Partial purification, characterization and kinetics of thermal inactivation of pectin methylesterase and polygalacturonase enzymes from Indian lemon (Citrus limon (L.)

• Published in: Journal of food measurement & characterization 2021-06, Vol.15 (3), p.2705-2715
• Main Authors: Bakshi, Gayatri, Ananthanarayan, Laxmi
• Format: Article
• Language: English
• Subjects: Anion exchanging; Anion-exchange chromatography; Cellulose; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Engineering; Enzymes; Food Science; Fruits; Gel electrophoresis; Inactivation; Lemons; Microorganisms; Original Paper; Pectin; Pectinesterase; pH effects; Polygalacturonase; Purification; Shelf life; Sodium lauryl sulfate
• ISSN: 2193-4126; 2193-4134
• DOI: 10.1007/s11694-021-00835-8

The extraction, purification, and characterization of PME and PG were studied for lemon fruit. Enzymes were partially purified by anion-exchange chromatography using UNOsphere™ Q anion exchanger for lemon PME and DEAE Cellulose anion exchanger for lemon PG. A single band with a fold purity of 20.95 and 15.75 for PME and PG respectively was observed on SDS-PAGE. Molecular weights of partially purified fractions of PME and PG as exhibited by SDS-PAGE were 48 kDa and 95 kDa respectively. Optimum pH and temperature of partially purified lemon PME and PG were pH 9, pH 5 and 45 °C. The crude PME and PG extracts exhibited D-values of 120.57–63.79 and 185.72–29.18 min; Z-values of 15.11 and 16.50 °C; and activation energies (E a ) of 58.23 and 57.18 kJ/mol, respectively. The enzyme stability was not significantly influenced by the fruit matrix as reflected by Z and E a values. D and Z-values of both the enzymes and microorganisms should be considered while designing thermal treatments to obtain a product with better shelf life.