RT info:eu-repo/semantics/conferenceObject T1 Supercritical carbon dioxide extraction of brewer´s spent grain (BSG) A1 Alonso Riaño, Patricia A1 Melgosa Gómez, Rodrigo A1 Trigueros Andrés, Ester A1 Benito Román, Oscar A1 Illera Gigante, Alba Ester A1 Beltrán Calvo, Sagrario A1 Sanz Díez, Mª Teresa K1 Ingeniería química K1 Chemical engineering AB Brewer’s spent grain (BSG) is one of the most important by-products in large and small-scale breweries. BSG is the solid residue generated after mashing and wort filtrationprocess, it is generated at an average rate of 20 kg per 100 L of beer and accounts forapproximately 85 % of the total residues of the brewing process [4]. Nowadays, it ismainly used for animal feed (70 %), biogas production (10 %), or landfilled [5].However, BSG presents a valuable chemical composition with a high content of proteinand carbohydrates, as well as important quantities of phenolic compounds with potentialbioactive properties. BSG also contains non-negligible amount of lipids (5 %) with morethan 50 % being linoleic acid (C18:2 ω-6) [6].Due to the valuable chemical composition of BSG, different techniques have beenproposed to valorize this lignocellulosic biomass, such as enzymatic and chemicalhydrolysis, ultrasound assisted extraction or microwave assisted extraction [7]. Highpressure processing of biomass has been also proposed since it offers unique opportunitiesin the extraction and valorization of the bioactive compounds of BSG. Among the different high-pressure processes, the use of supercritical CO2 (sc-CO2)presents a great attractive since it is considered a green solvent and it presents gas-like(high diffusivities) and liquid-like (good solvation power) properties at supercriticalconditions (Tc = 31.1 oC pc= 7.39 MPa). Sc-CO2 has been extensively studied as a greenextracting agent over traditional organic solvents to valorize the lipophilic fraction ofbiomass [8].From a biorefinery perspective and aiming at the integral valorization of BSG, sc-CO2extraction and enzymatic hydrolysis processes have been applied to this by-product. First,the extraction of the lipophilic fraction of BSG with sc-CO2 has been systematicallystudied. The most influential extraction conditions, namely pressure and temperature,were varied from 20 to 40 MPa and from 313 to 353 K, respectively. A maximum yieldof 5.70 ± 0.07 g /100 gBSG was obtained at 353 K and 40 MPa (see Graphical abstract, Fig.a)). High pressures and temperatures resulted in higher content of total phenolic andflavonoids compounds, as well as higher antioxidant capacity.Enzymatic hydrolysis was performed on samples after sc-CO2 treatment and non-treatedBSG samples. Enzymatic hydrolysis was carried out at 323 K in an acetate buffer at pH=5with a cellulase, 1,4-(1,3:1,4)-β-D-Glucan 4-glucanohydrolase, EC 3.2.1.4, fromAspergillus niger provided by Sigma-Aldrich.The graphical abstract b) represents the glucose yield along enzymatic hydrolysis for sc-CO2 treated and non-treated BSG at different enzyme concentrations. An improvement ofthe enzymatic hydrolysis yield by cellulase was observed in the sc-CO2 treated BSGcompared to the non-treated. This improvement could be partially attributed to theremoval of the lipid fraction and to morphological changes of BSG after sc-CO2. Basedon this double benefit, sc-CO2 can play an important role on biomass valorization [8]. YR 2022 FD 2022 LK http://hdl.handle.net/10259/6657 UL http://hdl.handle.net/10259/6657 LA eng NO Póster presentado en: EIFS2022, the 2nd Iberian Meeting on Supercritical Fluids (2º Encontro Ibérico de Fluidos Supercríticos / 2º Encuentro Ibérico de Fluidos Supercríticos), to be held on 28.February - 2.March 2022 in Coimbra, Portugal. NO AEI [PID2019-104950RB-I00 and PID2020-116716RJ-I00] and JCyL and ERDF [BU050P20]. P. AlonsoRiaño and E. Trigueros acknowledge funding from JCyL and ESF [Orden EDU/556/2019 and EDU/574/2018, respectively]. R.Melgosa is supported by a Beatriz Galindo Research Fellowship [BG20/00182]. Ó. Benito-Román post-doctoral contract was fundedby AEI [PID2020-116716RJ-I00/AEI/10.13039/501100011033]. A.E. Illera post-doctoral contract was funded by JCyL and ERDF[BU050P20]. DS Repositorio Institucional de la Universidad de Burgos RD 25-abr-2024