New Protease Produced by Solid State Fermentation of Penicillium camemberti 0798400075 Using Coffee Hull Applied in Milk Coagulation

Abstract

The milk clotting proteases have the specificity of hydrolyzing the k-casein fraction of milk casein micelles. In this study, the biochemical characterization and coagulation potential of a new milk coagulant derived from the enzymatic extract of Penicillium camemberti 0798400075 through solid state fermentation (SSF) using coffee husks are investigated. The caseinase produced showed low proteolytic activity (0.076 U/mL) and high coagulant activity (8 ACL/mL and 10 ACL/mL) for powdered and whole UHT milk, respectively, and reached optimal temperature at 50 ºC and optimal pH at 7, remained with 80% of its activity at 40 ºC, showed greater affinity for acidic conditions, containing more than 60% of its activity at pH 5.0 and exhibited an increase in its activity in the presence of Mg2+ ions. The new coagulant showed potential to be used as a substitute for rennet in the coagulation process of milk caseins.