Abstract:This study mainly investigated the phase separation behavior of the whole mixture of heat-denatured whey protein concentrate and high methoxy pectin at different quality ratios（1 ∶1，2 ∶1，3 ∶1，4 ∶1，5 ∶1）.The concentration of protein and polysaccharide in the upper phase and the lower phase of the complexes，as well as the apparent viscosity of the complexes were determined，and the appearance was observed.The results showed that the upper phase of the complexes was polysaccharide-rich phase，and the content of polysaccharide was significantly decreased with the increase of the mixture quality ratio（P<0.05）.The lower phase of the complexes was protein-rich phase，and the content of protein with the increase of the mixture quality ratio，it decreased significantly （P<0.05）.In addition，the apparent viscosity of the mixed system decreased significantly with the increase of the shear rate（P<0.05），and the apparent viscosity decreased with the increase of the mixing quality ratio （P<0.05）.The results showed that the phase separation behavior occurs in different quality proportions of the complexes，the upper phase was continuous phase，the lower phase was dispersed phase，which built a theoretical foundation for the subsequent application in hydrogels.