Estimating hydroxytyrosol-tyrosol derivatives amounts in cv. Cobrançosa olive oils based on the electronic tongue analysis of olive paste extracts. (July 2021)

• Record Type: Journal Article
• Authors: Marx, Ítala M.G.; Casal, Susana; Rodrigues, Nuno; Veloso, Ana C.A.; Pereira, José A.; Peres, António M.
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 147(2021)
• Publication Date: 2021-07
• Subjects: Lipid sensor membranes -- Potentiometric profiles -- Non-invasive indirect olive oil evaluation -- Health claim -- Multiple linear regression; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2021.111542
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: The estimation of hydroxytyrosol-tyrosol derivatives amounts in olive oils through the analysis of olive pastes collected during malaxation is of utmost relevance due to the relationship with the oils' health claim regarding the protection of blood lipids from oxidative stress. Olive pastes were collected during the industrial extraction of cv. Cobrançosa oils (0–60 min; 22–34 °C). Total phenolic contents of pastes' extracts were assessed (2800–5400 mg GAE/kg paste). Oils were laboratory-extracted from each paste and, after acid hydrolysis, the contents of hydroxytyrosol and tyrosol derivatives as their sum were determined (25–135, 62–120 and 68–255 mg/kg oil). Olive paste extracts were analyzed with a lab-made potentiometric electronic tongue. The device enabled estimating the total phenolic contents of the pastes (internal-validation: correlation coefficient ≥ 0.86, root mean square error ≤ 392 mg GAE/kg). Moreover, the electronic tongue allowed a more satisfactory indirect estimation of the total secoiridoids derivatives amounts of the oils (internal-validation: correlation coefficient ≥ 0.91, root mean square error ≤ 25 mg/kg), based on the olive pastes' potentiometric profiles, without requiring the oils' posteriori invasive/destructive analysis. Thus, the electronic tongue could be foreseen as a potential tool for anticipating the health claim fulfilment during oils industrial extraction. Graphical abstract: Image 1 Highlights: Olive producers and consumers seek for healthier olive oils. The HPLC analysis to confirm the health claim is time-consuming. The possibility to analyze olive pastes grants more expedite decisions. E-tongue analysis of olive paste extracts correlates with HPLC estimations. E-tongue analysis can be a valuable tool for olive oil producers.