Effective Production of Bioactive Phenolic Compounds from Olive Stones
Olive stones (OS) are a by-product generated in the olive oil production process. This residue is obtained in industries after the oil extraction process, and it is recognized as an interesting feedstock for the production of bioenergy and value-added products. Nevertheless, currently, it is only us...
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MDPI AG
2021-10-01
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| Series: | Biology and Life Sciences Forum |
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| Online Access: | https://www.mdpi.com/2673-9976/6/1/70 |
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| author | Carmen Padilla-Rascón Encarnación Ruiz Eulogio Castro Luisa B. Roseiro Luis C. Duarte Florbela Carvalheiro |
| author_facet | Carmen Padilla-Rascón Encarnación Ruiz Eulogio Castro Luisa B. Roseiro Luis C. Duarte Florbela Carvalheiro |
| author_sort | Carmen Padilla-Rascón |
| collection | DOAJ |
| description | Olive stones (OS) are a by-product generated in the olive oil production process. This residue is obtained in industries after the oil extraction process, and it is recognized as an interesting feedstock for the production of bioenergy and value-added products. Nevertheless, currently, it is only used as a low-cost solid biofuel for combustion. An alternative valorization approach has been developed based on an acid-catalyzed process for the solubilization of hemicelluloses [<sup>1</sup>] and the production of furfural [<sup>2</sup>]. This process yields a solid cellulose and lignin-rich material, which can be further upgraded. In this work, an organosolv process for the delignification of the material and improvement of the enzymatic digestibility was applied and optimized. The organosolv stage was carried out with an ethanol:water ratio (50:50, <i>w</i>/<i>w</i>) in a Parr reactor, varying the temperature (140–190 °C) and the addition of the catalyst (0–100 mM H<sub>2</sub>SO<sub>4</sub>). The liquid fraction obtained was analyzed to evaluate the presence of value-added products, such as phenolic compounds with antioxidant activity. The total phenolic content was determined by the Folin–Ciocalteu method, obtaining a phenol concentration between 5 and 13 g GAE/L, corresponding to a phenol yield of 8 g GAE/100 g of processed material, which ranks in the range of those obtained from other plant sources, in other olive by-products such as exhausted olive pomace, up to 9 g GAE/100 g of extract have been reported [<sup>3</sup>]. The phenolic profile was obtained by capillary electrophoresis analysis, allowing the identification, among others, of vanillin and syringaldehyde as naturally occurring flavor components exhibiting antioxidant and antimicrobial properties. Therefore, with the present study, we were able to determine that the liquor obtained after the organosolv pretreatment of olive stones can also be valued as a bio-source of non-synthetic preservatives and additives for the food industry. |
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| issn | 2673-9976 |
| language | English |
| last_indexed | 2024-03-11T06:51:09Z |
| publishDate | 2021-10-01 |
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| spelling | doaj.art-f89c279a02874084bc364b88a9951dfb2023-11-17T09:58:04ZengMDPI AGBiology and Life Sciences Forum2673-99762021-10-01617010.3390/Foods2021-10940Effective Production of Bioactive Phenolic Compounds from Olive StonesCarmen Padilla-Rascón0Encarnación Ruiz1Eulogio Castro2Luisa B. Roseiro3Luis C. Duarte4Florbela Carvalheiro5Department of Chemical, Environmental and Materials Engineering, Universidad de Jaén, 23071 Jaén, SpainDepartment of Chemical, Environmental and Materials Engineering, Universidad de Jaén, 23071 Jaén, SpainDepartment of Chemical, Environmental and Materials Engineering, Universidad de Jaén, 23071 Jaén, SpainLNEG Laboratório Nacional de Energia e Geologia, Unidade de Bioenergia e Biorrefinarias. Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalLNEG Laboratório Nacional de Energia e Geologia, Unidade de Bioenergia e Biorrefinarias. Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalLNEG Laboratório Nacional de Energia e Geologia, Unidade de Bioenergia e Biorrefinarias. Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalOlive stones (OS) are a by-product generated in the olive oil production process. This residue is obtained in industries after the oil extraction process, and it is recognized as an interesting feedstock for the production of bioenergy and value-added products. Nevertheless, currently, it is only used as a low-cost solid biofuel for combustion. An alternative valorization approach has been developed based on an acid-catalyzed process for the solubilization of hemicelluloses [<sup>1</sup>] and the production of furfural [<sup>2</sup>]. This process yields a solid cellulose and lignin-rich material, which can be further upgraded. In this work, an organosolv process for the delignification of the material and improvement of the enzymatic digestibility was applied and optimized. The organosolv stage was carried out with an ethanol:water ratio (50:50, <i>w</i>/<i>w</i>) in a Parr reactor, varying the temperature (140–190 °C) and the addition of the catalyst (0–100 mM H<sub>2</sub>SO<sub>4</sub>). The liquid fraction obtained was analyzed to evaluate the presence of value-added products, such as phenolic compounds with antioxidant activity. The total phenolic content was determined by the Folin–Ciocalteu method, obtaining a phenol concentration between 5 and 13 g GAE/L, corresponding to a phenol yield of 8 g GAE/100 g of processed material, which ranks in the range of those obtained from other plant sources, in other olive by-products such as exhausted olive pomace, up to 9 g GAE/100 g of extract have been reported [<sup>3</sup>]. The phenolic profile was obtained by capillary electrophoresis analysis, allowing the identification, among others, of vanillin and syringaldehyde as naturally occurring flavor components exhibiting antioxidant and antimicrobial properties. Therefore, with the present study, we were able to determine that the liquor obtained after the organosolv pretreatment of olive stones can also be valued as a bio-source of non-synthetic preservatives and additives for the food industry.https://www.mdpi.com/2673-9976/6/1/70olive stonesphenolic compoundsorganosolvcapillary zone electrophoresisagro-industrial residue valorization |
| spellingShingle | Carmen Padilla-Rascón Encarnación Ruiz Eulogio Castro Luisa B. Roseiro Luis C. Duarte Florbela Carvalheiro Effective Production of Bioactive Phenolic Compounds from Olive Stones Biology and Life Sciences Forum olive stones phenolic compounds organosolv capillary zone electrophoresis agro-industrial residue valorization |
| title | Effective Production of Bioactive Phenolic Compounds from Olive Stones |
| title_full | Effective Production of Bioactive Phenolic Compounds from Olive Stones |
| title_fullStr | Effective Production of Bioactive Phenolic Compounds from Olive Stones |
| title_full_unstemmed | Effective Production of Bioactive Phenolic Compounds from Olive Stones |
| title_short | Effective Production of Bioactive Phenolic Compounds from Olive Stones |
| title_sort | effective production of bioactive phenolic compounds from olive stones |
| topic | olive stones phenolic compounds organosolv capillary zone electrophoresis agro-industrial residue valorization |
| url | https://www.mdpi.com/2673-9976/6/1/70 |
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