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Advisor(s)
Abstract(s)
O glúten é uma fração proteica presente em diversos cereais (trigo, centeio, cevada, aveia e cereais derivados), responsável por provocar alergias ou intolerâncias. Sendo a cerveja uma bebida elaborada por cereais, é uma bebida com glúten, impossibilitando o seu consumo por indivíduos com estas patologias. Consequentemente, o desenvolvimento de cervejas com menor teor de glúten, e que simultaneamente mantenham as características sensoriais típicas desta bebida, constitui um desafio à Indústria Alimentar.
O principal objetivo deste trabalho foi desenvolver uma cerveja sensorialmente apelativa de estilo Weissbier, com menor teor de glúten por co-fermentação com bactérias ácido láticas (BAL). Assim, foi produzido um mosto típico de uma cerveja Weissbier, com elevado teor de glúten, realizando-se duas fermentações utilizando Lb. brevis e Lb. plantarum e uma estirpe comercial de S.cerevisiae (Blanche) (fermentação sequencial e fermentação simultânea), comparando os resultados com uma fermentação padrão apenas com S.cerevisiae.
Durante os ensaios fermentativos acompanhou-se a evolução microbiológica (contagem de células viáveis e cultiváveis) e físico-química (ºBrix, pH, açúcares e ácidos orgânicos por HPLC). As cervejas obtidas foram analisadas relativamente ao teor de glúten (método ELISA) e amido (método da alfa-amilase), e ao grau de aceitação através de uma análise sensorial.
As fermentações realizadas foram bem-sucedidas não se verificando um impacto considerável das BAL nos parâmetros físico-químicos da cerveja, sobretudo no ensaio em simultâneo, atingindo-se níveis de etanol (2,8-4,5 %(v/v)) e açúcares residuais (6,4-7,85 g/L) similares ao ensaio de controlo. Por sua vez, a fermentação com BAL levou à redução do teor de glúten, sendo esta redução mais significativa na Fermentação Sequencial (de 113,1 ppm para 83,4 ppm), podendo ser considerada uma cerveja com “teor muito baixo de glúten”. No entanto, dado que esta bebida ainda contém glúten, não será destinada a doentes celíacos, mas sim a indivíduos com interesse em produtos com menor teor de glúten.
Gluten is a protein fraction present in several cereals (wheat, rye, barley, oats and derived cereals), responsible for causing allergies or intolerances. Since beer is a drink made with malted cereals, it has gluten, and cannot be consumed by people with these pathologies. Consequently, the development of beers with lower gluten content, while simultaneously maintaining the typical sensory characteristics of this drink, constitutes a challenge for the Food Industry. The main objective of this work was to develop a sensory appealing Weissbier style beer, with lower gluten content by co-fermentation with lactic acid bacteria (LAB). A typical Weissbier beer wort was produced, with a high gluten content, by performing two fermentations using Lb. brevis and Lb. plantarum and a commercial strain of S. cerevisiae (Blanche) (sequential fermentation and simultaneous fermentation). Results were compared with a standard fermentation with S. cerevisiae. During the fermentation trials, the microbiological (count of viable and cultivable cells) and physicochemical (ºbrix, pH, sugars and organic acids by HPLC) characteristics evolution was monitored. The beers obtained were analysed for gluten (ELISA assays) and starch (alpha-amylase method) content, and the degree of acceptance was evaluated through a sensory analysis. The fermentations carried out were successful and there was no considerable observable impact of the LAB on the physical-chemical parameters of the final product, especially in the simultaneous fermentations, reaching ethanol levels (2.8-4.5% (v/v)) and residual sugars (6.4-7.85 g/ L) similar to the control test. Fermentation with LAB led to a reduction in the gluten content, which was significantly reduced in Sequential Fermentation (from a wort with 113.1 ppm to 83.4 ppm), which may bear the term “very low gluten”. However, as produced drinks still contain gluten, they are not adequate for celiac patients, but are great for individuals with an interest in products with lower gluten content.
Gluten is a protein fraction present in several cereals (wheat, rye, barley, oats and derived cereals), responsible for causing allergies or intolerances. Since beer is a drink made with malted cereals, it has gluten, and cannot be consumed by people with these pathologies. Consequently, the development of beers with lower gluten content, while simultaneously maintaining the typical sensory characteristics of this drink, constitutes a challenge for the Food Industry. The main objective of this work was to develop a sensory appealing Weissbier style beer, with lower gluten content by co-fermentation with lactic acid bacteria (LAB). A typical Weissbier beer wort was produced, with a high gluten content, by performing two fermentations using Lb. brevis and Lb. plantarum and a commercial strain of S. cerevisiae (Blanche) (sequential fermentation and simultaneous fermentation). Results were compared with a standard fermentation with S. cerevisiae. During the fermentation trials, the microbiological (count of viable and cultivable cells) and physicochemical (ºbrix, pH, sugars and organic acids by HPLC) characteristics evolution was monitored. The beers obtained were analysed for gluten (ELISA assays) and starch (alpha-amylase method) content, and the degree of acceptance was evaluated through a sensory analysis. The fermentations carried out were successful and there was no considerable observable impact of the LAB on the physical-chemical parameters of the final product, especially in the simultaneous fermentations, reaching ethanol levels (2.8-4.5% (v/v)) and residual sugars (6.4-7.85 g/ L) similar to the control test. Fermentation with LAB led to a reduction in the gluten content, which was significantly reduced in Sequential Fermentation (from a wort with 113.1 ppm to 83.4 ppm), which may bear the term “very low gluten”. However, as produced drinks still contain gluten, they are not adequate for celiac patients, but are great for individuals with an interest in products with lower gluten content.
Description
Mestrado em Engenharia Alimentar. Universidade de Lisboa, Instituto Superior de Agronomia
Keywords
glúten cerveja bactérias acido láticas co-fermentação Saccharomyces cerevisiae Weissbier lactic acid bacteria co-fermentation
Pedagogical Context
Citation
Sousa, M.G.C. Produção de cervejas com baixo teor de glúten por co-fermentação com bactérias láticas. Lisboa: ISA-Universidade de Lisboa, 2021. Dissertação de Mestrado
Publisher
Instituto Superior de Agronomia, Universidade de Lisboa