Stabilization of Chlorella Bioactive Hydrolysates Within Biopolymeric Carriers: Techno-functional, Structural, and Biological Properties

Chlorella vulgaris (CV) is a green unicellular microalga with various bioactive compounds (BACs) and is highly appreciated due to its variety of biological activities. Among different sources, bioactive peptides have positive biological effects and numerous health-promoting properties. However, instability, reactivity and high bitterness are the main challenges which may restrict the application of these components in the preparation of diverse food compounds. Therefore, the present investigation stresses the capability of the gum arabic (GA), maltodextrin (MD), pectin (PE) and alginate (AL), and combinations of them as carrier agents on the physicochemical, techno-functional, structural and bioactivity of spray-dried CV peptides. Biological indices were affected by the degree of hydrolysis and free amino acid values. The alteration in physicochemical, functional, flowability, along with color characteristics may be associated with the composition of the carriers. MD–AL combination showed the best performance on the mentioned indicators, physical stability and scavenging the ABTS (84%) and DPPH (77%) radicals of spray-dried (SD) peptides. The chemical structures (FTIR analysis) indicated the placement of peptides in the carrier matrix. SEM images of SD particles revealed wrinkled, irregular, and hollow structures (matrix-type microsphere) in different sizes. Referring to the findings, microencapsulated CV peptides are a valuable source of BACs in functional formulations. Graphical Abstract