Functional Activity of Oils from Brewer’s Spent Grain Extracted by Supercritical Carbon Dioxide
- 231 Downloads
This work explores the functionality of oils from brewer’s spent grain by supercritical fluid extraction. The process was performed at 20 and 30 MPa, and 40 and 50 °C without and with ethanol as co-solvent in percentages equal to 4 and 8%. Supercritical fluid extraction was compared with Soxhlet using hexane as solvent. The extracts were characterized for their antioxidant capacity by 2,2-diphenyl-1-picryhydrazyl radical (DPPH) assays, total phenolic content by Folin–Ciocalteu assay, fatty acid profile by GC-FID, and oxidative stability by isothermal calorimetry. Moreover, their capacity to retard the oxidation of linseed oil was also studied. Samples from Soxhlet and supercritical carbon dioxide (30 MPa, 50 °C, and 8% of ethanol) showed the highest yields (6.1 ± 0.3% and 6.5 ± 0.1%, w/w), recovery (78.3 ± 2.1% and 81.3 ± 1.8%, w/w), total phenolic contents (28.3 ± 0.5 and 26.2 ± 0.3 mg GAE/g of sample), and antioxidant activity (16.7 ± 0.1 and 14.2 ± 0.1 mg TEA/g of sample). The fatty acid composition of brewer’s spent oil extracted by SFE was similar to that extracted by Soxhlet. The same extracts also reported the highest oxidative stability and ability to slow down linseed oil oxidation.
KeywordsBrewer’s spent grain Supercritical carbon dioxide extraction Co-solvent Isothermal calorimetry Waste recovery
The authors received financial support from the Province of Bolzano (Landesregierung mittels Beschluss Nr. 1472, 07.10.2013).
- Benelli, P., Riehl, C. A. S., Smania, A., Smaniac, E. F. A., & Ferreira, S. R. S. (2010). Bioactive extracts of orange (Citrus sinensis L. Osbeck) pomace obtained by SCFE and low pressure techniques: mathematical modeling and extract composition. Journal of Supercritical Fluids, 55(1), 132–141.CrossRefGoogle Scholar
- Hayes, J. E., Allen, P., Brunton, N., O'grady, M. N., & Kerry, J. P. (2011). Phenolic composition and in vitro antioxidant capacity of four commercial phytochemical products: olive leaf extract (Olea europaea L.), lutein, sesamol and ellagic acid. Food Chemistry, 126(3), 948–955.CrossRefGoogle Scholar
- Labuza, T. P., & Dugan, L., Jr. (1971). Kinetics of lipid oxidation in foods. Critical Reviews in Food Science and Nutrition, 2, 355–405.Google Scholar
- Mccarthy, A. L., O'callaghan, Y. C., Piggott, C. O., Fitzgerald, R. J., & O'brien, N. M. (2013). Brewers’ spent grain; bioactivity of phenolic component, its role in animal nutrition and potential for incorporation in functional foods: a review. Proceedings of the Nutrition Society, 72(01), 117–125.CrossRefPubMedGoogle Scholar
- Moreira, M. M., Morais, S., Carvalho, D. O., Barros, A. A., Delerue-Matos, C., & Guido, L. F. (2013). Brewer’s spent grain from different types of malt: evaluation of the antioxidant activity and identification of the major phenolic compounds. Food Research International, 54(1), 382–388.CrossRefGoogle Scholar
- Singleton, V., & Rossi, J. A. (1965). Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. American Journal of Enology and Viticulture, 16, 144–158.Google Scholar