Effect of the heat-induced whey proteins/κ-casein complex on the acid gelation of yak milk

The effect of the heat-induced whey proteins/κ-casein complex on the acid gelation of yak milk was investigated. Both soluble whey protein/κ-casein complexes and the surface as micelle-bound complexes change the rheological properties of yoghurt. However, the soluble whey protein/κ-casein complexes were predominant in increasing the storage modulus (G′), water-holding capacity and firmness of acid gelation than micelle-bound complexes. The water-holding capacity and firmness increased with the increase of the amount of the soluble whey protein/κ-casein complexes. The water holding capacity and firmness of yoghurt from heated yak milk at pH 7.0 was higher than that at pH 6.6 and pH 7.4. The result also indicated that the amount of soluble heat-induced whey protein/κ-casein complexes were predominant in increasing the water holding capacity and firmness of yoghurt than the micelle-bound protein complexes.