Utilization of Infrared Drying as Alternative to Spray- and Freeze-Drying for Low Energy Consumption in the Production of Powdered Gelatin.

Abstract

This study evaluated possible utilization of infrared drying (ID) as an alternative to spray- (SD) and freeze-drying (FD) for fish skin-derived gelatins. Physical, functional, thermal, and spectroscopic analyses were conducted for characterization of the resulting gelatin powders. Energy consumption for the applied drying methods were 3.41, 8.46 and 25.33 kWh/kg for ID, SD and FD respectively, indicating that ID had the lowest energy consumption among the studied methods. Gel strength, on the other hand, was lower (398.4 g) in infrared-dried gelatin (ID-FG) compared to that (454.9 g) of freeze-dried gelatin (FD-FG) and that (472.7 g) of spray-dried gelatin (SD-FG). TGA curves indicated that ID-FG showed more resilience to thermal degradation. SDS-PAGE and UV-Vis spectra indicated that slight degradation was observed in the β-configuration of ID-FG. ID-FG and SD-FG gelatins had the highest water holding capacity (WHC), protein solubility and transparency values compared to that of FD-FG. Morphological structures of the samples were quite different as shown by SEM visuals. Ultimately, the findings showed that infrared drying may be a promising alternative for gelatin processing, maintaining product quality and supporting sustainable practices in food and other industries.