Estudo do efeito da agitação na fermentação alcoólica do suco de caju clarificado

Abstract

The cashew tree (Anacardium occidentale) is a native plant of Brazil, very common in the Northeast and North regions of the country. The cashew apple represents the fleshy and pulpy part of the cashew, often confused with the fruit of the cashew tree. Brazil is the world leader in cashew apple production, producing approximately 1.35 million tons per year, with Ceará being the Brazilian state with the largest share in the market. Despite high production, only 12% of the cashew apple is utilized in the industry. An interesting destination to reduce its waste is its use in the production of fermented alcoholic beverages, obtained from clarified cashew juice. The microorganism most used to produce fermented alcoholic beverages is Saccharomyces cerevisiae, which can ferment the substrate it is in and produce ethanol, carbon dioxide, water, and other products during the fermentation process. One important parameter in the production of alcoholic fermentations is the agitation of the medium, as the presence of oxygen can alter the physicochemical characteristics of the final fermented product. To investigate the influence of agitation on the production of cashew alcoholic fermentation using S. cerevisiae, two experimental cultivation conditions were tested: agitated, with medium agitation at 150 rpm, and static, without medium agitation, at two different fermentation times, 24h and 48h. The evaluated parameters were pH, acidity, soluble solids, total sugars, biomass production, and alcohol content. The cashew fermented in an agitated system obtained pH values of 4.5 and 4.35, acidity of 0.47% and 0.66% in % acetic acid, and alcohol content of 6.7% and 7.1%, for the 24h and 48h fermentation times, respectively. On the other hand, the fermented produced in static cultivation showed pH values of 4.59 and 4.67, acidity of 0.55% and 0.45% in % acetic acid, and alcohol content of 5.6% and 6.4%, at the same time. Biomass production was not satisfactory in both conditions, with values of 11.50 g/L and 10,01 g/L after 48h of fermentation. The final sugar content was around 3.65 g/L and 3.00 g/L, with soluble solids content of 4.0 and 4.3 °Brix at the end of fermentation, for static and agitated cultivation, respectively. At the end of the studies, it was possible to observe the positive effect of agitation on the physicochemical characteristics and the final quality of cashew fermentation, producing a greater amount of alcohol, in addition to presenting clarified cashew juice as a good potential for beverage production, utilizing regional raw materials.