ABSTRACT Soy protein remains the leading plant protein in the growing alternative protein market. While having remarkable functional and nutritional properties, the impact of breeding programs on altering various attributes of soy proteins has been underestimated. Therefore, this work aimed to provide a comprehensive evaluation of the structural, functional, nutritional, and off‐flavor profile of soy protein isolate (SPI) produced from soybeans of 12 different breeding lines. Findings of this research revealed a composition‐structure–function relationship among the SPI samples. All samples had a critical amino acid (CAA) content of less than 16%, contributing to high solubility. In addition, SPI samples with relatively higher contents of charged and uncharged amino acids and zeta potential had higher protein solubility. Samples with balanced content of hydrophobic and hydrophilic amino acids showed good gel strength owing to a desirable balance between protein–protein and protein‐water interactions. Also, SPI samples with less hydrophobic and sulfur‐containing amino acids showed lower thermal stability as well as gel strength. SPI samples with a relatively higher fat content were associated with higher levels of off‐flavor compounds, especially the aldehyde hexanal and the alcohol 1‐Octen‐3‐ol. Overall, this research provided a comprehensive and valuable insight into the importance of genotypic evaluation of soy protein. Results highlighted considerable variation that could impact the performance of soy protein ingredients in different food applications.
Feyzi et al. (Sun,) studied this question.