RT info:eu-repo/semantics/conferenceObject
T1 Modification of brewer’s spent grain after sc-CO2 extraction: improvement of sugar and phenolic compounds release
A1 Alonso Riaño, Patricia
A1 Melgosa Gómez, Rodrigo
A1 Trigueros Andrés, Ester
A1 Beltrán Calvo, Sagrario
A1 Sanz Díez, Mª Teresa
K1 Ingeniería química
K1 Chemical engineering
AB Brewer ́s spent grain (BSG) is the solid by-product generated in breweries after themashing and wort filtration process. It comprises about 85 % of the total by-products,generating approximately 20 kg per 100 L [1]. BSG presents a valuable chemicalcomposition with a high content of protein and carbohydrates, 5 % of lipids and animportant source of phenolic compounds. Among the different techniques proposed tovalorize BSG, supercritical CO2 (sc-CO2) has become a promising technology to processbiomass. The main aim of this work was to assess the effect of sc-CO2, after BSG oilextraction, on the subsequent enzymatic hydrolysis to hydrolyze the polysaccharidefraction into monomeric sugars by comparing the sugar yields of sc-CO2 and non-scCO2treated BSG.After sc-CO2 treatment at 40 MPa and 80 oC, the raffinate obtained was subjected toenzymatic hydrolysis by cellulase at different enzyme dose. At the sc-CO2 extraction thecarbohydrate fraction remained in the raffinate phase after extraction. Glucose yieldincreased with enzyme concentration for non-treated and sc-CO2 treated BSG. Higheryields of glucose were obtained for sc-CO2 treated compared to non-treated sc-CO2 for allthe enzymes concentrations. The percentage increase in glucose yield for sc-CO2 treatedand non-treated BSG was 8, 14 and 18 % for the three cellulase concentrations essayedin this work, 0.25, 0.5 and 1 %, respectively. The hydrolysis kinetics for xylose andarabinose have been also determined for non-treated and sc-CO2 treated BSG at 1 % ofcellulase dose. Although not big differences were observed in the final sugar yield in thehydrolysates, the initial hydrolysis rate were significant higher for the sc-CO2 treated BSGthan for the untreated samples. The higher enzymatic hydrolysis rate and yield obtained in the raffinate-BSG after sc-CO2 treatment compared with non-treated BSG could be attributed partially to the removalof the lipid fraction. As it has been described in literature [2], fats and oils could influencethe susceptibility of carbohydrates to enzymes. This improvement was also due to surfacemorphology modification. The structural and chemical changes of untreated and sc-CO2treated BSG was assessed by scanning electron microscopy and X-ray powder diffraction(XRD). Although the XRD pattern after sc-CO2 treatment indicated that the pre-treatmentwas not strong enough to modify the BSG crystallinity, the raffinate exhibited an irregularporosity and lamellar structure. sc-CO2 broke partially some structural barriers allowinga better enzyme access.Furthermore, some phenolic compounds were determined in the enzymatic hydrolysatesat the end of the hydrolysis by using 1 % of cellulase (Table 1). It was observed that forp-coumaric acid and ferulic acid, a concentration 31 and 24 % higher, respectively, wasobtained in the BSG hydrolysates after sc-CO2 treatment, while for vanillin similarconcentration was obtained in both hydrolysates. The concentration of p-coumaric acidand vanillin after cellulase hydrolysis was lower than the values previously reported forthe same BSG by alkaline, xylanase (1%) and subcritical water hydrolysis [3], [4].Nevertheless, for ferulic acid, only a higher value was reached for alkaline hydrolysis.
YR 2022
FD 2022
LK http://hdl.handle.net/10259/6658
UL http://hdl.handle.net/10259/6658
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 JCyL and ERDF for financial support of project BU050P20Agencia Estatal de Investigación for financial support of project PID2019-104950RB-I00 / AEI / 10.13039/501100011033JCyL and ESF for E. Trigueros (ORDEN EDU/574/2018) and P. Alonso-Riaño predoctoral (EDU/556/2019) contractsR. Melgosa is supported by a Beatriz Galindo Research Fellowship [BG20/00182]
DS Repositorio Institucional de la Universidad de Burgos
RD 26-abr-2024