Effect of microwave-assisted treatment on the composition of spray-dried Porphyridium cruentum extract

Abstract

Introduction Microalgae are a valuable source of natural products with bioactive properties, with applications in biomedicine, the pharmaceutical industry, nutrition, and cosmetics. Among them, the red microalga Porphyridium cruentum is notable for its high content of biomolecules with antioxidant, anti-inflammatory, and immunomodulatory effects. Efficient extraction and preservation methods are essential to optimize the use of these biomolecules. Material and methods Biomass from Porphyridium cruentum was treated with microwaves (MW) at 180 W, 300 W, and 450 W for 10, 20, and 30 seconds, followed by aqueous extraction at 80 °C. The resulting extracts were spray-dried into powders at 100 °C. Both aqueous extracts and powders were analyzed for their composition (proteins, carbohydrates, phenolic compounds) and antioxidant activity. Results Moderate microwave treatment (180 W for 20–30 seconds) enhanced the extraction of proteins and carbohydrates while preserving high antioxidant activity. The resulting powders retained up to 90.96% of proteins, 95.81% of carbohydrates, and 74.91% of phenolic compounds, with only minimal losses in antioxidant activity after six months of storage. Conclusions These findings demonstrate that microwave treatment of Porphyridium cruentum biomass, followed by aqueous extraction and spray drying, is an effective strategy for obtaining and preserving microalgal bioactive compounds. This approach supports their potential applications in the pharmaceutical, nutraceutical, and cosmetic fields.

Microalgele reprezintă o sursă valoroasă de produse naturale cu proprietăți bioactive, având aplicații în biomedicină, industria farmaceutică, nutriție și cosmetică. Microalga roșie Porphyridium cruentum se remarcă prin conținutul său bogat în biomolecule cu efecte antioxidante, antiinflamatoare și imunomodulatoare. Pentru valorificarea optimă a acestor biomolecule, este esențială aplicarea unor metode eficiente de extracție și conservare.