Comparative analysis of freeze drying and spray drying methods for encapsulation of chlorophyll with maltodextrin and whey protein isolate
Shahrbanoo Ahmadi Ledari, Jafar Mohammadzadeh Milani, Seyed‐Ahmad Shahidi, Abdolkhaleg Golkar
Abstract
Chlorophyll (Chl) is a healthy green pigment that is very unstable. So, chlorophyll microcapsules were fabricated using maltodextrin and whey protein isolate as carriers and freeze-drying (FD) and spray-drying (SD) as encapsulation methods. The microcapsules obtained by the freeze-drying method (FDM) had smaller particle sizes (1.087-0.165 µm) and higher ζ-potential (-10.6 to -18.3 mV) than the spray-drying method (SDM) (3.420-0.285 µm) and (-9.5 to -10.7 mV) respectively. FTIR, XRD, and DSC studies showed that the inclusion of Chl within microcapsules and FDM had a higher melting point (150.12 °C) than SDM (125.03 °C) and Chl (115.66 °C). FD was more effective in protecting Chl from changes in pH (pH 2 to 8, Chl retention; 49.67 %-91.28 %) and light (Chl retention; 38.12 %) than SD. Therefore, due to preserving Chl and increasing its stability, FDM could be a promising approach to use as a natural food colourant.