Characterization of microencapsulated spinach extract obtained by spray-drying and freeze-drying techniques and its use as a source of chlorophyll in a chewing gum based on Pistacia atlantica

Abstract

This study aimed to extract and encapsulate spinach extract as a source of chlorophyll (CHL) through freeze- (FD) and spray-dried techniques (SD), followed by utilizing microencapsulated CHL (mCHL) in development a functional chewing gum (CG) based on Pistacia atlantica. The characteristics of mCHL underwent significant alterations through the employment of various concentrations (25 and 35% w/w) and amalgamations of Arabic gum (0–8.75 g) and maltodextrin (18.75–35 g). The mean values for powder yield and encapsulation efficiency in FD powders at 25% total solid content (TS) were 19.24% and 5.28% greater, respectively, than those of spray-dried samples, while SD microcapsules exhibited significantly enhanced storage stability. Microscopic analysis revealed the considerable impact of drying method, carrier type, concentration, and ratio on both the size and surface properties of FD- and SD-mCHL. An increase in TS from 25% to 35% resulted in a significant increase in mean particle size for SD powders from 7.19 μm to 10.96 μm. The textural analysis of CG demonstrated that the incorporation of CHL, in both free and encapsulated forms, did not negatively affect its hardness, adhesiveness, springiness, cohesiveness, chewiness, and resilience. Furthermore, the sensorial attributes of the CG samples, including appearance, spinach taste, and overall acceptability, were improved. Oral release analysis showed that after 15 min of chewing, the CHL release from CG samples was 94.5% and 70.3%, respectively, indicating that SD provided a slow release mechanism for CHL. In conclusion, both FD and SD CHL exhibited favorable technological traits and can be utilized as a delivery vehicle towards development of functional food products.