Relatório de estágio na empresa Cervejas de Moçambique estudo de caso: ocorrência de leveduras selvagens no processo de produção da cerveja

Abstract

This report describes the activities of the training and pre-professional internship, carried out at company Cervejas de Moçambique in the period from November 1, 2022 to July 26, 2023. During the internship period it was possible to participate and follow routine activities in the Brewing departments, namely brewing, fermentation and filtration and in the Quality department, for collecting samples and carrying out analyzes microbiological. The internship culminated in the development of a case study related to occurrence of wild yeasts during the beer production process. Were realized microbiological analyzes on 16 samples: 4 from cultivated yeast, 4 from fermenting must, 4 of filtered beer and 4 of the beer before pasteurization. The analyzes were based on the method internal company for the isolation and identification of wild yeasts, through means selective and differential. The macro and microscopic characteristics of the colonies were observed suspected wild yeast. As a result, the presence of wild yeasts was detected in 26.9% of the samples, with filtered beer and beer filled before pasteurization being the critical steps. In the remaining stages, the occurrence of wild yeasts was not detected, satisfactory results have been obtained. Macroscopically, characteristics suggestive of presence of rough colonies, which are associated with hygiene problems in the industry, causing a drop in fermentation yield. Microscopically, the similarity of the characteristics observed with the presence of Brettanomyces spp, which has the ability to survive for long periods of time and grow into products in storage. The work allowed us to conclude that there is contamination of the production process by wild yeasts. This situation demonstrates that the procedures used are not sufficient to guarantee the quality standard. It was also found that the presence of wild yeast of the genus Saccharomyces, which presents similarities to cultivated yeast and the non- Saccharomyces