Improvement of soluble solids extraction of Coffee robusta using combinated Bio-products from aspergillus niger, bacillus subtilis HNL01 and issatchenkia orientalis

Abstract

The soluble solids extraction normally limited by two major components of coffee those are cellulose and pectin, they are very hard protective layers. The traditional coffee processing is often difficult to break down them. Therefore, there is still a quite large amount of soluble solids left in coffee residue after extraction process. In this research biocoffee-1 used to ferment coffee, the bio-product was produced from Aspergillus niger it had high enzyme activities (cellulase and pectinase). The enzymes hydrolyzed cellulose and pectin layers so that soluble solids content extracted has increased. In addition biocoffee-13 and biocoffee-15 produced from Bacillus subtilisHNL01 and Issatchenkia orientalis respectively also were used for studying combined fermentation, this was only primary study about combined fermentation. The coffee fermented process combined biocoffee-1 with biocoffee-13 and the coffee fermented process combined biocoffee-1 and biocoffee-15 have increased soluble solids content from 64 to 67.7% in comparison to traditional coffee process. In addition aroma and taste of fermented coffee was also improved. The coffee products have been tested to make sure that they are safe to human by TCVN [AOAC 2007 (991.31) method].