Stabilization of Chlorophylls and Carotenoids in Halospirulina tapeticola through Drying-Assisted Encapsulation: Effects of Excipient Matrices on Pigment Retention and Release

Abstract

Halospirulina tapeticola is a pigment-rich microalga with potential as a natural source of chlorophylls and carotenoids for functional food applications; however, its high moisture content and pigment susceptibility to degradation during processing and storage limit practical utilization. This study aimed to determine how drying technology and carrier composition affect powder recovery, pigment retention, morphology, and gastrointestinal release of H. tapeticola. Maltodextrin (MD), trehalose (Tre), hydroxypropyl methylcellulose (HPMC), and inulin were selected for their complementary encapsulation properties, including film formation, matrix stabilization, and protection of sensitive compounds during dehydration. Trehalose was included for its ability to form a protective glassy matrix, while inulin offers additional functional and prebiotic potential. Fresh biomass was converted into powders using freeze-drying (FD) and spray drying (SD) with different carrier combinations. Powder yields ranged from 50.31% to 91.46%, with FD generally achieving higher recovery. The highest yield (91.46%) was obtained with FD containing 15% Tre + 5% inulin, while FD with 15% MD + 5% inulin achieved the highest chlorophyll retention (88.75%). In contrast, SD with 20% MD produced the highest carotenoid retention (75.46%), indicating that optimal protection depended on pigment type and formulation. FD with 15% MD + 5% inulin also enhanced chlorophyll release under simulated intestinal conditions. Overall, this study demonstrates that drying method and carrier composition can be tailored to balance powder recovery, pigment preservation, and gastrointestinal delivery, supporting the development of stable H. tapeticola powders for functional food applications and future commercial ingredient development opportunities globally.