Effect of γ-oryzanol/β-sitosterol-based oleogels on the physicochemical and gel properties of Nemipterus virgatus myofibrillar protein.

BACKGROUND:The effect of oleogels prepared with peanut oil and different concentrations of γ-oryzanol and β-sitosterol mixture (γ/β; 20, 40, 60, 80 and 100 g kg-1) on the physicochemical and gel properties of myofibrillar protein (MP) was investigated. RESULTS:The solubility and average particle size of MP first decreased and then increased with increasing γ/β concentration. Peanut oil or oleogels could induce the exposure of hydrophobic amino acids and the unfolding of MP, thus significantly increasing the surface hydrophobicity, sulfhydryl content and absolute value of zeta potential, which reached maximum values when the γ/β concentration was 60 g kg-1 (P < 0.05). The addition of peanut oil decreased the gel strength and water holding capacity of MP gel. However, oleogels prepared with 60 g kg-1 γ/β could significantly increase the hydrophobic interactions and disulfide bond content of MP gel (P < 0.05), which promoted the crosslinking and aggregation of MP, enhancing the gel properties. Peanut oil had no significant influence on the secondary structure of MP, while oleogels promoted the transition of MP conformation from α-helix to β-sheet structure. The results of light microscopy and confocal laser scanning microscopy indicated that oleogels prepared with 60 g kg-1 γ/β filled in the pores of MP gel network to form denser and more uniform structure. CONCLUSION:Oleogels prepared with 60 g kg-1 γ/β could effectively improve the quality of MP gel and have promising application prospects in surimi products. © 2024 Society of Chemical Industry.