Oleogelation using modified milk protein concentrate produced by supercritical fluid extrusion

Abstract

In this work, we report on making oleogels based on functionalized milk protein concentrate. A protein-based oleogel was constructed and examined for the effect of lecithin and water addition on protein network formation in canola oil. To create oleogels, milk protein concentrate was modified by supercritical fluid extrusion (SCFX) into higher hydrophobicity extrudate (functionalized MPC). It was subsequently suspended in oil after the addition of lecithin and water in various concentrations. Compared to control (unextruded) MPC (CMPC), functionalized MPC (FMPC) exhibited interesting functionality as an oil-structuring ingredient. The incorporation of FMPC, water, and lecithin into canola oil formed gel by self-assembling, which differed from the oleogels made by a single gelator. It was water-induced self-assembly of protein that led to the formation of oleogels. It was further observed that the presence of lecithin in FMPC-stabilized oleogels altered the gel properties and strength. Microscopic images revealed that incorporation of lecithin led to the formation of smaller protein aggregates leading to higher strength. Non-covalent interactions between lecithin, protein, and water were also evaluated using FTIR spectroscopy, confirming the role of water and lecithin in gel formation of the mixed system.