Yeast composition of sugar cane juice in relation to plant varieties and seasonality / Composição de leveduras do caldo em relação às variedades de cana e sazonalidade

ABSTRACT

In the production of the artisanal cachaça, a beverage obtained after distillation of the fermented sugar cane juice, natural starter ferment ("fermento caipira") is utilized, in which crushed corn, rice bran and citric fruit juice are added to sugar cane juice. The primary microbial source is the juice itself, and although the cachaça sensorial quality is recognized when this ferment is utilized, difficulties in the quality control due to the high level of contaminants and extensive preparation periods are reported. In this context, this work aimed the evaluation of the yeast composition and physico-chemical characteristics of the juice extracted from 10 sugar cane RB-varieties during the harvest season in an area under organic management, seeking for information to contribute to the varietal management allowing a faster and efficient ferment preparation. A significant decrease in the yeast numbers in the juice was observed when the maximal point of maturity was reached for the majority of the varieties. However, the proportion (%) of Saccharomyces increased with the cane maturity, recommending the early and medium maturity varieties (RB835054, RB835486, RB845210 and RB855156) to be utilized at the beginning of the harvest period for the ferment preparation, which could result in diminished preparation time and faster fermentation. The variety RB845210 is indicated because it also presented high reducing sugar and protein concentrations in the juice. The varietal management can facilitate the production and performance of the natural starter ferment, in order to contribute for the organic cachaça production.