Evaluation of a potential starter culture for enhance quality of coffee fermentation

Abstract

The coffee fermentation is characterized by the presence of different microorganisms belonging to the groups of bacteria, fungi and yeast. The objectives of this work were to select pectinolytic microorganisms isolated from coffee fermentations and evaluate their performance on coffee pulp culture medium. The yeasts and bacteria isolates were evaluated for their activity of polygalacturonase (PG), pectin lyase (PL) and pectin methylesterase (PME) and metabolites production. Among 127 yeasts isolates and 189 bacterial isolates, 15 were pre-selected based on their ability to produce PL and organic compounds. These isolates were strains identified as Bacillus cereus, Bacillus megaterium, Bacillus subtilis, Candida parapsilosis, Pichia caribbica, Pichia guilliermondii and Saccharomyces cerevisiae. When cultivated in Coffee peel and pulp media in single culture or two by two mixed inocula, different behavior concerning to PME, PL and PG were found. The two principal components PC1 and PC2 accounted for 45.27 and 32.02 % of the total variance. UFLA CN727 and UFLA CN731 strains were grouped in the positive part of PC1 being characterized by 1,2-propanediol, hexanoic acid, decanoic acid, nonanoic acid and ethyl acetate. The UFLA CN448 and UFLA CN724 strains were grouped in the negative part of PC1 and were mainly characterized by guaiacol, butyric acid and citronellol. S. cerevisiae UFLACN727, P. guilliermondii UFLACN731 and C. parapsilosis UFLACN448 isolates are promising candidates to be tested in future studies as coffee starter cultures.

Coffee fermentation and flavor – An intricate and delicate relationship

“…Recently, there are two studies in which indigenous and nonindigenous bacterial and yeast species showing pectinolytic activity were screened for their suitability to act as starter cultures for the fermentation process in coffee processing (de Melo Pereira et al, 2014;Silva et al, 2013). The microorganisms were screened based on the polygalacturonase, pectin lyase and pectin methylesterase activities they exhibited.…”

Caracterización De Los Procesos Tradicionales De Fermentación De Café en El Departamento De Nariño

“…Estudios realizados por Jackels y Jackels (2005) [5], Puerta-Quintero (2013) [10], Puerta-Quintero y Ríos-Arias (2011) [15], Lee et al, (2015) [16], afirman que los cambios de acidez en el mucílago de café presentan un crecimiento exponencial en las primeras horas de fermentación, generándose variaciones significativas durante el proceso, las cuales dependen de muchos factores como los métodos de procesamiento, los factores ambientales, procesos de cosecha y almacenamiento del grano antes de someterse al proceso de fermentación [16,17].…”

Exploring the Impacts of Postharvest Processing on the Microbiota and Metabolite Profiles during Green Coffee Bean Production

“…However, it is not yet clear to what extent microorganisms are essential for the production of high-quality coffee (2). Recently, the ability of naturally occurring yeasts to act as selected starter cultures and to influence the in-cup attributes of coffee has been shown during semidry processing (14,15,27). Also, the beans (endosperms) remain metabolically active during coffee processing and are impacted by the processing method implemented, thereby affecting the final coffee cup quality (2,(28)(29)(30)(31)(32)(33).…”