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.     

Studies on glass transition temperature of mono and bilayer protein films plasticized by glycerol and olive oil

Thermomechanical and thermal properties of whey protein, maize prolamin protein (zein), and the laminated whey protein–zein films were studied. The dynamic mechanical (thermal) analysis (DMTA) results showed that the single zein film had higher T_g than single whey protein and zein–whey laminated films. The shift in the T_g values of films from 31.2°C in whey protein film and 88.5°C in the zein film to 82.8°C in the laminated whey protein–zein films may be implied some interaction formation between the two polymers. The small tan δ peaks were observed at ?50°C in zein–glycerol films and at ?22.37°C in the whey protein films and can be related to β‐relaxation phenomena or presence of glycerol rich region in polymer matrix. Zein‐olive oil and zein–whey protein–olive oil films showed tan δ peaks corresponded the T_g values at 113.8, and 92.4°C, respectively. Thus, replacing of glycerol with olive oil in film composition increased T_g. A good correspondence was obtained when DSC results were compared with the tan δ peaks in DMTA measurements. DSC thermograms suggested that plasticizers and biopolymers remained a homogeneous material throughout the cooling and heating cycle. The results showed that T_g of zein–glycerol films predicted by Couchman and Karasz equation is very close to value obtained by DSC experiments. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of Extraction Solvent on Oil and Bioactives Composition of Commercial Indian Niger (Guizotia abyssinica (L.f.) Cass.) Seed

Commercially available niger (Guizotia abyssinica (L.f.) Cass.) seed was investigated to evaluate the effect of extraction solvent on oil and bioactives composition. For this purpose, niger seeds were subjected to solvent extraction using solvents of different polarity, viz., hexane, petroleum ether, chloroform, acetone, methanol and ethanol. The oil content of niger seeds obtained after extraction with solvents of different polarities was in the range of 31.8–41.3 g/100 g. The extracted oil was characterized by the following parameters: color (40.0–95.0 Lovibond units), free fatty acids (3.6–12.3 g/100 g), peroxide value (3.2–7.8 mequiv O₂/kg), iodine value (137.6–140.3 cg I₂/g), saponification value (177.3–185.9 mg KOH/g) and unsaponifiable matter (1.3–4.3 g/100 g). Among fatty acids, linoleic acid (69.4–73.2 %) was the major fatty acid and trilinolein (31.2–33.4 %) was the major triacylglycerol. The composition of bioactive molecules was 171.9–345.8 ppm of total tocopherols; 247.1–2,647.7 ppm of total phenolics; 1,249.6–6,309.3 ppm of total sterols and 18.9–181.0 ppm of total carotenoids. Among the tocopherols, α-tocopherol was the major component with 154–276 ppm. Of the total phenolics, vanillic acid with 176–1,709 ppm was the major phenolic compound in the oil extracted using different solvents. Ethanol-extracted oil showed a 13.9-fold better oxidative stability and a higher radical scavenging activity (IC₅₀ value of 9.2 mg/mL) compared to hexane-extracted oil (IC₅₀ value of 40.3 mg/mL). This is probably the first report of its kind on solvent extractability of bioactives of niger seed.     

Effect of microencapsulation and spray drying on oxidative stability of flaxseed oil and its release behavior under simulated gastrointestinal conditions

Flaxseed oil is one of the richest sources of omega-3 fatty acid (α-linolenic acid, ALA). It contains high amounts of polyunsaturated fatty acids, making it extremely susceptible to oxidation. In the present study, flaxseed oil was stabilized using microencapsulation followed by spray drying and studied for its oxidative stability in terms of peroxide value (PV), thiobarbituric acid, and p-anisidine value at room temperature (35 ± 1°C) and low temperature (4–7°C) storage for 6 months. Results revealed that the developed flaxseed oil powder was stable throughout the storage period and PV remained below to the maximum permissible limit (≤5 mEq/kg oil) prescribed by the Codex Alimentarius Commission. The fatty acids profile measured by gas–liquid chromatography indicated a 14.28–15.13% decrease in ALA content in flaxseed oil as a result of microencapsulation and storage at room temperature. In vitro digestion behavior of microcapsules showed 4.39 ± 0.53 to 19.87 ± 0.47% release of flaxseed oil under simulated gastric continued, whereas under gastrointestinal conditions it was 20.00 ± 3.66 to 59.99 ± 9.29%.     

Production of Hydrogen and Syngas via Steam Gasification of Glycerol in a Fixed-Bed Reactor

Glycerol is one of the by-products of transesterification of fatty acids to produce bio-diesel. Increased production of bio-diesel would lead to increased production of glycerol in Canadian market. Therefore, the production of hydrogen, syn gas and medium heating value gas is highly desirable to improve the economics of bio-diesel production process. In this study, steam gasification of pure and crude glycerol was carried out in a fixed-bed reactor at the liquid hourly space velocity (LHSV) and temperature of 0.77 h^?1 and 800 °C, respectively. In this process, the effects of different packing materials such as quartz particle and silicon carbide were studied. Catalytic steam gasification was performed in the presence of commercial Ni/Al₂O₃ catalyst in the range of steam to glycerol weight ratio of 0:100–50:50 to produce hydrogen or syngas when LHSV was maintained constant at 5.4 h^?1. Pure glycerol was completely converted to gas containing 92 mol% syngas (molar ratio of H₂/CO ≈ 1.94) and the calorific value of 13 MJ/m³ at 50:50 weight ratio of steam to glycerol. Hydrogen yield was increased by 15 mol% via the steam gasification process when compared to pyrolysis process. The presence of catalyst increased further the production of hydrogen and total gas in case of both pure and crude glycerol indicating their strong potential of making hydrogen or syngas. Maximum hydrogen, total gas and syn gas production of 68.4 mol%, 2.6 L/g of glycerol and 89.5 mol% were obtained from glycerol using Ni/Al₂O₃ catalyst at temperature and steam to glycerol ratio of 800 °C and 25:75, respectively.     

In situ forming poly(lactic acid-co-glycolic acid) implants containing leuprolide acetate/β-cyclodextrin complexes: preparation,characterization, and in vitro drug release

In situ forming implants (ISIs) based on poly(lactic acid-co-glycolic acid) (PLGA) containing leuprolide acetate/β-cyclodextrin (LA/β-CD) complexes were prepared. Incorporation of LA or complexes did not change T_g values of ISIs (48.4–49.6°C). ISIs containing complexes with more β-CD content showed higher surface and bulk porosity. Higher β-CD portion in complexes improved solvent release, decreased initial burst release and facilitated diffusion out of drug for corresponding ISIs. Complexation of LA with β-CD (1/10, w/w) significantly improved its stability within PLGA matrix before release (total LA release of 91.3%). ISIs did not show any cellular cytotoxic effects against L929 fibroblast cells.     

Wax Ester Variation in Olive Oils Produced in Calabria (Southern Italy) During Olive Ripening

The wax ester composition of pressed olive oil and its variation during olive ripening were investigated by column chromatography/GC-on column technique. Six compounds were identified: C₃₆, C₃₈, C₄₀, C₄₂, C₄₄ and C₄₆ wax esters, which were grouped as total detected wax esters (TDWEs). The European Union (EU) includes C₄₀, C₄₂, C₄₄ and C₄₆ waxes (TEWEs) as a distinctive characteristic between different categories, with a maximum total content ≤250 mg/kg for an extra virgin olive oil. The International Olive Council (IOC) includes C₄₂, C₄₄ and C₄₆ waxes (TIOCWEs) as a purity parameter, with a maximum total content ≤150 mg/kg for an extra virgin olive oil. The analytical technique proposed by EU and IOC do not separate the wax esters from fatty acids esters with diterpenic alcohols (phytol and geranylgeraniol) that interfere with detected peaks. Although the examined cultivars were grown in the same geographical area and the same agricultural practices were applied to the trees, ANOVA analysis found significant differences among the oils extracted with the same machinery. The oil produced from the Itrana cultivar showed the lowest content in TEWEs (25.00–39.00 mg/kg) and in TIOCWEs (5.67–9.00 mg/kg). Wax content in Leccino and Pendolino cultivars showed a significant tendency to decrease during olive maturation, and a tendency to increase in all other cultivars from the first to the last harvest date when olive pigmentation changed from green to black.     

A kinetic model for enzymatic reactions in reverse micellar systems involving water‐insoluble substrates and enzyme activators

The activity of Chromobacterium viscosum lipase (glycerol‐ester hydrolase, EC 3.1.1.3) entrapped in AOT/isooctane reverse micelles was significantly increased by the addition of short chain polyethylene glycols (PEGs) or methoxypolyethylene glycols (MPEGs) for the hydrolysis of olive oil. To understand enzyme activity in the presence of PEG 400 or MPEG 550 molecules, a kinetic model was proposed. The validity of this model was verified by experimental data on the lipase‐catalyzed hydrolysis of olive oil in AOT/isooctane reverse micellar systems, in which PEG 400 or MPEG 550 had been added. The large value of the equilibrium constant (k_D) for enzyme activation indicated that the affinity between C viscosum lipase and PEG 400 or MPEG 550 molecules was very strong. The Michaelis constant (K_m) predicted by the proposed model explained enzymatic reactions more exactly than that by the previously published model. Copyright © 2003 Society of Chemical Industry     

Efficacy of Ozonated Water Against Erwinia carotovora subsp. carotovora in Brassica campestris ssp. chinensis

Erwinia carotovora subsp. carotovora (Ecc) is a bacterial pathogen that causes decay of vegetables and is found in a wide range of Brassica crops in the Shanghai area, particularly in non-heading Chinese cabbage (NHCC). In this study, aqueous ozone was used as an antimicrobial agent to prevent the growth of Ecc bacterial colonies. Ecc that were treated with aqueous ozone were completely inactivated after the bacteria had been exposed to 0.5 mg/L ozone at 28 °C. Furthermore, a susceptible NHCC cultivar was directly sprayed with different concentrations of dissolved ozonated water as a pesticide substitute. The effects of the treatments on morphology were analyzed, and some treatments were characterized by induction of visible symptoms of senescence. No negative effects were observed after treatment by spraying ozonated water compared with the control at concentrations below 8 mg/L. However, visible damage to leaves was observed after the plants were exposed to 10 mg/L ozonated water via spraying for 15 days during the plant reproductive stage. Additionally, enzyme activities and antioxidant responses gradually increased to a certain degree and then decreased in the untreated and ozonated water-treated plants. These results showed that ozonated water was effective in restraining pathogens and potentially defending against disease in growing NHCC plants within a certain concentration range. These results provide a theoretical basis for preventing disease by applying ozonated water to vegetables as an alternative to pesticides.     

Antifungal Activity of Olive Oil and Ozonated Olive Oil Against Candida Spp. and Saprochaete Spp.

Ozonated olive oil was investigated for their capacity to inhibit growth of 38 yeast strains of Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, and Saprochaete capitata. Two different ozonated olive oil (OZO1, OZO2) and two different olive oil (OL1, OL2) samples having different biochemical parameters were assessed in terms of their antifungal ability and comparison was made. Fluconazole was chosen as control antifungal agent. Each sample’s antifungal activity decreased in the following order: OZO1 > OZO2 > OL1 ≥ OL2. This study demonstrated that ozonated olive oil may help to control some fluconazole-resistant and dose-dependent sensitive fungal strains.     

Characterisation of acorn oils extracted by hexane and by supercritical carbon dioxide

Acorn fruit oils from two species of oak, Quercus rotundifolia L. (holm‐oak) and Quercus suber L. (cork‐oak), were extracted by n‐hexane. The acorn fruit of Quercus rotundifolia L. was also extracted by supercritical CO₂ at 18 MPa and 313 K, a superficial velocity of 2.5 × 10^?4 ms^?1, and a particle size diameter of 2.7 × 10^?4 m. The oils were characterised in terms of fatty acids, triglycerides, sterols, tocopherols, and phospholipids. The main fatty acid in both fruit species was oleic acid (about 65%), followed by linoleic acid (about 16.5–17%) and palmitic acid (about 12.1–13.4%). The main triglyceride found in acorn oils was the OOO (oleic, oleic, oleic) triglyceride (33–38%), followed by the POO (palmitic, oleic, oleic) triglyceride (12.6–18.2%). In terms of sterols, the main component in acorn oils of both species was β‐sitosterol (83.5–89%), followed by stigmasterol (about 3%). However, in Quercus suber L., acorn oil was found to consist to 10.2% of campesterol. The amount of cholesterol was low (0.27% for the Quercus rotundifolia L. oil extracted by supercritical fluid extraction, and 0.18% for the oil extracted by n‐hexane). The Quercus suber L. acorn oil presented 0.1% of cholesterol. The total amount of tocopherols in Quercus rotundifolia L. acorn oils was almost the same when the oil was extracted by n‐hexane (973 mg/kg oil) or by supercritical CO₂ (1006 mg/kg oil). The Quercus suber L. acorn oil presented a high value of total tocopherols (1486 mg/kg oil). The supercritical CO₂ did not extract the phospholipids. The amount of phospholipids was very similar for both species of oak acorn oils extracted by n‐hexane. Oxidative stability was also studied, by using the peroxide value and the Rancimat method, revealing that all the oils were significantly protected against oxidation. The influence of storage, under several conditions, on the oxidative stability was also studied. The Quercus rotundifolia L. oil extracted by n‐hexane was better protected against oxidation after a few days of storage at 60 °C.     

Impact of Microwave Assisted Infusion on the Quality and Volatile Composition of Olive Oil Aromatized with Rosemary Leaves

Olive oil with rosemary leaves by microwave assisted infusion (MAI) as an alternative to conventional infusion (CI) was evaluated. Microwave heating was applied to the mixture in order to accelerate diffusion of the rosemary volatile compounds into the olive oil. The volatile components of the aromatized oils were quantified by HS‐SPME/GC–MS, as well as several quality indexes such as free fatty acids (FFA), peroxide value (PV), specific coefficients of extinction, chlorophyll and carotenoid content, and color assessment. Fatty acid profiles of the oils aromatized by MAI were compared to those produced by CI. Results showed that the infusion time is reduced from 12 h to 10 min when utilizing MAI in place of CI. MAI treatment caused a slight increase in FFA levels, and specific extinction coefficient indices (K₂₃₂ and K₂₇₀). PV during MAI remained unchanged for the first 3 min, after which there was an observable increase. All physico‐chemical values were found to be well below the maximum permitted limits. The MAI treatment reduced chlorophyll and carotenoid levels during the final step of aromatization, thus affecting final color. The MAI aromatized oil was characterized by its clear green color (L*, a*, b* parameters). Fatty acid analysis showed that MAI slightly changed the fatty acid composition of the olive oil. This study indicates that MAI appears to be a viable and rapid method to flavor olive oil with rosemary leaves.     

The Effects of Infrared Roasting on HCN Content,Chemical Composition and Storage Stability of Flaxseed and Flaxseed Oil

Flaxseeds were roasted at 1150 W/m² radiation intensity with short and medium wave infrared (IR) emitters for specific durations, which provided good visual and sensory quality. The effects of IR roasting on color properties, hydrogen cyanide (HCN) content, tocopherols and fatty acid composition of the flaxseed and flaxseed oil were investigated. Further, flaxseeds were stored for 6 months and free fatty acid content and peroxide values were followed at 1-month intervals to understand the effect of IR treatment on hydrolytic and oxidative stability. HCN content of the flaxseeds was reduced up to 59% with IR roasting. Tocopherol content of the IR roasted flaxseed oil was higher than that of the control. No notable variation was observed in fatty acid composition with regard to IR treatment. Free fatty acid content of IR roasted flaxseeds did not increase during storage, while peroxide value of the seeds significantly increased up to 95 mEq O₂/kg oil.     

Low-pressure plasma surface modification of polyurethane films with chitosan and collagen biomolecules

Polyurethane (PU) was synthesized using castor oil and a trade grade of hexamethylene diisocyanate, and then PU films were prepared for wound dressing applications. The PU films were then plasma treated with the low-pressure nitrogen plasma to functionalize with peroxide and hydroperoxide groups in order to attach with acrylic acid monomers. Therefore, the polyacrylic acid polymer branches were formed on the film surfaces. Carboxylic acid groups were activated by N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide and bonded with chitosan and collagen biomolecules. Untreated, nitrogen plasma treated, polyacrylic acid grafted, and finally chitosan and collagen-immobilized PU films were characterized by several tests. The tests included the attenuated total reflectance Fourier transform infrared spectroscopy, static contact angle, atomic force microscopy, scanning electron microscopy, fibroblast L929 cell culture, and antibacterial activity assay to evaluate their in vitro cytocompatibility. The results confirmed that chitosan and collagen were immobilized successfully on the PU surfaces. The chitosan-immobilized PU and collagen-immobilized PU improved the adhesion and proliferation of fibroblast cells compared to untreated PU films. The chitosan-modified PU films exhibit the best antibacterial properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47567.     

Phytonutrient content and oil quality of selected edible oils upon twelve months storage

Edible oils contain naturally occurring phytonutrients and therefore exhibit numerous beneficial health effects. However, the phytonutrients tend to degrade in different extent with storage duration and temperature. In this study, the impact of storage conditions on the stability of phytonutrients, including vitamin E, carotenoid, phytosterols and squalene, and oil quality, including free fatty acids (FFA), peroxide value (PV), anisidine value (AV), and oxidative stability index (OSI) of red palm-pressed mesocarp olein, palm olein, extra virgin olive oil, and sunflower oil were investigated. The oils were stored in three conditions, 23°C (with light and without light) and 35°C (without light). Results showed that the retention percentages of phytonutrients where in the range of 0%–100% for vitamin E, 51.24%–83.63% for carotenoid, 83.40%–100% for phytosterols and 27.94%–100% for squalene. Pearson correlation analysis between phytonutrients and oil quality of oils in different storage conditions showed that correlation coefficient values (r) were in the range of −1 to 0 for FFA, −1 to 0.22 for PV, −1 to 0.33 for AV, and −0.23 to 1 for OSI, implying that correlations between both variables are not in same direction. Degradation studies of phytonutrients using zero-order kinetic model where optimum-case conditions exhibited highest half-life (t_1/2) among the three conditions. In conclusion, storage conditions and synergistic effect affected the phytonutrients stability in the oils and oil quality in different extent. In general, storage at ambient temperature and dark condition contributed to the best phytonutrients retention and oil quality.     

Pyropheophytin a and 1,2-Diacyl-glycerols Over Time Under Different Storage Conditions in Natural Olive Oils

The effect of storage conditions (light, temperature, container types) and time on the quality of natural olive oils from different cultivars and Australian regions were studied. The oils’ changing quality was monitored through several physico-chemical methods (free fatty acids, peroxide value, UV-spectrometry (K₂₃₂, K ₂₇₀ and ΔK), induction time, total polyphenol content, bitterness, pyropheophytin a and 1,2-diacyl-glycerol content) and sensory analysis over 24 months. Pyropheophytins a and 1,2-diacyl-glycerols criteria showed very good performance as indicators of overall olive oil quality and freshness as well as highlighting any problems during the storage of the product. Pyropheophytin a increment averaged 7 % per year and the 1,2-diacyl-glycerols decreased at an average of 23 % per year at normal storage conditions over time.     

Oxidative stability of olive oil flavoured by Capsicum frutescens supercritical fluid extracts

The effect of red pepper supercritical fluid extracts (SFE) on the oxidative stability of extra‐virgin olive oil was evaluated using accelerated stability tests [Rancimat and differential scanning calorimetry (DSC) methods] and by measuring the changes in the levels of polyunsaturated fatty acid primary and secondary oxidation products during storage under ambient conditions. SFE were produced according to a central composite rotatable design, at a constant temperature (40 °C), different pressures (15–23 MPa) and superficial velocities (0.04–0.08 cm/s). The results showed that the red pepper extracts produced at low extraction pressure and superficial velocity (e.g. 16.2 MPa and 0.046 cm/s) containing low/intermediate capsaicinoid levels did not affect olive oil stability. The extracts produced at higher pressure showed a slight pro‐oxidant activity. The K₂₃₂ and K₂₇₀ values always fell within the limit set by the European legislation for the quality characteristics of olive oil containing no additives. Evaluation of oxidative stability using DSC was found to be a useful methodology, which demands smaller oil samples and shorter times in comparison with the methodology using the Rancimat apparatus. Red pepper SFE obtained at low extraction pressures can be used in order to produce stable flavoured olive oils.     

Logit modeling for classification of monocultivar olive oils from southwest Spain: A preliminary study

A characterization study of the main olive oil cultivars of southwest Spain (Picual, Arbequina, and Verdial) has been performed in order to establish logistic regression models. Several quality characteristics (free acidity, peroxide value, K₂₃₂, K₂₇₀, oxidative stability index) and chemical data (fatty acids, sterols, erythrodiol–uvaol composition) were measured. Logit regressions were used to evaluate the correlation of the parameters and to create models that allow saving costs on identifying oils as Arbequina, Picual, or Verdial type. Multiple logit regression models were developed: one for Arbequina, three models for Picual, and two models for Verdial cultivar, allowing in this way to minimize the cost for classifying oil samples. Practical application: The olive oil marketing is increasingly focused on the chemical differentiation and characterization of the product because the chemical composition of these virgin oils is responsible for their valuable sensory and nutritional properties. Here we present a characterization study (quality characteristics and chemical data) from the main olive oil cultivars of southwest Spain, Picual, Arbequina, and Verdial, as a first step for the traceability of these three types of monocultivar virgin olive oils. The results may be used as a training to create models for other olive oil cultivars.     

Optimization of Enzymatic Synthesis of n-Propyl Acetate (Fruit Flavor Ester) – Effect of the Support on the Properties of Biocatalysts

The present study deals with the optimization of the enzymatic synthesis of n-propyl acetate using response surface methodology (RSM). The biocatalysts were prepared by physical adsorption of lipase from Thermomyces lanuginosus (TLL) on mesoporous hydrophobic supports – poly-hydroxybutyrate (PHB) and poly-methacrylate (PMA) particles. Their catalytic properties were also assayed in the hydrolysis of olive oil emulsion. The biocatalyst TLL–PMA presented the highest immobilization yield (IY, 90.6 ± 2.8%), immobilized protein concentration (36.5 ± 0.4 mg/g of PMA), and catalytic activity in esterification reaction. TLL–PHB was more active in the hydrolysis of olive oil emulsion by a four-fold factor (1240.5 ± 29.2 IU/g of PHB). Maximum acid consumption percentage of 84.3% was observed after 50 min of reaction catalyzed by TLL–PMA using 2000 mM of each reactant (n-propanol and acetic acid) in heptane medium. The purified ester was confirmed by gas chromatography mass spectrometry (GC–MS) analysis. After six consecutive cycles of esterification reaction, the biocatalyst retained around 50% of its initial activity. The results show that PMA may be an interesting support to prepare active biocatalysts in the synthesis of fruit flavor ester by esterification reaction.     

Detection of Olive Oil Adulteration Using FT-IR Spectroscopy and PLS with Variable Importance of Projection (VIP) Scores

Determination of adulteration and authenticity of extra virgin olive oil (EVOO) was investigated by means of infrared spectroscopy and chemometric methods. The study was focused on the detection and quantification of extra virgin olive oil adulteration by soybean (SB) and sunflower (SF) oils using FT-IR spectroscopy based on the use of PLS modeling and variable importance of projection (VIP) scores. A PLS model, using orthogonal signal correction and mean centering data pretreatments, and VIP scores variable preselection, was able to predict the concentration of sunflower and soybean oil adulterants in the 1–24 % weight ratio range with relative prediction errors lower than 3 % (w/w), for external validation samples. Moreover, the PLS-DA (discriminant analysis) model using the same preselected wavelengths was able to explain 99.9 % of variance and to predict with 100 % accuracy both classes of adulteration (EVOO–SB and EVOO–SF) in the external validation.