Influence of extraction pH and homogenization on soybean oleosome emulsion stability

Abstract

Oleosomes are highly conserved organelles that store oil and can be utilized as a natural oil-in-water emulsion for food products when isolated intact. Although soybeans are a rich source of oleosomes, their potential has not been fully realized due to significant aggregation within the emulsion, which limits their applications. This study investigates the effect of homogenization as a strategy to prevent oleosome aggregation and coalescence. Our results indicate that homogenization at pressures of 10–30 MPa effectively prevents phase separation and preserves the initial particle size of oleosomes. However, at pressures of 40–50 MPa, oleosome particles are disrupted, leading to the formation of smaller particles that stabilize the emulsion against coalescence. We found that extracting oleosomes at a pH of 9 consistently produces stable emulsions, suggesting this method as a viable approach to enhance the stability of these emulsions. Furthermore, extraction at a pH of 7 followed by homogenization enhances the physical stability of the mixtures. Additionally, our findings demonstrate that performing extractions at pH 9 helps in preserving oleosome membrane-associated proteins, thereby further improving the stability and extending the storage potential of soybean oleosomes to up to 20 days.