Ozonated Olive Oil with a High Peroxide Value for Topical Applications: In-Vitro Cytotoxicity Analysis with L929 Cells

Previous studies have shown that ozonated vegetable oils have been used topically for healing of cutenous wounds. The aim of this study is to evaluate the dose dependent use of ozonated olive oil with high peroxide value (OZ) on the viability of cells for preventing side effects in topical applications. To the best of our knowledge, there are no reports investigaing the effect of peroxide value of ozonated olive oil associated with its cytotoxic activity on mouse non-neoplastc fibroblast cell lines (L929). Therefore, the present study was carried out by using OZ alone and/or in combination with glycerol and olive oil. In our study OZ was prepared by using pure olive oil. Both olive oil and glycerol are non-toxic and can be mixed with OZ uniformly. The cytotoxic activity of samples against L929 fibroblasts was assessed using the tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay. The peroxide value of synthesized OZ was found to be in the range of 2700–2900 mEq O₂/kg oil. The OZ/olive oil group did not show any cell death at all concentrations tested (p > 0.05) however OZ/glycerol group showed statistically significant reductions in viability at higher concentrations (p = 0.004–0.006) compared to the control group. Conclusively, using OZ/olive oil with a peroxide value of 2700–2900 mEq O₂/kg oil for short-term incubation was non-cytotoxic to the L929 fibroblast cell line.     

Effect of Ozonated Water Treatment on Fatty Acid Composition and Some Quality Parameters of Olive Oil

The organic olives from Çine-Ayd?n (Turkey) were washed with tap or ozonated water for 2 and 5 min, respectively, and pressed to olive oil. The effects of wash treatments on fatty acid composition and several quality parameters of the oils were determined. The maximum values after 2-min ozonated water washes were 9.58 meqO₂/kg, 0.73%, 2.44 and 0.16 for peroxide, free acid, K₂₃₂ and K₂₇₀ values, respectively, which were under the standard limits for extra-virgin olive oil. Five min of ozonated water washes also yielded acceptable results, except for a slight excess on K₂₃₂ value. Ozonated water washes had almost no effect on fatty acid composition.     

Ozonated Olive Oil Enhances the Growth of Granulation Tissue in a Mouse Model of Pressure Ulcer

The curative effect of ozonated olive oil was evaluated using mouse models of cut wounds and pressure ulcers (decubitus or bedsores). Although ozonated olive oil did not significantly accelerate or decelerate wound contraction in either model, some histological modifications were observed. Ozonated olive oil induced blood coagulation in the hypodermis and cell infiltration in the dermis 1 day after its application. Moreover, it enhanced the formation of granulation tissue 10 days after application. These results indicate that ozonated olive oil promotes granulation tissue formation and is effective in the healing of wounds and pressure ulcers.     

Germicidal Properties of Ozonated Sunflower Oil

The aim of this work was to establish the minimal inhibition concentration (MIC) of ozonated sunflower oil for various microorganisms. To determine the influence of the ozonated medium on the growth of bacteria Bacillus subtilis, Escherichia coli and yeast Candida albicans the Petri dish method was used. Chemical and physical properties of ozonated sunflower oil were additionally studied. Microbiological studies proved that these microbes have various sensibility against ozonated oil. The most resistant are gram-negative bacteria E. coli and the yeast C. albicans. Gram-positive bacteria, B. subtilis turned out to be less resistant, because no growth was observed for preparation with an ozone dose of 200 mgO₃/g oil.     

Transfer of Phenolic Compounds from Olive Mill Wastewater to Olive Cake Oil

The transfer of the phenolic compounds from olive mill wastewater (OMW) to oil extracted under microwave from olive cake (OC) was carried out by using the following operations: mixing of the olive mill wastewater with the olive cake, drying of the mixture and recovery by solvent of the olive cake oil enriched by phenolic compounds. In the first part of this work, we made a screening design using a Hadamard matrix to quickly locate the factors influencing the process. Among five potentially influential parameters, we found that only three were actually active (OMW/OC ratio noted R, mixing velocity of mixture Vm and mixing time Tm). In the second part, fractional factorial design (2^5?1) was performed to evaluate the effects of five variables (three of them being selected by screening with exposition time Te and radiation power P) and their eventual interactions. The p value (p < 0.05) indicated that R, P,Te, Vm and Tm had significant effects on the response followed by the interaction effects between R‐P, P‐Te, R‐Vm, Te‐Vm, Te‐Tm, and Vm‐Tm. Under optimal conditions, the addition of OMW to OC increased the phenolic compounds content in the oil from 0.04 ± 0.01 to 0.13 ± 0.02 g/L.     

Heat Treatment Improves Olive Oil Extraction

To determine the effect of hot water pre-treatment on olive oil extraction, six cultivars of olive fruit (Olea europaea L. cvs. “Arbequina”, “Hojiblanca”, “Lechín”, “Manzanilla”, “Picual”, and “Verdial”) were heated at 50, 55, and 60 °C prior to laboratory scale oil extraction. Heat treatment resulted in higher oil extraction than unheated control samples. Quality parameters of the oils were not significantly (P < 0.05) affected by these treatments; however, oil stability and bitterness intensity were reduced and pigment content was increased through pre-heat treatment. This process may be incorporated economically into olive oil processing.     

Influence of Water Deficit in Bioactive Compounds of Olive Paste and Oil Content

The main objective of this study was to evaluate the effect of different deficit irrigation treatments (control, regulated deficit irrigation [RDI]‐1, RDI‐2, and RDI‐3) on the phenolic profile of the olive paste and oil content. Irrigation treatments with more stress water led to a considerable increase in the phenolic compounds of olive paste, especially in oleuropein (60.24%), hydroxytyrosol (82%), tyrosol (195%), and verbascoside (223%) compared to control. A significant increase in the content of total flavonoids and phenolic acids was also observed for these samples. In virgin olive oils (VOO) elaborated from the most stressed olive trees (RDI‐2 and RDI‐3), a noticeable increase in phenolic substances with antioxidant properties (oleuropein, hydroxytyrosol, tyrosol, secoiridoid derivatives, and o‐vanillin) was observed. Consequently, water stress conditions improved antioxidant activity of VOO.     

Changes in Olive and Olive Oil Characteristics During Maturation

Changes in olive properties and oil quality, oxidative stability, phenolic and chemical composition of two common Turkish varieties (Memecik and Edremit) during maturation were investigated. Olive samples were collected in their own growing region for five different harvest dates and processed to oil with a laboratory scale mill. Metabolic behaviors of these two varieties along with the maturation were different in terms of some compositional parameters. Oleic acid, triolein, β-sitosterol, oleuropein, hydroxytyrosol, and tyrosol contents of olive or olive oils fluctuated with maturation. However, changes in average weight, flesh/pit ratio, water and oil contents of the olives were observed. Phenolics such as trans cinnamic acid contents of both olive fruits decreased whereas cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside anthocyanins increased. Free fatty acids of virgin olive oils were found independent of maturity although some slight changes were determined in peroxide value, dien and trien conjugations. Some compositional parameters such as pigment concentration, tocopherols, stearic acid, linolenic acid, palmitodiolein and monounsaturated/polyunsaturated fatty acid ratio decreased while linoleic acid, dioleolinolein, palmitooleolinolein and Δ-5-avenasterol percentages increased with the maturation. A clear discrimination was observed with principal component analysis. The data obtained can also be considered useful for providing information to determine the ideal maturity stage.     

Proinflammatory Event of Ozonized Olive Oil in Mice

Ozonized olive oil inhibited the swelling reaction of 2, 4-dinitrofluorobenzene-induced mouse-contact hypersensitivity, which is a model for chronic skin diseases involved in the initiation and propagation of several inflammatory processes, mainly due to type IV hypersensitivity. On the other hand, ozonized olive oil itself stimulated the development of inflammatory responses, such as vasodilation, swelling and epidermal hyperplasia. When repeatedly applied to the skin, ozonized olive oil caused hair loss at the site and contact hypersensitivity. These findings identify a new biological function for ozonized olive oil and indicate the risk of adverse effects with repeated application.     

Study of Ozonated Olive Oil: Monitoring of the Ozone Absorption and Analysis of the Obtained Functional Groups

The peculiarities of ozone absorption during olive oil ozonolysis have been studied by continuous monitoring of ozone concentrations at the bubbling reactor outlet. The determined amount of ozone, consumed during the ozonolysis of the double bonds, was used as alternative way for evaluation of the degree of unsaturation of the oil. The basic functional groups, products of the reaction: ozonides and aldehydes have been quantitatively characterized by means of ¹H-NMR spectroscopy, whereupon their ratio was found to be 93.4:6.6 (mol. %), respectively. The determined ratio between the cis and trans ozonides was 46:54.     

Rapid Determination of Free Fatty Acid in Extra Virgin Olive Oil by Raman Spectroscopy and Multivariate Analysis

We introduce a visible Raman spectroscopic method for determining the free fatty acid (FFA) content of extra virgin olive oil with the aid of multivariate analysis. Oleic acid was used to increase the FFA content in extra virgin olive oil up to 0.80% in order to extend the calibration span. For calibration purposes, titration was carried out to determine the concentration of FFA for the investigated oil samples. As calibration model for the FFA content (FFA%), a partial least squares (PLS) regression was applied. The accuracy of the Raman calibration model was estimated using the root mean square error (RMSE) of calibration and validation and the correlation coefficient (R ²) between actual and predicted values. The calibration curve of actual FFA% obtained by titration versus predicted values based on Raman spectra was established for different spectral regions. The spectral window (945–1600 cm⁻¹), which includes carotenoid bands, was found to be a useful fingerprint region being statistically significant for the prediction of the FFA%. High R ² and small RMSE values for calibration and validation could be obtained, respectively.     

Evaluation of Authenticity of Iranian Olive Oil by Fatty Acid and Triacylglycerol Profiles

For evaluation of the authenticity of Iranian olive oil, samples from many Iranian olive oil producers especially north of Iran in the production year 2007 were collected. The fatty acid and triacylglycerol compositions were measured. The most recent calculation methods including ∆ECN the difference between the actual and theoretical ECN42 (equivalent carbon number), triglyceride content and R of olive oils according to IOOC methods were applied. On the basis of our results, we were able to classify the olive oils into the extra virgin, virgin olive and olive oil categories. The important fatty acids are oleic, palmitic and linoleic acids and their main triacylglycerols are OOO, POO, OOL, PLO, SOS plus POP, and OLL, respectively. On the basis of the triacylglycerol results, experimental ECN48, ECN46, ECN50, ECN44 and ECN42 were obtained. By using the fatty acids results and a computer program, the theoretical ECN42 and ECN44 were calculated. Then R values, being the ratio of r ECN42/r ECN44 for authenticity of all olive oils and ∆ECN for determining categories of olive oils, were defined. The results of olive oil samples were in the accepted limits of Codex and IOOC. Finally we suggest that the R and ∆ECN can be used in identification of adulteration of olive oils and also they are useful from the point of view of authenticity and classification.     

The Effect of Boron Application on Chemical Characterization and Volatile Compounds of Virgin Olive Oil of Ayvalik Olive Cultivar

In this study, the Ayvalik olive variety, an important and widely grown olive variety in Turkey, was chosen. A month prior to blooming and 2 months prior to harvesting in 2011 and 2012, three different concentrations of boron (100, 150 and 250 ppm) were applied to the olive leaves with or without boron deficiencies. After the application, quality criteria, fatty acid composition, total phenol contents and major volatile compounds of olive oil that was obtained from the harvested olives were investigated. Boron application to the olive trees with boron deficiencies has improved both the amount and the olive oil quality. Experimental results show the significance of boron for olive farming. Application of boron in 150 ppm led to a better olive oil quality by improving fatty acid composition [oleic acid (76.03 %), linoleic acid (9.68 %), linolenic acid (0.56 %), monounsaturated fatty acid (77.24 %)], total phenol content (422.94 ppm) and major volatile compounds [E‐2‐hexenal (43.12 ppm), hexanal (3.02 ppm), Z‐3‐hexenol (1.13 ppm)] in both harvest seasons (2011–2012) and in both olive orchards with or without boron deficiencies.     

Enhancement of Antioxidants in Olive Oil by Foliar Fertilization of Olive Trees

Oxidative stability (OS) of virgin olive oil is affected by different antioxidants whose levels may be influenced by nutrients availability. Changes in OS of virgin olive oil and antioxidants levels were evaluated according to foliar application of six nutrient-based treatments: T1 (rich in nitrogen), T2 (rich in boron, magnesium, sulfur and manganese), T3 (rich in phosphorus and potassium), T4 (rich in phosphorus and calcium), T5 (application of T1 and T2) and T6 (application of T1, T2, T3 and T4). The foliar applications were carried out during two successive growing seasons and oils were extracted and analyzed at the end of the experiment (after 2 years). T3 and T6 treatments improved oil stability by increasing the content of antioxidants, while T2 and T4 affected negatively the antioxidant profile of oils. Measured correlations between OS and compositional variables showed that total phenols had the highest value (R = 0.937, p < 0.001), followed by α-tocopherol (R = 0.775, p < 0.001) and oleic/linoleic ratio (R = 0.625, p < 0.05). These findings suggest that the changing levels of antioxidant compounds, due to fertilization, may be used to obtain oils with the highest quality.     

Olive Oil Quality and Sensory Changes During House‐Use Simulation and Temporal Assessment Using an Electronic Tongue

During domestic usage, olive oil bottle manipulation may lead to a quality decrease due to agitation and oxygenation. Therefore, assessing the domestic consumption time period during which the initial quality grade is retained may allow including this information as a recommendation, ensuring olive oil consumers’ satisfaction. Temporal changes of physicochemical, chemical, and sensory parameters of extra‐virgin olive oils (EVOO) were monitored during 1‐month simulated house‐use conditions. It was observed that K₂₃₂ (R‐Pearson ≥+0.81) and ΔK increased resulting in a significant olive oil quality decrease from EVOO (during the initial 21 days of simulated usage) to lampante olive oil (after 28 days of simulated usage) as well as the appearance of rancid sensation. As lampante olive oils cannot be commercialized, it is pertinent to establish olive oil shelf life under usual home‐use conditions. Principal component analysis allowed grouping the olive oils according to home‐use time period and how bottles are stored after their first opening, showing that the overall olive oil physicochemical and sensory characteristics changed with the domestic‐use time period. Finally, a potentiometric electronic tongue coupled with linear discriminant analysis was used to discriminate olive oils according to the domestic‐use time period (leave‐one‐out cross‐validation sensitivities ≥95%). Thus, this device could be used to indirectly assess the quality of the remaining bottled olive oil by establishing for how long an olive oil bottle has been used under domestic conditions.     

Fish Oil and Olive Oil Supplementation in Late Pregnancy and Lactation Differentially Affect Oxidative Stress and Inflammation in Sows and Piglets

This study was conducted to compare the effects of fish oil and olive oil supplementation in late pregnancy and during lactation on oxidative stress and inflammation in sows and their piglets. A total of 24 sows were fed a basal diet supplemented with additional corn starch (CON), fish oil (FO) or olive oil (OO). Sows fed an OO diet during late gestation had a higher piglet birth weight compared with CON‐fed and FO‐fed sows (P < 0.05). Furthermore, sows from the OO group had a higher milk fat content than sows from CON and FO groups, and a lower pre‐weaning mortality of piglets was observed in the OO group (P < 0.05). Maternal FO supplementation resulted in increased malondialdehyde concentration in sow plasma, colostrum, milk and piglet plasma than in CON and OO groups (P < 0.05). However, an increased total antioxidant capacity (T‐ACC) and activities of glutathione peroxidase (GSH‐Px) and total superoxide dismutase (T‐SOD) were also observed in the FO group (P < 0.05). Sows fed an OO diet had significantly decreased interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6) and tumor necrosis factor‐α (TNF‐α) concentrations in milk compared with CON and FO fed sows (P < 0.05). Moreover, lower plasma IL‐1β and TNF‐α levels were observed in piglets from the OO group compared with the CON group (P < 0.05). Collectively, these results suggest that an OO diet is most beneficial in late gestation and during lactation in sows. However, FO increases the susceptibility to oxidative stress in sows and piglets.     

Effect of Lipase Activity and Specificity on the DAG Content of Olive Oil from the Shodoshima-Produced Olive Fruits

Olive oils have a higher relative diacylglycerol (DAG) content than other plant oils. The lipase in olive fruits is involved in DAG production and is directly related to the acidity of the olive oil. However, the lipase activity and positional selectivity have not been clarified. To investigate the properties of olive fruit lipase, olive fruits of the Mission variety harvested during mid-December of 2005 on Shodoshima Island (Japan) were stored at 20, 30 or 40 °C for 4 weeks. Changes in the acidity and acylglycerol content of the oils extracted from the stored fruits were analyzed. The acidity and DAG content of the olive oils increased due to triacylglycerol (TAG) hydrolysis during storage. sn-1,2-DAGs preferentially increased during the early stages of storage, indicating that the olive fruit lipase is enantioselective for the sn-3 position, while non-enzymatic isomerization of sn-1,2-DAGs was observed throughout the entire duration of storage. Kinetic analysis revealed that the enantioselectivity of olive fruit lipase for the sn-3 position was approximately four times greater than for the sn-1 position. The lipase was gradually inactivated at temperatures of 30 °C or higher, and the ratios of the rate constant for inactivation to TAG hydrolysis at the sn-3 position was 0.2, 13, and 23 at 20, 30, and 40 °C, respectively.     

Evolution of Oxidative Values during Kinetic Studies on Olive Oil Oxidation in the Rancimat Test

A comparative study was carried out in order to evaluate the kinetics of the formation of a number of primary and secondary oxidation products during oxidation of olive oil in the Rancimat test at 100–130 °C. There were good correlations between the Rancimat index (OSI) and stability indices (IP) measured in the Rancimat test with no significant differences in kinetic parameters calculated from them. Mean values of the temperature coefficient, Q₁₀ number, activation energy (E_a), frequency factor (A), and free energy of activation (ΔG⁺⁺) for olive oil oxidation were calculated to be ?3.44 × 10^?2°C^?1, 2.21, 98.91 kJ/mol, 12.17 × 10¹² h^?1, and 128.25 kJ/mol, respectively. Each unit change in E_a was accompanied by an average 1.43 × 10¹² change in A, indicating a higher contribution for factor A than for E_a to the olive oil stability. The E_a and A correlated well with the values of enthalpy and entropy, respectively. The values of OSI or IP could be described well by the ΔG⁺⁺ values. Kinetic data indicated that olive oil stability is more affected by the indigenous antioxidants than by the fatty acid composition.     

Modification of Phenolic Compounds and Volatile Profiles of Chemlali Variety Olive Oil in Response to Foliar Biofertilization

The main objective of this work was to study the effects of foliar biofertilizers on individual volatile profiles and phenolic compounds of olive oil (Olea europaea L. cv. Chemlali). Three foliar biofertilizers were used in two successive application seasons: T1 (rich in nitrogen, phosphorus and potassium); T2 (rich in calcium); and T3 (application of both T1 and T2). Results showed that foliar fertilization with T2 increased the phenolic compound contents (e.g., oleuropein aglycone and decarboxymethyl ligstroside aglycone) of Chemlali olive oil. It also enhanced the levels of many volatile compounds responsible for the good flavor of olive oil such as hexanal. However, T1-tested fertilizer led to a significant decrease in the content of phenolic compounds, although they seemed to improve significantly the levels of the majority of volatile compounds, especially hexanal. Based on these results, a significant relationship between plant nutrition and quality of oil was observed. Our results demonstrated a potential positive influence on the concentration of sensory quality compounds under T2 (Ca²⁺-based fertilizer). This result should be considered in the design of foliar nutrient application management strategies for olive trees.     

Modulation of Olive Oil Quality Using NaCl as Extraction Coadjuvant

The use of four concentrations of common salt (NaCl) used as coadjuvant for the extraction of virgin olive oil has been tested on a laboratory scale and the quality attributes of the oils obtained were compared to those obtained with talc as coadjuvant. The oils extracted from Picual fruits after NaCl addition were not significantly affected in terms of the physicochemical requirements established for extra virgin olive oil, the best level of quality of this produce. Addition of NaCl during the extraction process was positively correlated with the presence of o-diphenol compounds and the stability of the oils obtained. Moreover the use of NaCl resulted in a significant increase in contents of pigments (β-carotene, lutein and chlorophylls a and b) and volatile compounds in the oils.