Using detailed milk protein composition to explain variations in rennet gelation properties

Abstract

Individual milk samples were used to investigate how much of the variation in rennet gelation properties that can be explained by variation in milk composition by linear regression using the ordinary least squares method so as to optimise cheese milk. Natural variation in casein (CN) content was shown to have a large effect on gel strength but did not affect gel formation kinetics. Ionic calcium concentration was more important for initial gel formation whereas total calcium content is a better predictor for the developed gel structure. Of the individual milk proteins, κ-CN had the largest effect on gelation explaining up to 20% of the variation in gel forming kinetics and gel strength, while post-translational modifications of κ-CN did not explain more variation than total κ-CN. However, the relative concentration of glycosylated κ-CN seems to be more important for gel-build-up kinetics and un-glycosylated κ-CN for the gel-structure.