Transformation of organic acids and sugars in the mucilage and coffee beans during prolonged fermentation

Abstract

During the mucilage fermentation process, external and internal conditions originated changes in the characteristics of the coffee bean. The mucilage is a dynamic media that allows the development and interaction of microorganisms that modify the profiles of organic acids and sugars that are associated with the quality of the beverage. In order to determine the transformations of these compounds, coffee fruits at different stages of maturity were monitored at two temperatures and two prolongation times. Citric, malic, quinic and succinic acids are present in higher concentrations in the bean and were not influenced by the fermentation time, in contrast to tartaric and acetic acids which are directly associated with the extension time. Through carbon isotope tracing, diffusion from the exterior to the interior of the grain was demonstrated; however, it was evidenced that this process is not immediate and, at the same time, does not respond to the same behavior observed in the mucilage for the compounds evaluated.