Pectinase Production from Cocoa Pod Husk in Submerged Fermentation and Its Application in the Clarification of Apple Juice

Abstract

The present work aimed to use cocoa pod husk (CPH) and its extracted pectin as a potential substrate for the production of pectinase and to test the enzyme produced in the clarification process of apple juice. CPH with a particle size of <0.84 mm was employed for pectinase production by a selected strain of Aspergillus niger NRRL 2270. The optimization of the physicochemical conditions of the production medium led to an enzymatic activity of 602.03 U/g dry CPH, which was obtained under the following conditions: 110.25 g/L of CPH, 5% w/v pectin extract, 0.05 g/L of yeast extract, incubation at 28 °C, and pH 4, representing a 176% increase in enzymatic activity under the evaluated conditions. The production kinetics of pectinase showed maximum enzymatic activity at 96 h. Subsequently, the enzymatic extract was precipitated, microfiltered, and ultrafiltrated, resulting in 4852.50 U/mg of specific activity. The enzymatic activity after recovery and purification processes corresponded to 819 U/g dry CPH. Finally, a clarification stage of apple juice was carried out, in which the produced pectinase (CauPec) showed turbidity of 448.89 NTU compared to 417.89 NTU for the commercial enzyme and a viscosity of 1.86 cP, CauPec, and 1.19 cP, commercial pectinase, as well as soluble solids of 8.0 for commercial pectinase and 8.73 for CauPec. Therefore, it can be concluded that CPH and its pectin extract were excellent substrates for the production of pectinases, whose formulation is highly stable and can be applied in the clarification of apple juice.