Dados do Trabalho

Título

Comparative untargeted metabolic profiling of NADES-mediated extracts of olive oil by-products by LC-QTOF-MS and their biological activity

Introdução

Olive oil by-products (OOBPs) contain significant amounts of bioactive compounds with relevant biological properties that are often underutilized by the industry. Commonly, the extraction process for the bioactive compounds is carried out using organic solvents, which have several drawbacks for human health and the environment. In recent years, Natural Deep Eutectic Solvents (NADES) have attracted attention due to their outstanding properties, especially as green extraction solvents. In addition, NADES-mediated extracts have demonstrated successful antimicrobial activity against several pathogenic microorganisms, including Phytophthora palmivora. This pathogenic microorganism responsible for “dry branch” disease in olive trees, which is particularly destructive and causes significant economic losses.

Material e Métodos

The aim of this work was to perform a comparative untargeted metabolic profiling and biological activity assessment of the by-products obtained from different olive oil cultivars based on a lactic acid, glucose, and water (LGH) NADES extraction, positive mode LC-QTOF-MS analysis, and in vitro antimicrobial activity bioassay. Chemometrics was used for the comparison of the comprehensive metabolic profiles of Arauco (Ara), Arbequina (Arb), Coratina (Cor), Frantoio (Fra), Manzanilla (Man) y Nevadillo (Nev) varieties, as well as to establish a relationship between the elucidated phytochemical profiles and biological activity. The effect of the extracts on P. palmivora mycelial growth was evaluated using the solid agar bioassay.

Resultados e Discussão

In total, 133 metabolites from different classes were annotated and the efficiency of the six OOBP-LGH based systems decreased in the order: Cor (86) > Ara (78) > Manz (72) > Nev (67) > Arb (65) > Fra (64) in terms of their biocompounds recovery yield. Multivariate data analysis revealed the compositional similarities and differences in metabolites among the six extracts.

Conclusão

Ara and Cor extracts presented higher levels of phenolic acids and volatiles than Arb, Man, and Fra extracts, which were characterized by higher concentrations of amino acids, fatty acids, and phospholipids, respectively. Furthermore, the extracts showed biological activity against P. palmivora mycelial growth at the concentrations studied. Finally, OOBPs represent a valuable source of bioactive compounds with significant biological properties, yet they are still underexploited by the industry. This research highlights the importance of sustainable extraction methods and exploring and revalorizing OOBPs.