Características químicas, microbiológicas e sensoriais de leite de cabra congelado
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Data
1997-08-01
Autores
Gomes, Maria Isabel F.Vasconcelos [UNESP]
Bonassi, Ismael Antonio [UNESP]
Roça, Roberto de Oliveira [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Resumo
O objetivo deste trabalho foi avaliar as modificações químicas, microbiológicas e sensoriais do leite caprino pasteurizado e congelado durante armazenamento por 90 dias. Foram realizadas análises para caracterização química da matéria prima utilizada nos experimentos (gordura, acidez Dornic, densidade, extrato seco total, pH e ácidos graxos livres-AGL) e caracterização microbiológica (contagem total, psicrotróficos, coliformes totais e fecais). Utilizou-se pasteurização lenta a 63°±1°C por 30 minutos para as amostras de leite seguido de armazenamento em freezer à temperatura de -18°C±1°C. Nos tempos 0, 30, 60 e 90 dias de congelamento foram efetuadas análises químicas (pH, acidez e AGL), microbiológicas (contagem total, psicrotróficos e coliformes) e sensoriais (sabor e aroma característico, sabor e odor estranho e aparência geral). Também, realizou-se análise sensorial do leite nos tempos zero e com 90 dias de armazenamento, após descongelamento e homogeneização em liquidificador por dois minutos. Foi observado que o congelamento prolongado do leite pasteurizado não alterou significativamente suas características químicas e microbiológicas. Apenas a acidez apresentou decréscimo significativo. No entanto, a qualidade do leite do ponto de vista sensorial apresentou modificações significativas, com perdas de sabor e aroma característicos e declínio acentuado da aparência geral durante o armazenamento. A homogeneização do leite em liquidificador, após o descongelamento melhorou a aparência geral e a aceitação do produto pela equipe de provadores.
The aim of this work was evaluate the chemical, microbiological and sensorials modifications of the pasteurized caprine milk, stored frozen by 90 days. Were realized analyses for the chemical caracterization of the pile used in the experiments (fat, Dornic acidity, density, total dry extract, pH and free fatty acids) and microbiological caracterization (total count, psychrotrofics, total and fecals coliforms). Slow pasteurization at 63°±1°C by 30 minutes was applied to the milk samples, followed by storage in freeze under a temperature of -18°±1°C. Were realized chemical analysis (pH, acidity and FFA), microbiologicals (total counts, psychrotrofics and coliformes) and sensorials (taste, characteristc flavor, taste, strange smell and general aspect) at 0, 30, 60, 90 days of freezing. It was also realized milk sensorial analysis at 0 and 90 days of storage, after thawing and homogenization in blender during two minutes. It was observed that the prolonged freezing of the pasterized milk did not altered significantly its chemical and microbiological characteristics. Only acidity showed significant decrease. Nevertheless, the milk quality from the sensorial point of view, presented significants modifications, with damage of characteristics taste and flavour and accentuated decrease of the general aspect during the storage. The milk homogenization in blender, after thawing improve the general aspect and the product acceptacion by the sensorial panel.
The aim of this work was evaluate the chemical, microbiological and sensorials modifications of the pasteurized caprine milk, stored frozen by 90 days. Were realized analyses for the chemical caracterization of the pile used in the experiments (fat, Dornic acidity, density, total dry extract, pH and free fatty acids) and microbiological caracterization (total count, psychrotrofics, total and fecals coliforms). Slow pasteurization at 63°±1°C by 30 minutes was applied to the milk samples, followed by storage in freeze under a temperature of -18°±1°C. Were realized chemical analysis (pH, acidity and FFA), microbiologicals (total counts, psychrotrofics and coliformes) and sensorials (taste, characteristc flavor, taste, strange smell and general aspect) at 0, 30, 60, 90 days of freezing. It was also realized milk sensorial analysis at 0 and 90 days of storage, after thawing and homogenization in blender during two minutes. It was observed that the prolonged freezing of the pasterized milk did not altered significantly its chemical and microbiological characteristics. Only acidity showed significant decrease. Nevertheless, the milk quality from the sensorial point of view, presented significants modifications, with damage of characteristics taste and flavour and accentuated decrease of the general aspect during the storage. The milk homogenization in blender, after thawing improve the general aspect and the product acceptacion by the sensorial panel.
Descrição
Palavras-chave
leite de cabra congelado, armazenamento, modificações, qualidade, freezed goat milk, stored, modifications-quality
Como citar
Food Science and Technology (Campinas). Sociedade Brasileira de Ciência e Tecnologia de Alimentos, v. 17, n. 2, p. 111-114, 1997.