Protein-Flavor Interactions in Plant Protein Food Matrix: Molecular Binding Mechanisms, Influencing Factors, and Modulation Strategies

As plant-based diets gain momentum for health, environmental, and ethical reasons, the demand for plant-based protein foods is accelerating. However, a critical barrier to consumer acceptance lies in their flavor profiles, which are often perceived as off-putting due to complex interactions between plant proteins and flavor compounds. While individual interactions have been explored, an integrated understanding of their mechanisms and modulation remains limited. This review synthesizes current knowledge on plant protein-flavor interactions across molecular, physicochemical, and sensory levels. We examine the structural and functional diversity of plant proteins (legumes, cereals, nuts, seeds, and novel sources), categorize their interaction modes (non-covalent and covalent), and assess the impact of intrinsic (e.g. protein conformation, hydrophobicity) and extrinsic factors (e.g. pH, ionic strength, processing). Analytical models such as Scatchard and Hill equations, alongside QSAR and molecular docking approaches, are discussed. We further explore emerging strategies-physical, chemical, biological, and hybrid-for targeted flavor modulation. It is noted that plant protein-flavor interactions play a dual role: enabling flavor retention and protection, but also triggering off-flavors through irreversible binding or volatile entrapment. These interactions vary across protein types, flavors properties and processing conditions, requiring tailored strategies for optimization. For instance, enzymatic hydrolysis, micro-encapsulation, and data-driven protein engineering (leveraging computational tools to design proteins) offer promising solutions. Future progress hinges on combining sensory physiology with computational modeling and structural bioengineering to develop plant-based foods with improved flavor authenticity, stability, and consumer appeal.