Pressurized liquid extraction of brewer’s spent grain: Kinetics and crude extracts characterization

Abstract

In this study, extraction yield of valuable compounds from brewer's spent grain (BSG) using pressurized liquid extraction (PLE) was investigated varying temperature, solvent type, and flow rate at a constant pressure. The results were compared with Soxhlet extractions using the total phenolic compounds (TPC), total flavonoid compounds (TFC), antioxidant activity (AA), reducing sugars (RS), and total reducing sugars (TRS) as indices. The highest PLE extraction yield was 20.1 wt%, at 120°C, 2 mL/min using ethanol to water volume ratio of 0.5, at 10 MPa. The TPC, TFC, and AA content were favored by water and water/ethanol extractions and temperature increase. The highest AA was obtained with water at 120 °C and 4 mL/min achieving 9944, 4769 and 4096 µmol TE/100 g of BSG extract, respectively. PLE was capable of present high extraction yields maintaining the RS and TRS in the BSG matrix. In addition, BSG was defatted with compressed propane before the extraction with PLE, showing that 2 compressed propane is highly efficient in recovering the lipid fraction from BSG. The results demonstrated a great potential of water and different EtOH/Water solvent ratio at pressurized conditions for obtaining bio-compounds of BSG in a crude extract with expressive biological activity.

Valorizing Brewer's Spent Grain: A Sequential Pathway of Supercritical Extraction, Hydrolysis, and Fermentation

“…observed an extraction yield in ethanol of 14.39±0.10 after 24 h. This value appears aligned with the value obtained in this work considering the difference in the extraction time. Extraction yields in acetone and n-hexane are in agreement with the results reported by Herbst et al(Herbst et al, 2021) DoE for sulfuric and nitric acid pre-treatment.…”

“…Similar results were observed considering the total yield (p = 0.011). Unlike the results reported by Herbst et al (Herbst et al, 2021), the extraction sequence with the highest yield was the ethanol-water. A similar behavior was observed by Spigno et al (Spigno et al, 2007) for the extraction of phenolic components from grape seeds.…”

Valorization of coffee bean husk via pressurized liquid extraction for production of physicochemical extract

“…This result demonstrates the favoring of the extraction mainly arising from the mass transfer between the solvent and the matrix, propitiated by the thermodynamic properties that the mixture between water and ethanol assumes, when compared to the use of absolute ethanol. 61 For the TPA, the modification of the temperature and the solvent demonstrated an influence similar to that previously reported for the liquid extract (Table 2), so that the interaction of these variables promoted the extraction of these compounds (runs 3 and 12). The increase in the TPC content is related to the modification of the extractor solvent (runs 3 and 12), following the trend of the data obtained for TPA and demonstrating a synergistic effect between these compounds, as reported by Aguilera et al 41 Due to the greater G Y of PLE, the purity of TPC and TF was lower than that resulting from the Soxhlet (Table 3), and this is due to the technique being less selective for these compounds under the investigated conditions.…”

“…Regarding the PLE data, it could be verified that the greatest influence exerted on the G Y was the composition of the extraction solvent (runs 10 and 12), in which the variation between absolute ethanol and hydroethanolic solvent (50%, v/v) provided a percentage increase of ~543.5% in the mass of extract obtained. This result demonstrates the favoring of the extraction mainly arising from the mass transfer between the solvent and the matrix, propitiated by the thermodynamic properties that the mixture between water and ethanol assumes, when compared to the use of absolute ethanol 61 …”

Investigation of the Genotoxic, Antigenotoxic and Antioxidant Profile of Different Extracts from Equisetum arvense L.

“…Plant extracts are widely used for the production of novel therapeutic drugs against a number of ailments [ 1 , 2 ]. Solvents, such as ethanol, methanol and water, are extensively used for the extraction of valuable compounds of different origin [ 10 , 35 , 36 , 37 , 38 ]. The results of the present study show that these solvents were very effective and could mediate the beneficial effects of the plant E. arvense L., at least in the case of its cytogenotoxic potential.…”