Glucosinolate profiles of authenticated Brassica vegetables, pungent plant species, and commercial dietary supplements: Implications for food composition and product authenticity

Glucosinolates (GSLs) are bioactive, sulfur-containing phytochemicals abundant in Brassica vegetables and pungent plant species, yet limited compositional data continue to hinder the quality assessment and standardization of commercial dietary supplements. In this study, a validated UHPLC-QToF-MS method was used to quantify 15 desulfoglucosinolates in 44 authenticated plants representing Brassica vegetables and pungent species, and 69 dietary supplements. The method showed excellent linearity ( R² > 0.998), sensitivity, and precision. Authenticated plants displayed distinct group–specific profiles. Kale, broccoli, cauliflower, and Brussels sprouts contained higher levels of indole GSLs (glucobrassicin, neo -glucobrassicin) along with glucoraphanin and glucoiberin, whereas turnip, horseradish, wasabi, and watercress were characterized by elevated sinigrin, gluconasturtiin, and total aliphatic GSLs. Meanwhile, commercial supplements exhibited substantial compositional variability, with products marketed under the same botanical ingredient differing markedly in total GSL content and individual profiles. Several supplements showed patterns inconsistent with their purported plant sources, suggesting variability in raw materials, processing, or labeling. Exploratory chemometric analyses revealed group-associated patterns in authenticated materials and highlighted the compositional heterogeneity of commercial products. These results provide comprehensive GSL composition data and demonstrate that many current supplements do not reliably reflect authentic GSL profiles, underscoring challenges for product standardization, authenticity evaluation, and dietary intake assessment.