Benefits and Drawbacks of Ultrasound-Assisted Extraction for the Recovery of Bioactive Compounds from Marine Algae

Abstract

The increase in life expectancy has led to the appearance of chronic diseases and interest in healthy aging, in turn promoting a growing interest in bioactive compounds (BCs) and functional ingredients. There are certain foods or products rich in functional ingredients, and algae are one of them. Algae consumption has been nominal in Europe until now. However, in recent years, it has grown significantly, partly due to globalization and the adoption of new food trends. With the aim of obtaining BCs from foods, multiple methods have been proposed, ranging from conventional ones, such as maceration or Soxhlet extraction, to more innovative methods, e.g., ultrasound-assisted extraction (UAE). UAE constitutes a novel method, belonging to so-called green chemistry, that enables the extraction of BCs requiring lower amounts of solvent and energy costs, preserving the integrity of such molecules. In recent years, this method has been often used for the extraction of different BCs from a wide range of algae, especially polysaccharides, such as carrageenans and alginate; pigments, including fucoxanthin, chlorophylls, or β-carotene; and phenolic compounds, among others. In this way, the application of UAE to marine algae is an efficient and sustainable strategy to pursue their deep characterization as a new source of BCs, especially suitable for vegetarian and vegan diets.

Critical Variables Influencing the Ultrasound-Assisted Extraction of Bioactive Compounds—A Review

“…However, the use of high ultrasound power without control can overheat the reactor producing degradation of labile compounds and solvent evaporation [13]. In addition, the higher ultrasound power, the higher UI, so that when UI reaches the maximum value can produce liquid agitation and the consequent loss of ultrasound wave and the reduction of cavitation efficiency [14].…”

“…Finally, high extraction temperatures not only affect the extraction yield but could also have negative effects due to the possible degradation of thermolabile compounds [14]. For this reason, the cooling system must allow the extraction of compounds avoiding the overheating of the medium by controlling the temperature of the system.…”

Determination of Glycerophospholipids in Biological Material Using High-Performance Liquid Chromatography with Charged Aerosol Detector HPLC-CAD—A New Approach for Isolation and Quantification

“…Each extraction step involved pulsed ultrasound driven mixing of organic and water layers to increase the surface of lipid exchange between phases (see Section 3.3 ). In contrary to other reports [ 22 , 23 ], the isolation of lipid fractions from cell membranes was carried out at low temperature due to the need to limit the activity of phospholipases and reduce the decomposition of phospholipids in the samples. Both the energy and time of sonication were not optimized, because other data indicate that in a few seconds, in small volumes, adequate phase dispersion occurs and cell membranes completely disintegrate [ 24 ].…”

From Seaweeds to Cosmeceutics: A Multidisciplinar Approach

“…Indeed, the performance of UAE as the most efficient technology for the extraction of phenolic compounds is not clearly defined [40]. Some authors evidenced that the response to UAE was species-dependent, and that a matrix pretreatment was sometimes needed [41].…”