"Extraction séquentielle de molécules à haute valeur ajoutée à partir de pulpes de raisin en utilisant des fluides supercritiques avec l'eau comme co-solvant

Inspired by the concept of organic waste valorisation and heading towards a sustainable economy, a green chemistry extraction technique involving supercritical carbon dioxide (SC-CO2) along with water as a cosolvent was employed for the main winery by-product (grape pomaces). The objective was to selectively extract high-value added molecules, in particular phenolic compounds and polysaccharides. The experimental design involved applying three distinct temperature conditions (40, 60, and 80 °C), and a constant pressure of 400 bar. Phenolic compounds and high-molecular weight isolates (449-478 kDa) containing low methoxyl (% DE = 23) pectic substances were detected in the SC-CO 2 extracts accompanied by water as a co-solvent. The phenolic acids, namely, gallic (GA), protocatechuic (PCA), coumaric (CouA), and caftaric (CTA), and flavonoids, namely, procyanidin B1 (PRC B1), procyanidin B 2 (+) (PRC B 2), (+) catechin (CT), and (−) epicatechin (ECT) were found in all the extracts under the tested experimental conditions. The following study underscores the potential of the pressurized CO 2 /H 2 O medium as an effective solvent with minimal environmental impacts for the comprehensive valorisation of the main winery by-product, specifically targeting polysaccharides and phenolic compounds. Sustainability spotlight This study focuses on the extraction of valuable molecules such as polyphenols and bers from grape pomace, a by-product of wine production, using a green chemistry technique called supercritical uid extraction. These extracted molecules have potential applications as antioxidants in wine production. The research highlights the signicance of specic United Nations sustainable development goals, including affordable and clean energy (SDG 7), industry, innovation, and infrastructure (SDG 9), and climate action (SDG 13)