Liberação das enzimas LDH e PepX e evolução da maturação de queijo parmesão adicionado de culturas autolíticas de Lactobacilus helveticus
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Data
2009-02-17
Autores
Azevedo, Analice Cláudia de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O parmesão é um queijo típico italiano e possui como características peculiares o baixo teor de umidade, a textura granular e o sabor picante. Seu processamento é sempre lembrado pelo longo período de maturação e durante esta etapa ocorrem numerosas reações bioquímicas de degradação de seus componentes pelas enzimas oriundas do leite e do coalho e daquelas produzidas pelas bactérias, causando mudanças na textura e sabor desse produto. A autólise espontânea de microrganismos termófilos, como Lactobacillus helveticus, é uma característica tecnológica importante para a escolha de culturas com potencial de aplicação na fabricação de queijos de massa dura como o Parmesão. Desta forma o objetivo do presente trabalho é avaliar, durante a maturação do queijo Parmesão, o desempenho autolítico de culturas de Lb. helveticus autóctones, previamente isoladas de soro fermento. Foram utilizadas as culturas autóctones de Lb. helveticus, E5 com perfil autolítico elevado e A e D1 com perfil autolítico intermediário. A cultura comercial Cc1 (Lh-B02, Chr. Hansen) com perfil autolítico elevado foi utilizada como controle. A atividade das enzimas intracelulares LDH e PepX, bem como a viabilidade foram realizadas durante 48 horas de crescimento das culturas. Após a elaboração dos queijos com as diferentes culturas, mensalmente, foi determinada a contagem de lactobacilos termófilos, a atividade das enzimas LDH e PepX, a evolução dos teores de acidez, tirosina, triptofano e índice de maturação no queijo Parmesão ao longo de 180 dias de maturação. A maior liberação das enzimas LDH e PepX in vitro foi observada na cultura comercial Cc1 e autóctone E5 e comportamento semelhante entre as análises de CDM e cultivo em placa foi observado apenas para a cultura autóctone A e cultivo comercial Cc1. A maior população de lactobacilos termófilos nos queijos experimentais...
The Parmesan is a typical Italian cheese and has peculiar characteristics such as low moisture level, a granular texture and spicy flavor. Its processing involves long period of ripening and during this stage there are many biochemical reactions produced by enzymes from the raw milk, rennet and those produced by bacteria, resulting in changes in texture and taste of this product. The spontaneous autolysis of thermophilous microorganisms, such as Lactobacillus helveticus, is an important technological feature for the choice of cultures with potential application in the production of hard cheeses, such as Parmesan. The objective of this study was to assess the autolytic performance of cultures of autochthonous Lb. helveticus, previously isolated from natural whey starter during the ripening of Parmesan cheese. Autochthonous cultures of Lb. helveticus, E5 with high autolytic profile and A and D1 with intermediary autolytic profile were used. The commercial culture Cc1 (Lh-B02, Chr. Hansen) with high autolitic profile was used as control. The activity of in situ intracellular enzymes LDH and PepX, and the cell viability after 48 hours of growth were determined. Every month during the 180 days of ripening the population of thermophilous lactobacilli, the activity of enzymes LDH and PepX, the acidity, tyrosine, tryptophan contents and the index of ripening on Parmesan cheese were determined. The highest release in vitro of the LDH and PepX enzymes was observed in the commercial culture Cc1 and autocthonous E5 and similar culture A and the commercial culture Cc1. The highest population of thermophilous lactobacilli in the experimental cheeses was observed at the 30 days of ripening. In all cheeses samples it was observed in the cheeses produced with cultures with higher autolytic profile. There was a significant increase in acidity, tyrosine and tryptophan contents and IR in all samples... (Complete abstract click electronic access below)
The Parmesan is a typical Italian cheese and has peculiar characteristics such as low moisture level, a granular texture and spicy flavor. Its processing involves long period of ripening and during this stage there are many biochemical reactions produced by enzymes from the raw milk, rennet and those produced by bacteria, resulting in changes in texture and taste of this product. The spontaneous autolysis of thermophilous microorganisms, such as Lactobacillus helveticus, is an important technological feature for the choice of cultures with potential application in the production of hard cheeses, such as Parmesan. The objective of this study was to assess the autolytic performance of cultures of autochthonous Lb. helveticus, previously isolated from natural whey starter during the ripening of Parmesan cheese. Autochthonous cultures of Lb. helveticus, E5 with high autolytic profile and A and D1 with intermediary autolytic profile were used. The commercial culture Cc1 (Lh-B02, Chr. Hansen) with high autolitic profile was used as control. The activity of in situ intracellular enzymes LDH and PepX, and the cell viability after 48 hours of growth were determined. Every month during the 180 days of ripening the population of thermophilous lactobacilli, the activity of enzymes LDH and PepX, the acidity, tyrosine, tryptophan contents and the index of ripening on Parmesan cheese were determined. The highest release in vitro of the LDH and PepX enzymes was observed in the commercial culture Cc1 and autocthonous E5 and similar culture A and the commercial culture Cc1. The highest population of thermophilous lactobacilli in the experimental cheeses was observed at the 30 days of ripening. In all cheeses samples it was observed in the cheeses produced with cultures with higher autolytic profile. There was a significant increase in acidity, tyrosine and tryptophan contents and IR in all samples... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Tecnologia de alimentos, Queijo parmesão - Indústria, Lactobacilo, Lactobacillus helveticus, Queijo parmesão - Maturação, Autolysis, Direct counting by microscopy, Parmesan, LDH and PepX
Como citar
AZEVEDO, Analice Cláudia de. Liberação das enzimas LDH e PepX e evolução da maturação de queijo parmesão adicionado de culturas autolíticas de Lactobacilus helveticus. 2009. 64 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências, Letras e Ciências Exatas, 2009.