Impact of genetic diversity on soy protein profiles, extraction efficiency, and gelation properties

Impact of genetic diversity on soy protein profiles, extraction efficiency, and gelation properties

Shima Momen ¹, Benjamin D. Fallen ^2,3, and Audrey L. Girard ¹

¹ Department of Food Science, University of Wisconsin-Madison, Madison, WI 53706, USA

² Soybean and Nitrogen Fixation Research Unit, USDA-ARS, Raleigh, North Carolina, USA

³ Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA

Abstract




Soy proteins are a key part of the food industry, but most commercial soybeans come from a narrow genetic pool. This limits their potential for better sustainability and functionality. Expanding genetic diversity is essential to developing soybean varieties that are more environmentally resilient and offer unique functional properties. By tapping into natural genetic variation, we can unlock new uses for soy proteins, reduce the need for additives, and create more sustainable, high-performing products.

This study evaluated 20 soybean genotypes to assess the effects of genetic variation on protein composition, extraction efficiency, and gelation properties.

Protein profiles were analyzed using SDS-PAGE before and after extraction, while protein and mass recovery quantified extraction efficiency. Gelation capacity was determined by preparing protein suspensions (5–10% w/v) and measuring the least gelation concentration (LGC).

Protein and mass recovery varied significantly, reflecting genetic effects on extraction efficiency. High-recovery genotypes (e.g., SP-10, ~74%) exhibited early gelation at 7% LGC due to glycinin and β-conglycinin solubility and strong disulfide bonding. Low-recovery genotypes (e.g., SP-3, ~43%) showed weaker interactions, requiring 10% LGC for gelation. SDS-PAGE revealed selective loss of β-conglycinin subunits (e.g., α′, β) in SP-7, but its glycinin dominance enabled superior gelation at 7% LGC, while β-conglycinin-dominant genotypes (e.g., SP-12) required 9–10% LGC.

This study underscores the importance of genetic diversity in optimizing soy protein functionality. These finding support developing tailored ingredients for high-protein gels, fostering sustainability and innovation in the food industry.