Ultrasound, microwave and enzyme-assisted multiproduct biorefinery of Ascophyllum nodosum.

This study investigated the multiproduct (fucoidans, ß-glucans, proteins, carotenoids, fatty acids, amino acids and polyphenols) valorization of the invasive macroalgae Ascophyllum nodosum within a green biorefinery concept using ultrasound (US), microwave (MW) treatment followed by supercritical CO2 (SC-CO2) with co-solvent and enzymatic extraction. Water and 50% aqueous ethanol were used as green extraction solvents. The extraction methods using 50% ethanol as extraction solvent improved the yields of phenolic compounds and glucan and enhanced in vitro antioxidant activity. The characterization of SC-CO2 extracts revealed that pretreatment with US and MW improved the 2-fold yield of carotenoids, total phenolics and fatty acids. However, US/MW pretreatment and enzymatic extraction did not improve the yields of proteins and free amino acids. Overall, using concurrent green US/MW-assisted extraction methods enhanced the yields of the bioactive compounds in a short duration and provided extracts with a better antioxidant capacity in the field of food applications.

Supercritical-CO2 extraction, identification and quantification of polyprenol as a bioactive ingredient from Irish trees species.

This study ascertained the accumulation of polyprenol from four Irish conifer species Picea sitchensis, Cedrus atlantica 'Glauca', Pinus sylvestris and Taxus baccata and one flowering tree Cotoneaster hybrida using supercritical fluid extraction with carbon dioxide (SFE-CO2) and solvent extraction. The effects of SFE-CO2 parameters such as temperature (ranged from 40 to 70 [Formula: see text]), pressure (ranged from 100 to 350 bars) and dynamic time (from 70 min to 7 h) were analysed on the extraction efficiency of polyprenol. Qualitative and quantitative analysis of polyprenol was examined using high-performance liquid chromatography. Results showed that P. sylvestris accumulated the highest polyprenol yield of 14.00  ± [Formula: see text]mg g-1 DW when extracted with hexane:acetone (1:1 v/v). However, with SFE-CO2 conditions of 200 bars, 70 [Formula: see text], 7 h, with absolute ethanol as a cosolvent with a flow rate of 0.05 ml min-1, P. sitchensis accumulated the highest polyprenol yield of 6.35 ± [Formula: see text] mg g-1DW. This study emphasised the potential application of SFE-CO2 in the extraction of polyprenol as an environmentally friendly method to be used in pharmaceutical and food industries.