Metabolomics Approach to Site-Specific Differential Analysis of Heat-Processed Chicory

Chicory (Cichorium intybus L.; witloof) contains bioactive compounds such as sesquiterpene lactones (SLs) and inulin, providing potential health benefits. However, the effects of cooking and processing on chicory's nutritional composition remain underexplored, particularly regarding its metabolite profile during low-temperature processing. We aimed to investigate how different heating temperatures and processing times affect the nutritional composition of the whole chicory plants. We employed a targeted metabolomics approach to analyze the impact of low (30°C, 60°C) and high (100°C, microwave)-temperature processing on chicory's nutritional profile, focusing on amino acids, sugars, organic acids, fatty acids, and other metabolites in both leaves and roots. Lower temperatures (≤ 60°C) influenced the concentration of nutritional components (sugars, free amino acids, organic acids), branched-chain amino acids (which improve exercise performance), and γ-aminobutyric acid (which has antihypertensive effects), depending on the composition of raw chicory. In contrast, high temperatures (100°C) and microwave processing, especially in chicory leaves, induced the formation of low molecular weight sugars from polysaccharides and glycosides, reduced free amino acid concentrations, and triggered heat-induced aminocarbonyl reactions. This study provides valuable information for improving the flavor profile and potential health benefits of chicory by identifying optimal heat processing parameters to maintain desirable nutritional value.