Clarification of olive juice by α-alumina microfiltration membranes with enhanced packing density

The development of innovative designs has enabled the creation of new-generation mineral membranes with enhanced filtration packing densities, improving their competitiveness against polymeric membranes. This study evaluates the performance of two α-Al2O3 membranes with mean pore sizes of 800 and 60...

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Detalles Bibliográficos
Autores: Gutiérrez Docio, Alba, Prodanov Prodanov, Marin, Ruiz Rodríguez, Alejandro
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/719716
Acceso en línea:http://hdl.handle.net/10486/719716
https://dx.doi.org/10.1016/j.ifset.2025.104031
Access Level:acceso abierto
Palabra clave:Clarification
Microfiltration
Olive juice
Phenolic and secoiridoids compounds
Tangential flow membrane filtration
α-Al O membranes 2 3
Química
Descripción
Sumario:The development of innovative designs has enabled the creation of new-generation mineral membranes with enhanced filtration packing densities, improving their competitiveness against polymeric membranes. This study evaluates the performance of two α-Al2O3 membranes with mean pore sizes of 800 and 600 nm and a filtration packing density of 184 m2.m−3, focusing on their operational parameters and the quality of olive juice clarification. Filtration with the 800 nm membrane achieved 2.4 times higher productivity than the 600 nm membrane. However, it left 14–19 NTU of haze in the final product and was more prone to fouling. In contrast, the 600 nm membrane produced fully clarified juice (<2 NTU) and was more resistant to fouling. Clarification with both membranes didn't produce significant retentions of the majority of the 29 examined phenolic compounds. However, retentions of 7.0 to 7.5 % of total dissolved substances, likely polysaccharide colloids, and complete removal of residual oil were achieved. Both membranes were capable of catalyzing spontaneous hydrolysis reactions that produced a significant increase in the contents of tyrosol, hydroxytyrosol and verbascoside, with oleacein concentration rising by up to 893 % in the clarified juices. Industrial relevance: fresh olive juice is an excellent source of phenolic and secoiridoid antioxidants. However, converting it into a value-added product remains a challenge for the olive oil industry due to technical difficulties in its on-line processing. A critical bottleneck of this activity is the removal of suspended solid impurities. This study shows that α-Al2O3 microfiltration membranes with mean pore sizes of up to 600 nm are able to clarify a minimally pre-treated (by centrifugation at 17568.g) olive juice in only one step and with very high quality. The treatment is scalable for industrial applications