Oil chain length matters: From interfacial protein adsorption to emulsion stabilization

The vegetable oils with varied chain length are commonly incorporated as protein-stabilized emulsion droplets to replace fats in the emulsified meat products. In this paper, we explored the effects of oil chain length (OCL) on the interfacial behaviour of myofibrillar protein (MP) and emulsion stability. The long chain triglyceride (LCT, soybean oil in this research) and medium chain triglyceride (MCT), which possessed similar polarity, were mixed in different volume ratios as model oils. The results suggested that the longer chain oil could impose a stronger hydrophobic effect on the protein, which promoted the structural unfolding and intermolecular interaction of interfacial MP. This contributed to the formation of a stiffer interfacial film (about 26.2 mN/m), which provided sufficient protection against coalescence. While on the other hand, the MP diffused faster towards the shorter chain interface (0.58 ± 0.1 mN m −1 s −0.5 ), leading to a fast decrease of interfacial tension and a larger magnitude of interfacial pressure (about 10.3 mN/m) herein. Therefore, with the extension of storage time, the shorter chain oil emulsion possessed smaller droplets (D 3,2  = 7.3 ± 0.4 μm; D 4,3  = 26.3 ± 1.3 μm) and creaming rate (14.5 ± 0.2%), which was overall more stable against macroscopic phase separation.