Emerging Technologies to Extract Fucoxanthin from Undaria pinnatifida: Microwave vs. Ultrasound Assisted Extractions

Abstract

Macroalgae are an extensive resource for the obtention of bioactive compounds, mainly phenolic compounds, phlorotannins, and pigments. Fucoxanthin (Fx) is the most abundant pigment present in brown algae and has shown several useful bioactivities that can be used to fortify products in the food and cosmetic industries. Nevertheless, to date, there is still insufficient literature reporting on the extraction yield of Fx from U. pinnatifida species from green technologies. In this regard, the present study aims to optimize the extraction conditions to obtain the highest Fx yield from U. pinnatifida through emerging techniques, namely microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). These methods will be compared with the conventional methodologies of heat-assisted extraction (HAE) and Soxhlet-assisted extraction (SAE). According to our results, even though the extraction yield could be slightly higher when using MAE than UAE, the Fx concentration obtained from the alga was double when using UAE. Thus, the Fx ratio in the final extract reached values of 124.39 mg Fx/g E. However, the optimal conditions should also be considered since UAE needed 30 min to perform the extraction, whereas MAE was able to obtain 58.83 mg Fx/g E in only 3 min and 2 bar, meaning less energy expenditure and minimum cost function. To our knowledge, this study obtains the highest concentrations of Fx ever reported (58.83 mg Fx/g E for MAE and 124.39 mg Fx/g E for UAE), with low energy consumption and short times (3.00 min for MAE and 35.16 min for UAE). Any of these results could be selected for further experiments and proposed for industrial scaling-up.

Recent Progress in Understanding the Impact of Food Processing and Storage on the Structure–Activity Relationship of Fucoxanthin

“…Heating is the most extensively studied factor influencing fucoxanthin extractability and stability. Some studies have found that temperature has a significant effect on fucoxanthin recovery using pressurized-liquid extraction and microwave-assisted extraction from different macro-and microalgae species [5,6]. Fucoxanthin extractability increases as temperature increases up to a certain value (around 100 • C, depending on species).…”

Biocosmetics Made with Saccharina latissima Fractions from Sustainable Treatment: Physicochemical and Thermorheological Features

“…Based on the principles of this technology, several parameters, such as solid liquid ratio, temperature, frequency and power, must be defined in an experimental work to achieve the desired product [20]. Lourenço-Lopes and coauthors (2023), focusing on the extraction of fucoxanthin, the main pigment in brown algae, explored ultrasound-assisted extraction and microwave-assisted extraction to obtain this valuable fraction from Undaria pinnatifida [21]. Based on the biorefinery concept, several fractions with potential research interests can be obtained from brown seaweeds [22].…”