Freeze dried extract from olive leaves: Valorisation, extraction kinetics and extract characterization
Valorization of olive leaves (OL) in a biorefinery context should include extraction of bioactive compounds, specially taking into account the high content of extractives of this by-product. Extraction of bioactive compounds from Spanish OL (cultivar “Serrana de Espadán”) was studied by conventional...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad de Burgos (UBU) |
| Repositorio: | Repositorio Institucional de la Universidad de Burgos (RIUBU) |
| OAI Identifier: | oai:riubu.ubu.es:10259/5472 |
| Acceso en línea: | http://hdl.handle.net/10259/5472 |
| Access Level: | acceso abierto |
| Palabra clave: | Olive leaves Phenolic compounds Oleuropein Mannitol Kinetic model Freeze-dried extract Ingeniería química Alimentos Chemical engineering Food |
| Sumario: | Valorization of olive leaves (OL) in a biorefinery context should include extraction of bioactive compounds, specially taking into account the high content of extractives of this by-product. Extraction of bioactive compounds from Spanish OL (cultivar “Serrana de Espadán”) was studied by conventional and ultrasound assisted extraction (UAE). Faster extraction was observed by UAE, although similar final extraction yield was reached by both technologies. The best extraction solvent was an 80% ethanol hydroalcoholic mixture at a ratio of 20 mL per gram of dried OL (DOL). At these conditions the highest content of oleuropein and luteolin-7-O-glucoside was determined as 31 ± 2 and 4.1 ± 0.2 mg/gDOL. The power law and the Weibull models fitted the total phenolic compounds extraction kinetics quite well. The major soluble carbohydrate was mannitol, with a content of 4.48 ± 0.09 mg/gDOL in the extract. The influence of OL source was also studied and it was concluded that the leaves collected as wastes from the factory presented the highest phenolic yield and antioxidant capacity. The optimum extract was freeze dried resulting in a solid power with more than 11% of oleuropein and 17% of mannitol. Antioxidant activity of the freeze-dried extract was preserved for two months. |
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