A Critical Comparison of the Advanced Extraction Techniques Applied to Obtain Health-Promoting Compounds from Seaweeds

Abstract

Marine macroalgae are rich in bioactive compounds that can be applied in several fields, mainly food, cosmetics, and medicine. The health-promoting effects of bioactive compounds, such as polyphenols, polysaccharides, carotenoids, proteins, and fatty acids, have been increasingly explored, especially regarding their antioxidant activity and improvement in human health. To extract these valuable compounds, advanced technologies that include Supercritical-Fluid Extraction (SFE), Pressurised-Liquid Extraction (PLE), Ultrasound-Assisted Extraction (UAE), Microwave-Assisted Extraction (MAE), Enzyme-Assisted Extraction (EAE), Ultrasound-Microwave-Assisted Extraction (UMAE) and Liquefied Gas Extraction (LGE) have been assessed due to their notable advantages over the conventional methods (Solid–Liquid and Soxhlet extraction). These advanced techniques are considerably influenced by different extraction parameters such as temperature, pressure, type of solvent, extraction time, solvent:solid material ratio, power (MAE, UAE, and UMAE), enzymes used (EAE), and factors related to the macroalgae matrix itself. Optimizing these process parameters for each method is critical to obtain better efficiency results for the targeted bioactive compounds. Macroalgae are natural sources with undeniable beneficial effects on human health. In this context, optimising the extraction techniques discussed in this review should prioritise exploiting these valuable resources' wide range of bioactive properties.

Cosmeceutical Effects of Ishige okamurae Celluclast Extract

“…The extraction of bioactive compounds from seaweeds is restricted by the complexity of their cell wall polysaccharides. As Celluclast can degrade the seaweed cell wall, enzyme-assisted extraction helps the release of biologically active substances and contributes to increasing the content of polysaccharides and fucose in the extract [ 19 ]. As shown in Table 1 , carbohydrates were concentrated during the precipitation process, and high amounts of sulfated polysaccharides were confirmed, which contributed to the cosmeceutical effects.…”

“…A variety of extraction technologies are widely used, such as enzyme-assisted extraction, ultra-high-pressure extraction, microwave-assisted extraction technology, and supercritical fluid extraction. Compared with organic and water extraction, enzymatic extraction has a high catalytic efficiency and is more conducive to destroying the cell walls, which can not only improve the extraction yield but also show better biological activity, which is suitable for algae extraction [ 18 , 19 ]. In addition, enzyme-assisted extraction technology has mild reaction conditions and is safe.…”

Major Phytochemicals: Recent Advances in Health Benefits and Extraction Method

“…It can be used for the extraction of flavonoids, phytosterols, alkaloids, and volatile oils. Cyclohexanes are used for the extraction of fats, waxes, and oils [ 10 , 97 , 98 , 99 ]. The detailed considerations for the suitable solvent for the extraction of phytochemicals have been discussed by Kim and Wijesekra [ 69 ].…”

“…rapa L.), and green leafy vegetables. The commonly found carotenoids are α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and fucoxanthin [ 10 ]. β-carotene is the most abundant carotenoid in most fruits and vegetables, followed by α-carotene; β-cryptoxanthin is a major carotenoid in tangerines, persimmons, and oranges; lutein and zeaxanthin are found mainly in green leafy vegetables; lycopene is found in tomatoes; and fucoxanthin is found in brown algae.…”

“…Hence, it is imperative to select a suitable method of phytochemical extraction. Some of the widely used conventional methods are maceration, percolation, decoction, reflux extraction, and Soxhlet extraction, and the novel methods are pressurized liquid extraction (PLE), high hydrostatic pressure extraction (HHP), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), pulsed electric field extraction (PEF), vibro-cavitation extraction, extraction under vacuum-oscillating boiling conditions, extractions in mills, extraction in rotary-pulsation apparatus (RPE), liquid gas extraction (LGS), enzyme-assisted extraction (EAE), supercritical fluid extraction (SFE), and natural deep eutectic solvent extraction (NADES) [ 8 , 10 ]. This article discusses the suitability of phytochemical extraction methods under different extraction conditions such as substrate type, type of matrix, the solvent used, extraction temperature, etc.…”