Large Scale Determination of Glucosinolates in Brussels Sprouts Samples after Degradation of Endogenous Glucose

Abstract

A method was developed for the determination of the glucosinolate content in glucose-rich samples of Brassica vegetables such as Brussels sprouts. Glucose in the samples was enzymatically degraded by the enzyme glucose oxidase (GOD). The resulting hydrogen peroxide and the enzyme GOD were thereafter respectively dissociated and inactivated by a heat treatment at 100 degrees C. After the degradation of endogenous glucose the glucosinolates were converted into glucose and related metabolites with the enzyme thioglucosidase originating from Brussels sprouts seeds. Glucose released was determined enzymatically with a glucose oxidase/peroxidase assay as a measure for the glucosinolate content of samples. The method was used to study the influence of harvest time, crop production location, and the choice of parental lines on the glucosinolate content of Brussels sprouts F1-hybrids. The sum of sinigrin and progoitrin of F1-hybrids was found to be significantly correlated to the glucosinolate content.

The nutritional significance, biosynthesis and bioavailability of glucosinolates in human foods

“…Finally van Doorn14, 98 has recently described a novel ELISA procedure for the determination of sinigrin and progoitrin in Brussels sprouts extracted with phosphoric acid, using antisera raised against hemisuccinate‐linked glucosinolate conjugates. The method tended to overestimate glucosinolate content in comparison to HPLC methods but seems to offer great potential advantages in terms of the cost and time needed for routine analysis in breeding programmes.…”

“…13 One consequence of this is that glucosinolates are important target compounds for plant breeders who wish to modify the flavour of commercial varieties to satisfy particular consumer preferences 13. 14…”

“…Conventional plant breeding has been successful in making changes to the total amount of glucosinolates and to side‐chain structure 14. The best known example is, as described above, the reduction in seed glucosinolate content in oilseed B napus .…”

Determination of two intact glucosinolates in vegetables and Chinese herbs

“…Negative ion mode was used for the analysis of the glucosinolates. The following parameters of the turbo ionspray were used: ionspray voltage -3,600 V, declustering potential 1 (DP1) -65 V, focusing potential (FP) -165 V, declustering potential 2 (DP2) -15 V. The ion source gas 1 (GS1), gas 2 (GS2), curtain gas (CUR), and collision gas (CAD) were 25,8,15, and 3, respectively. The temperature of GS2 was 350°C.…”

“…For the indirect analysis, enzymatically or chemically released products such as isothiocyanates [11,12,13,14], oxazolidinethiones, thiocyanate ion, or glucose [15,16] are measured. Because structures of the degradation products are all reflective of various parent glucosinolates, the indirect methods lack specificity for the analysis of each individual glucosinolate and thus are often used for the determination of total glucosinolates in natural products.…”