• Thermal gelation and hardening of whey protein beads for subsequent dehydration and encapsulation using vitrifying sugars

      Hansen, Mackenzie M.; Maidannyk, Valentyn; Roos, Yrjö H.; Lauritzson Foundation; University College Cork (Elsevier BV, 2020-08)
      Solid beads were developed using whey protein isolate (WPI) and sugars for controlled hardening and vitrification of wall materials. A concentrated mixture of WPI and sucrose in water, intended for use as gelling and glass-forming ingredients, respectively, was used to form liquid feeds with varying pH, viscosities, surface tensions, solids contents and compositions. Using a peristaltic pump, feeds flowed continuously through silicon tubing and formed droplets. Rapid solidification occurred when droplets were submerged in heated, stirred oil; beads were harvested for vacuum oven drying. Dispersions were characterized by viscosity and flow testing. Dried beads were characterized for porosity, hardness, diameters, and water activity, and microstructures were analyzed with microscopy. Drop-forming dispersions comprised of 40% WPI with 10% sucrose by mass possessed structure forming and shape retention qualities. Feed composition influenced characteristics of the final product more strongly than processing conditions including heating times and temperatures.