| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 4.65 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
A cerveja é considerada uma das bebidas alcoólicas mais antigas produzidas e consumidas no mundo. Atualmente, dependendo do modo de produção, existem dois estilos de indústria, a de cerveja artesanal, e a de cerveja industrial, sendo que, ao longo dos últimos anos, a cerveja industrial tem vindo a perder cota de mercado para a cerveja artesanal. O processo de produção de cerveja artesanal na Fábrica de Cervejas Portuense engloba as etapas de Moagem do Malte – Brassagem – Filtração – Ebulição – “Whirlpool” – Arrefecimento – Fermentação – Maturação – Centrifugação – Enchimento. A ausência de uma etapa de filtração esterilizante e/ou pasteurização antes do enchimento, torna este modo de produção mais suscetível a contaminações microbiológicas e consequente deterioração. Na fase quente da produção (desde a moagem do malte até ao “Whirlpool”), onde são aplicadas temperaturas elevadas, considera-se que o controlo é assegurado, mas o mesmo não acontece na fase fria (desde o arrefecimento até ao enchimento). No estágio realizado, além do acompanhamento da produção cervejeira, foram realizadas análises microbiológicas a amostras colhidas de equipamentos e materiais utilizados na fase fria do processo, assim como à cerveja em tanque e à cerveja final, de modo a avaliar a qualidade da cerveja e a identificar potenciais pontos de contaminação. Para tal, foi analisada a presença de Lactobacillus e de Acetobacter, como bactérias indicadoras de qualidade, e a presença de bactérias pertencentes à família Enterobacteriaceae, como indicadoras de higiene. Os resultados mostraram que, apesar de existirem cervejas com elevada qualidade microbiológica, algumas apresentavam níveis de contaminação acima do esperado e, que esta contaminação poderia ocorrer em vários pontos do processo.
Beer is considered one of the oldest alcoholic beverages produced and consumed in the world. Currently, depending on production process, there are two styles of industry, craft beer and industrial beer, and over the last few years, industrial beer has been losing market share to craft beer. The craft beer production process at Fábrica de Cervejas Portuense contains the following steps: Malt Milling – Brassing – Filtration – Boiling – "Whirlpool" – Cooling – Fermentation – Maturation – Centrifugation – Filling. The absence of a sterilizing filtration and/or pasteurization step prior to filling makes this style more susceptible to microbiological contamination and wastage. In the hot phase of production (from the malt milling to the “Whirlpool”), where high temperatures are applied, control is considered to be ensured, but the same is not true in the cold phase (from cooling to filling). In the intership carried out, in addition to monitoring the brewing production, a microbiological study was performed on the equipment and materials used in the cold phase of the process, as well to the beer in tank and to the final beer, in order to evaluate the quality of the beer and determine points of contamination. For this purpose, it was analyzed the presence of Lactobacillus and Acetobacter, as quality indicator bacteria, and the presence of bacteria belonging to the Enterobacteriaceae family, as hygiene indicators. The results showed that, despite the existence of high-quality beers, some were contaminated and that the contamination could occur at various points in the process.
Beer is considered one of the oldest alcoholic beverages produced and consumed in the world. Currently, depending on production process, there are two styles of industry, craft beer and industrial beer, and over the last few years, industrial beer has been losing market share to craft beer. The craft beer production process at Fábrica de Cervejas Portuense contains the following steps: Malt Milling – Brassing – Filtration – Boiling – "Whirlpool" – Cooling – Fermentation – Maturation – Centrifugation – Filling. The absence of a sterilizing filtration and/or pasteurization step prior to filling makes this style more susceptible to microbiological contamination and wastage. In the hot phase of production (from the malt milling to the “Whirlpool”), where high temperatures are applied, control is considered to be ensured, but the same is not true in the cold phase (from cooling to filling). In the intership carried out, in addition to monitoring the brewing production, a microbiological study was performed on the equipment and materials used in the cold phase of the process, as well to the beer in tank and to the final beer, in order to evaluate the quality of the beer and determine points of contamination. For this purpose, it was analyzed the presence of Lactobacillus and Acetobacter, as quality indicator bacteria, and the presence of bacteria belonging to the Enterobacteriaceae family, as hygiene indicators. The results showed that, despite the existence of high-quality beers, some were contaminated and that the contamination could occur at various points in the process.
Description
Keywords
Cerveja artesanal Microbiologia Lactobacillus Acetobacter Enterobacteriaceae Craft beer Microbiology