Optimization of growing conditions of aspergillus niger for cellulase and pectinase production and application the bioproduct for peppercorn fermentation

Abstract

Cellulase and pectinase are the most common enzymes which used in skin removal of black pepper. In this study, Aspergillus niger was cultured in solid state fermentation (SSF) for high cellulase and pectinase activities and then the bioproduct named bioproduct-2 originated from that fungus was applied in peppercorn fermentation for the highest percentage of husk removal. The highest cellulase and pectinase activities were achieved when Asp. niger was grown in SSF during 48 hours with soybean residue used as a substrate added with 1% sucrose, 1% yeast extract, 1% MnSO4.H2O at pH 4.5 and 70% moisture. The application of bioproduct-2 (after cultured with the optimal conditions shown above) in pepper fermentation brought very high efficiency in peeling black peppercorn. Only using 12% ratio of bioproduct-2 and moisture content at 50.85%, black peppercorns were almost peeled totally up to 98.23% during 66

hours fermentation.

The little amount of the bioproduct as well as the short processing duration and high percentage of husk removal prove the bioproduct-2 that originated from Asp. niger can be used for white peppercorn processing broadly with high quality.

Keywords: Aspergillus niger, cellulase, pectinase, solid state fementation, peppercorn, husk removal.