With the growing consumer demands for greener alternatives that do not involve toxic chemicals as well as the industry concerns of sustainable, nontoxic routes of extraction, the applications of novel extraction technologies in the food industry have been widely studied. This review discussed the novel extraction technologies including their mechanisms, protocols, influencing factors, advantages and drawbacks, as well as a comprehensive summary of the combination of the novel extraction technologies for phyto-bioactive compounds. Novel extraction methods, including ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE), are considered as clean, green and efficient alternative to conventional extraction technologies. Their combinations, ultrasound-assisted enzymatic extraction (UAEE), microwave-assisted enzymatic extraction (MAEE) and ultrasonic microwave-assisted extraction (UMAE), can exhibit higher potential extraction ability. However, some of them need specific equipment. The food industry in the extraction sector should choose a proper extraction method which has a balance between product quality, process efficiency, production costs and environmentally friendly processes. The current review presented comprehensive references for future research on the novel extraction of phyto-bioactive compounds extraction.

The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO₂ (SC-CO₂) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO₂ method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO₂ (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO₂ oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO₂. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO₂ extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.