Suplementação de nitrogênio sobre a fermentação alcoólica para produção de cachaça, cerveja e vinho

• Autor(a) principal: Pereira, Alexandre Fontes
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2820
• topic: Nitrogênio; Saccharomyces; Carbamato de etila; Nitrogen; Saccharomyces; Ethyl carbamate; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS

The alcoholic fermentation step is of major importance on the sensory and chemical composition of alcoholic beverages. The fermentation process is influenced by the yeast strain, by the presence of nitrogen compounds on the environment, by the temperature and other factors. The objective of this paper was to evaluate the influence of two different yeast strains, of high and low fermentation, three nitrogen sources, ammonium sulfate, casein peptone and a pool of amino acids, in three different concentrations, 0 (with no addition), 5 g/L and 25 g/L, on the fermentation kinetics and on the chemical composition of three different types of liquors: cachaça , beer and wine. The analyzed parameters for the fermentation kinetic evaluation were the pH, the total acidity, the total soluble solid content (°Brix) and the alcoholic content (°GL), on samples collected between 12, 24, 48, 72 and 96 hours of fermentation in musts for the experimental production of cachaça , beer and wine. The pH on the three musts had a falling tendency with time. On the must for cachaça production, the pH varied between 5,4 and 3; on the beer must, between 4,8 and 3,0 and on the wine must, it varied between 3,6 and 3. The acidity increased with time for the three musts, but did not reach the values considered out of the Brazilian legal standard. The higher productivity of the alcoholic fermentation, that is, the higher production of ethanol per consumption of substrate was obtained by the low fermentation (Saflager) yeast strain, using as nitrogen source ammonium sulfate 5 g/L, on the musts of cachaça , beer and wine. The final ethanol concentration average on the musts were 7,7°GL for cachaça , 4,8°GL for beer and 14,6°GL for wine. The major volatile compounds and organic contaminants contained on the cachaça , beer and wine samples were analyzed by gas chromatography (GC). The ethyl carbamate was also analyzed by gas chromatography with mass spectrometry (GCMS). The main volatile compounds analyzed were: acetaldehyde, ethyl acetate, 1-propanol, isobuthylic alcohol, isoamilic alcohol, acetic acid. The organic contaminants were methanol, 1-butanol, 2-butanol e ethyl carbamate. On the cachaça sample, the higher alcohols, 1- propanol, isobuthylic alcohol and isoamilic alcohol had different results for the low fermentation yeast (Saflager) and for the high fermentation yeast (Safbrew). The addiction of 5 g/L of the nitrogen source was enough to elevate considerably the concentrations of higher alcohols. On the beer samples, the compounds 1-propanol and isoamilic alcohol had their values increased with a higher concentration of ammonium sulfate. On the other hand, the isoamilic alcohol reached bigger values with the addiction of the amino acids pool. The high fermentation yeast induced a higher production of isobuthylic alcohol and isoamilic alcohol, while the low fermentation yeast induced a higer production of 1-propanol. The ethyl carbamate values increased on the cachaça, beer and wine samples with the increase of the nitrogen source concentration; on the beer and wine samples, the ethyl carbamate values were higher on the low fermentation, while on the cachaça sample these values were higher on the high fermentation.