HYDROCOLLOID MILK GEL FORMATION AND PROPERTIES

Three rheological measurements, as well as cryo-scanning electron microscopy, were used to study the mechanism of gel formation and structure of a hydrocolloid-based milk gel. Processing conditions included combinations of pH level and total solids concentration as well as fat content. The first two variables and their interaction influenced gel point, gel strength, viscoelasticity and syneresis; while fat served primarily as a filler of the gel matrix, it also influenced those properties. In model studies of carrageenan and kappa-casein, calcium ions promoted gelation. Gel microstructure was dictated by processing variables and governed physical properties. The cold-setting mechanism occurred in three stages, hypothesized to include increased viscosity and molecular alignment, molecular interaction, and aggregation.