title: Effects of food processing on polyphenol contents: a systematic analysis using Phenol-Explorer data.
abstract: METHODS
  The Phenol-Explorer web database (http://www.phenol-explorer.eu) was recently updated with new data on polyphenol retention due to food processing. Here, we analyze these data to investigate the effect of different variables on polyphenol content and make recommendations aimed at refining estimation of intake in epidemiological studies.
  
  
  RESULTS
  Data on the effects of processing upon 161 polyphenols compiled for the Phenol-Explorer database were analyzed to investigate the effects of polyphenol structure, food, and process upon polyphenol loss. These were expressed as retention factors (RFs), fold changes in polyphenol content due to processing. Domestic cooking of common plant foods caused considerable losses (median RF = 0.45-0.70), although variability was high. Food storage caused fewer losses, regardless of food or polyphenol (median RF = 0.88, 0.95, 0.92 for ambient, refrigerated, and frozen storage, respectively). The food under study was often a more important determinant of retention than the process applied.
  
  
  CONCLUSIONS
  Phenol-Explorer data enable polyphenol losses due to processing from many different foods to be rapidly compared. Where experimentally determined polyphenol contents of a processed food are not available, only published RFs matching at least the food and polyphenol of interest should be used when building food composition tables for epidemiological studies.
authors.affiliation: International Agency for Research on Cancer (IARC), Nutrition and Metabolism Section, Biomarkers Group, Lyon, France.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Rothwell
authors.forename: Alexander
authors.initials: A
authors.lastname: Medina-Remón
authors.forename: Jara
authors.initials: J
authors.lastname: Pérez-Jiménez
authors.forename: Vanessa
authors.initials: V
authors.lastname: Neveu
authors.forename: Viktoria
authors.initials: V
authors.lastname: Knaze
authors.forename: Nadia
authors.initials: N
authors.lastname: Slimani
authors.forename: Augustin
authors.initials: A
authors.lastname: Scalbert
mesh_terms: D016208:Databases, Factual; D057140:Fast Foods; D005504:Food Analysis; D005511:Food Handling / Q000379:methods*; D059808:Polyphenols / Q000032:analysis*
chemical_list: D059808:Polyphenols
keywords: Food composition; Food processing; Phenol-Explorer database; Polyphenols; Retention factors