Mechanisms of Formation and Alleviation of Bitter Taste in Food: A Review From the Perspectives of Metabolite–Habitat Coupling and Material Interaction Relationship

Bitterness in food exhibits a dual nature. It functions as a distinctive flavor attribute but also triggers consumer aversion, despite the health benefits of certain bitter compounds. This constitutes a "sensory-health paradox" that complicates their commercial value. Conventional strategies for mitigating bitterness often rely on isolated techniques. However, they lack an integrated framework that considers bitterness through the continuum of "compound formation-perception-regulation." This article systematically reviews the mechanisms underlying bitterness formation and mitigation from two primary perspectives. These include metabolite-habitat coupling (interactions between bitter compounds and environmental factors) and material interactions (interactions between bitter compounds and other components). It provides a comprehensive overview of bitter compound accumulation during food growth, storage, and processing. Furthermore, it critically examines factors influencing bitterness perception, including saliva, bitter taste receptors (TAS2Rs), cortical processing, and cross-modal integration. Recent advances in bitterness mitigation strategies are highlighted alongside promising directions for future research. A comprehensive approach that regulates internal metabolism (e.g., breeding, feeding) and external factors (e.g., environment, processing) can effectively reduce bitter compounds in organisms. Moreover, the bitterness perception mechanism has been clarified by integrating bitter compound binding to TAS2Rs, specific recognition processes, and neural signaling pathways. Small-molecule bitter taste inhibitors (BTIs) alleviate bitterness by blocking receptor activation or signaling. Macromolecular BTIs prevent TAS2R activation by interacting with bitter compounds. Future research should combine targeted debittering and bitterness inhibition strategies, promoting the creation of healthy, palatable foods.