title: In vivo formation and bioavailability of isothiocyanates from glucosinolates in broccoli as affected by processing conditions.
abstract: METHODS
  To study the effect of residual myrosinase (MYR) activity in differently processed broccoli on sulforaphane (SR) and iberin (IB) formation, bioavailability, and excretion in human volunteers.
  
  
  RESULTS
  Five different broccoli products were obtained with similar glucoraphanin (GR) and glucoiberin (GI) content, yet different MYR activity. Excretion of SR and IB conjugates in urine were determined in 15 participants after ingestion of the broccoli products. A reduction of 80% of MYR in the product did not cause differences in the total amount of SR and IB found in urine compared to the product with 100% MYR. Complete inactivation of MYR gave the lowest total amount of SR and IB in urine (10 and 19%). A residual MYR of only 2% in the product gave an intermediate amount (17 and 29%). The excretion half-lives of SR and IB conjugates were comparable for all the products (2.5 h on average), although the maximum excretion peak times were clearly shorter when the residual MYR was higher (2.3-6.1 h).
  
  
  CONCLUSIONS
  For the first time, the effect of residual MYR activity on isothiocyanate bioavailability was systematically and quantitatively studied. Processing conditions have a large effect on the kinetics and bioavailability of isothiocyanates from broccoli.
authors.affiliation: Food Quality and Design Group, Wageningen University, Wageningen, The Netherlands.
authors.forename: Teresa
authors.initials: T
authors.lastname: Oliviero
authors.forename: Ruud
authors.initials: R
authors.lastname: Verkerk
authors.forename: Martijn
authors.initials: M
authors.lastname: Vermeulen
authors.forename: Matthijs
authors.initials: M
authors.lastname: Dekker
mesh_terms: D000328:Adult; D001682:Biological Availability; D001937:Brassica / Q000737:chemistry*; D018592:Cross-Over Studies; D005260:Female; D005961:Glucosinolates / Q000032:analysis; D006026:Glycoside Hydrolases / Q000378:metabolism; D064368:Healthy Volunteers; D006801:Humans; D007096:Imidoesters / Q000032:analysis; D017879:Isothiocyanates / Q000493:pharmacokinetics* / Q000652:urine; D008297:Male; D008875:Middle Aged; D010091:Oximes; D013454:Sulfoxides
chemical_list: D005961:Glucosinolates; D007096:Imidoesters; D017879:Isothiocyanates; D010091:Oximes; D013454:Sulfoxides; C037152:isothiocyanic acid; C457341:glucoiberin; C082585:iberin; D006026:Glycoside Hydrolases; C022739:thioglucosidase; C016766:sulforaphane; C119494:glucoraphanin
keywords: Broccoli; Iberin; Kinetics; Myrosinase; Sulforaphane