RESUMEN
El objetivo del presente estudio fue evaluar la calidad bacteriológica de lechugas comercializadas en el Área Metropolitana de San José, Costa Rica y cultivadas de diversas maneras, con el fin de discernir diferencias entre los métodos de cultivo y el riesgo a la Salud Pública que estos productos pueden representar. El estudio se llevó a cabo en el Laboratorio de Microbiología de Alimentos de la Facultad de Microbiología, Universidad de Costa Rica, durante los meses de marzo a julio, 2010. Se analizaron 30 muestras de lechuga (10 cultivadas por el método tradicional, tradicional, 10 de cultivo orgánico y 10 producidas mediante hidroponía). Cada muestra fue adquirida en supermercados donde se certifica el origen de las mismas. A cada muestra se le determinó el recuento total de aerobios mesófilos aerobio, recuento de coliformes totales, fecales y de Escherichia coli, así como la presencia/ausencia en 25 g de Salmonella spp. y Listeria monocytogenes. Los resultados obtenidos demuestran que no existe una diferencia, estadísticamente significativa (p>0,001) entre los diferentes tipos de cultivo para ninguno de los parámetros evaluados. Un porcentaje importante de las muestras presentó colifomes, no obstante, únicamente se aisló una cepa de Escherichia coli, a partir de una lechuga cultivada de manera tradicional. Se logró aislar cuatro cepas de Salmonella spp así como una cepa de Listeria monocytogenes. Los datos obtenidos permiten evidenciar el hecho de que el consumo del producto crudo y sin una adecuada limpieza y desinfección representa un riesgo para la salud del consumidor, así como que no existe, desde el punto de vista bacteriológico, una diferencia significativa entre el cultivo tradicional, orgánico e hidropónico de la lechuga, lo que hace suponer que no se siguen los lineamientos específicos de cada tipo de cultivo, o se da un mal manejo y contaminación post cosecha en los productos.
The main objective of this work was to evaluate the microbiological quality of lettuces commercialized in the Metropolitan Area of San José, Costa Rica, and cultured in different ways, in order to detect differences between the culturing methods and the risk that these products may represent for Public Health. The study was done at the Food Microbiology Laboratory, Universidad de Costa Rica, from March to July, 2010. 30 lettuce samples were analyzed (10 obtained by traditional culture, 10 by organic culture and 10 by hydropony). All samples were obtained from markets where their origin was certified. Total aerobic plate count, total and fecal coliforms count and Escherichia coli were determined to all samples, as well as the presence/abscense of Salmonella spp. and Listeria monocytogenes in 25 g. Results obtained show that there is no statistically significant difference (pE. coli strain was isolated from a traditionally cultured lettuce sample. Four different Salmonella spp. strains were isolated from the samples as well as one Listeria monocytogenes strain. Data obtained show that the consumption of this product, raw or without an adequate hygiene and disinfection may represent a risk for health. Also, from the bacteriological point of view, there is no significant difference between the culturing methods evaluated, suggesting that the specific directions for each type of culture are not followed or that there is an inadequate handling of the products or post harvest contamination.
Asunto(s)
Microbiología de Alimentos , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Hidroponía , Lactuca/microbiología , Agricultura/métodos , Costa Rica , Agricultura OrgánicaRESUMEN
Conduziu-se este este trabalho, com o objetivo de estudar a viabilidade econômica da babosa e verificar se o cultivo desta planta é ou não, uma alternativa economicamente viável ao produtor rural. Os dados relativos ao custo de produção, utilizados neste trabalho, foram obtidos junto às áreas de produção e instalações industriais da NATURAMA - Indústria e Comércio de Produtos Agropecuários Ltda, estabelecida no município de Paulo Lopes, SC. Na determinação do custo de produção de um hectare de babosa, em cultivo orgânico, foram consideradas todas as etapas, desde a obtenção das mudas até a conclusão do processamento, quando o produto final encontra-se apto ao consumo, e neste caso, é uma bebida em forma de suco. O processamento dos dados foi realizado utilizando uma planilha eletrônica desenvolvida especificamente para esse fim, a qual estimou os custos utilizando as metodologias do custo total (custos fixos e variáveis) e do custo operacional total (custo operacional efetivo e depreciações). Pela análise da rentabilidade, conclui-se que a atividade é economicamente viável.
The aim of this work is to study the economic viability of Aloe vera L. and verify if the culture of this plant is or not an alternative economically viable for the farmer. The data of production cost used in this work were gotten in the areas of production and industrial installations of NATURAMA- Industry and Trade of Farming Products LTDA, settled in Paulo Lopes, SC. In the determination of the production cost of one Aloe vera L hectare, all the phases were taken into consideration, from the getting of molts up to the conclusion of the processing, when the final product is ready to the consumption, and in this case, it's a beverage in a way of juice. The processing data was made by using an electronic spread sheet developed specifically for this reason, which estimated the costs using the methodologies of the total cost (steady and variable costs) and of the total operational cost (effective operational cost and depreciations). By analyzing the profitability, it was concluded that the activity is economically viable.
RESUMEN
Objective: To explore the effects of zinc on bone development in vitro. Methods: Mice of 16 gestation were killed by snapping cervical vertebra, and the front limbs were cut off and cultured in basic medium. Which contained 20 ?mol/L Zn 2+ (control group). In Zn deprived group, the basic medium was added TPEN to final concentration 20 ?mol/L. In other three groups, the basic medium was added ZnSO 4 to final concentration of Zn 2+ at 45, 70, and 120 ?mol/L respectively. Results: 1. Compared with control limb(uncultivated),the test limb(cultivated for 6 d)showed longer bone length and higher bone density.Histological analysis showed active bone cell differentiation, proliferation, increased bone trabecula.2.Compared with control group, the Zn-deprived and Zn 2+ 120 ?mol/L group expressed decreased osteocalcin (OC) and 45 Ca content and lower activity of AKP; Zn 2+ 45 ?mol/L and 70 ?mol/L group presented increased OC and 45 Ca content and higher activity of AKP.3.Compared with the control group, Zn-deprived and Zn 2+ 120?mol/L group showed shorter bone length and lower bone density; Zn 2+ 45 ?mol/L and 70?mol/L group showed longer bone length and higher bone density. Conclusion: Zinc is involved in bone metabolism and growth; both zinc-deficiency and zinc-excess can alter bone growth and normal metabolism.