Impact of soybean genotype diversity on the structure and gelation properties of soy proteins

Understanding the genetic basis of soy protein gelation performance differences is essential for developing clean-label, high-functionality ingredients. Here, we systematically compared the structural and gelation behavior of soy protein isolates from 20 genetically diverse soybean genotypes. Protein yield, subunit composition, sulfhydryl content, surface hydrophobicity, intrinsic fluorescence, secondary and thermal structures (FTIR, DSC), and gelation behavior (flow and rheology) were evaluated under standardized conditions. Glycinin-dominant isolates showed compact, thermally stable structures but formed weak gels, whereas genotypes with balanced 11S/7S profiles and higher conformational accessibility formed elastic gels with superior water-holding capacity. Highly aggregated isolates displayed high pre-gel viscosity yet poor gel strength, confirming that viscosity alone does not predict gelation. This side-by-side analysis links secondary structure fractions and reactive group exposure to gel viscoelasticity, providing a comprehensive genotype-function dataset for soy proteins. These findings establish a mechanistic framework for breeding and ingredient selection toward texture-focused, plant-based food formulations.