Oxidative Stability of Edible Vegetable Oils Enriched in Polyphenols with Olive Leaf Extract

Commercially available oils (olive oil, sunflower oil, palm oil, and a vegetable shortening) were enriched in polyphenols, by adding olive leaf extract. Addition of the extract was performed in such way that the oils were enriched with 200 mg/kg polyphenols. Total polyphenols of both enriched and commercial oils were estimated by the Folin—Ciocalteau assay, while identification and quantification of individual simple phenolic compounds was performed by GC/MS and of oleuropein by HPLC analysis. The enrichment resulted in the supplementation of the commercial oils mainly with oleuropein, hydroxytyrosol, and quercetin. Antioxidant capacity and oxidative stability of the enriched oils and the commercial ones were assessed by the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging assay and the Rancimat method, respectively. Both antioxidant capacity and oxidative stability were substantially improved for all the oils studied after supplementation. By the procedure adopted, oils rich in polyphenols, mainly in oleuropein, can be produced with olive leaf extract supplementation.

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Phenolic composition and in vitro antioxidant capacity of four commercial phytochemical products: Olive leaf extract (Olea europaea L.), lutein, sesamol and ellagic acid

Food Chemistry ◽

10.1016/j.foodchem.2010.11.092 ◽

2011 ◽

Vol 126 (3) ◽

pp. 948-955 ◽

Cited By ~ 112

Author(s):

J.E. Hayes ◽

P. Allen ◽

N. Brunton ◽

M.N. O’Grady ◽

J.P. Kerry

Keyword(s):

Antioxidant Capacity ◽

Ellagic Acid ◽

Olea Europaea ◽

Leaf Extract ◽

Phenolic Composition ◽

Olive Leaf ◽

Olea Europaea L ◽

Olive Leaf Extract ◽

Olea Europaéa

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Application of nano-encapsulated olive leaf extract in controlling the oxidative stability of soybean oil

Food Chemistry ◽

10.1016/j.foodchem.2015.05.115 ◽

2016 ◽

Vol 190 ◽

pp. 513-519 ◽

Cited By ~ 142

Author(s):

Adeleh Mohammadi ◽

Seid Mahdi Jafari ◽

Afshin Faridi Esfanjani ◽

Sahar Akhavan

Keyword(s):

Soybean Oil ◽

Oxidative Stability ◽

Leaf Extract ◽

Olive Leaf ◽

Olive Leaf Extract

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Microbiological and Antioxidant Activity of Phenolic Compounds in Olive Leaf Extract

Molecules ◽

10.3390/molecules25245946 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5946

Author(s):

Dragana Borjan ◽

Maja Leitgeb ◽

Željko Knez ◽

Maša Knez Hrnčič

Keyword(s):

Phenolic Compounds ◽

Leaf Extract ◽

Biological Activities ◽

Olive Leaf ◽

Olive Leaves ◽

Olive Leaf Extract ◽

Antimicrobial Potential ◽

Isolation And Characterization ◽

Wide Range

According to many reports, phenolic compounds isolated from olive leaves have very good biological activities, especially antimicrobial. Presently, the resistance of microorganisms to antibiotics is greater than ever. Therefore, there are numerous recent papers about alternative solutions for inhibiting their influence on human health. Olive leaf is studied as an important source of antimicrobials with low cost and used in medicine. Numerous publications on involving green technologies for isolation of active compounds from olive leaves have appeared over the past few decades. The present review reports on current knowledge of the most isolated phenolic compounds from olive leaf extract as well as methods for their isolation and characterization. This paper uses recent research findings with a wide range of study models to describe the antimicrobial potential of phenolic compounds. It also describes the vast range of information about methods for determination of antimicrobial potential focusing on effects on different microbes. Additionally, it serves to highlight the role of olive leaf extract as an antioxidants and presents methods for determination of antioxidant potential. Furthermore, it provides an overview of presence of enzymes. The significance of olive leaves as industrial and agricultural waste is emphasized by means of explaining their availability, therapeutic and nutritional effects, and research conducted on this field.

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Evolution of the phenolic compounds profile of olive leaf extract encapsulated by spray-drying during in vitro gastrointestinal digestion

Food Chemistry ◽

10.1016/j.foodchem.2018.11.127 ◽

2019 ◽

Vol 279 ◽

pp. 40-48 ◽

Cited By ~ 22

Author(s):

Estefanía González ◽

Ana María Gómez-Caravaca ◽

Begoña Giménez ◽

Rubén Cebrián ◽

Mercedes Maqueda ◽

...

Keyword(s):

Phenolic Compounds ◽

Spray Drying ◽

Leaf Extract ◽

Olive Leaf ◽

Gastrointestinal Digestion ◽

Olive Leaf Extract ◽

In Vitro Gastrointestinal Digestion

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Characterization and Bio-Accessibility Evaluation of Olive Leaf Extract-Enriched “Taralli”

Foods ◽

10.3390/foods9091268 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1268 ◽

Cited By ~ 2

Author(s):

Annamaria Cedola ◽

Carmen Palermo ◽

Diego Centonze ◽

Matteo Alessandro Del Nobile ◽

Amalia Conte

Keyword(s):

Antioxidant Capacity ◽

Leaf Extract ◽

Total Content ◽

White Wine ◽

Olive Leaf ◽

Olive Leaves ◽

Ultrasound Assisted Extraction ◽

Leaf Extracts ◽

Digestion Process ◽

Olive Leaf Extract

Olive leaves are rich in many compounds precious for human health. Due to this property, the current study was aimed to valorize the extract from this by-product in a cereal-based food, very popular all around the world, the “taralli”. To this aim, ultrasound-assisted extraction was applied to dried olive leaves to obtain the extract, used as “taralli” ingredient, instead of white wine. The “taralli” with and without extract was subjected to in vitro digestion to assess the quantity of polyphenolic compounds released in the gastrointestinal tract to become available for absorption. Total content of phenols and flavonoids, as well as the antioxidant capacity, was measured on both cooked and uncooked samples, before and after digestion. In addition, High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) of the three most abundant polyphenols present in olive leaf extracts, such as oleuropein, hydroxytyrosol, and verbascoside, was carried out at the three stages of the digestion process. The results showed that the substitution of white wine with olive leaf extract increased the total content of polyphenols and flavonoids and the antioxidant capacity. Bio-accessibility of the main phenolic compounds demonstrated that oleuropein resisted slightly after gastric digestion but was almost completely degraded in the intestinal phase, while hydroxytyrosol and verbascoside were not resistant to the digestion process from the gastric phase.

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Improving the Biological Value of Olive and Soybean Oil Blends with Olive Leaf Extract Obtained by Ultrasound-Assisted Extraction towards the Preparation of a Sauce Product

Life ◽

10.3390/life11090974 ◽

2021 ◽

Vol 11 (9) ◽

pp. 974

Author(s):

Mohammad Amin Aliyari ◽

Karamatollah Rezaei

Keyword(s):

Oxidative Stability ◽

Olive Oil ◽

Leaf Extract ◽

Control Sample ◽

Olive Leaf ◽

Ultrasound Assisted Extraction ◽

Olive Leaf Extract ◽

Polyphenolic Extract ◽

Assisted Extraction ◽

Ultrasound Assisted

French sauce from different blends of soybean and olive oils was prepared and the oxidative stability of the optimum sauce sample, enriched with various amounts of olive leaf polyphenolic extract (OLE) (obtained via ultrasound-assisted extraction), was investigated over 90 days of storage. The microbiological and sensory properties of the samples containing the optimum amounts of OLE, as a substitution for synthetic preservatives, were studied. According to the results, the addition of olive oil at higher levels (75% and 100%) could affect the physicochemical properties of the sauce as compared to the control sample. It was also found that the addition of olive oil (up to 50%) would not significantly impact the sauce properties. Regarding the OLE enrichment in the samples, it was found that high levels of OLE could improve the oxidative stability of the samples. It was also found that OLE could be used as a preservative instead of commercial ones. Overall, this study suggests the potential use of olive oil and olive leaf extract in the preparation of French sauce to boost its nutritional value and its stability.

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Antioxidant Activity and Thermal Stability of Oleuropein and Related Phenolic Compounds of Olive Leaf Extract after Separation and Concentration by Salting-Out-Assisted Cloud Point Extraction

Antioxidants ◽

10.3390/antiox3020229 ◽

2014 ◽

Vol 3 (2) ◽

pp. 229-244 ◽

Cited By ~ 17

Author(s):

Konstantinos Stamatopoulos ◽

Evangelos Katsoyannos ◽

Arhontoula Chatzilazarou

Keyword(s):

Thermal Stability ◽

Antioxidant Activity ◽

Phenolic Compounds ◽

Cloud Point ◽

Leaf Extract ◽

Cloud Point Extraction ◽

Olive Leaf ◽

Salting Out ◽

Olive Leaf Extract ◽

Thermal Stability Of

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Polylactide Films with the Addition of Olive Leaf Extract—Physico-Chemical Characterization

Materials ◽

10.3390/ma14247623 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7623

Author(s):

Sylwia Grabska-Zielińska ◽

Magdalena Gierszewska ◽

Ewa Olewnik-Kruszkowska ◽

Mohamed Bouaziz

Keyword(s):

Phenolic Compounds ◽

Food Packaging ◽

Leaf Extract ◽

Color Change ◽

Antioxidant Properties ◽

Radical Scavenging ◽

Total Content ◽

Degree Of Crystallinity ◽

Olive Leaf ◽

Olive Leaf Extract

The aim of this work was to obtain and characterize polylactide films (PLA) with the addition of poly(ethylene glycol) (PEG) as a plasticizer and chloroformic olive leaf extract (OLE). The composition of OLE was characterized by LC-MS/MS techniques. The films with the potential for using in the food packaging industry were prepared using a solvent evaporation method. The total content of the phenolic compounds and DPPH radical scavenging assay of all the obtained materials have been tested. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (FTIR-ATR) allows for determining the molecular structure, while Scanning Electron Microscopy (SEM) indicated differences in the films’ surface morphology. Among other crucial properties, mechanical properties, thickness, degree of crystallinity, water vapor permeation rate (WVPR), and color change have also been evaluated. The results showed that OLE contains numerous active substances, including phenolic compounds, and PLA/PEG/OLE films are characterized by improved antioxidant properties. The OLE addition into PLA/PEG increases the material crystallinity, while the WVPR values remain almost unaffected. From these studies, significant insight was gained into the possibility of the application of chloroform as a solvent for both olive leaf extraction and for the preparation of OLE, PLA, and PEG-containing film-forming solutions. Finally, evaporation of the solvent from OLE can be omitted.

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