Quality of veiled olive oil: Role of turbidity components

Main Article Content

Carlotta Breschi
Lorenzo Guerrini
Ferdinando Corti
Luca Calamai
Paola Domizio
Alessandro Parenti
Bruno Zanoni


biophenols, hydrolysis, oil-borne microorganism, olive oil quality, volatile compounds


This study investigated the effects of water and content of solid particles, taken together as well as separately, on stability of veiled olive oil. The following oil samples were obtained through four different separation treatments: veiled, filtered, ‘solid-only’, and ‘water-only’. Changes in chemical, microbial, and sensory characteristics were evaluated during storage (240 days). A significant effect of hydrolysis was shown in veiled and ‘water only’ oils; in ‘solid-only’ oils, a slow increase of phenols was observed. A notable microbial activity, with resulting formation of volatile metabolites and sensory defects, was observed in veiled samples. Filtered oils underwent less significant changes.

Abstract 743 | PDF Downloads 734 HTML Downloads 483 XML Downloads 115


Ambrosone, L., Angelico, R., Cinelli, G., Di Lorenzo, V., Ceglie, A., et al. 2002. The role of water in the oxidation process of extra virgin olive oils. J. Am. Oil Chem. Soc. 79(6), 577–582. https://doi.org/10.1007/s11746-002-0525-3

Bimbo, F., Roselli, L., Carlucci, D., and de Gennaro, B.C. 2020. Consumer misuse of country-of-origin label: insights from the Italian extra-virgin olive oil market. Nutrients. 12(2150), 1–12. https://doi.org/10.3390/nu12072150

Brenes, M., Garcia, A., Garcia, P., and Garrido, A. 2001. Acid hydrolysis of secoiridoida glycons during storage of virgin olive oil. J. Agr. Food Chem. 49(11), 5609–5614. https://doi.org/10.1021/ jf0107860

Breschi, C., Guerrini, L., Domizio, P., Ferraro, G., Calamai, L., Canuti, V., et al., 2019. Physical, chemical, and biological characterization of veiled extra virgin olive oil turbidity for degradation risk assessment.  Eur. J. Lipid Sci. Tech. 121(11), 1900195, 1–6. https://doi.org/10.1002/ejlt.201900195

Bubola, K.B., Lukić, M., Mofardin, I., Butumović, A., and Koprivnjak, O. 2017. Filtered vs. naturally sedimented and decanted virgin olive oil during storage: effect on quality and composition. LWT. 84, 370–377. https://doi.org/10.1016/j.lwt.2017.05.069

Cayuela, J.A., Gómez-Coca, R.B., Moreda, W., and Pérez-Camino, M.D.C. 2015. Sensory defects of virgin olive oil from a microbiological perspective.  Trends Food Sci. Tech. 43(2), 227–235. https://doi.org/10.1016/j.tifs.2015.02.007

Cayuela-Sánchez, J.A. and Caballero-Guerrero, B. 2019. Fresh extra-virgin olive oil, with or without veil.  Trends Food Sci. Tech. 83, 78–85. https://doi.org/10.1016/j.tifs.2018.11.014

Cecchi, L., Breschi, C., Migliorini, M., Canuti, V., Fia, G., Mulinacci,  N., et al. 2019. Moisture in rehydrated olive paste affects oil extraction yield and phenolic compound content and profile of extracted olive oil.  Eur. J. Lipid Sci. Tech. 121(4), 1800449, 1–10. https://doi.org/10.1002/ejlt.201800449

Cecchi, L., Migliorini, M., Zanoni, B., Breschi, C., and Mulinacci, N. 2018. An effective HPLC-based approach for the evaluation of the content of total phenolic compounds transferred from olives to virgin olive oil during the olive milling process. J. Sci. Food Agr. 98(10), 3636–3643. https://doi.org/10.1002/jsfa.8841

Ciafardini, G. and Zullo, B.A. 2002a Survival of micro-organisms in extra-virgin olive oil during storage.  Food Microbiol. 19(1), 105–109. https://doi.org/10.1006/fmic.2001.0458

Ciafardini, G. and Zullo, B.A. 2002b. Microbiological activity in stored olive oil. Int. J. Food Microbiol. 75(1–2), 111–118. https://doi.org/10.1016/S0168-1605(01)00739-5

Ciafardini, G. and Zullo, B.A. 2018. Virgin olive oil yeasts: a review. Food Microbiol. 70, 245–253. https://doi.org/10.1016/j.fm.2017.10.010

Cinquanta, L., Esti, M., and La Notte, E. 1997. Evolution of phenolic compounds in virgin olive oil during storage.  J. Am. Oil Chem. Soc. 74(10), 1259–1264. https://doi.org/10.1007/s11746-997-0054-8

Derossi, A., Severini, C., and Cassi, D. 2011. Mass transfer mechanisms during dehydration of vegetable food: traditional and innovative approaches. Ch. 15. In: “Advanced topics in mass transfer”. IntechOpen (Ed.), pp. 305–354. https://doi.org/10.5772/14725

El haouhay, N., Samaniego-Sánchez, C., Asehraou, A., Jesús, R., Villalón-Mir, M., et al. 2018. Effects of olive storage and packaging on microbial and fatty acids profiles of olive oil produced in traditional mills in Morocco. J. Mat. Env. Sci. 2508, 854–863. https://doi.org/10.26872/jmes.2018.9.3.94

El Riachy, M., Priego-Capote, F., León, L., Rallo, L., and Luque de Castro, M.D. 2011. Hydrophilic antioxidants of virgin olive oil. Part 1: Hydrophilic phenols: a key factor for virgin olive oil quality. Eur. J. Lipid Sci. Tech. 113(6), 678–691. https://doi.org/10.1002/ejlt.201000400

European Union Commission. 2003. Commission implementing regulation (EC) No. 2016/2095 of 26 September 2016 amending regulation No. 2568/91 on the characteristics of olive oil and olive-residue oil and on the relevant methods of analysis. Off. J. Eur. Union. L 295, 57–77.

filtration on virgin olive oil stability during storage. Eur. J. Lipid Sci. Tech. 108(2), 134–142. https://doi.org/10.1002/ejlt.200501175

Guerrini, L., Breschi, C., Zanoni, B., Calamai, L., Angeloni, G., Masella, P., et al. 2020a. Filtration scheduling: quality changes in freshly produced virgin olive oil. Foods. 9(8), 1067, 1-14. https://doi.org/10.3390/foods9081067

Guerrini, L., Zanoni, B., Breschi, C., Angeloni, G., Masella, P., Calamai, L., et al. 2020b. Understanding olive oil stability using filtration and high hydrostatic pressure.  Molecules. 25(2), 420, 1–15. https://doi.org/10.3390/molecules25020420

Guerrini, S., Mari, E., Migliorini, M., Cherubini, C., Trapani, S., Zanoni, B., et al. 2015. Investigation on microbiology of olive oil extraction process. Italian J. Food Sci. 27(2), 236–247. https://doi.org/10.14674/1120-1770/ijfs.v190

International Olive Council (IOC). 2018. Best practice guidelines for the storage of olive oils and olive-pomace oils for human consumption. IOC/BPS/DOC.1/2018. International Olive Council, Madrid, Spain.

International Olive Council (IOC). 2017. Determination of biophe-nols in olive oils by HPLC. IOC/T.20/Doc. No. 29/Rev. 1/2017. International Olive Council, Madrid, Spain.

International Olive Council (IOC). 2018a. Guide for the selection, training and quality control of virgin olive oil tasters-qualifications of tasters, panel leaders and trainers. IOC/T.20/Doc. No. 14/Rev. 5/2018. International Olive Council, Madrid, Spain.

International Olive Council (IOC). 2018b Sensory analysis of olive oil. method for the organoleptic assessment of virgin olive oil. IOC/T.20/Doc. No. 15/Rev. 10/2018. International Olive Council, Madrid, Spain.

JermanKlen, T., GolcWondra, A., Vrhovšek, U., Sivilotti, P., and Vodopivec, B.M. 2015. Olive fruit phenols transfer, transformation, and partition trail during laboratory-scale olive oil processing. J. Agr. Food Chem. 63(18), 4570–4579. https://doi.org/10.1021/jf506353z

Koidis, A. and Boskou, D. 2006. The contents of proteins and phospholipids in cloudy (veiled) virgin olive oils.  Eur. J. Lipid Sci. Tech. 108(4), 323–328. https://doi.org/10.1002/ejlt.200500319

Koidis, A., Triantafillou, E., and Boskou, D. 2008. Endogenous microflora in turbid virgin olive oils and the physicochemical characteristics of these oils. Eur. J. Lipid Sci. Tech. 110(2), 164– 171. https://doi.org/10.1002/ejlt.200700055

Lercker, G., Frega, N., Bocci, F., and Servidio, G. 1994. Veiled extra-vir-gin olive oils: dispersion response related to oil quality. J. Am. Oil Chem. Soc. 71(6), 657–658. https://doi.org/10.1007/BF02540597

Lozano-Sánchez, J., Cerretani, L., Bendini, A., Segura-Carretero, A., and Fernández-Gutiérrez, A. 2010. Filtration process of extra virgin olive oil: effect on minor components, oxidative stability and sensorial and physicochemical characteristics.  Trends Food Sci. Tech. 21(4), 201–211. https://doi.org/10.1016/j. tifs.2009.12.004

Migliorini, M., Cherubini, C., Zanoni, B., Mugelli, M., Cini, E., and Berti, A. 2009. Influence of operating conditions of malaxation on the quality of extra virgin olive oil. Riv. It. Sostanze Grasse. 86(2), 92–102.

Morales, M.T., Luna, G., and Aparicio, R. 2005. Comparative study of virgin olive oil sensory defects. Food Chem. 91(2), 293–301. https://doi.org/10.1016/j.foodchem.2004.06.011

Romo-Sánchez, S., Alves-Baffi, M., Arévalo-Villena, M., Úbeda-Iranzo,  J., and Briones-Pérez, A. 2010. Yeast biodiversity from oleic ecosystems: study of their biotechnological properties. Food Microbiol. 27(4), 487–492. https://doi.org/10.1016/j.fm.2009.12.009

Xenakis, A., Papadimitriou, V., and Sotiroudis, T.G. 2010. Colloidal structures in natural oils.  Curr. Opin. Colloid Interface Sci. 15(1–2), 55–60. https://doi.org/10.1016/j.cocis.2009.11.007

Zanoni, B. 2014. Which processing markers are recommended for measuring and monitoring the transformation pathways of main components of olive oil? Italian J. Food Sci. 26(1), 3–11.

Zullo, B.A., Cioccia, G., and Ciafardini, G. 2010. Distribution of dimorphic yeast species in commercial extra virgin olive oil. Food Microbiol. 27(8), 1035–1042. https://doi.org/10.1016/j.fm.2010.07.005

Zullo, B.A., Cioccia, G., and Ciafardini, G. 2013. Effects of some oil-born yeast on the sensory characteristics of Italian virgin olive oil during its storage. Food Microbiol. 36(1), 70–78. https://doi.org/10.1016/j.fm.2013.04.006

Zullo, B.A. and Ciafardini, G. 2018. Changes in physicochemical and microbiological parameters of short and long-lived veiled (cloudy) virgin olive oil upon storage in the dark.  Eur. J. Lipid Sci. Tech. 120(1), 1700309, 1–8. https://doi.org/10.1002/ejlt.201700309

Zullo, B.A., Pachioli, S., and Ciafardini, G. 2020. Reducing the bitter taste of virgin olive oil Don Carlo by microbial and vegetable enzymes linked to the colloidal fraction. Colloids Interfaces. 4(1), 11, 1–13. https://doi.org/10.3390/colloids4010011

Zullo, B.A. and Ciafardini, G. 2020a. Differential microbial composition of monovarietal and blended extra virgin olive oils deter-mines oil quality during storage.  Microorganisms. 8(3), 402, 1–16. https://doi.org/10.3390/microorganisms8030402

Zullo, B.A. and Ciafardini, G. 2020b. Virgin olive oil quality is affected by the microbiota that comprise the biotic fraction of the oil.  Microorganisms. 8(5), 663, 1–13. https://doi.org/10.3390/microorganisms8050663