Effect of formation of the maltodextrin/gelatin emulsion on gel properties of gelatin

This work investigated the influence of formation of the maltodextrin/gelatin emulsion on gel properties of gelatin. When the maltodextrin/gelatin emulsion was formed, adding maltodextrin increased the gelling temperature (Tg) but decreased the hardness of the gelatin gel. However, adding sucrose increased both the Tg and hardness, since no emulsion was formed. Thus, this work further investigated effects of the initial volume ratio of the gelatin and maltodextrin solutions (VGE/VMD), the dextrose equivalent (DE) of maltodextrin and the biopolymer concentrations on microstructure and properties of the emulsion gel. When the VGE/VMD was 3:7, 5:5, and 7:3, the Tg was 21.6, 24.6, and 23.8 °C, respectively, while the hardness was 365.2, 570.1, and 708.7 g, respectively. The droplet size decreased, as the VGE/VMD increased. These results suggested that smaller droplets induced a stronger emulsion gel. Similarly, maltodextrin of higher DE induced smaller droplets, lower Tg and larger hardness. Moreover, the gelatin concentration was positively correlated with the Tg and hardness but had no linear correlation with the droplet size, which suggested that more gelatin improved the gelling ability, and the emulsion gel strength depended on the gelling ability rather than the microstructure. Similarly, more maltodextrin induced higher Tg and hardness but bigger droplets.