title: Inactivation of polyphenoloxidase by pulsed light.
abstract: The effect of pulsed light on the inactivation of polyphenoloxidase (PPO) in model solutions was investigated focusing on the effect of enzyme concentration and total energy dose of the treatment. PPO inactivation increased with the dose of the treatment. Complete enzyme inactivation was achieved by pulsed light doses higher than 8.75 J cm(-2) . At low PPO concentrations (4 to 10 U), the enzyme resulted highly inactivated by pulsed light treatment. Further increase in enzyme units determined a progressive decrease in PPO inactivation. The latter was attributed to protein structural modifications including cleavage and unfolding/aggregation phenomena. PPO amounts higher than 10 U probably favoured enzyme conformations that were less prone to intermolecular rearrangements leading to inactivation.
authors: Dipartimento di Scienze degli Alimenti, Univ. di Udine, via Sondrio 2/A, 33100 Udine, Italy. lara.manzocco@uniud.it
authors: Lara
authors: L
authors: Manzocco
authors: Agnese
authors: A
authors: Panozzo
authors: Maria Cristina
authors: MC
authors: Nicoli
mesh_terms: D004156:Catechol Oxidase / Q000378:metabolism* / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D004307:Dose-Response Relationship, Radiation; D005506:Food Contamination / Q000517:prevention & control; D005514:Food Irradiation / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D008027:Light; D015416:Maillard Reaction / Q000528:radiation effects
chemical_list: D004156:Catechol Oxidase
keywords: cleavage; polyphenoloxidase; pulsed UV-light; structure; unfolding/aggregation