Articles
PRE-HARVEST EFFECTS ON NATURALLY OCCURRED ISOTHIOCYANATES (ITCS) OF CRUCIFEROUS SPROUTS
Article number
712_60
Pages
497 – 504
Language
English
Abstract
An anticarcinogenic property of crucifers has been elucidating.
Cruciferous vegetables contain glucosinolates.
When raw crucifers are grated, chewed or chopped, glucosinolates come into contact with endogenous myrosinase (thioglucoside glucohydrolase EC 3:2:3:1), and isothiocyanates (ITCs), nitriles, etc are released as the breakdown products of glucosinolates.
ITCs are responsible for the protection from carcinogen. 4-Methylsulfinylbutyl ITC (L-sulforaphane) of broccoli sprouts is famous for strongly inducing phase 2 detoxication enzymes. 4-Methylthio-3-butenyl ITC (MTB-ITC) of Japanese radish sprouts called kaiware-daikon in Japan has also an anticarcinogenic property.
Therefore, preharvest effects on naturally occurred both ITCs content were researched.
In advance, a rapid and simple L-sulforaphane determination method using a gas chromatograph (GC) was developed.
Varieties and harvest time had an effect on both ITCs content.
The earlier harvest time was, the more both ITCs content was.
A greening period had no effect on the L-sulforaphane content and also appeared to have no effect on the MTB-ITC content.
GC and GC-mass spectrometry analysis of broccoli sprouts revealed 4-methylthiobutyl ITC and 4-methylthiobutyl nitrile as the main components that were similar to the structure of L-sulforaphane.
The L-sulforaphane content was lower than the MTB-ITC content though exogenous myrosinase treatment after a microwave treatment increased the L-sulforaphane content about twentyfold.
The MTB-ITC content was almost unchangeable more than 17 days under the storage of 7 degrees centigrade.
The low content of L-sulforaphane should be considered.
Cruciferous vegetables contain glucosinolates.
When raw crucifers are grated, chewed or chopped, glucosinolates come into contact with endogenous myrosinase (thioglucoside glucohydrolase EC 3:2:3:1), and isothiocyanates (ITCs), nitriles, etc are released as the breakdown products of glucosinolates.
ITCs are responsible for the protection from carcinogen. 4-Methylsulfinylbutyl ITC (L-sulforaphane) of broccoli sprouts is famous for strongly inducing phase 2 detoxication enzymes. 4-Methylthio-3-butenyl ITC (MTB-ITC) of Japanese radish sprouts called kaiware-daikon in Japan has also an anticarcinogenic property.
Therefore, preharvest effects on naturally occurred both ITCs content were researched.
In advance, a rapid and simple L-sulforaphane determination method using a gas chromatograph (GC) was developed.
Varieties and harvest time had an effect on both ITCs content.
The earlier harvest time was, the more both ITCs content was.
A greening period had no effect on the L-sulforaphane content and also appeared to have no effect on the MTB-ITC content.
GC and GC-mass spectrometry analysis of broccoli sprouts revealed 4-methylthiobutyl ITC and 4-methylthiobutyl nitrile as the main components that were similar to the structure of L-sulforaphane.
The L-sulforaphane content was lower than the MTB-ITC content though exogenous myrosinase treatment after a microwave treatment increased the L-sulforaphane content about twentyfold.
The MTB-ITC content was almost unchangeable more than 17 days under the storage of 7 degrees centigrade.
The low content of L-sulforaphane should be considered.
Authors
H. Ito, M. Kimura
Keywords
variety, harvest time, light, L-sulforaphane, 4-methylsulfinylbutyl,
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