title: Application of decolourized and partially purified polygalacturonase and α-amylase in apple juice clarification.
abstract: Polygalacturonase and α-amylase play vital role in fruit juice industry. In the present study, polygalacturonase was produced by Aspergillus awamori Nakazawa MTCC 6652 utilizing apple pomace and mosambi orange (Citrus sinensis var mosambi) peels as solid substrate whereas, α-amylase was produced from A. oryzae (IFO-30103) using wheat bran by solid state fermentation (SSF) process. These carbohydrases were decolourized and purified 8.6-fold, 34.8-fold and 3.5-fold, respectively by activated charcoal powder in a single step with 65.1%, 69.8% and 60% recoveries, respectively. Apple juice was clarified by these decolourized and partially purified enzymes. In presence of 1% polygalacturonase from mosambi peels (9.87 U/mL) and 0.4% α-amylase (899 U/mL), maximum clarity (%T(660 nm) = 97.0%) of juice was attained after 2 h of incubation at 50 °C in presence of 10 mM CaCl2. Total phenolic content of juice was reduced by 19.8% after clarification, yet with slightly higher %DPPH radical scavenging property.
authors.affiliation: Microbial Biotechnology and Downstream Processing Lab Agricultural and Food Engineering Department Indian Institute of Technology Kharagpur India ; Lignocellulose Biotechnology Laboratory Department of Microbiology University of Delhi South Campus Benito Juarez RoadNew Delhi India.
authors.forename: Tapati Bhanja
authors.initials: TB
authors.lastname: Dey
authors.affiliation: Microbial Biotechnology and Downstream Processing Lab Agricultural and Food Engineering Department Indian Institute of Technology Kharagpur India.
authors.forename: Rintu
authors.initials: R
authors.lastname: Banerjee
mesh_terms: D001230:Aspergillus / Q000201:enzymology* / Q000254:growth & development; D001628:Beverages; D003470:Culture Media / Q000737:chemistry; D005511:Food Handling / Q000379:methods*; D016166:Free Radical Scavengers / Q000032:analysis; D010636:Phenols / Q000032:analysis; D011096:Polygalacturonase / Q000302:isolation & purification* / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D000516:alpha-Amylases / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D003470:Culture Media; D016166:Free Radical Scavengers; D010636:Phenols; D000516:alpha-Amylases; D011096:Polygalacturonase
keywords: activated charcoal; apple juice clarification; decolourization; polygalacturonase; α-amylase