Effect of gelatine on the texture of yoghurt and of acid-heat-induced milk gels

A penetrometry study was made of the effect of the addition of gelatine on the texture characteristics of yoghurts and acid-heat-induced milk gels. Detailed analysis of the various penetration profiles provided valuable information about the nature of the samples studied. Gelatine was compatible with the milk systems over a wide range of concentrations and it prevented syneresis. In yoghurts prepared with and without the addition of skim-milk powder, the addition of increasing concentrations of gelatine up to 1.5% gradually modified the mechanical characteristics of the final gels. In acid-heat-induced milk gels, whose mechanical characteristics depend on the final pH value, the addition of increasing quantities of gelatine up to 6.67% practically eliminated this dependence, and the effect of pH was only significant in the gels with 1.5% gelatine, which were structurally weaker.