title: Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp) consumed in Brazil.
abstract: BACKGROUND
  The cowpea (Vigna unguiculata L. Wap.) is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources.
  
  
  OBJECTIVE
  The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing.
  
  
  METHODS
  Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications.
  
  
  RESULTS
  When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron.
  
  
  CONCLUSIONS
  Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.
authors.affiliation: Department of Natural Products and Food, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; elenjesus2@gmail.com.
authors.forename: Elenilda J
authors.initials: EJ
authors.lastname: Pereira
authors.affiliation: Department of Natural Products and Food, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Lucia M J
authors.initials: LM
authors.lastname: Carvalho
authors.affiliation: School of Pharmacy, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Gisela M
authors.initials: GM
authors.lastname: Dellamora-Ortiz
authors.affiliation: Department of Natural Products and Food, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Flávio S N
authors.initials: FS
authors.lastname: Cardoso
authors.affiliation: Embrapa Food Technology, Rio de Janeiro, Brazil.
authors.forename: José L V
authors.initials: JL
authors.lastname: Carvalho
keywords: Vigna unguiculata; bioaccessibility; home-cooking methods; iron; zinc