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Sensory quality of French cheese Brie de Meaux in connection with chemical and microbial composition
Májková, Monika ; Němcová, Andrea (referee) ; Vítová, Eva (advisor)
This thesis deals with the assessment of the effect of storage of French Brie de Meaux (AOC) on its volatile (aromatic) compounds, free and bound fatty acids and microbial composition, in relation to its sensory quality. The theoretical part is devoted to cheeses with white mould on the surface. In the experimental part, the influence of temperature and storage time on the sensory quality and safety of cheese is assessed. In the storage experiment, the cheeses were stored for 21 days at 5 °C (one bulk, one vacuumed) and at 20 °C. The samples were evaluated by SPME-GC-MS for volatile (aromatic) compounds. Fatty acids were identified and quantified by GC-FID after conversion to methyl esters using BF3. RT-PCR method was used for microbial profile. Fifty-nine volatile compounds were identified in the samples and contribute to the flavour characteristics of the cheese. Among the fatty acids, palmitic, oleic, myristic and stearic acids were predominant. The microbial profile confirmed Micrococcus luteus as a contaminant in cheese stored at 20°C, while the other contaminants were not detected positively. From a sensory point of view, the standard cheese (analysed immediately after purchase) together with cheese stored at 5 °C in vacuum form for 21 days was the best performing cheese.
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Sensory quality of French cheese Brie de Meaux in connection with chemical and microbial composition
Májková, Monika ; Němcová, Andrea (referee) ; Vítová, Eva (advisor)
This thesis deals with the assessment of the effect of storage of French Brie de Meaux (AOC) on its volatile (aromatic) compounds, free and bound fatty acids and microbial composition, in relation to its sensory quality. The theoretical part is devoted to cheeses with white mould on the surface. In the experimental part, the influence of temperature and storage time on the sensory quality and safety of cheese is assessed. In the storage experiment, the cheeses were stored for 21 days at 5 °C (one bulk, one vacuumed) and at 20 °C. The samples were evaluated by SPME-GC-MS for volatile (aromatic) compounds. Fatty acids were identified and quantified by GC-FID after conversion to methyl esters using BF3. RT-PCR method was used for microbial profile. Fifty-nine volatile compounds were identified in the samples and contribute to the flavour characteristics of the cheese. Among the fatty acids, palmitic, oleic, myristic and stearic acids were predominant. The microbial profile confirmed Micrococcus luteus as a contaminant in cheese stored at 20°C, while the other contaminants were not detected positively. From a sensory point of view, the standard cheese (analysed immediately after purchase) together with cheese stored at 5 °C in vacuum form for 21 days was the best performing cheese.
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