Study on coffee fermentation by using microbial enzymes from penicillium citrinum for coffee quality improvement

Abstract

This study was aimed to improve the coffee quality by using pectinase and cellulase extracted from Penicillium citrinum culture by molasses. The purposes of coffee fermentation are removing of viscous layer, keeping the concentration of chlorogenic acid (CGA), and extracting the soluble solids content. It was carried out with four enzyme solutions and ratios of enzyme changed from 2% to 12%. The combination of cellulase and pectinase (1:1) with the ratio 6% within 24 hrs fermentation at initial 56% moisture content was the best to improve coffee quality. Viscous layer could be removed completely (98.11%) by weighing before and after fermentation. The highest concentration of CGA was 4.91% determinate by UV-Vis spectrophotometer. Refractometer was used to calculate soluble solids content (4.98%). In conclusion, the combination of cellulase and pectinase (1:1) extracted from Penicillilum citrinum with the ratios of 6% can be applied to coffee fermentation in industrial scale to improve coffee quality. Keywords: Chlorogenic acid (CGA) Coffee Fermentation Penicillium citrinum Soluble solids content Viscous layer ABBREVIATIONCGA Chlorogenic Acid Hr hour MEA Malt Extraction Agar Min minute OD Optical Density P.citrinum Penicillium citrinum PGA Potato Glucose