Gelling Properties and Drying Behavior of Gelatin-Based Candies

This work reports the results of the first task of the PhD project on the gelling properties and drying of gelatin-based gummy candies, combining an industrial-scale study with a parallel laboratory investigation. At industrial scale, the drying of different types of gummies was studied in a pilot plant reproducing the production line, monitoring temperature and relative humidity and in parallel with the evaluation of the product properties (moisture and aw) over time. Independently on the drying cycle, a decrease of 50 % of the total moisture occurred within the first 20 % of the process time; a falling-rate moisture loss trend with no constant-rate period, consistent with the diffusion-limited drying of starch-moulded candies was observed. In parallel, the gelling behaviour of the gelatins at different Bloom was studied through the least gelation concentration (LGC) of binary water–gelatin and ternary water–gelatin–sugar systems (with glucose or sucrose). In water, the LGC decreased with increasing bloom strength, whereas in the presence of sugar all gelatins gelled at a lower common concentration, with no difference between glucose and sucrose. Gel strength, evaluated by texture profile analysis, increased with gelatin concentration and bloom strength, and the addition of sugar. These results link the macroscopic behavior of the industrial drying process to the technological functionality of gelatin, providing a basis for the optimization of the process.