Teor de nitrato e nitrito e análise microbiológica em linguiças e queijos
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Data
2016-05-10
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Oliveira, Eniz Conceição
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A utilização de sais de nitrato e nitrito em produtos cárneos é secular e, com a evolução das técnicas de conservação alimentar, estes vêm sendo cada dia mais utilizados, pois melhoram o sabor e a cor. Os objetivos deste estudo foram realizar análises microbiológicas, de atividade de água, pH, concentração de nitritos e nitratos presentes em amostras de linguiças (tipo mistos e suínos) com Inspeção do Serviço Municipal e queijos (tipo colonial e prato), fiscalizados pelos Serviços de Inspeção Municipal e Estadual, produzidos na região do Vale do Taquari, Rio Grande do Sul. As amostras de queijos Prato (n=14) e Colonial (n=10) foram adquiridas diretamente nas indústrias com Inspeção Sanitária Municipal (n=11) e Estadual (n=13), produzidas em municípios do Vale Taquari durante os meses de abril, maio e junho de 2013. Para a coleta das amostras houve o cuidado de mantê-las íntegras, com o mínimo de contato ou manipulação. As amostras de linguiça foram coletadas em 11 estabelecimentos fiscalizados pelo Sistema de Inspeção Municipal (SIM). Os teores residuais de nitratos e nitritos, pH e atividade de água das amostras foram avaliados segundo as metodologias analíticas oficiais previstas na Instrução Normativa n° 20, de 21 de julho de 1999, do Ministério da Agricultura, Pecuária e Abastecimento (MAPA). As análises microbiológicas foram realizadas em laboratório certificado no Ministério da Agricultura (MAPA), na Rede Metrológica do Rio Grande do Sul, cadastrado na Fundação Estadual de Proteção Ambiental (FEPAM) e com ISO 17025. As concentrações de nitrato e nitrito encontradas acima do recomendado pela legislação nas amostras foram de 33,3% (p=0,030) e 100% (p<0,001), respectivamente. Em 41,7% (n=10) e 25% (n=6) do total das amostras de queijo foram encontrados índices de contaminação por coliformes termotolerantes e Staphylococcus coagulase positiva acima do preconizado pela legislação, respectivamente, contudo não foi verificada diferença significativa para os valores encontrados em relação ao valor de referência, e 100% das amostras de queijo estavam isentas de Salmonella spp. Em relação as linguiças, 30,3% das amostras apresentaram teor de nitrito e 69,7% apresentaram teor de nitrato acima do previsto pela legislação brasileira. As médias de atividade de água e do teor de nitrato apresentaram-se significativamente acima do valor de referência. Enquanto as médias de pH não demonstrou diferença significativa em relação ao valor de referência e a média de nitrito apresentou-se inferior a legislação, mas com elevado desvio padrão. Conclui-se que a totalidade das amostras de queijo analisadas neste estudo apresentou concentrações acima do recomendado pela legislação para nitrito e um terço apresentou-se não conforme em relação à concentração de nitrato. Sobre a linguiça, foi observada inadequação ao que é determinado pela legislação brasileira em relação à quantidade de nitrito e nitrato, parâmetros microbiológicos de coliformes termotolerantes, Staphylococcus coagulase positiva e Salmonella spp., atividade de água, e adequação em relação ao pH.
The use of nitrate and nitrite salts in meat products is centuries old and with the development of food preservation techniques they are being more used every day because it improves flavor and color. The objective of this study were to perform the microbiological analysis, and also analysis of water activity, pH, concentration of nitrites and nitrates in sausage samples (mixed type and pigs) with inspection of the Municipal Service, and cheese (colonial type and plate), supervised by Service Municipal and State Inspection, produced in the region of Vale do Taquari, Rio Grande do Sul. The sample of plate cheese (n=14) and colonial (n=10) were acquired directly in industries with Municipal Sanitary Inspection (n=11) and State (n=13), produced in municipalities in the Taquari Valley during the months of April, May and June 2013. The samples were collected with care to keep them intact and a minimal contact or manipulation. The sausage samples were collected from 11 establishments inspected by the Municipal Inspection System. The samples' residual levels of nitrates and nitrites, pH and water activity were evaluated according to the official analytical methods provided by the Normative Ruling No. 20 of July 21, 1999, of Ministry of Agriculture, Livestock and Supply. The microbiological analyzes were performed in laboratory certified by Ministry of Agriculture in the Metrology Network of Rio Grande do Sul, registered in the State Environmental Protection Foundation, with ISO 17025. The nitrate and nitrite concentrations found above the recommended by the legislation in the samples was 33.3% (p=0.030) and 100% (p <0.001), respectively. In 41.7% (n = 10) and 25% (n = 6) of the total samples of cheese contamination rates were found by thermotolerant coliform and Staphylococcus coagulase positive above recommended by law, respectively, but there was no significant difference to those found in relation to the reference value and 100% of cheese samples were free of Salmonella spp. In relation to the sausages, 30.3% of the samples had nitrite content and 69.7% had nitrate levels higher than expected by Brazilian law. The average of water activity and nitrate levels were significantly above the reference value. While the average of pH showed no significant difference from the reference value and the nitrite average has performed under law, but with high standard deviation. It is concluded that all the cheese samples analyzed in this study had higher concentrations than recommended by law for nitrite and a third it is not in accordance to the concentration of nitrate. Regarding the sausage, it was observed inadequacy in relation to what is required by Brazilian law in relation to the amount of nitrite and nitrate, microbiological parameters of thermotolerant coliform, Staphylococcus coagulase positive and Salmonella spp., water activity and suitability in relation to the pH.
The use of nitrate and nitrite salts in meat products is centuries old and with the development of food preservation techniques they are being more used every day because it improves flavor and color. The objective of this study were to perform the microbiological analysis, and also analysis of water activity, pH, concentration of nitrites and nitrates in sausage samples (mixed type and pigs) with inspection of the Municipal Service, and cheese (colonial type and plate), supervised by Service Municipal and State Inspection, produced in the region of Vale do Taquari, Rio Grande do Sul. The sample of plate cheese (n=14) and colonial (n=10) were acquired directly in industries with Municipal Sanitary Inspection (n=11) and State (n=13), produced in municipalities in the Taquari Valley during the months of April, May and June 2013. The samples were collected with care to keep them intact and a minimal contact or manipulation. The sausage samples were collected from 11 establishments inspected by the Municipal Inspection System. The samples' residual levels of nitrates and nitrites, pH and water activity were evaluated according to the official analytical methods provided by the Normative Ruling No. 20 of July 21, 1999, of Ministry of Agriculture, Livestock and Supply. The microbiological analyzes were performed in laboratory certified by Ministry of Agriculture in the Metrology Network of Rio Grande do Sul, registered in the State Environmental Protection Foundation, with ISO 17025. The nitrate and nitrite concentrations found above the recommended by the legislation in the samples was 33.3% (p=0.030) and 100% (p <0.001), respectively. In 41.7% (n = 10) and 25% (n = 6) of the total samples of cheese contamination rates were found by thermotolerant coliform and Staphylococcus coagulase positive above recommended by law, respectively, but there was no significant difference to those found in relation to the reference value and 100% of cheese samples were free of Salmonella spp. In relation to the sausages, 30.3% of the samples had nitrite content and 69.7% had nitrate levels higher than expected by Brazilian law. The average of water activity and nitrate levels were significantly above the reference value. While the average of pH showed no significant difference from the reference value and the nitrite average has performed under law, but with high standard deviation. It is concluded that all the cheese samples analyzed in this study had higher concentrations than recommended by law for nitrite and a third it is not in accordance to the concentration of nitrate. Regarding the sausage, it was observed inadequacy in relation to what is required by Brazilian law in relation to the amount of nitrite and nitrate, microbiological parameters of thermotolerant coliform, Staphylococcus coagulase positive and Salmonella spp., water activity and suitability in relation to the pH.
Descrição
Palavras-chave
Microbiologia; Nitrito; Conservantes de alimentos; Queijo; Produtos cárneos
Citação
ADAMI, Fernanda Scherer. Teor de nitrato e nitrito e análise microbiológica em linguiças e queijos. 2015. Tese (Doutorado) – Curso de Ambiente e Desenvolvimento, Universidade do Vale do Taquari - Univates, Lajeado, 30 out. 2015. Disponível em: http://hdl.handle.net/10737/985.