Academic literature on the topic 'Olive leaves extract'

Ceylon olive (Elaeocarpus serratus L.) leaves have shown many pharmacological effects. Standardization of crude drug and extract needs to be conducted to assure the quality of the said material and further to support the pharmacological, pharmacokinetics, and toxicity effects. Standardization of Ceylon olive leaf extract is carried out to determine the standard parameters of crude drug and ethanolic extract of Ceylon olive leaves. Determination of the quality standard of crude drug and extract includes specific and non-specific parameters. The extract was obtained from a 70% ethanol maceration method with a yield of 16.02%. Macroscopic observations showed crude drugs of Ceylon olive leaves occurred as green in color, lanceolate leaves, 2-12 mm stems, and jagged leaves not deep, black spots, 10-15 side leaf bones, 6-18 cm long and 2-6 cm wide. Organoleptic of ethanolic extract of Ceylon olive showed thick consistency, blackish-brown colored, with a distinctive odor and a bitter taste. The water-soluble extractive value in crude drugs and extract was 16.48 and 51.54%, while the ethanol-soluble extractive value was 23.17 and 53.67%, respectively. The extract contained tannins, flavonoids, terpenoids, and saponins. Moisture content in the crude drugs and extracts was 22.09 and 25.53%. Total ash content in crude drugs and extracts was 33.53 and 30.62%, while their acid-insoluble ash content was 15.94 and 10.06%, respectively. Loss on drying of the crude drugs and extracts was 20.52 and 23.84% respectively. As the standard parameters of crude drugs and ethanolic extract of Ceylon olive leaves are not yet included in any formal monograph in Indonesia, the values of parameters reported in this study should be used as the reference of the standard quality parameter for those materials.

Introduction. The article presents the results of a study of the physicochemical properties of dry extract of olive leaves, standardized by hydroxythyrozol - a biologically active substance that is part of the chemical composition of aerial parts of the olive tree.Aim. The purpose of the study is to develop tablet Formulations containing dry extract of olive leaves and to standardize by hydroxythyrozol by reversed-phase-HPLC method on the main substancecontent.Materials and methods. Substance of dry extract of olive leaves, microcrystalline cellulose (Avicel® PH-112), Aerosil® (Aeroperl® 300 Pharma), Ludipress® (Ludipress®), lactose, potato starch, sodium salt of carboxymethyl starch, magnesium stearate, direct pressing, HPLC.Results and discussion. Studies of the physicochemical properties of dry extract of olive leaves have been carried out. Selected excipients for the study of tablettable masses. Formulations for further tabletting have been developed. A complex of studies of the obtained tablets was carried out according to Russian Pharmacopoeia XIV for compliance with quality indicators.Conclusion. The biological properties of dry extract of olive leaves are have been studied, indicating the prospect of developing drugs based on it. Formulations of tablets with dry extract of olive leaves have been developed and their quality indicators have been investigated.

The main goal of this project consisted of the conceptualization and development of a product related to the olive tree chemical features to monetize the wastes of the olive fruit exploitation. The most abundant by-product of the olive fruit harvest is the olive leaves, used as the raw material in this project. By following the steps of Chemical Product Design, it was decided to pursue the idea of creating antibacterial cotton bed sheets impregnated with olive leaves extract, mainly composed of oleuropein. The production process includes a pre-treatment of the olive leaves, oleuropein extraction, and supercritical impregnation. The estimated amount of leaves required is 39 g/m2 of cotton, considering a cotton fabric with 115 GSM.

This study was designed to determine the best olive variety for cultivation in Pakistan. The leaves of eight locally grown varieties were analyzed for levels of moisture, total solids, ash, fat, fibre, protein, K, Ca, Mg, Na, Fe, Mn, Zn and Cu levels. Leaves were then subjected to solvent extraction with each of water ratio in, 75% ethanol, 75% methanol, 95% ethanol and 95% methanol. The extract yield was significantly highest for 75% ethanol extract of all varieties. Significantly highest polyphenol and flavonoid contents were examined for Gemlik leaves extracted with 75% ethanol. We recommend cultivation of Gemlik in Pakistan and extraction of bioactive compounds from olive leaves will be the most efficient with a binary solution of 75% ethanol in water. Further studies should be planned to assess antioxidant, antimicrobial and food preservation properties of olive leaf extract from locally grown varieties.

Aim: This study was designed to investigate the phytochemical profile and the cytotoxic activities of the eco-friendly extracts of olive leaves from Chemlali cultivar. Materials and Methods: The Phenolic composition of olive leaves extracts, the antioxidant activity and the cytotoxic effects against MCF-7 and HepG2 cells were determined. Results: Olive leaves extracts showed relevant total polyphenols contents. Oleuropein was the major detected phenolic compound reaching a concentration of 16.9 mg/ml. The antioxidant potential of the studied extracts varied from 23.7 to 46.5mM Trolox equivalents as revealed by DPPH and ABTS assays. Cytotoxicity experiments showed similar trends for both HepG2 and MCF-7 cells with the infusion extract being the most active. Conclusion: This study denotes that olive leaves may have great potential as endless bioresource of valuable bioactive compounds which may have a wide application.

This research was done to investigate the effectiveness of the presence of olive leaf extract in vacuum packaging in maintaining the physicochemical properties of fresh-cut snake fruit under ambient temperature. The snake fruits were vacuum packaged in the presence of 3% (v/w) olive leave extract (OLE) and stored in room temperature for 8 days of storage. The physicochemical properties including color changes, firmness, and total dissolved solid (TDS) were observed. The results indicated that addition olive leaves extract in vacuum packaging gave the best result by inhibiting color changes by declining in total color difference by 10.88, BI 5.08, absorbance 2.750 Ǻ declining in hardness by 14.61% and lowest TDS level. As an alternative method of storing fresh-cut snake fruit under ambient conditions, vacuum packaging containing olive leave extract can be used.

AbstractOlea europaea L. (olive, Oleaceae) constitutes a source of many bioactive compounds, which have recognized benefits for both human health and technological purposes. The present article was carried out to evaluate the biological activity of oleuropein (an ester of 2-(3,4-dihydroxyphenyl) ethanol (hydroxytyrosol) which has the oleosidic skeleton that is common to the secoiridoid glucosides of Oleaceae). It occurred in leaf extracts of the four olive cultivars (Chemlali, Manzanilla, Picaul and Toffahi) as a source for some anticancer and antioxidant agents and their consequences on the action of Hordeum vulgare (barley). The total phenolic and flavonoid compounds were extracted from olive leaves by ethanol 95% then analyzed by high-performance liquid chromatography (HPLC). The study evaluates the anticancer activity of the ethanolic extract of olive leaves against breast and hepatocellular carcinoma cells showing high values. Also, the extract exhibited highly consequence on the antioxidant potentiality of barley which was assessed using the diphenyl picryl hydrazyl method (DDPH). These results pave the way for utilization of olive leaves as a source of natural anticancer and antioxidant agents.

In this study, we reported the determination of phenolic compounds in olive leaves by reversed phase HPLC/DAD and the evaluation of their in vitro activity against several microorganisms. These organisms might however, be causal agents of human intestinal and respiratory tract infections. Extract of the leaves of two varieties of Olea europaea L. (Chemlel and Dathier) was investigated for antibacterial activity against four pathogenic bacteria. Leaves extract was prepared using water and methanol (20/80) in a cold extraction process. The tested bacteria were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus .The extracts were found to be effective against all isolates tests. Ethanolic extract at a concentration of 100 % presented the highest potential of inhibiting variety of Dathier against S.aureus .This is with an inhibition zone of 17.49 mm and 15.66 mm for the variety Chemlel against S.aureus. The high Oleuropein content and the important antibacterial activities of olive leaves extract could be useful sources for industrial extraction and pharmacological application.

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.

L’olio extravergine d’oliva (Extra-Virgin Olive Oil, EVOO) e l’estratto di foglie d’ulivo (Olive Leaves Extract, OLE) rappresentano un'importante fonte di composti nutraceutici, tra cui si annoverano composti a struttura fenolica e polifenolica come i fenil alcoli, gli acidi fenolici, i lignani, i flavoni, i flavonoli ed i secoiridoidi, una classe di composti esclusivi della famiglia delle Oleaceae. I secoiridoidi principalmente presenti nell’EVOO sono l’oleaceina e l’oleocantale, mentre nelle foglie si ritrova l’oleuropeina. Questi composti possiedono proprietà nutraceutiche, quali quelle antiproliferative, cardioprotettive, antiossidanti ed antinfiammatorie. Il progetto di ricerca della mia tesi di dottorato è stato focalizzato sullo studio dei composti fenolici e polifenolici presenti nell’EVOO e nell’OLE e si è articolato in varie direttrici:  Sviluppo di metodi efficienti per l'estrazione e la purificazione di oleocantale ed oleaceina da EVOOs Durante il dottorato sono state messe a punto delle procedure che hanno permesso di ottimizzare le precedenti metodiche di estrazione e purificazione ottenendo quantità significative di oleaceina ed oleocantale con buona purezza, partendo da EVOO fresco.  Studio delle proprietà nutraceutiche di oleocantale ed oleaceina L’oleocantale e l’oleaceina estratti e purificati dagli EVOOs sono stati sottoposti a studi farmacologici al fine di investigare le loro proprietà nutraceutiche. Questi studi hanno evidenziato il ruolo dei due secoiridoidi nell'infiammazione degli adipociti associata all'obesità e nella via di segnale NF-κB. È stato possibile evidenziare la capacità dell'oleaceina di inibire la proliferazione delle cellule di melanoma cutaneo in vitro (cellule 501Mel). Inoltre, è stato provato che l'oleocantale esercita un effetto anti-fibrotico, sia su modelli in vitro che in vivo di fibrosi epatica.  Studio delle variazioni della composizione fenolica e polifenolica degli EVOOs nel tempo Queste ricerche sono state condotte analizzando differenti EVOOs mediante metodiche HPLC sviluppate in questo dottorato. I risultati di queste analisi hanno confermato che i composti fenolici presenti nell’EVOO subiscono nel tempo un processo idrolitico, che differisce in ciascun campione di EVOO ed è fortemente correlato alle condizioni di conservazione.  Studio di nuovi componenti negli EVOOs e delle loro potenziali proprietà nutraceutiche Tra i pochi studi relativi ai processi ossidativi subiti dai composti fenolici e polifenolici presenti nell’EVOO, recentemente è stato individuato un nuovo prodotto di ossidazione dell’oleocantale, l’acido oleocantalico, che da studi preliminari è risultato essere particolarmente interessante per le sue potenziali proprietà neuroprotettive. La mia attenzione si è quindi focalizzata sull’acido oleocantalico al fine di ottenerlo ad alto grado di purezza, per poterlo poi sottoporre ad ulteriori studi per investigare le sue proprietà nutraceutiche. È stata valutata per la prima volta la sua attività antiossidante, dimostrando che l’acido oleocantalico possiede un’attività radical scavenging di specie reattive dell’ossigeno.  Studio della composizione di EVOOs toscani per la determinazione della loro tracciabilità geografica Questa parte della mia attività è stata svolta nell’ambito di un progetto che si propone di sviluppare un modello che permetta di verificare e garantire l’origine dell’olio, legandolo indissolubilmente al suo territorio di produzione. In particolare, mi sono dedicata allo studio delle caratteristiche di quaranta EVOOs toscani (acidità totale, contenuto dei composti fenolici e dei principali acidi grassi) al fine di correlarle con dati relativi ad altri parametri, quali la concentrazione di macroelementi, microelementi, elementi in traccia essenziali e non essenziali, nonché terre rare, presenti sia nei campioni di EVOOs che in quelli di suolo dove gli ulivi sono stati coltivati.  Sviluppo di device utili nel campo della rigenerazione tissutale a partire da fitoestratti di foglie d’ulivo (OLEs) ottenute da ulivi di Cultivar autoctone toscane Questa parte dell’attività di ricerca è stata svolta nell’ambito di un progetto che ha come obiettivo quello di studiare fibre biocompatibili che incorporano OLEs per lo sviluppo di dispositivi biomedicali utili nel processo di rigenerazione tissutale. Nell’ambito di questo progetto mi sono dedicata all’analisi di diversi OLEs al fine di selezionare quello più appropriato in termini di composizione fenolica e polifenolica, che è stato quindi incorporato nei biopolimeri. Ho quindi confermato l’avvenuta incorporazione dell’OLE nei biopolimeri e verificato che questi fossero in grado di rilasciare i fenoli ed i polifenoli dell’OLE. Inoltre, è stato dimostrato che i biopolimeri che incorporano l’OLE possiedono promettenti proprietà anti-infiammatorie ed immunomodulatorie, utili per il possibile sviluppo dei device.
Extra-virgin olive oil (EVOO) and olive leaves extract (OLE) represent an important source of nutraceutical compounds, including phenolic and polyphenolic compounds such as phenyl alcohols, phenolic acids, lignans, flavones, flavonols and secoiridoids. Secoiridoids are a class of compounds exclusive of Oleaceae family. Oleocanthal and oleacein are the most important secoiridoids present in EVOO, while oleuropein is the main representative in OLE. These compounds possess nutraceutical properties, such as antiproliferative, cardioprotective, antioxidant and anti-inflammatory properties. My PhD project was focused on the study of the phenolic and polyphenolic compounds in EVOO and in OLE and it was aimed to several parallel objectives:  Development of efficient methods for the extraction and the purification of oleocanthal and oleacein from EVOOs During this PhD, new procedures were developed by improving previous extraction and purification methods, obtaining significant quantities of oleacein and oleocanthal from fresh EVOO, with good purity.  Study of the nutraceutical properties of oleocanthal and oleacein Oleocanthal and oleacein extracted and purified from EVOOs were then submitted to pharmacological studies to investigate their nutraceutical properties. The results of these studies highlighted the role of the two secoiridoids in obesity-associated adipocytes inflammation and in the NF-κB pathway. The ability of oleacein to inhibit the proliferation of skin melanoma cells in vitro (501Mel cells) was demonstrated. Moreover, the antifibrotic effect of oleocanthal, in both in vitro an in vivo models of liver fibrosis, was proved.  Study of the variations in the phenolic and polyphenolic composition of EVOOs during storage This study was conducted by analysing several EVOOs using HPLC methods developed during this PhD thesis. The results of these analyses confirmed that the phenolic compounds present in EVOO underwent a hydrolytic process during storage. However, the evolution of this pathway differs in each EVOO sample, and it is strongly related to storage condition.  Study of novel components in EVOOs and their potential nutraceutical properties The oxidative process involving phenolic and polyphenolic compounds in EVOO are poorly investigated. A new oleocanthal oxidation product, named oleocanthalic acid, has been recently identified and preliminary studies showed the potential neuroprotective properties of this compound. My attention was therefore focused on obtaining oleocanthalic acid with high purity in order to submit it to further studies for its nutraceutical properties investigation. A detailed assessment of its in vitro radicals quenching activity was performed for the first time, demonstrating its scavenging capacity against reactive oxygen species.  Study of composition of Tuscan EVOOs for the determination of their geographical traceability This part of my PhD work was carried out as a part of a project aimed to develop a model that would allow to verify and guarantee the origin of the oil, indissolubly linking it to its production area. In particular, I studied the characteristics of forty Tuscan EVOOs (free acidity, phenolic compounds content and main fatty acids content). The results of these analyses will be correlated with other parameters studied, such as the concentration of macro-elements, micro-elements, essential and non-essential trace elements, as well as rare earth elements, present both in the samples of EVOOs and in those of soil where the olive trees were cultivated.  Development of devices useful in tissue regeneration fields from olive leaves phytoextracts (OLEs) obtained from autochthonous Tuscan olive trees Cultivars This part of my research was carried out under a project that aims to study biocompatible fibers incorporating OLEs for the development of biomedical devices useful in the tissue regeneration field. In particular, I analysed the phenolic and polyphenolic composition of several OLEs in order to select the most appropriate one to incorporate into the biopolymers. I therefore confirmed the incorporation of the OLE into the biopolymers and their capability to release the OLE phenols and polyphenols. Furthermore, the biopolymers incorporating OLE showed promising anti-inflammatory and immunomodulatory properties, useful for the development of devices.

Introduzione. L'Olea europaea è uno degli alberi più antichi della regione mediterranea. Gli estratti di foglie di olivo (Olive Leaf Extracts, OLE) hanno suscitato interesse nei ricercatori di diverse discipline scientifiche principalmente a causa della particolare composizione fenolica, presumibilmente correlata alla sua potente attività biologica. Obiettivi. Lo scopo di questo studio è stato valutare: a) le proprietà degli OLE di Olea europaea Toscana per proteggere le cellule endoteliali dallo stress ossidativo generato dalle specie reattive dell'ossigeno (ROS), sia in coltura 2D sia in innovativi scaffold 3D (P (VDF-TrFE)); b) studiare l'effetto antimicrobico di OLE rispetto alla tecnologia Cold Atmospheric Plasma (CAP), o la loro combinazione, contro agenti patogeni, ad esempio Escherichia coli, Staphylococcus aureus e Listeria innocua, cresciuti a livello esponenziale o in fase stazionaria; c) caratterizzare fibre composite elettrofilate a base di PHBHV caricate con OLE per applicazioni nella guarigione delle ferite; d) valutare la capacità di OLE incorporato nelle fibre di poliidrossialcanoati (PHA) di modulare il rilascio di citochine da cheratinociti umani sani (HaCaT). Metodi: I polifenoli totali (total polyphenols, TP) di OLE sono stati caratterizzati con il metodo di Folin-Ciocalteu. Le cellule endoteliali sono state coltivate in colture convenzionali (cioè bidimensionali, 2D) e su impalcature tridimensionali fabbricate tramite elettrofilatura. La vitalità cellulare e la misurazione dei ROS dopo lo stress indotto da H2O2 sono state eseguite tramite WST-1, alamar Blue e la sonda CM-H2DCFDA per ROS. La crescita di E. coli, S. aureus e L. innocua è stata valutata mediante il test di unità (CFU) formanti colonie (espressa in CFU/ml) e CAP. È stata eseguita la reazione a catena della polimerasi in tempo reale (real-time PCR) per valutare le proprietà immunomodulatorie; analisi di spettroscopia infrarossa in trasformata di Fourier (FT-IR), per discriminare la composizione chimica in entrambe le fibre elettrofilate; cromatografia a permeazione su gel (GPC) per consentire l'analisi della biodegradazione; microscopia SEM per lo studio della morfologia delle fibre ed in fine, HPLC per eseguire lo studio di rilascio. Risultati: il contenuto in TP di OLE era 23,29 mg di acido gallico equivalente (GAE)/g e l'oleuropeina era il composto principale. La curva di vitalità dose-dipendente ha evidenziato l'assenza di effetti citotossici significativi a concentrazioni di OLE inferiori a 250 μg GAE/ml di TP. Il pretrattamento di 100 μg GAE/ml di TP di OLE ha avuto effetti protettivi sullo stress ossidativo indotto da H2O2 in entrambi i modelli (2D e 3D). La combinazione di CAP e OLE ha determinato una sostanziale inattivazione microbica contro tutti i ceppi in fase esponenziale mostrando una completa inattivazione. OLE ha dimostrato una significativa attività antinfiammatoria, sottoregolando l'espressione di tutte le citochine proinfiammatorie e sovraregolando IL-8, IL-1α e TNF-α nel modello HaCaT. Conclusione: OLE possiede una significativa attività antiossidante e antinfiammatoria; la fibra a base di PHBHV + OLE preserva gli effetti benefici di OLE e rappresenta uno scaffold 3D di alto valore con un grande potenziale nella rigenerazione dei tessuti. CAP e OLE possiedono un'attività antibatterica sinergica; pertanto, la tecnologia CAP in combinazione con OLE può essere utilizzata per una decontaminazione efficace, ad esempio nella guarigione delle ferite ed in dispositivi biomedicali.
Background. Olea europaea is one of the most ancient trees of the Mediterranean region. Olive leaf extracts (OLE) have aroused interest in researchers from different scientific disciplines mainly due to the distinctive phenolic composition allegedly related to potent biological activities. Objectives. The aim of the present s study was to evaluate: A) the properties of OLE extracted from the Tuscan Olea europaea to protect endothelial cells against oxidative stress generated by reactive oxygen species (ROS) in 2D culture and innovative 3D scaffold (P(VDF-TrFE)); B) to investigate the antimicrobial effect of OLE versus Cold Atmospheric Plasma (CAP) technology or their combination against pathogens, i.e., Escherichia coli, Staphylococcus aureus and Listeria innocua, grown to exponential (24h) or stationary (6h) phase; C) to characterize electrospun OLE-loaded PHBHV based composite fibers for wound healing applications; D) to evaluate the ability of OLE incorporated in Polyhydroxyalkanoates (PHAs) fibers to modulate the release of cytokines from healthy Human Keratinocytes (HaCaT). Methods: OLE total polyphenols (TPs) were characterized by the Folin–Ciocalteu method. Endothelial cells were grown in conventional cultures (two-dimensional, 2D) and on three-dimensional scaffold fabricated via electrospinning. Cell viability and ROS production after H2O2 insults were evaluated by WST-1, AlamarBlue and Probe CM-H2DCFDA assays. The E.coli, S.aureus and L.innocua growth were assessed by CFU/mL and CAP methods; Real-time polymer chain reaction (PCR) was carried out to evaluate the immunomodulatory properties; Fourier Transform Infrared Spectroscopy (FT-IR) Analysis was performed to discriminate the chemical composition in both electrospun fibers. Moreover, Gel Permeation Chromatography (GPC) to allow biodegradation analysis, SEM microscopy to study fiber morphology and HPLC to carry out the release study, were performed. Results: OLE TP content was 23.29 mg of gallic acid equivalent (GAE)/g, and oleuropein was the principal compound. The dose-dependent viability curve highlighted the absence of significant cytotoxic effects at OLE concentrations below 250 μg GAE/ml TPs. OLE preconditioning at 100 μg GAE/ml was protective against ROS in both models. The combination of CAP and OLE resulted in substantial microbial inactivation against all strains at exponential phase showing a complete inactivation. OLE possess a significant anti-inflammatory activity, downregulating the expression of all proinflammatory cytokines, upregulating IL-8, IL- 1α and TNF-α in HaCaT model. Conclusion. OLE possess a significant antioxidant and anti-inflammatory activities; PHBHV+OLE retains OLE beneficial effects and represents a high-value 3D scaffold with great potential in tissue regeneration. CAP and OLE have synergistic antibacterial activity; therefore, CAP technology in combination with OLE can be utilized for effective decontamination when required for example in wound healing and biomedical devices.

[EN] The main goal of this Thesis was to determine the influence of the main processing stages involved in obtaining natural extracts with high antioxidant potential from byproducts originating in the olive oil industry. Firstly, the effect of freezing and/or the drying methods applied to olive oil byproducts on the polyphenol content and antioxidant capacity of the extracts subsequently obtained was addressed. For this purpose, two byproducts were considered: olive leaves and olive pomace. Secondly, the feasibility of intensifying the extraction of olive leaf polyphenols by means of a new technology, such as power ultrasound, was approached taking both compositional and kinetic issues into account. Thirdly, how the processing conditions (drying and extraction) influence the extract's stability was evaluated. Thus, on the one hand, extracts obtained from olive leaves were subjected to in vitro digestion or dehydrated and stored at different conditions. Finally, the possibility of obtaining a dried vegetable matrix (apple) rich in olive leaf phenolic compounds was explored by addressing the influence of apple pretreatments (blanching and freezing) and drying on the final retention of infused phenolics. The antioxidant potential of extracts and the retention of infused polyphenols in apple were evaluated by means of the total phenolic content and antioxidant capacity analysis, as well as the identification and quantification of the main olive leaf polyphenols by HPLC-DAD/MS-MS. Moreover, in apple samples, the polyphenol oxidase and peroxidase activity and microstructure were also analyzed. The experimental results highlighted that both drying and freezing methods significantly (p<0.05) influenced the concentration of the main polyphenols identified in the olive leaf extracts. Thus, drying at the highest temperature tested was the best processing condition in which to obtain extracts with high antioxidant capacity and phenolic content. Ultrasound application was found to be a relevant, non-thermal way of speeding-up the antioxidant extraction from olive leaves. Thus, by appropriately tuning-up the process variables, the ultrasonic assisted extraction shortened the extraction time from the 24 h needed in conventional extraction to 15 min, without modifying either the extract composition or the antioxidant potential. As far as extract stability is concerned, the processing conditions used for obtaining the olive leaf extracts did not have a meaningful influence on bioaccessibility. Regardless of the method used, stabilizing the extracts by means of dehydration only reduced both the antioxidant capacity and the total phenolic content by around 10 %. Moreover, storage conditions did not show a significant (p<0.05) effect on the antioxidant potential of the extracts for 28 days of storage. A stable dried product (apple), rich in natural phenolic compounds (from olive leaves or tea extracts), was obtained by combining drying-impregnation-drying steps. However, it should be considered that the role of fresh apple drying on the retention of infused olive leaf polyphenols was more important than the further drying of the impregnated apple. In overall terms, olive leaves can be considered a potential source of natural phenolic compounds. Notwithstanding this, the previous drying and freezing steps applied in the raw material processing are decisive factors in the obtaining of natural extracts with high antioxidant potential. Moreover, enhancing the extraction by applying power ultrasound was stated as a non-thermal way of shortening processing times. The stability of olive polyphenols during storage and in vitro digestion was closely related to the individual component considered. Finally, the exploitation of olive leaf extracts as a means of enriching solid foodstuffs requires the use of porous solid matrices free of oxidative enzymes.
[ES] El objetivo principal de esta Tesis fue determinar la influencia de las principales etapas de procesado implicadas en la obtención de extractos naturales con alto potencial antioxidante a partir de los subproductos originados en la industria del aceite de oliva. En primer lugar, se evaluó el efecto de los métodos de congelación y/o secado de la materia prima (hojas y orujo), sobre el contenido polifénolico y la capacidad antioxidante de los extractos. En segundo lugar, se abordó la intensificación de la extracción de polifenoles de hoja de olivo con ultrasonidos de potencia, teniendo en cuenta: composición y la cinética del proceso. A continuación, se estudió cómo las condiciones de procesado (secado y extracción) podían influir en la estabilidad de los extractos. Así, extractos de hojas de olivo fueron sometidos a digestión in vitro o deshidratados y almacenados a distintas condiciones. Por último, se exploró la posibilidad de obtener una matriz vegetal deshidratada (manzana) y rica en compuestos fenólicos de hoja de olivo. Para ello, se evaluó la influencia de los pretratamientos de la manzana (escaldado y congelación) y del secado en la retención final de los polifenoles impregnados. El potencial antioxidante se determinó a través del contenido total en compuestos fenólicos y la capacidad antioxidante y la identificación y cuantificación (HPLC-DAD/MS-MS) de los principales polifenoles. Además, en manzana, se midió la actividad enzimática de la polifenol oxidasa y peroxidasa y se analizó la microestructura. Los resultados manifestaron que el método de secado y el de congelación influyeron significativamente (p<0.05) en la concentración de los principales polifenoles en los extractos. Así, el secado a mayor temperatura resultó ser el mejor tratamiento para obtener extractos con alta capacidad antioxidante y alto contenido fenólico. La aplicación de ultrasonidos resultó ser una alternativa no térmica muy interesante para acelerar la extracción de antioxidantes de hojas de olivo. Con la combinación adecuada de las variables del proceso, la aplicación de ultrasonidos redujo el tiempo de extracción de 24 h necesarias en extracción convencional a 15 min, sin modificar la composición de los extractos y su potencial antioxidante. En cuanto a la estabilidad del extracto, las condiciones de procesado no tuvieron una influencia significativa en la bioaccesibilidad de los extractos. Independientemente del método utilizado, la estabilización de extractos por deshidratación sólo redujo la capacidad antioxidante y el contenido total en compuestos fenólicos en torno a un 10 %. Además, las condiciones de almacenamiento no mostraron ningún efecto significativo (p<0.05) sobre el potencial antioxidante durante los 28 días de almacenamiento. Combinando secado-impregnación-secado, fue posible desarrollar un producto deshidratado (manzana), estable y rico en compuestos fenólicos naturales (de hojas de olivo o extractos de té). No obstante, cabe destacar que el secado de la manzana fresca jugó un papel más importante en la retención de los polifenoles de hoja de olivo infundidos que el secado final de la manzana impregnada. En términos generales, las hojas de olivo pueden considerarse como una fuente potencial de compuestos fenólicos naturales. No obstante, el secado y la congelación durante el procesado de la materia prima son factores decisivos para la obtención de extractos naturales con alto potencial antioxidante. Además, la aplicación de ultrasonidos de potencia durante la extracción puede resultar una alternativa no térmica muy interesante de cara a acortar el tiempo de procesado. La estabilidad de los polifenoles de la hoja de olivo, durante el almacenamiento y la digestión in vitro, dependió claramente del compuesto individual considerado. Finalmente, el empleo del extracto de hoja de olivo como medio para enriquecer alimentos sólidos requiere del uso de matrices s
[CAT] L'objectiu principal d'aquesta tesi va ser determinar la influència de les principals etapes de processament implicades en l'obtenció d'extractes naturals amb alt potencial antioxidant procedents de subproductes de la indústria de l'oli d'oliva. En primer lloc, es va estudiar l'efecte de la congelació i/o els mètodes d'assecatge aplicats a fulles d'olivera i pinyolada sobre el contingut fenòlic i la capacitat antioxidant dels extractes. En segon lloc, es va avaluar, tenint en compte la composició i la cinètica del procés, la intensificació de l'extracció de polifenols de fulla d'olivera amb ultrasons de potència. En tercer lloc, es va avaluar com les condicions de processament (assecatge i extracció) poden influir en l'estabilitat dels extractes. Així, extractes de fulles d'olivera van ser sotmesos a una digestió in vitro o deshidratats i emmagatzemats a distintes condicions. Finalment, es va explorar la obtenció d'una matriu vegetal deshidratada (poma) i rica en compostos fenòlics de fulla d'olivera considerant la influència del pretractament de la poma (escaldament i congelació) i de l'assecatge sobre la retenció final dels fenòlics introduïts en la poma. El potencial antioxidant es va avaluar determinant el contingut fenòlic total i la capacitat antioxidant, així com identificant i quantificant els principals polifenols (HPLC-DAD/MS-MS). A més, en poma l'activitat enzimàtica de la polifenoloxidasa i la peroxidasa i la microestructura. Els resultats experimentals van destacar que el mètode d'assecatge i el de congelació van influir significativament (p<0,05) en la concentració dels principals polifenols identificats en els extractes. L'assecatge a la temperatura més alta que es va provar va resultar la millor condició de processament per a obtenir extractes amb una alta capacitat antioxidant i un alt contingut fenòlic. L'aplicació d'ultrasons va ser una manera rellevant i no tèrmica d'accelerar l'extracció d'antioxidants de les fulles d'olivera. Així, amb la combinació adequada de les variables del procés, l'extracció assistida per ultrasons va escurçar el temps d'extracció, de les 24 h requerides en l'extracció convencional a 15 min, sense modificar la composició de l'extracte ni el potencial antioxidant. Quant a l'estabilitat de l'extracte, les condicions de processament utilitzades per a l'obtenció dels extractes de fulla d'olivera no van tenir una influència significativa en la bioaccessibilitat. Independentment del mètode utilitzat, l'estabilització dels extractes per mitjà de la deshidratació només va reduir la capacitat antioxidant i el contingut fenòlic total al voltant d'un 10 %. A més, les condicions d'emmagatzematge (temperatura i forma de l'extracte: líquid o pols) no van mostrar cap efecte significatiu (p<0,05) en el potencial antioxidant dels extractes durant els 28 dies d'emmagatzematge. Combinant etapes d'assecatge-impregnació-assecatge fou possible obtenir un producte assecat estable (poma) i ric en compostos fenòlics naturals (de fulles d'olivera o te). No obstant això, cal destacar que l'assecatge de la poma fresca va ser més important i determinant en la retenció dels polifenols de fulla d'olivera que no l'assecatge de la poma impregnada. En termes generals, les fulles d'olivera es poden considerar com una font potencial de compostos fenòlics naturals. No obstant això, l'aplicació d'assecatge i congelació durant el processament de la matèria primera són factors decisius per a l'obtenció d'extractes naturals amb un alt potencial antioxidant. A més, l'aplicació d'ultrasons de potència durant l'extracció resultà ser una forma no tèrmica de millorar el procés, tot reduint-ne el temps d'extracció. L'estabilitat dels polifenols d'olivera durant l'emmagatzematge i la digestió in vitro va dependre del compost individual considerat. Finalment, la utilització d'extractes de fulla d'olivera per a desenvolupar aliments sòlids enriquits requ
Ahmad-Qasem Mateo, MH. (2015). ASSESSMENT OF THE INFLUENCE OF PROCESSING CONDITIONS ON THE ANTIOXIDANT POTENTIAL OF EXTRACTS OBTAINED FROM OLIVE OIL INDUSTRY BYPRODUCTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/53452
TESIS
Premiado

碩士
國立中興大學
食品科學系
92
Abstract The aim of this study was to investigate the hepatic protection and antioxidation of water extract from Du-Zhong (Eucommia ulmoides Oliv.) leaves (WEDZ) (including its active compounds: chlorogenic acid and protocatechuic acid) and water extract of Cassia tora L. (WECT) against carbon tetrachloride (CCl4) induced hepatic damage in rats. The oral treatment with WEDZ (0.1, 0.5 and 1.0 g/kg rat) for 28 consecutive days and the administration of CCl4 (0.5 mL/rat, 20%) induced hepatic damage in rats. It could find that CCl4 decrease the weight grain rate and increase the relative organ weights of liver and kidney, and treatment with WEDZ could significantly (p < 0.05) increase weight grain rate and decrease the relative organ weight of liver and kidney. In serum biochemical parameters, CCl4 induced rats liver damage could significantly (p < 0.05) increase the GOT, GPT, LDH, ALP, -GT, BUN, TBil, Chol and TG level as compared with normal control in serum. Treatment with WEDZ and its active compounds could decrease the GOT, GPT, LDH, ALP, -GT, BUN and TG level when compared with negative control. In antioxidant activity evaluation, administration of CCl4 induced rats liver damage caused the GSH content significantly (p < 0.05) decreased and MDA content increased (p < 0.05) both in liver and serum as compared with normal control. Treatment with WEDZ and its active compounds also could significantly increase (p < 0.05) the GSH content and decreased the MDA content both in liver and serum. Administration of WEDZ and its active compounds could increase the activites of GPx, GRd, GST and SOD, and the trolox equivalent antioxidant capacity (TEAC) in serum. Liver histopathology showed that WEDZ and its active compounds reduced the incidence of liver lesions including hepatic cells cloudy swelling, lymphocytes infiltration, cytoplasmic vacuolization, hepatic necrosis and fibrous connective tissue proliferated induced by CCl4 in rats. The administration of CCl4 (0.5 mL/rat, 20%) induced hepatic damage could decrease the weight grain rate and increase the liver weight in rats. Administration of WECT could significantly (p < 0.05) increase the weight grain rate, but no significant different (p > 0.05) in rats organ weight. In serum biochemical parameters, CCl4 induced rats liver damage could significantly (p < 0.05) increase the GOT, GPT and LDH activities and TBil, Crea and Chol content as compared with normal control in serum. Treatment with WECT could significantly (p < 0.05) decrease the GOT, GPT and LDH activities, and decrease the Crea content. WECT could decrease the MDA content and increase GSH content both in liver and serum induced by CCl4. WECT could significantly (p < 0.05) increase the activites of GPx, GRd, GST, Cat and SOD decreased by CCl4. WETC could significantly (p < 0.05) increase the trolox equivalent antioxidant capacity (TEAC) in serum. Liver histopathology showed that WECT reduced the incidence of liver lesions including cloudy swelling, cytoplasmic vacuolization, ballooning degeneration and necrotic cell formation induced by CCl4 in rats. The data suggest that oral administration with WEDZ and WECT for 28 consecutive days could significant decrease the hepatic damage level induced by CCl4 in rats. Moreover, WEDZ and WECT could increase the activites of antioxidant enzymes in liver and increase the total antioxidant capacity decrease by CCl4 in vivo to protect the liver damage.

Abstract Chapter One discusses the ‘prehistory’ of Athenian ostracism by studying both the attested cases of ostracism outside Athens (in Megara, Argos, Tauric Chersonesos, Cyrene, Thourioi, the Sicilian Naxos and possibly in Miletus, as well as the petalismos, or vote using olive leaves, in Syracuse) and conceivable traces of ostracism-like institutions or procedures in Athens of the archaic period. Here, on the one hand, both the famous late Byzantine testimony of the so-called ‘bouleutic ostracism’ (the manuscript Vaticanus Graecus 1144) and that of the archaic ostraca, from the Athenian Agora and the Acropolis, are discounted as unreliable witnesses to the alleged ‘ostracism before ostracism’ in Athens. On the other hand, all extra-Athenian ostracisms seem to post-date the Athenian institution by at least two decades, which bespeaks against the widely held hypothesis that ostracism in Athens was just one local elaboration of a more general Greek practice. More probably, all those institutions in the wider Greek world followed the Athenian model. Additionally, the hypothesis of the ritual origins of ostracism is reassessed and rejected. All in all, it turns out that Athenian ostracism (properly speaking) was an unprecedented Athenian invention.

Olive leaves (OL) are considered a potential source of bioactive compounds mainly due to its high content of polyphenols, widely known as natural antioxidants. The objective of this study was to optimize supercritical fluid extraction conditions from OL in order to obtain natural extracts with high antioxidant activity. OL (belong to the Arbequina cultivar) were collected from a local producer (Uruguay) and subjected to a drying and milling (1 mm particle size) pre-treatment. Supercritical fluid extractions were carried out using a laboratory-built system equipped with a 25 mL stainless steel vessel filled with 10 g of OL. A total of 10 extractions were carried out following a Central Composite Design in which the two independent variables considered were: extraction temperature (40–60 °C) and extraction pressure (150-350 bar). In all cases, extraction solvent was CO2 with 10% of ethanol as modifier. A constant flow rate of 0.5 L/min CO2 was set and each run was finished when 100 L of CO2 were measured in the flow totalizer. Extraction yield (% wt), total phenolic content (Folin-Ciocalteau) and antioxidant activity (ABTS+. assay) of the extracts were considered as response variables. Extraction yield was positively correlated with temperature and pressure, while total phenolic content and antioxidant activity were negatively correlated with temperature. Phenolic content of the extracts varied from 22.9 to 53.6 mg GAE/g. For the extract obtained at optimal conditions, the identification of individual polyphenols was performed by RP/HPLC-Q-TOF MS/MS, being phenolic acids, simple phenols and secoiridoids the most abundant compounds. Finally, oxidative stability of canola oil with or without the incorporation of 250 ppm of some extracts was assessed during five weeks of storage at 60°C. Peroxide, K232, K270, and Rancimat values, besides tocopherol content were determined. Results obtained reinforce the use of supercritical fluid technology to obtain antioxidants compounds from natural sources.

Worldwide, around 50 million people have dementia with nearly 10 million new cases every year. Alzheimer’s Disease (AD) is the most common form of dementia, and it may contribute to 60–70 % of these cases. This multifactorial pathophysiology has been widely characterized by neuroinflammation, extensive oxidative damage, synaptic loss and neuronal cell death. However, only a few drugs have been approved for the therapeutic treatment of AD (with unpleasant side effects), and many studies have suggested that diet and/or food components can prevent the onset of AD. Among these constituents, terpenoids and carotenoids from diverse natural sources have been investigated, and based on a Foodomics approach, our group has demonstrated that an olive leaves extract enriched in triterpenoids and a carotenoids-enriched extract from Dunaliella salina microalgae have neuroprotective potential using in vitro assays. In addition, the neuroprotective and anti-inflammatory potential of these extracts have been confirmed in a neuronal in vitro cell culture model and in vivo using a transgenic Caenorhabditis elegans model. Moreover, different lipidomics studies were performed using advanced analytical methodologies, namely, charged-surface hybrid chromatography-quadrupole-time of flight mass spectrometry (CSH-Q-TOF MS/MS). This technology allowed the annotation of more than 250 intracellular lipids, and among them, a number of phosphatidylcholines, phosphatidylethanolamines and triacylglycerols were significantly altered, suggesting triterpenoids from olive leaves and carotenoids from microalgae as good neuroprotective candidates.