Genetic determinants of glucosinolate degradation

Genetic determinants of glucosinolate degradation during food processing in Brassica oleracea

PhD fellow: Kristin Hennig  


Dr. Ing. R. Verkerk (PDQ)
Dr. Ir. M. Dekker (PDQ)
Dr. Ir. G. Bonnema (Plant Breeding) M. A.J. S van Boekel (PDQ)

Project term:
February 2009 – February 2013



Nowadays there is growing awareness of nutritionists, food scientists, food industry and consumers on the relation between health and diet. Brassica vegetables have shown negative associations between the consumption and colon cancer risk in men and women. The protected effects of Brassicacea are ascribed to high levels of some glucosinolates (GS’s). Various steps in the food production chain have a wide influence on the levels and bioavailability of these phytochemicals. In the cultivation stage genetic and environmental factors contribute significantly to the variation in GS levels. The following steps in the food production chain are storage and processing, which affect the cellular integrity and may result in GS degradation. Furthermore it was shown that thermal stability varies for different GS and for different vegetable types.


The aim of this thesis is to reveal genetic factors, which determine GS degradation. Possible influencing factors are morphological and biochemical traits, which are genetically determined. The objective of the research are:
- establishing genetic role in GS degradation;
- identification responsible QTL’s on genome;
- assessing biochemical factors that play a role in thermal degradation of GS


A segregating double-haploid (DH) population developed by crossing broccoli and Chinese kale is used to study thermal stability of GS’s. After harvesting, the endogenous enzyme myrosinase, which hydrolyse GS, was inactivated. Heat treatment will be performed over various times and the GS concentration
will be measured. These data will be modelled to obtain kinetic parameters for GS degradation, which will be used to conduct quantitative trait loci (QTL) analysis. QTLs are regions within genomes that contain genes associated with a particular quantitative trait.

Future research

It is hypothesized that biochemical traits influence GS degradation. A possible correlation between the water content and degradation rates, could indicate that metabolite composition is involved in GS degradation. A following metabolite analysis of the plant material and a correlation with GS degradation parameters could reveal biochemical influencing factors, which possibly will be verified in model studies.
Cooking of vegetables leads to cell lysis, where GS and further plant constituents are released into the cooking water. Morphological plant traits can influence the velocity of this process. Leaching of GS during cooking will be measured in the DH population and QTL analysis will be performed with the resulting kinetic data, giving information about structural traits involved in GS leaching.