Competitive binding of flavors in the preparation of soy protein: Screening based on molecular docking

Competitive binding of flavor compounds to proteins offers a strategy for mitigating off-flavors in soy protein isolate (SPI). We hypothesized that highly competitive pleasant flavor compounds can facilitate the release of off-flavors by occupying their binding sites during SPI preparation. Molecular docking identified four binding pockets on β-conglycinin (7S) and glycinin (11S) proteins interacting with off-flavors. From 54 pleasant flavors, 30 were screened, focusing on seven: δ-nonalactone, δ-decalactone, δ-undecalactone, furaneol, geraniol, nerol, and geranyl acetate. Sensory evaluation and gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that these compounds significantly reduced the intensity of unpleasant flavor attributes and decreased off-flavor content under high concentration neutral conditions (10 % w/v, pH 7.0) and low concentration acidic conditions (3 % w/v, pH 4.0). Structural differences influenced binding efficacy, with shorter-chain compounds like furaneol outperforming long-chain lactones. These findings provide a novel strategy for off-flavor removal in SPI, supporting the development of consumer-preferred soy products.