Effect of wall materials on the spray drying encapsulation of brown seaweed bioactive compounds obtained by subcritical water extraction

Abstract

Incorporation of algae bioactive compounds in real food systems requires integrated extraction and encapsulation processes to ensure the stability of highly sensitive and perishable compounds of interest. This study presents the spray drying encapsulation of brown seaweed (Saccharina japonica) bioactive compounds obtained by subcritical water extraction using different coating materials. Polysaccharides (dextrin, maltodextrin, lactose, and gum arabic) and proteins (whey protein, gelatin, and sodium caseinate) were studied for S. japonica polyphenolic compounds (PCs) encapsulation efficiency (EE) and retention of antioxidant activities (AAs). Particles were characterized for the content in phenolic compounds, physicochemical properties for moisture content, solubility, bulk and tapped densities, particle size distribution, morphology (SEM), and infrared absorption spectroscopy (FT-IR). Whey protein and gelatin exhibited best EE (87.11% and 86.59%, respectively), and more than two-fold EE in polysaccharides coating materials. Smallest particles were observed in maltodextrin with a Cumulative particle size distribution (D90) of 9.4 μm while D90 was large in protein coating materials with 148.6 μm and 1290.8 μm for whey protein and gelatin, respectively. Lowest bulk and tapped densities were observed in gelatin coated microparticles with 0.10 and 0.17 g/cm3 and highest values in lactose with 0.33 and 0.56 g/cm3. p-Hydroxybenzoic acid (HA) was the most predominant phenolic acid recovered by subcritical water extraction with 23.58 mg/g, and well retained in gelatin coated microparticles (27.99 mg/g). Based on the EE whey protein and gelatin were more suitable for encapsulation of PCs from aqueous S. japonica extracts. The combined use of subcritical water extraction and spray drying encapsulation could be an effective approach toward the recovery and formulation of algae bioactive compounds with potential applications in functional food product development and cosmetics.