RT info:eu-repo/semantics/conferenceObject T1 Hydrothermal fractionation of Gelidium sesquipedale alga residue by subcritical water extraction A1 Trigueros Andrés, Ester A1 Alonso Riaño, Patricia A1 Sanz Díez, Mª Teresa A1 Beltrán Calvo, Sagrario A1 Ramos Rodríguez, Cipriano A1 Benito Román, Oscar K1 Ingeniería química K1 Chemical engineering AB IntroductionGelidium sesquipedale residue after industrial agar extraction is a very valuable by-product because of its carbohydrate, protein and bioactive compounds content. Subcritical water (SW) extraction was carried out by using different solvent flow rates (4, 6 and 8ml/min) to study the effect of residence time (RT = 6.0, 4.2 and 3.0 minutes, respectively) on sugars hydrolysis and fractionation at 185°C.Results and discussionMacroalga residue after industrial agar extraction presents an important fraction of carbohydrate composed by glucans (23.4%), galactans (10.9%) and arabinans (2.9%).Accumulated hydrolysis curves for arabinans, galactans and glucans by using SW are shown in Figure 1.No monomers were observed under work conditions in subcritical water extracts so that carbohydrate fraction was recovered as sugar oligomers.Sugars extraction curves show how the lower the residence time, the higher extraction yields for all components. Moreover, a preferential hydrolysis was observed for galactans, followed by arabinans and glucans that showed the lowest yield.As has been seen, increasing and faster extraction has been found at increasing flow rate due to promotion of mass transfer of the solutes from by-product matrix1, that is translated into a greater compounds extraction. Similar results were found in literature about residence time effect on bioactive compounds extraction2,3.ConclusionsSWE constitutes an interesting technique for sugars recovery, promoting a better use of the alga residue generated in the food industry without using organic solvents in compare to conventional treatments. Low residence times led to higher sugars recovery by SW treatment. YR 2021 FD 2021 LK http://hdl.handle.net/10259/5857 UL http://hdl.handle.net/10259/5857 LA eng NO Trabajo presentado en: 18th European Meeting on Supercritical Fluids. 2021, 4-6 de mayo, Burdeos (online) NO JCyL and ERDF for financial support of projects BU301P18, BU050P20 and O. Benito-Román’s post-doctoral contract. To Agencia Estatal de Investigación for project funding PID2019-104950RB-I00/AEI/10.13039/501100011033. To the company Hiperbaric through project BIOLIGNO (10/16/BU/0017), funded by ERDF and JCyL through ICE. DS Repositorio Institucional de la Universidad de Burgos RD 26-abr-2024