Introduction
Glucosinolates (GLSs) are a group of β-thioglucoside
N-hydroxysulphates with a sulphur-linked β-d-glucopyranose
moiety and side-chain group. GLSs are secondary metabolites
derived mainly from one of certain amino acids, such
as methionine, tryptophan, and phenylalanine. Depending on
side-chain group, glucosinolate (GLS) can be classified either
as aliphatic, aromatic, or indolyl [1–3].
Reviews of epidemiological studies reported inverse
associations between intake of Brassica vegetables and the
risk of certain cancers [4, 5]. Isothiocyanates, one of the
GLS breakdown products, are assumed to lower the risk of
cancer by inhibiting phase 1 and inducing phase 2 enzymes
during carcinogen metabolism [6]. Upon damage of plant
tissue, GLSs are highly prone to hydrolysis catalysed by
myrosinase (β-thioglucosidase EC 3.2.1.147), an enzyme
that occurs in Brassica vegetables [2, 7].
Fermentation is a processing method commonly performed
on milks, meats, and vegetables [8]. Fermentation
of Brassica vegetables involves the growth and metabolic
activity of lactic acid bacteria (LAB), either spontaneously
or starter-induced to produce fermented products [9]. Previous
studies reported that fermentation considerably reduces