title: Pectin modifications and the role of pectin-degrading enzymes during postharvest softening of Jonagold apples.
abstract: This study aimed at understanding softening in Jonagold apple (Malus×domestica Borkh.) fruits, by investigating pectin modifications and the evolution of pectin-modifying enzymes during postharvest storage and ripening. Jonagold apples were harvested at commercial maturity and stored at different temperatures and controlled atmosphere conditions for 6 months, followed by exposure to ambient shelf life conditions (20 °C under air) for 2 weeks. The composition of the pectic material was analysed. Furthermore, the firmness and the ethylene production of the apples were assessed. Generally, the main changes in pectin composition associated with the loss of firmness during ripening in Jonagold apples were a loss of side chains neutral sugars, increased water solubility and decreased molar mass. Also, the activities of four important enzymes possibly involved in apple softening, β-galactosidase, α-arabinofuranosidase, polygalacturonase and pectin methylesterase, were measured. Pectin-related enzyme activities highly correlated with ethylene production, but not always with pectin modifications.
authors.affiliation: Division of Mechatronics, Biostatistics and Sensors (MeBioS), Department of Biosystems (BIOSYST), KU Leuven, W. de Croylaan 42, bus 2428, B-3001 Leuven, Belgium.
authors.forename: Sunny George
authors.initials: SG
authors.lastname: Gwanpua
authors.affiliation: Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, B-3001 Leuven, Belgium.
authors.forename: Sandy
authors.initials: S
authors.lastname: Van Buggenhout
authors.affiliation: Flanders Centre of Postharvest Technology, W. de Croylaan 42, B-3001 Leuven, Belgium.
authors.forename: Bert E
authors.initials: BE
authors.lastname: Verlinden
authors.affiliation: Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, B-3001 Leuven, Belgium.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Christiaens
authors.affiliation: Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, B-3001 Leuven, Belgium.
authors.forename: Avi
authors.initials: A
authors.lastname: Shpigelman
authors.affiliation: Division of Mechatronics, Biostatistics and Sensors (MeBioS), Department of Biosystems (BIOSYST), KU Leuven, W. de Croylaan 42, bus 2428, B-3001 Leuven, Belgium.
authors.forename: Victor
authors.initials: V
authors.lastname: Vicent
authors.affiliation: Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, B-3001 Leuven, Belgium.
authors.forename: Zahra Jamsazzadeh
authors.initials: ZJ
authors.lastname: Kermani
authors.affiliation: Division of Mechatronics, Biostatistics and Sensors (MeBioS), Department of Biosystems (BIOSYST), KU Leuven, W. de Croylaan 42, bus 2428, B-3001 Leuven, Belgium; Flanders Centre of Postharvest Technology, W. de Croylaan 42, B-3001 Leuven, Belgium.
authors.forename: Bart M
authors.initials: BM
authors.lastname: Nicolai
authors.affiliation: Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, B-3001 Leuven, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Hendrickx
authors.affiliation: Division of Mechatronics, Biostatistics and Sensors (MeBioS), Department of Biosystems (BIOSYST), KU Leuven, W. de Croylaan 42, bus 2428, B-3001 Leuven, Belgium. Electronic address: annemie.geeraerd@biw.kuleuven.be.
authors.forename: Annemie
authors.initials: A
authors.lastname: Geeraerd
mesh_terms: D005638:Fruit / Q000737:chemistry*; D027845:Malus / Q000201:enzymology*; D010368:Pectins / Q000737:chemistry*
chemical_list: D010368:Pectins
keywords: Cell wall-modifying enzymes; Controlled atmosphere; Firmness; Malus×domestica; Pectin