en leche cruda de tambos que caracterizan la zona noroeste de Santa Fe y sur de Santiago del Estero. / [Total bacterial count in raw milk from the dairy farms that characterize the zone northwest of Santa Fe and south of Santiago del Estero]

A total of 6,998 raw milk samples of bulk tank, belonging to 55 dairy farms associated to the Cooperativa Tambera Nueva Alpina Ltda., were collected between the years 1993 and 2002. The Total Mesophilic Aerobic Microorganisms Count was analyzed, obtaining a medium value of 1.2 x 10(5) +/- 2.4 x 10(5) CFU/ml that characterizes the zone. The final year of experience, observed a 97

of dairy farms evaluated with averages < or = 1.0 x 10(5) CFU/ml. Only a 3

it surpasses this limit, not being found establishments with levels over 1.5 x 10(5) CFU/ml. Relating this indicators with compositionals parameters, the most significant correlation resulted for: Total Bacterial Count vs Acidity (r = 0.292; P < 0.001) and Total Bacterial Count vs Freezing Point (r = 0.157; P < 0.001. The microbiological quality in raw milk of dairy farms belonging to the northwest zone of Santa Fe and south of Santiago del Estero showed a significant improvement during this time.

Potencialidades y limitaciones del uso de recursos multimediales en la enseñanza de anatomía veterinaria / Potentiality and limitations in the use of multimedial resources in the teaching of veterinary anatomy

El presente trabajo persigue el propósito de demostrar las potencialidades de los recursos multimediales utilizados como herramientas complementarias a los materiales usados de manera tradicional, durante el proceso de enseñanza-aprendizaje de Anatomía Veterinaria. Asimismo, pretende evidenciar el impacto que dichos soportes producen en la motivación de los alumnos, frente a las tareas áulicas, así como en instancias de aprendizaje autónomo. La experiencia se lleva a cabo en el marco de un proyecto de investigación educativa, desarrollado en la Universidad Nacional del Litoral (Argentina) por docentes de la cátedra de Anatomía Veterinaria, en articulación con docentes de la cátera homónima de la Universidad de Zaragoza (España). A través de la investigación, se procura evaluar los resultados de aprendizaje de los alumnos ante esta innovación didáctica y metodológica. Las entidades educativas involucradas interactúan entre sí mediante la comunicación electrónica. En tal sentido, se destaca que la producción de los recursos multimediales es desarrollada en Zaragoza y la etapa experimental de dicha investigación se lleva a cabo en ambos contextos educativos

[Nutritional study relative to proteins, energy, and calcium in children eating school meals]. / Estudio nutricional relativo a proteínas, energía y calcio en niños que concurren a comedor escolar.

Food consumption and nutritional status were evaluated on 419 children having meals at school located in the surrounding of Santa Fe (Argentina). The protein, energy and calcium content of the meals were analyzed. Anthropometrical evaluation was made by the following indicators: weight to age, height to age and weight to height. Biochemical evaluation to a sample of the children, was made by urea/creatinine and calcium/creatinine indicators. Recommended protein consumption is achieved but a biological efficiency loss is detected, probably due to an insufficient energy intake. School meals provide about 50% of the daily energy requirements. Regarding calcium consumption, the dinner cover about 15% of the recommendations but they achieve 47-49% with the cup of milk. As in the case of energy, the calcium daily intake is insufficient as we can see by the calcium/creatinine indicator which shows that a 60% of the people are below of the normal values. All these results suggest that is necessary to increase the energy intake and calcium consumption to improve the nutritional status.

Efectos del uso de tecnologías de imagen en el aprendizaje de materiales fácticos en los estudiantes de anatomía veterinaria / The effects of the use of image technologies in the learning of factic subjects upon students of veterinary anatomy

En el presente trabajo se incluyen los resultados de una investigación educativa aplicada en dos grupos experimentales y uno control de alummos, realizada en la cátedra de Anatomía Veterinaria, en la que se estudió los efectos sobre el aprendizaje y su perdurabilidad mediante el uso de un vídeo educativo con imágenes tridimensionales computarizadas del colon mayor del caballo

[Thermal inactivation of the enzymes polyphenoloxidase and peroxidase in Swiss chard (Beta vulgaris, cicla)]. / Inactivación térmica de las enzimas polifenoloxidasa y peroxidasa en acelga (Beta vulgaris, cicla).

The freezing of Swiss chard has just started in Argentina. The blanching stage is fundamentally important to avoid damage of sensorial and nutritional properties during storage. If the process is not properly carried out, darkening can seriously affect the product. In this research work the thermal inactivation of polyphenoloxidase and peroxidase enzymes has been studied, in water at 80, 90 and 96 degrees C, as well as the polyphenoloxidase isoenzymes in the spear and leaf of the plant and the water-holding capacity after thermal treatment. Blanching has to be performed at a temperature higher than 90 degrees C in order to inactivate the enzyme polyphenoloxidase at a suitable rate which will avoid the formation of the characteristic colored substances.

Inactivacion termica de las enzimas polifenoloxidasa y peroxidasa en Acelga (Beta vulgaris, cicla). / Thermal inactivation of the enzymes polyphenoloxidase and peroxidase in Swiss chard (Beta vulgaris, cicla)

La acelga (Beta vulgaris, cicla), es una verdura de hoja cuyo procesamiento por congelacion se inicio recientemente en Argentina. La etapa de escaldado es de especial importancia para evitar el deterioro de sus atributos sensoriales durante el almacenamiento. Si dicha operacion no se realiza adecuadamente, puede producirse un oscurecimiento que devaloriza significativamente el producto. Este trabajo tuvo por objeto estudiar la inactivacion termica en agua a 80oC, 90oC, y 96oC, de las enzimas polifenoloxidasa y peroxidasa, asi como las isoenzimas de la polifenoloxidasa en penca o tallo y hoja. Se investigo tambien la capacidad de retencion de agua, despues del tratamiento termico y del enfriamiento correspondiente. Se determino que es necesario llevar a cabo el escaldado a una temperatura mayor de 90oC, a efecto de inactivar rapidamente la enzima polifenoloxidasa, y evitar asi que los compuestos quimicos formados en la reaccion catalizada por dicha enzima, reaccionen a su vez y formen las sustancias coloreadas caracteristicas