Influence of droplet size and surface hydrophobicity of soybean protein-based nanoemulsion fillers on the quality of silver carp myofibrillar protein gels

Abstract

This study investigated the mechanisms underlying the influence of droplet size and emulsifier wettability on gel properties when oil-in-water (O/W) emulsions serve as fillers in myofibrillar protein (MP) gels. Pickering emulsions with varying droplet sizes were prepared using soybean protein isolate (SPI) and SPI-curcumin nanoparticles, then used to construct composite gels. Findings showed that decreased droplet size and increased emulsifier surface hydrophobicity enhanced hydrophobic interactions in the gel, increasing the β-sheet content of MP molecules. Upon the introduction of SPI-Cur-NPs stabilized nanoemulsion (SCNE), the hydrophobic force in the gel was approximately 2.6-fold more remarkable than that of the control, and the β-sheet content increased to 16.51 %. This resulted in a denser mesh framework and more uniform oil droplet distribution, increasing the hardness value from 26.993 g to 41.847 g. Moreover, SCNE addition improved gel antioxidant properties, reducing carbonyl and peroxide levels to 31.82 % and 24.15 % of the control, respectively. These findings offer insights for improving MP-based gel products.

Keywords

• Nanoemulsion
• Surimi gel
• Soybean isolate protein
• Droplet size
• Hydrophobic interaction