Glucosinolate Derivatives in Stored Fermented Cabbage

Abstract

The research focused on the glucosinolate (GLS) breakdown products formed during the fermentation of cabbage. A relationship between the contents of degradation products in fermented cabbage and native GLS in raw cabbage was investigated. The effect of fermented cabbage storage on the contents of individual compounds was also assayed. Ascorbigen formed from one of the degradation products of glucobrassicin (indole GLS) was found to be a dominating compound in fermented cabbage. Irrespective of the time of fermented cabbage storage, the content of ascorbigen reached approximately 14 micromol/100 g. Neither the content of isothiocyanates, the major degradation products of aliphatic GLS, nor that of cyanides exceeded 2.5 microM. Storage of cabbage caused periodical increases and decreases in the contents of cyanides and consequent declines in the contents of isothiocyanates. The highest relative contents (expressed as a percentage of the native GLS content) of degradation products--ranging from >70 to 96%--were reported for the products of glucoraphanin degradation, whereas the lowest-- <5% --were reported for the products of sinigrin degradation.

Glucosinolates inBrassicavegetables: The influence of the food supply chain on intake, bioavailability and human health

“…In view of literature data, it appears that fermentation favours GLS hydrolysis in the direction of releasing isothiocyanates. Their content in the final product was generally higher than that of respective cyanates [133,138].…”

“…As a result of various directions of change the total content of aliphatic GLS decomposition products decreased by 30% between the second and seventeenth week. Storing cabbage had no effect on the content of indole compounds from glucobrassicin decomposition [133].…”

“…Cabbage fermented with aliphatic GLS hydrolysis products contained isothiocyanates, nitriles and cyclisation products of some isothiocyanates [133,134,138]. In view of literature data, it appears that fermentation favours GLS hydrolysis in the direction of releasing isothiocyanates.…”

“…Experimental data seem to indicate that GLS can be hydrolysed already in the initial stage of fermentation [133]. In this stage, lasting 2 -3 days, intensive respiration processes of plant tissues proceeded leading to a rapid release of carbon dioxide and environment acidification.…”

“…The main product of indole GLS hydrolysis was ascorbigen [133,139]. This compound is formed in acid environment during the reaction of indole-3-carbinol (I3C) with ascorbic acid [137].…”