scholarly journals 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 ◽  
2014 ◽  
Vol 3 (2) ◽  
pp. 229-244 ◽  
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

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

2007 ◽  
Vol 13 (6) ◽  
pp. 413-421 ◽  
Author(s):  
F.N. Salta ◽  
A. Mylona ◽  
A. Chiou ◽  
G. Boskou ◽  
N.K. Andrikopoulos
Keyword(s):  
Phenolic Compounds ◽  
Oxidative Stability ◽  
Antioxidant Capacity ◽  
Hplc Analysis ◽  
Leaf Extract ◽  
Olive Leaf ◽  
Total Polyphenols ◽  
Olive Leaf Extract ◽  
Rancimat Method ◽  
Oil Sunflower

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.

scholarly journals Microbiological and Antioxidant Activity of Phenolic Compounds in Olive Leaf Extract

Molecules ◽  
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.

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

2019 ◽  
Vol 279 ◽  
pp. 40-48 ◽  
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

Thermal stability and products chemical analysis of olive leaf extract after enzymolysis based on TG–FTIR and Py–GC–MS

2018 ◽  
Vol 132 (3) ◽  
pp. 1729-1740 ◽  
Author(s):  
Jiao-jiao Yuan ◽  
Jun-ling Tu ◽  
Yong-jun Xu ◽  
Frank G. F. Qin ◽  
Bing Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Analysis ◽  
Leaf Extract ◽  
Olive Leaf ◽  
Olive Leaf Extract

Bio-nanofibrous mats as potential delivering systems of natural substances

2016 ◽  
Vol 87 (4) ◽  
pp. 444-459 ◽  
Author(s):  
Zdenka Peršin ◽  
Matej Ravber ◽  
Karin Stana Kleinschek ◽  
Željko Knez ◽  
Mojca Škerget ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
High Performance ◽  
Leaf Extract ◽  
Radical Scavenging Activity ◽  
Release Kinetics ◽  
Radical Scavenging ◽  
Olive Leaf ◽  
Olive Leaf Extract ◽  
Natural Substances ◽  
Phenolic Components

Considering the increasing resistance of numerous bacteria to antibiotics, a novel wound dressing material was developed with naturally acquired olive leaf extract, which shows not only good antimicrobial activity, but also very good antioxidant activity. Besides that, the leaves are treated as waste in agriculture, giving an impact on waste management. An environmentally friendly procedure, electrospinning, was used for the first time to prepare polysaccharide nanofibrous mats with incorporated olive leaf extract, with the unique property of releasing the active phenolic components in a prolonged manner over 24 hours. The developed electrospun mats were characterized using scanning electron microscopy, high-performance liquid chromatography and ultraviolet-visible spectroscopy for determination of free radical scavenging activity by 2,2-diphenyl-1-picrylhydrazyl, antimicrobial testing and release kinetics. Antimicrobial tests have shown that electrospun mats with olive leaf extract achieve reduction towards the tested microorganisms: Staphylococcus aureus (G+), Escherichia coli (G-), Enterococcus faecalis (G+) and Pseudomonas aeruginosa (G-), while the high antioxidant activity of olive leaf extract was preserved during the electrospinning procedure. Release of olive leaf extract from electrospun mats was mathematically modeled, and the release kinetics evaluation indicates the appropriateness of the Korsmeyer–Peppas model for fitting the obtained results of release ability due to erosion of polysaccharide nanofiber mats.

scholarly journals Journal of Food Quality Evaluation of Effect of Extraction Solvent on Selected Properties of Olive Leaf Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Won-Young Cho ◽  
Da-Hee Kim ◽  
Ha-Jung Lee ◽  
Su-Jung Yeon ◽  
Chi-Ho Lee
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Leaf Extract ◽  
Radical Scavenging ◽  
Total Phenolic ◽  
Distilled Water ◽  
Olive Leaf ◽  
Leaf Extracts ◽  
Antioxidant Power ◽  
Olive Leaf Extract

The quest for natural preservatives and functional foods with health benefits has seen an increasing demand for natural products having therapeutic value. Herein, we investigated the influence of ethanol, methanol, acetone (50%, 70%, and 90% v/v), and distilled water on selected properties of olive leaf extract and determined the yield, total phenolic content (TPC), antioxidant activity, and antimicrobial activity. Extracts were analyzed for their oleuropein, hydroxytyrosol, and tyrosol contents by high-performance liquid chromatography (HPLC). The highest extraction yield of 20.41% was obtained when using 90 vol% methanol, while the highest total polyphenol contents of 232 and 231 mggallic-acid-equivalent/100 g were obtained for 90 vol% methanol and 90 vol% ethanol, respectively. Antioxidant activity was determined using the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging assay, by determining the ferric reducing antioxidant power (FRAP), and using the Fe2+-chelating activity assay, which provided the highest values when 90 vol% methanol was used (33.84%, 0.75, and 12.91%, respectively). HPLC analysis showed that the highest oleuropein contents corresponded to the extracts obtained using 90 and 70 vol% methanol (26.10 ± 0.20 and 24.92 ± 1.22 g/L, respectively), and the highest antimicrobial activity was observed for 90 vol% methanol and distilled water. Olive leaf extracts using 90 vol% methanol had high levels of polyphenols and were highly antioxidant and antimicrobial. The results of this study facilitate the commercial applications of natural extracts with antioxidant and antibacterial activities and are expected to establish a foundation for further optimization studies.

scholarly journals In vitro antioxidant activity of olive leaf extract (Olea europaea L.) and its protective effect on oxidative damage in human erythrocytes

Heliyon ◽  
2018 ◽  
Vol 4 (9) ◽  
pp. e00805 ◽  
Author(s):  
Patricia Goldschmidt Lins ◽  
Silvana Marina Piccoli Pugine ◽  
Antonio Márcio Scatolini ◽  
Mariza Pires de Melo
Keyword(s):  
Antioxidant Activity ◽  
Oxidative Damage ◽  
Protective Effect ◽  
Leaf Extract ◽  
Human Erythrocytes ◽  
Olive Leaf ◽  
Olea Europaea L ◽  
Olive Leaf Extract ◽  
In Vitro Antioxidant Activity

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

Materials ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document