title: Biochemical markers to predict internal browning disorders in 'Rocha' pear during storage under high CO2.
abstract: BACKGROUND
  The aim of this study was to identify biochemical markers to predict internal browning disorders (IBD) in 'Rocha' pear. Fruits from five orchards were stored for 45 days under cold air followed by 100 days in browning-inducing controlled atmosphere (CA) conditions (1 kPa O2+ 10 kPa CO2).
  
  
  RESULTS
  Relationships between concentrations of ethanol (EtOH), acetaldehyde (AcDH) and ascorbic acid (AA), activities of peroxidase (POX) and polyphenoloxidase (PPO) and IBD incidence were established. The partial least square (PLS) model using the most promising markers, EtOH and AcDH, explained 89% of the variance in IBD incidence, whereas the univariate models based on the same markers explained between 89 and 94%. In contrast, the models based on AA levels and AA depletion rate only explained 57 and 82% of the variance in IBD incidence respectively. Model validation confirmed the robustness of EtOH for the prediction (R2= 0.91, RMSE = 11.1) and allowed proposing a threshold level of 30 µL EtOH L-1above which IBD may occur. Using this threshold value, the storage time limit associated with the occurrence of the first IBD symptoms was predicted with an acceptable RMSE of 9 days.
  
  
  CONCLUSIONS
  This work clearly identifies biochemical IBD markers for 'Rocha' pear and shows that dynamic changes in ethanol concentration during the beginning of storage may be used to predict IBD development. Therefore the results presented herein represent a major step forward in the prediction of IBD in 'Rocha' pear. © 2017 Society of Chemical Industry.
authors.affiliation: Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado, Porto, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Deuchande
authors.affiliation: IRTA, Postharvest Department, PCiTAL, Parc de Gardeny, Edifici Fruitcentre, Lleida, Spain.
authors.forename: Christian
authors.initials: C
authors.lastname: Larrigaudière
authors.affiliation: GreenUP/CITAB-UP & DGAOT, Faculty of Sciences, University of Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, Vairão, Portugal.
authors.forename: Umbelina
authors.initials: U
authors.lastname: Guterres
authors.affiliation: Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado, Porto, Portugal.|GreenUP/CITAB-UP & DGAOT, Faculty of Sciences, University of Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, Vairão, Portugal.
authors.forename: Susana Mp
authors.initials: SM
authors.lastname: Carvalho
authors.affiliation: Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado, Porto, Portugal.
authors.forename: Marta W
authors.initials: MW
authors.lastname: Vasconcelos
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D004156:Catechol Oxidase / Q000032:analysis*; D003116:Color; D005519:Food Preservation; D061353:Food Storage; D005638:Fruit / Q000737:chemistry*; D010088:Oxidoreductases / Q000032:analysis*; D010940:Plant Proteins / Q000032:analysis*; D031989:Pyrus / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D010940:Plant Proteins; D002245:Carbon Dioxide; D010088:Oxidoreductases; D004156:Catechol Oxidase
keywords: acetaldehyde; ascorbic acid; ethanol; internal browning disorders; modelling; prediction