Phytochemical fingerprinting of vegetable Brassica oleracea and Brassica napus by simultaneous identification of glucosinolates and phenolics

Abstract

Introduction: Brassica vegetables have been related to the prevention of cancer and degenerative diseases, owing to their glucosinolate and phenolic content.

Objective: Identification of glucosinolates, flavonoids and hydroxycinnamic acids in representative varieties of kale, cabbage and leaf rape.

Methodology: One local variety of each crop was evaluated in this study using a multi-purpose chromatographic method that simultaneously separates glucosinolates and phenolics. Chromatograms were recorded at 330 nm for flavonoid glycosides and acylated derivatives and 227 nm for glucosinolates.

Results: Eight glucosinolates were identified in kale and cabbage, which exhibited the same glucosinolate profile, and 11 glucosinolates were identified in leaf rape. Furthermore, 20 flavonoids and 10 hydroxycinnamic acids were detected in kale and cabbage, while 17 flavonoids and eight hydroxycinnamic acids were found in leaf rape.

Conclusions: This study has provided a deeper and comprehensive identification of health-promoting compounds in kale, cabbage and leaf rape, thus showing that they are a good source of glucosinolates and phenolic antioxidants.