Advances in cereal-derived ferulic acid: Sources, extraction, purification, metabolism, and applications in the food industry.

Ferulic acid is an abundant hydroxycinnamic acid covalently bound with cereal cell wall matrices, representing a valuable natural phenolic compound known for its antioxidant capacity and potential biological activities. However, complex crosslinked structures with cereal matrices severely restrict its efficient release and extraction. Moreover, the biological effects of cereal-derived FA are influenced by its release from food matrices, gastrointestinal availability, and subsequent microbial transformation. In this review, we summarize the major cereal sources and recent advances in extraction and purification strategies, including emerging green technologies and AI-assisted approaches for process prediction and optimization. We further discuss how cereal matrix structures, digestion processes, and gut microbial transformation influence FA bioaccessibility, absorption, bioavailability, and metabolic fate. Current evidence indicates that cereal-derived FA undergoes microbial conversion into diverse low-molecular-weight phenolic metabolites, while its biological activities are influenced by FA chemical forms, cereal matrices, metabolic pathways, and experimental models. Although purified FA and FA-containing cereal fractions exhibit promising antioxidant and other biological activities, differences in recovery efficiency, metabolite profiles, and limited human evidence remain major challenges for translating these findings into dietary applications. Future research should focus on standardized recovery approaches, mechanistic characterization of metabolites, and well-controlled clinical studies to support the sustainable and broader application of cereal-derived ferulic acid in food systems.