Study on coffee fermentation by bioproducts produced by penicillium citrinum, wickerhamomyces edaphicus to increase soluble solids extraction

Abstract

Pectin and cellulose are mentioned as two main components of coffee beans. Pectin and cellulose make the cell wall and envelop the molecules as caffeine, reducing sugar, carbon hydrate, so these molecules cannot released to the outside the cells…that lead to reducing SSC extraction from coffee product. Wickerhamomyces edaphicus and Penicillium citrinum were isolated from weasel that can produce high cellulase and pectinase activities which have abilities to breakdown pectin and cellulose in coffee beans. The bio-products named biocoffee-23, biocoffee-24, and biocoffee mix were made from these microorganisms and considered as high enzymatic activity of pectinase and celllulase. That’s why these bio- products were applied to optimize the C. robusta fermentation conditions to improve the soluble solids extraction as well as the quality of coffee products. The optimal moisture content of C. robusta was 49.39% in fermentation with biocoffee-23, while it was 52.38% and 51.27% in fermentation with biocoffee-24 and biocoffee-mix. It means that the soaking duration was short when using biocoffee-23 in fermentation. The ratio of biocoffee-mix to coffee weight was lowest (1%) in comparison with biocoffee-23 (2.5%) and biocoffee-24 (2%). The duration fermented with biocoffee-23, biocoffee-24, and biocoffee-mix were 15 hours, 3 hours, and 6 hours. After studying, the soluble solids extraction has increased from 30-37%, and caffeine increase 27-31% in comparing with the control samples (fermentation without any bioproduct). The coffee products did not content any toxin (Aflatoxin and Ochratoxin); it is safe for human use.

Keywords: Coffee, C. robusta, biocoffee-23, bio-coffee24, biocoffee-mix, fermentation.