title: Kinetic changes in glucosinolate-derived volatiles by heat-treatment and myrosinase activity in nakajimana (Brassica rapa L. cv. nakajimana).
abstract: Nakajimana (Brassica rapa L. cv. nakajimana), of the family Brassicaceae, is a traditional vegetable in Japan. Three isothiocyanates and five cyanides in the leaves of nakajimana were identified by gas chromatography (GC) and GC-mass spectrometry (GC-MS), and their kinetic changes using heat-treatment (temperature and time) were investigated. In addition, myrosinase activity of extracts prepared from fresh nakajimana leaf was determined. In crushed heat-treated leaves of nakajimana (70 °C for 30 s), formation of isothiocyanates and myrosinase activity increased, whereas formation of 1-cyano-3,4-epithiobutane and 1-cyano-4,5-epithiopentane decreased. Heat-treatment can significantly alter the content of potentially beneficial compounds in nakajimana, and ingestion of suitable isothiocyanates for human health may be better facilitated by mild boiling.
authors.affiliation: Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Oura-gun, Gunma 374-0193, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Kato
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Imayoshi
authors.forename: Hisakatsu
authors.initials: H
authors.lastname: Iwabuchi
authors.forename: Koichiro
authors.initials: K
authors.lastname: Shimomura
mesh_terms: D029741:Brassica rapa / Q000737:chemistry*; D003486:Cyanides / Q000032:analysis; D004355:Drug Stability; D005961:Glucosinolates / Q000032:analysis / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006358:Hot Temperature; D017879:Isothiocyanates / Q000032:analysis / Q000737:chemistry; D007564:Japan; D007700:Kinetics; D018515:Plant Leaves / Q000737:chemistry / Q000201:enzymology; D014835:Volatilization
chemical_list: D003486:Cyanides; D005961:Glucosinolates; D017879:Isothiocyanates; D006026:Glycoside Hydrolases; C022739:thioglucosidase