Widely targeted metabolomics of different colored cauliflower cultivars reveals key metabolites associated with nutritional value

Abstract

Colored cauliflower cultivars are increasingly valued for their nutritional properties. However, the specific metabolic constituents driving their nutritional divergence remain poorly understood. Here, we applied widely targeted metabolomics to profile the curds of white (‘C’), green (‘G’), purple (‘P’), and yellow (‘Y’) cauliflowers. Pigment analysis demonstrated that ‘G’ accumulated the highest levels of chlorophyll a (46.76 mg/kg) and b (33.11 mg/kg), alongside active chlorophyll intermediates and moderate carotenoids (7.14 mg/kg). ‘Y’ accumulated the highest levels of carotenoids (11.17 mg/kg), which became visually dominant following partial chlorophyll degradation. The distinct coloration of ‘P’ was attributed to anthocyanins (0.63 mg/g), primarily delphinidin 3-glucoside, whereas ‘C’ retained minimal pigments. Compared to ‘C’, 1922, 1544, and 1607 differentially accumulated metabolites were identified in ‘G’, ‘P’, and ‘Y’, respectively. KEGG pathway and chemical classification analyses demonstrated that these DAMs were predominantly enriched in primary carbohydrate metabolism, amino acid biosynthesis, and secondary metabolic pathways. Our analysis revealed that colored cultivars broadly accumulated higher levels of soluble sugars, inulin, and essential amino acids, with a distinct elevation of l-lysine in ‘G’. Secondary metabolism exhibited strict cultivar specificity, as anthocyanins and specific hepatoprotective phenolics were found exclusively in ‘P’. Moreover, the anticancer precursor glucoraphanin peaked in ‘G’, while anti-inflammatory sinigrin and goitrogenic progoitrin were enriched in ‘P’ and ‘Y’. Overall, this comprehensive metabolic profiling serves as a valuable resource for cauliflower germplasm evaluation and guides target selection in quality-improved breeding.