Improvement of Robusta Coffee Fermentation with Microbial Enzymes

Pectinase was produced by solidstate fermentation utilizing coffee pulp with Aspergillus niger CFR 305. The exogenous pectinase contained 7539 ±70 U/g of enzyme activity. Further the pectinase enzyme was partially decolorized with activated carbon and 80 % recovery of enzyme activity was obtained. The optimum pH and temperature of the crude decolorized pectinase was 4.5 and 50°C respectively. The intensity of decolorisation and recovery of the enzymes was found to be beneficial. Generally, robusta coffee takes longer fermentation duration due to hemicelluloses, pectic substances and sugars making it difficult to fasten demucilage process. Thus to improve primary processing, the isolated pectinase was treated to robusta coffee, Pectolysis enabled reduction of time in demuclisation which was evident with reduction in pH and sugars released. The organoleptic characters on evaluation were on par with traditional fermentation. This is the first report on treatment of the pectinase produced by coffee pulp and application of the same on demucilage of coffee pulp indicating waste recycle with value addition and is also economical for coffee industry.