Marine macroalgae represent a rich source of bioactive compounds that can be implemented in various food, cosmetic, and pharmaceutical products for health improvement.
Macroalgae contain various bioactive compounds with application in the food, cosmetic, and pharmaceutical industry. They showed potential for developing of new functional products which can have a positive influence on human health.
The alternative modern green extraction techniques which were presented in this review showed their potential for implementation in the industry for the isolation of bioactive compounds from marine macroalgae.
Green, red, and brown macroalgae showed significant differences in their chemical composition and each of these algae have great potential for different products.
SFE has been a good method for obtaining the extracts with fatty acids and lipids, including carotenoids, such as fucoxanthin. UAE is mostly used for the extraction of polyphenols and their correlation with antioxidant capacity of macroalgae is given.
Water and ethanol were shown as the best solvents for UAE of polyphenols. Water has been successful solvent also under the subcritical conditions in SWE. The most analyzed compounds in SWE extracts were polyphenols.
Authors established that during SWE, new antioxidants were formed and they contribute to the antioxidant capacity of the extracts. Formation of new antioxidants is the result of Maillard reactions and caramelization which occurred during the extraction process under the subcritical conditions.
MAE is the most studied extraction process and successful for isolation of bioactive compounds from marine macroalgae and obtained extracts are rich in sulfated polysaccharides, such as fucoidan, ulvan, and rhamnan sulfate, which exhibit antioxidant, anti-hyperlipidemic, and hypoglycemic activity.
Also, polyphenols, especially phlorotannins from brown algae, have been shown to possess strong antioxidant activity. Regarding the given information, it can be concluded that methods, such as SFE, UAE, SWE, and MAE can be applied for the isolation of specific bioactive compounds.
The chemical composition of the extracts
Optimizing their process parameters, desired extraction yield, and chemical composition of the extracts can be achieved. The main advantage is that the applied process parameters of each method can control the extraction of targeted compounds and their solubility.
On each of the above-mentioned extraction methods, different process parameters showed direct influence on the extracted bioactive compounds. The presented data about macroalgae contributed updating information of great potential of these marine organisms.
Due to their biological activity, application in the functional products and the influence on human health are inevitable. Preserving sensitive compounds by using novel methods that are mentioned in the present review makes them suitable for producing the extracts of higher value.