Chromatographic Separation of Phenolic Compounds from Extra Virgin Olive Oil: Development and Validation of a New Method Based on a Biphenyl HPLC Column

Three different high performance liquid chromatography columns were accessed for phenolic compounds (PC) separation in the hydrophilic fraction of extra virgin olive oil (EVOO). Two fully porous C18 bonded silica phases and one partially porous biphenyl column were used. Biphenyl column allowed for an increase of more than 30% in peak capacity (nc), higher selectivity (α) (1.045), and improved retention (k), with a reduction of 22.1% in the retention time. The higher resolution (Rs) was obtained by using the biphenyl column, with a fair separation of oleuropein aglycone isomers (OAI) and a good identification of caffeic acid (CA). Tyrosol (T), hydroxytyrosol (HT), and dihydroxyphenyl glycol (DHPG) were also well separated and identified. Moreover, the method using a biphenyl column was fully validated according to the requirements for new methods. For all parameters, the method applying the biphenyl column proved to be a reliable, accurate, and robust tool for separation, identification, and quantification of the main PCs in EVOOs.

Download Full-text

Preliminary Investigation of Different Drying Systems to Preserve Hydroxytyrosol and Its Derivatives in Olive Oil Filter Cake Pressurized Liquid Extracts

Foods ◽

10.3390/foods10061407 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1407

Author(s):

Lucía López-Salas ◽

Inés Cea ◽

Isabel Borrás-Linares ◽

Tatiana Emanuelli ◽

Paz Robert ◽

...

Keyword(s):

Phenolic Compounds ◽

Olive Oil ◽

High Performance ◽

Filter Cake ◽

Preliminary Investigation ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Drying Methods ◽

Flight Mass Spectrometry ◽

Optimum Extraction

Phenolic compounds present in extra virgin olive oil (EVOO) could be retained in its byproducts during processing. Among them, hydroxytyrosol and its derivatives deserve special attention due to their health benefits recognized by The European Food Safety Authority (EFSA). In the present research, the presence of these compounds in the filter cake byproduct was studied by combining pressurized liquid extraction (PLE) and high-performance liquid chromatography coupled to time-of-flight mass spectrometry (HPLC-TOF-MS). The applied optimum extraction parameters were 1500 psi, 120 °C and aqueous ethanol (50:50, v/v). The influence of different drying methods (vacuum-, freeze- and spray-drying) in the recovery of phenolic compounds was also evaluated. A total of 16 compounds from EVOO were identified in the extracts, 3 of them being hydroxytyrosol-related compounds, 6 substances of oleoside and elenolic acid derivatives, together with 6 secoiridoids and 1 lignan. The results highlighted the great number of phenolic compounds recovered from filter cake with these techniques, being even higher than the reported content in EVOO and other byproducts. The combination of PLE and freeze-drying resulted in being the best procedure for the recovery of phenolic compounds from filter cake byproduct.

Download Full-text

Evolution of Flavors in Extra Virgin Olive Oil Shelf-Life

Antioxidants ◽

10.3390/antiox10030368 ◽

2021 ◽

Vol 10 (3) ◽

pp. 368

Author(s):

Paula Garcia-Oliveira ◽

Cecilia Jimenez-Lopez ◽

Catarina Lourenço-Lopes ◽

Franklin Chamorro ◽

Antia Gonzalez Pereira ◽

...

Keyword(s):

Phenolic Compounds ◽

Shelf Life ◽

Olive Oil ◽

Unsaturated Fatty Acids ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Volatile Fraction ◽

Organoleptic Characteristics ◽

Olive Variety ◽

Minor Compounds

Extra virgin olive oil (EVOO) is one of the most distinctive ingredients of the Mediterranean diet. There are many properties related to this golden ingredient, from supreme organoleptic characteristics to benefits for human health. EVOO contains in its composition molecules capable of exerting bioactivities such as cardio protection, antioxidant, anti-inflammatory, antidiabetic, and anticancer activity, among others, mainly caused by unsaturated fatty acids and certain minor compounds such as tocopherols or phenolic compounds. EVOO is considered the highest quality vegetable oil, which also implies a high sensory quality. The organoleptic properties related to the flavor of this valued product are also due to the presence of a series of compounds in its composition, mainly some carbonyl compounds found in the volatile fraction, although some minor compounds such as phenolic compounds also contribute. However, these properties are greatly affected by the incidence of certain factors, both intrinsic, such as the olive variety, and extrinsic, such as the growing conditions, so that each EVOO has a particular flavor. Furthermore, these flavors are susceptible to change under the influence of other factors throughout the oil's shelf-life, such as oxidation or temperature. This work offers a description of some of the most remarkable compounds responsible for EVOO’s unique flavor and aroma, the factors affecting them, the mechanism that lead to the degradation of EVOO, and how flavors can be altered during the shelf-life of the oil, as well as several strategies suggested for the preservation of this flavor, on which the quality of the product also depends.

Download Full-text

Green Route for the Isolation and Purification of Hyrdoxytyrosol, Tyrosol, Oleacein and Oleocanthal from Extra Virgin Olive Oil

Molecules ◽

10.3390/molecules25163654 ◽

2020 ◽

Vol 25 (16) ◽

pp. 3654

Author(s):

Antonio Francioso ◽

Rodolfo Federico ◽

Anna Maggiore ◽

Mario Fontana ◽

Alberto Boffi ◽

...

Keyword(s):

Olive Oil ◽

High Performance ◽

Virgin Olive Oil ◽

Deep Eutectic Solvent ◽

Extra Virgin Olive Oil ◽

Hazardous Substances ◽

Purification Method ◽

Total Recovery ◽

Isolation And Purification ◽

Natural Deep Eutectic Solvent

Extra virgin olive oil (EVOO) phenols represent a significant part of the intake of antioxidants and bioactive compounds in the Mediterranean diet. In particular, hydroxytyrosol (HTyr), tyrosol (Tyr), and the secoiridoids oleacein and oleocanthal play central roles as anti-inflammatory, neuro-protective and anti-cancer agents. These compounds cannot be easily obtained via chemical synthesis, and their isolation and purification from EVOO is cumbersome. Indeed, both processes involve the use of large volumes of organic solvents, hazardous reagents and several chromatographic steps. In this work we propose a novel optimized procedure for the green extraction, isolation and purification of HTyr, Tyr, oleacein and oleocanthal directly from EVOO, by using a Natural Deep Eutectic Solvent (NaDES) as an extracting phase, coupled with preparative high-performance liquid chromatography. This purification method allows the total recovery of the four components as single pure compounds directly from EVOO, in a rapid, economic and ecologically sustainable way, which utilizes biocompatible reagents and strongly limits the use or generation of hazardous substances.

Download Full-text

Wastes Generated during the Storage of Extra Virgin Olive Oil as a Natural Source of Phenolic Compounds

Journal of Agricultural and Food Chemistry ◽

10.1021/jf202596q ◽

2011 ◽

Vol 59 (21) ◽

pp. 11491-11500 ◽

Cited By ~ 42

Author(s):

Jesus Lozano-Sánchez ◽

Elisa Giambanelli ◽

Rosa Quirantes-Piné ◽

Lorenzo Cerretani ◽

Alessandra Bendini ◽

...

Keyword(s):

Phenolic Compounds ◽

Olive Oil ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Natural Source

Download Full-text

Fe, Zn and Se Bioavailability in Chicken Meat Emulsions Enriched with Minerals, Hydroxytyrosol and Extra Virgin Olive Oil as Measured by Caco-2 Cell Model

Nutrients ◽

10.3390/nu10080969 ◽

2018 ◽

Vol 10 (8) ◽

pp. 969 ◽

Cited By ~ 4

Author(s):

Lorena Martínez ◽

Gaspar Ros ◽

Gema Nieto

Keyword(s):

Phenolic Compounds ◽

Olive Oil ◽

Cell Model ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Chicken Meat ◽

Future Research ◽

Meat Industry ◽

Organic Zn

There is a high demand for functional meat products due to increasing concern about food and health. In this work, Zn and Se bioavailability was increased in chicken meat emulsions that are enriched with Hydroxytyrosol (HXT), a phenolic compound obtained from olive leaf. Six different chicken emulsions were elaborated. Three were made with broiler chicken meat supplemented with inorganic Zn and Se: control, one with HXT (50 ppm) added and one with HXT (50 ppm) and Extra Virgin Olive Oil (EVOO) (9.5%) added; and, three were made with chicken meat from chickens fed a diet that was supplemented with organic Zn and Se: control, one with HXT (50 ppm) added and one with HXT (50 ppm) and EVOO (9.5%) added. The samples were digested in vitro and the percent decomposition of phenolic compounds was measured by HPLC. Mineral availability (Fe, Zn and Se) was measured by cell culture of the Caco-2 cell line and the results were compared with mineral standards (Fe, Zn, and Se). The data obtained showed that neither HXT resistance to digestion nor Fe availability was affected by the presence of organic Zn and Se or phenolic compounds. Zn uptake increased in the presence of HXT, but not when its organic form was used, while Se uptake increased but it was not affected by the presence of HXT. It was concluded that the enrichment of meat—endogenously with organic minerals and exogenously with phenolic compounds—could be considered an interesting strategy for future research and applications in the current meat industry.

Download Full-text