Optimizing microalgae bioprocessing and digestibility: Spraying techniques for drying and encapsulation

Microalgae are a promising food source due to their abundance of proteins, lipids, carbohydrates, pigments, and carotenoids. This review focuses on the application of spray drying for producing dry powdered microalgae biomass and encapsulating bioproducts derived from microalgae. It highlights specific advancements in optimizing spray drying conditions to improve production yields, stabilize bioactive compounds, and enhance digestibility. This review identifies optimal spray drying conditions for making dry powdered microalgae biomass, including inlet air temperatures of 150–170 °C and outlet temperatures of 40–80 °C, which can retain bioactive compounds while maintaining high efficiency. Additionally, the present review examines the use of encapsulating materials, such as maltodextrin and inulin, which have achieved a high carotenoid yield over 95%. For encapsulated bioproducts, wall materials like chitosan and whey proteins are explored for their ability to improve intestinal permeability, maintain stability across pH ranges, and minimize toxicity to intestinal mucosa. By providing detailed analysis and examples, this review outlines the technological and practical contributions of spray drying and encapsulation to enhancing the usability and nutritional potential of microalgal products in food and nutraceutical applications. • Spray drying and encapsulation enhance the stability and bioavailability of microalgae. • Encapsulation materials like maltodextrin and inulin ensure >95% carotenoid recovery. • Mannitol boosts the digestibility of microalgae for improved nutritional applications. • Advances in spray drying and encapsulation support industrial microalgae applications.