This study aimed to investigate the composition of phenolic compounds and glucosinolates in cauliflower and broccoli byproduct purees after fermentation with two selected strains of Lactiplantibacillus (Lp.) plantarum. UHPLC-HRMS (Q-Orbitrap) was used to analyze semi-targeted metabolic differences between non-fermented and Lp. plantarum-fermented byproducts. The fermentation process resulted in a reduction of glycoside phenolic compounds, such as kaempferol glucoside, and a decrease in phenolic acids like caffeic acid, p-coumaric acid, protocatechuic acid, quinic acid, and methyl gallate. Increased levels of deglycosylated or newly formed metabolites such as kaempferol, were observed. Additionally, dihydrocaffeic acid and phloretic acid were identified, likely formed from the conversion of caffeic and p-coumaric acids during fermentation. The percentage of glucosinolates remaining after fermentation averaged 79 %, and differences in the preservation of glucosinolates were observed between the two Lp. plantarum strains used. Overall, the study confirmed the modification of phenolic compounds and the preservation of glucosinolates after fermentation with Lp. plantarum.
