Ultrasound, microwave and enzyme-assisted multiproduct biorefinery of Ascophyllum nodosum

This study investigated the multiproduct (fucoidans, beta-glucans, proteins, carotenoids, fatty acids, amino acids and polyphenols) valorization of the invasive macroalgae Ascophyllum nodosum within a green biorefinery concept using ultrasound (US), microwave (MW) treatment followed by supercritical CO2 (SC-CO2) with cosolvent and enzymatic extraction. Water and 50% aqueous ethanol were used as green extraction solvents. The extraction methods using 50% ethanol as extraction solvent improved the yields of phenolic compounds and glucan and enhanced in vitro antioxidant activity. The characterization of SC-CO2 extracts revealed that pretreatment with US and MW improved the 2-fold yield of carotenoids, total phenolics and fatty acids. However, US/MW pretreatment and enzymatic extraction did not improve the yields of proteins and free amino acids. Overall, using concurrent green US/MW-assisted extraction methods enhanced the yields of the bioactive compounds in a short duration and provided extracts with a better antioxidant capacity in the field of food applications.

Automated summary

This study investigated the valorization of the invasive macroalgae Ascophyllum nodosum by exploring the extraction of multiple products using ultrasound, microwave, and supercritical CO2 techniques. The results showed that using ethanol as the extraction solvent improved the yields and antioxidant activity. Furthermore, pretreatment with ultrasound and microwave enhanced the yield of carotenoids, total phenolics, and fatty acids in the extracts.