title: Targeted analysis of polyphenol metabolism during development of hop (Humulus lupulus L.) cones following treatment with prohexadione-calcium.
abstract: Hops (Humulus lupulus), a main ingredient in beer, are valued as a source of bitter flavour and biologically active polyphenols. We treated immature hop cones with prohexadione-calcium (Pro-Ca), a flavanone-3-hydroxylase (F3H) inhibitor, to perturb the flavonoid pathway, and conducted a targeted analysis of 29 compounds from the phenolic acid, flavonoid, and terpenophenolic pathways, using photodiode array (UHPLC-PDA), and time of flight mass spectrometry (LC-TOF-MS) analysis. Hop cones were analysed over four stages of development spanning 22days following Pro-Ca treatment. The content of terpenophenolics as well as metabolic precursors upstream from F3H significantly increased, and levels of flavonoid products downstream from F3H decreased. The methods developed here serve to compliment flavour analysis of polyphenol rich foods, and our results suggest ways to improve upon traditional agricultural methods to produce hops with altered chemical profiles.
authors.affiliation: Department of Biological Sciences, Lehman College and The Graduate Center, The City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA. Electronic address: adamkavalier@gmail.com.
authors.forename: Adam R
authors.initials: AR
authors.lastname: Kavalier
authors.forename: Chunhui
authors.initials: C
authors.lastname: Ma
authors.forename: Mario
authors.initials: M
authors.lastname: Figueroa
authors.forename: Dwight
authors.initials: D
authors.lastname: Kincaid
authors.forename: Paul D
authors.initials: PD
authors.lastname: Matthews
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Kennelly
mesh_terms: D001515:Beer / Q000032:analysis; D005511:Food Handling / Q000379:methods; D027582:Humulus / Q000737:chemistry*; D007656:Ketoglutaric Acids / Q000737:chemistry*; D016014:Linear Models; D010936:Plant Extracts / Q000378:metabolism*; D059808:Polyphenols / Q000378:metabolism*
chemical_list: D007656:Ketoglutaric Acids; D010936:Plant Extracts; D059808:Polyphenols; C479018:prohexadione-Ca
keywords: Flavonoids; Humulus lupulus; Phenolic acids; Prohexadione-calcium; Terpenophenolics