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

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1268 ◽  
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.

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.

scholarly journals Zeytin Yaprağı Ekstraktı ve Oleuropeinin Antioksidan, Antimikrobiyal Aktivitesi, Gıdalarda Kullanım Olanakları

2020 ◽  
Vol 8 (2) ◽  
pp. 337
Author(s):  
Mustafa Bayram ◽  
Semra Topuz ◽  
Cemal Kaya
Keyword(s):  
Phenolic Compound ◽  
Leaf Extract ◽  
Folk Medicine ◽  
Value Added ◽  
Olive Tree ◽  
Antimicrobial Activities ◽  
Olive Leaf ◽  
Olive Leaves ◽  
Food Preservatives ◽  
Olive Leaf Extract

Olive leaves which is one of the by-products of olive tree cultivation and olive processing industry, have been used in traditional folk medicine for centuries. In recent studies, it has been determined that olive leaf has many bioactivities and these effects have been associated with high phenolic compound content. The most dominant phenolic compound of olive leaf is oleuropein, which is the heterosidic ester of elenolic acid and 3,4-dihydroxyphenylethanol. Therefore, some studies have been carried out for extracting high value added compounds from olive leaves in recent years. Antioxidant and antimicrobial activities of crude phenolic extract and oleuropein have been investigated. Moreover, some studies have been carried out to increase the possibility of using olive leaf extract and oleuropein in food industry due to increasing suspicion of side effects and toxicity of synthetic food preservatives. In this review, it was aimed to investigate phenolic compounds of olive leaf extract, phenolic compound extraction from olive leaf as well as antioxidant, antimicrobial activity of olive leaf extract and oleuropein and possibilities of use in foods.

scholarly journals Effect of Nitrite Substitution with Olive Leaves Extract on Color and Sensory Properties of Beef Mortadella

2015 ◽  
Vol 7 (12) ◽  
pp. 120 ◽  
Author(s):  
Khalid Al Marazzeq ◽  
Malik Haddadin ◽  
Basem Al Abdullah ◽  
Malak Angor
Keyword(s):  
Sodium Nitrite ◽  
Leaf Extract ◽  
Sensory Attributes ◽  
Negative Control ◽  
Combined Effect ◽  
The Other ◽  
Olive Leaf ◽  
Olive Leaves ◽  
Overall Acceptability ◽  
Olive Leaf Extract

<p>Six mortadella treatments were prepared for studying the effect of olive leaf extract (OLE) at a level of 240 mg OLE/100 g meat as nitrite alternative on the color and sensory characteristics. These treatments were: control with the addition of 120 ppm sodium nitrite only, and the second one with the addition of 240 mg OLE/100 g meat but without the addition of sodium nitrite as a negative control, the other four treatments were combination of 240 mg OLE/100 g meat with 80, 60, 40 and 20 ppm sodium nitrite, respectively. All samples were stored at 5 °C for 1, 3, 6, 9, and 12 weeks.<strong></strong></p><p>There were no significance differences (P &gt; 0.05) between all mortadella treatments regarding their proximate parameters.<strong> </strong>Hunter lightness (<em>L</em>), redness (<em>a</em>), and yellowness (<em>b</em>) color, and sensory attributes including the appearance, color, tenderness, juiciness, flavor, and overall acceptability showed that 80 and 60 ppm nitrite in combination with OLE at 240 mg/100 g meat had the best results in comparison with the other four treatments indicating an additive combined effect of the OLE with nitrite that enhanced mortadella characteristics.</p><p>These results revealed the ability to substitute 50% of the used nitrite in mortadella stored at 5 °C when using combinations of 60 ppm nitrite with 240 mg OLE/100 g meat.</p>

scholarly journals 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 ◽  
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.

Olive leaf extracts for shelf life extension of salmon burgers

2018 ◽  
Vol 25 (2) ◽  
pp. 91-100 ◽  
Author(s):  
Ibtihel Khemakhem ◽  
Ana Fuentes ◽  
María Jesús Lerma-García ◽  
Mohamed Ali Ayadi ◽  
Mohamed Bouaziz ◽  
...  
Keyword(s):  
Shelf Life ◽  
Leaf Extract ◽  
Life Extension ◽  
Total Volatile ◽  
Olive Leaf ◽  
Leaf Extracts ◽  
Life Study ◽  
Olive Leaf Extract ◽  
Fish Product

In this work, the effect of the addition of olive leaf extracts on the quality of vacuum-packed salmon burgers stored at 4 ℃ during 16 days has been studied. Olive leaf extract and its hydrolysate were initially characterized and then incorporated to salmon burgers. A shelf life study was conducted in three different batches (control, olive leaf extract, and hydrolyzed olive leaf extract burgers). Among the chemical indices determined, total volatile base nitrogen values were lower in hydrolyzed olive leaf extract and olive leaf extract burgers than in control samples. Lipid oxidation was lower in salmon burger with olive leaf extract. Salmon mince treated with hydrolyzed olive leaf extract showed lower microbial counts during the whole study, which extended the shelf life of the fish product. Therefore, the potential of olive leaf extracts to preserve salmon burgers during cold storage has been demonstrated.

scholarly journals Hepatoprotective Effect of Oleuropein-Rich Extract from Olive Leaves against Cadmium-Induced Toxicity in Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Hedya Jemai ◽  
Asma Mahmoudi ◽  
Anwar Feryeni ◽  
Ines Fki ◽  
Zouhaier Bouallagui ◽  
...  
Keyword(s):  
Leaf Extract ◽  
Cadmium Toxicity ◽  
Immunohistochemical Analysis ◽  
Olive Leaf ◽  
Olive Leaves ◽  
Olive Leaf Extract ◽  
The Third ◽  
Liver And Kidney ◽  
Hepatoprotective Effects ◽  
Apoptosis And Inflammation

Cadmium (Cd) is a harmful pollutant which mainly affects the liver and kidney. In this work, we investigated the hepatoprotective effects of olive leaf extract based on oleuropein against hepatic cadmium toxicity in mice. Three groups of animals were used: the first one served as the control (C); the second one received intraperitoneal injection of cadmium 2 mg/kg b.w. (CD), administered five times during two weeks; and the third group received the same doses of Cd and simultaneously 16 mg/kg b.w. of oleuropein. Results showed that Cd induced a significant increase in liver injury biomarkers coupled with enhanced lipid peroxidation (MDA) and significant depletion of antioxidants (CAT and SOD). Histological and immunohistochemical analysis confirmed these findings. In fact, we observed a severe central lobular apoptosis and inflammation around central veins. Cotreatment with oleuropein significantly reduced the oxidative damage induced by cadmium. Our findings suggest that oleuropein could be used in the prevention of Cd hepatotoxicity.

Potential Herb-Drug Pharmacokinetic Interactions between African Wild Olive Leaf Extract and Selected Antihypertensive Drugs

Planta Medica ◽  
2018 ◽  
Vol 84 (12/13) ◽  
pp. 886-894
Author(s):  
Katlego Mmopele ◽  
Sandra Combrinck ◽  
Josias Hamman ◽  
Clarissa Willers ◽  
Weiyang Chen ◽  
...  
Keyword(s):  
Prescription Drugs ◽  
Leaf Extract ◽  
Antihypertensive Drugs ◽  
Blood Levels ◽  
Olive Leaf ◽  
Leaf Extracts ◽  
Olive Leaf Extract ◽  
Wild Olive

AbstractThe African wild olive (Olea europaea subsp. africana) is traditionally used as a hypotensive agent. Herb-drug interactions may result from the concurrent use of herbal medicines and conventional prescription drugs. This aspect was investigated by determining the effect of the extract on the in vitro intestinal epithelial permeation of selected hypotensive drugs using the Caco-2 cell culture model. The phytochemical profiles of leaf extracts of African wild olive from different localities in South Africa were compared, since efficacy is determined by the chemical composition. Extracts were analysed using ultra-performance liquid chromatography. The oleuropein concentration varied considerably from below the detection limit (4.94 µg/mL) to 59.4 mg/g dry weight. Chemometric models constructed from the aligned chromatographic data indicated only quantitative differences between the profiles. The leaf extract was found to increase the permeability of propranolol in the absorptive direction (Papp = 8.93 × 10−6 cm/s) across Caco-2 cell monolayers, but considerably decreased transport in the secretory direction (Papp = 3.68 × 10−6 cm/s). The permeation of diltiazem was enhanced by the extract in both the absorptive (Papp = 7.33 × 10−6 cm/s) as well as in the secretory direction (Papp = 7.16 × 10−6 cm/s), but a decrease in the efflux ratio was observed. The extract therefore caused a net increase in the transport of both drugs in the absorptive direction due to an inhibition effect on their efflux. This suggests a potential increase in the blood levels of these drugs when taken simultaneously with African wild olive leaf extract, indicating potential adverse effects that must be verified in vivo.

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