Whey protein concentrate/λ-carrageenan systems: Effect of processing parameters on the dynamics of gelation and gel properties

The thermal characteristics, dynamics of gelation and gel properties of commercial whey protein concentrate (WPC), WPC/λ-carrageenan (λ-C) mixtures (M) and WPC/λ-C spray-dried mixtures (DM) have been characterized. In a second stage, the effect of the gelling variables (T, pH, total solid content) on gelation and textural properties of DM was evaluated through a Doehlert uniform shell design. The presence of λ-C either in mixtures (M) or in DM promoted the WPC gelation at lower concentration (8%). M showed higher rates of formation and better gel properties (higher hardness, adhesiveness, springiness and cohesiveness) than DM. Nevertheless, when the effects of pH (6.0–7.0), heating temperature (75–90 °C) and total solid content (12–20 wt%) on gelation dynamics and gel properties of DM were studied, gels with a wide range of rheological and textural properties were obtained. While pH did not affect the gelation dynamics, it had some effect on rheological and textural properties. Total solid content and heating temperature were the most important variables for the dynamics of gelation (gelation rate (1/tgel), gelation temperature (Tgel), rate constant of gel structure development (kG), elastic modulus after cooling (G′c) and textural parameters (hardness, springiness and cohesiveness).