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Abstract(s)
O estudo da vida útil de um produto alimentar é fundamental para o desenvolvimento e fornecimento de alimentos seguros e com qualidade. O desperdício alimentar que resulta da rejeição de alimentos em condições para consumo e o seu impacto nas quebras financeiras de uma empresa alimentar, foi uma das bases para a realização do presente estudo. Neste trabalho, avaliou-se a possibilidade de aumentar o tempo de vida útil de dois produtos (queijo fresco de cabra e fiambre da pá) durante o período de permanência na secção de charcutaria, após abertura da embalagem original e depois de fatiados. Simularam-se as condições após abertura do produto e utilizaram-se duas temperaturas de armazenamento: 4 ºC como temperatura recomendada e 10 ºC como temperatura de abuso. O estudo do tempo de vida dos produtos foi feito com base nos resultados de análises microbiológicas (Listeria monocytogenes, Enterobacteriaceae e bactérias do ácido lático), sensoriais e físico-químicas (aw e pH) durante um período de 72 horas de armazenamento a 4ºC e a 10 ºC. Realizou-se também um teste de desafio (challenge testing) por inoculação de L. monocytogenes nos dois produtos, de modo a analisar o seu comportamento durante as 72 horas. Para além disso, realizou-se uma experiência laboratorial para determinar mecanismos de inibição, provenientes de bactérias do ácido lático, dos dois produtos, no crescimento de L. monocytogenes. Com base nos resultados obtidos da análise sensorial, verificou-se que os produtos não apresentam qualquer alteração nas suas características organoléticas após 24 horas de armazenamento. No entanto, ao fim de 72 horas e nas amostras armazenadas a 10 ºC, detetou-se um odor ácido não característico e no caso do fiambre da pá, a presença de soro em torno do produto. Relativamente às determinações físico químicas, não se verificaram alterações nos parâmetros valor de pH e aw nos produtos após 72 horas. As análises microbiológicas de L. monocytogenes determinaram que não existe qualquer evidência destes microrganismos nos dois produtos. Em relação às restantes análises microbiológicas, verificou-se também que as contagens de Enterobacteriaceae no queijo fresco de cabra se encontram acima dos limites definidos pela autoridade de controlo. Relativamente ao crescimento de bactérias do ácido lático isoladas dos dois produtos de charcutaria, não se registou qualquer evidência de um mecanismo de inibição no crescimento de L. monocytogenes por parte destes microrganismos. Verificou-se que a extensão do período de validade indicativa de 72 horas é uma possibilidade para o fiambre da pá, no entanto, no caso do queijo fresco, determinou-se que o produto não cumpre com os requisitos microbiológicos estabelecidos logo no primeiro dia de análise, o que impede a avaliação desta extensão de validade.
The study of shelf life in food products has a vital role in the development and supply of safe and good quality products for consumption. The waste of food products that are safe and meet the quality standards and the financial loss that this represents on a food company, was one of the reasons for carrying out the present study. The aim of this report was to evaluate the shelf life of two charcuterie products: fresh goat cheese and dry cured pork ham after slicing and during their stay at the charcuterie section. The studies developed on these products were made considering their durability in the respective retail section of 24-hours. The experimental work was made by replicating the opening conditions of the 2 products and two storage temperatures were used: 4 ºC as the recommended temperature and 10 ºC as the abuse temperature. The determination of the life span of the products was based on the results of microbiological (Enterobacteriaceae, Lactic Acid Bacteria and Listeria monocytogenes), sensory and physical-chemical (aw and pH) analyzes during a period of 72 hours and storage at 4ºC and 10ºC. A challenge test was also carried out by inoculation of Listeria monocytogenes in both products, in order to evaluate its behavior for 72 hours. It was also tested if the presence of lactic acid bacteria isolated from both products could provide some sort of inhibition mechanism against L. monoyctogenes growth. The sensory analysis results showed that the products do not show any change in their organoleptic characteristics after 24 hours of storage. However, after 72 hours in the samples stored at 10 ºC, an acidic smell was detected in both products. In the samples of dry cured ham stored at 10 ºC and after 72 hours, the release of serum surrounding the the product was detected. Regarding the physical and chemical determinations, there were no changes in the pH and aw parameters in the products after 24 hours. The data collected from the microbiological analyzes indicated that there was no evidence of growth of L. monocytogenes in the products. Regarding the results of the remaining microbiological analyzes, it was also found that fresh goat cheese surpasses the limits of Enterobacteriaceae counts defined by the quality department in charge. In the experiment performed with Lactic Acid Bacteria isolated from the two products, it was determined that the presence of these microorganisms does not have a role in the inhibition of growth of L. monocytogenes. With this study, it was found that the extension of the self-life of 72 hours for dry cured pork ham is a possibility, however, in the case of fresh goat cheese, it was determined that the product does not comply with the established microbiological requirements, on the first day of analysis, which prevents the evaluation of this extension of shelf life.
The study of shelf life in food products has a vital role in the development and supply of safe and good quality products for consumption. The waste of food products that are safe and meet the quality standards and the financial loss that this represents on a food company, was one of the reasons for carrying out the present study. The aim of this report was to evaluate the shelf life of two charcuterie products: fresh goat cheese and dry cured pork ham after slicing and during their stay at the charcuterie section. The studies developed on these products were made considering their durability in the respective retail section of 24-hours. The experimental work was made by replicating the opening conditions of the 2 products and two storage temperatures were used: 4 ºC as the recommended temperature and 10 ºC as the abuse temperature. The determination of the life span of the products was based on the results of microbiological (Enterobacteriaceae, Lactic Acid Bacteria and Listeria monocytogenes), sensory and physical-chemical (aw and pH) analyzes during a period of 72 hours and storage at 4ºC and 10ºC. A challenge test was also carried out by inoculation of Listeria monocytogenes in both products, in order to evaluate its behavior for 72 hours. It was also tested if the presence of lactic acid bacteria isolated from both products could provide some sort of inhibition mechanism against L. monoyctogenes growth. The sensory analysis results showed that the products do not show any change in their organoleptic characteristics after 24 hours of storage. However, after 72 hours in the samples stored at 10 ºC, an acidic smell was detected in both products. In the samples of dry cured ham stored at 10 ºC and after 72 hours, the release of serum surrounding the the product was detected. Regarding the physical and chemical determinations, there were no changes in the pH and aw parameters in the products after 24 hours. The data collected from the microbiological analyzes indicated that there was no evidence of growth of L. monocytogenes in the products. Regarding the results of the remaining microbiological analyzes, it was also found that fresh goat cheese surpasses the limits of Enterobacteriaceae counts defined by the quality department in charge. In the experiment performed with Lactic Acid Bacteria isolated from the two products, it was determined that the presence of these microorganisms does not have a role in the inhibition of growth of L. monocytogenes. With this study, it was found that the extension of the self-life of 72 hours for dry cured pork ham is a possibility, however, in the case of fresh goat cheese, it was determined that the product does not comply with the established microbiological requirements, on the first day of analysis, which prevents the evaluation of this extension of shelf life.
Description
Keywords
Vida útil Produtos de charcutaria Microbiologia Fiambre Queijo fresco de cabra Shelf life Charcuterie products Microbiology Dry cured ham Fresh goat cheese