Phenolic compounds and other constituents of extra virgin olive oil: Exploring the impact of cultivar, ripeness, malaxation, and high hydrostatic pressure
[eng] Olive oil represents a very important part of the economy of Spain and Catalonia. The value of this product, specifically extra virgin olive oil (EVOO), lies in its quality, both in terms of organoleptic and nutritional aspects, which are determined by its composition. The richness in oleic ac...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/215975 |
| Acceso en línea: | https://hdl.handle.net/2445/215975 http://hdl.handle.net/10803/692373 |
| Access Level: | acceso abierto |
| Palabra clave: | Oli d'oliva Fenols Antioxidants Olive oil Phenols |
| Sumario: | [eng] Olive oil represents a very important part of the economy of Spain and Catalonia. The value of this product, specifically extra virgin olive oil (EVOO), lies in its quality, both in terms of organoleptic and nutritional aspects, which are determined by its composition. The richness in oleic acid, as well as the presence of bioactive compounds with antioxidant capacity, such as phenolic compounds, vitamin E, and carotenoids, endow EVOO with oxidative stability and health properties. In particular, a group of phenolic compounds specific to the Oleaceae family, secoiridoids, is of interest for its strong antioxidant activity, health benefits, and contribution to organoleptic properties. Several factors affect the final composition of the oil, including the cultivar, agroclimatic and environmental conditions, olive health, ripeness, technological factors in oil production, storage, and cooking. In this thesis, with the aim of obtaining an EVOO with a higher content of phenolic compounds, particularly secoiridoids, the effect of cultivar, degree of ripeness, malaxation, and the emerging technology of high hydrostatic pressure (HHP) on the composition has been studied. The olive cultivars studied were ‘Arbequina’, the most representative of Catalonia, and ‘Corbella’, an ancient cultivar recently reintroduced for oil production. Results indicate that the genetics of the cultivar is the most contributing factor. The differential expression of genes encoding enzymes involved in the metabolism of oleuropein, as well as their variation during fruit development and ripening, are the main factors responsible for the modulation of the content and profile of secoiridoids. The high expression of β-glucosidase detected in ‘Corbella’ and ‘Arbequina’ compared to ‘Picual’ can explain the higher content of oleuropein aglycone found in the first two cultivars, as well as the higher content of oleacein and oleocanthal in their respective EVOOs. Therefore, the cultivar affects other factors, such as malaxation. In the case of ‘Arbequina’ and ‘Corbella’, the use of temperatures up to 30 °C favored the increase in oleacein and oleocanthal. Additionally, in ‘Corbella’ EVOOs, a strong correlation was established between the content of these two secoiridoids and oxidative stability. Storage of olives at ambient temperature overnight also favored their content. Regarding the degree of ripeness, ‘Corbella’ olives showed a reduction in the content of phenolic compounds during the early stages of maturation. Finally, the use of HHP promoted the synthesis of oleocanthal and oleacein in ‘Arbequina’ olive fruit but not in the EVOO. |
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