| dc.description.abstract | Cellulase and pectinase are enzymes which catalyze the hydrolysis reactions to convert cellulose and pectin into monosaccharides and galacturonic acid, respectively. Those enzymes can be produced by microorganisms, such as yeast, bacteria and molds. Cellulase and pectinase play an important role in removing the mucilage layer of coffee bean, and can be applied in improving the extraction of soluble solid content, especially for instant coffee. The objective of this thesis is to study on the production of cellulase and pectinase by using Aspergillus oryzae, investigate the optimal concentration of total soluble solid in molasses, initial pH and duration of incubation for harvesting the highest enzyme activity; investigate the optimal duration of treatment and concentration of enzymes to achieve the highest soluble solid content extraction from coffee. Both enzymes were produced by incubating A. oryzae in molasses with the supplement of (NH4)2SO4 and substrates at specific conditions. Cellulase and pectinase activities were determined by measuring the absorbance at λ = 540 nm with 3,5-DNS reagent. Then, those enzymes were treated on coffee beans to enhance the extraction of soluble solid content. As the result, the highest cellulase activity was 27.99 U/mL and achieved at 6oBrix of molasses concentration, 0.5% of CMC as substrate, 1% of (NH4)2SO4 as nitrogen source, initial pH 5.0, incubated in 50 mL falcons at 35oC for 72 hours. The highest pectinase activity was 19.49 U/mL and obtained at 8oBrix of molasses concentration, 1% of pectin as substrate, 1% of (NH4)2SO4 as nitrogen source, initial pH 5.0, incubated in 50 mL falcons at 35oC for 72 hours. For coffee treatment, the concentration of soluble solid content extracted was 4.87oBrix with 4% of crude enzymes treated, incubated at 35oC for 20 hours, and increased 51.24% compared to the control. This result could be used as reference for further study or applied in industry for coffee production.
Keywords:
Aspergillus oryzae, Cellulase, Coffee treatment, Pectinase, Soluble solid content | en_US |
