Evaluation on the potential of alpha and beta-by hop in control biocidal of the fermentation and its influence on the number of recycling in the production of cachaça

Abstract

The cane rum has alcohol content between 38 and 40% v/v and it is considered a beverage produced only in Brazil. The government action plan, which denominated the cane rum as "cachaça", placed it among the identified and prioritized products to be assessed their compliance between the periods 2004 to 2007. The "cachaça" identity and quality standards must contain certain legal requirements according to the instructions of the Normative Ministry of Agriculture, Livestock and Supply as volatile acidity control.However, despite the beverage volatile acidity contribute to its aroma and flavor; it is not a defining characteristic of the rum quality because the acidity could be especially produced by yeast action in presence of oxygen. Moreover, very high concentrations of acidity in the rum are attributed to contamination by acetic bacteria and other factors. Another important factor in the fermentation process refers to the yeast, which must provide invertase activity and efficiency to ferment the substrate.Furthermore, because of the fermentation production cost the cell recycling are carried out regardless of the yeast origin (wild or selected strain). However, the cells are exposed to multiple stress conditions during fermentation such as high osmolarity due to the sugars and salts concentration in the fermentation medium and also by the presence of ethyl alcohol intra-and extracellular content. Also, during fermentation there is cell disruption causing acetaldehyde release, which is an energy metabolite for the cells, but it is an inadmissible compound in the rum manufacture. It should be noted that the hops used in brewing to impart bitterness to the beverage has contribute to the beer organoleptic properties and it can also provide bactericidal activity during the fermentation process. In this context, this work has propose to use the hop products, Alpha and Beta acids, as a bactericidal or bacteriostatic agents during "cachaça" production. The bacteria of the family Lactobacillaceae, standing out the species of Lactobacillus plantarum and Lactobacillus casei, are considered fermentation contaminants. This study will determine the Minimum Inhibitory Concentration (MIC) of the hop alpha and beta acids products and their combination as biocides for these bacteria in Agar Man Rogosa Sharpe - MRS synthetic medium culture. We'll also test the action of these compounds on cell viability of Saccharomyces cerevisiae yeast. After careful checking in agar Man Rogosa Sharpe synthetic medium - MRS, the best biocides results associated with the less interference on Saccharomyces cerevisiae cells viability will be used in treated sugar cane juice during the fermentation process.We also intend to assess the yeast cell recycling number with respect to the process productivity and the beverage quality evaluation through its sensory characteristics. In this case, we will have a preliminary bench scale volume fermentation corresponding to 1500 mL following its optimization the fermentation will be carried out in pilot scale by using a corresponding volume of 200L in the Alembic of Silveiras Itagaçaba Beverages (Silveiras, SP). (AU)