Abstract:The effect of preheated treatment（90℃，5 min）on the physical stability of rapeseed oil-in-water emulsion of prepared by using whey protein concentrate as stabilizer were investigated.The changes trend of ζpotential，particle size，flocculation index，creaming index，rheological property and the partition coefficient of protein in the emulsion during the whole storage period（0-14 days）were measured.The results showed that the preheated treatment of whey protein concentrate could significantly reduce the physical stability of the emulsion during during the whole storage period compared with the natural whey protein concentrate （p＜ 0.05），especially the lower ζ-potential（p ＜ 0.05），and higher particle size，flocculation index，creaming index and viscosity （p ＜ 0.05）.Furthermore，the denaturation and aggregation of whey protein concentrate caused by preheat-treated could significantly increase the distribution of the protein on the surface of the emulsion membrane（p ＜ 0.05），thus confirming the physical stability of the emulsions.The results indicated that the thermal pretreatment significantly reduced the physical stability of the whole emulsion during storage and provided a theoretical basis for the rational application of whey protein concentrate in the emulsion-based food.