A Comparative Study of O/W Nanoemulsions Using Extra Virgin Olive or Olive‐Pomace Oil: Impacts on Formation and Stability

Nanoemulsions are considered an innovative approach for industrial food applications. The present study explored the potential use of olive‐pomace oil (OPO) for oil‐in‐water (o/w) nanoemulsion preparations and compared the effectiveness of extra virgin olive oil (EVOO) and OPO at nanoemulsion formulations. The ternary‐phase diagrams were constructed and the o/w nanoemulsions properties were evaluated in relation to their composition. The results showed that it is possible to form OPO nanoemulsions using Polysorbate 20 or Polysorbate 40. Nanoemulsions with EVOO and OPO presented desirable properties, in terms of kinetic stability (emulsion stability index % [ESI%]), mean droplet diameter (MDD), polydispersity index (PDI), ζ‐potential, viscosity, and turbidity. EVOO exhibited lower surface and interfacial tension forming nanoemulsions with a high ESI% and a low MDD. However, OPO led to nanoemulsions with a high ESI% but with a higher MDD. It was observed that by increasing the emulsifier concentration the MDD decreased, while increasing the dispersed phase concentration led to a higher MDD and a lower ESI%. Finally, nanoemulsions with the smallest MDD (99.26 ± 4.20 nm) and PDI (0.236 ± 0.010) were formed using Polysorbate 40, which presented lower surface and interfacial tension. Specifically, the nanoemulsion with 6 wt% EVOO and 6 wt% Polysorbate 40 demonstrated an interfacial tension of 51.014 ± 0.919 mN m^?1 and an MDD of 99.26 ± 4.20 nm. However, the nanoemulsion with 6 wt% OPO and 8 wt% Polysorbate 20 presented an interfacial tension of 54.308 ± 0.089 mN m^?1 and an MDD of 340.5 ± 7.1 nm.     

Statistical Analysis of Optimal Ultrasound Emulsification Parameters in Thistle-Oil Nanoemulsions

Thistle oil (INCI: Silybum marianum seed oil) is known as an anti-oxidant, moisturizing and skin regenerating cosmetic raw material. Nanoemulsions are a new form of cosmetic product showing very good user properties (ease of spreading over the skin with no greasy feeling). Moreover, due to their structure, they can also transport both hydrophilic and hydrophobic active substances to the skin. The aim of this work was the preparation and characterization of nanoemulsions, based on thistle oil. The non-ionic surfactants polysorbate 80 (PEG-20 sorbitan monooleate), decyl glucoside, and a polyglyceryl-4 ester blend were applied to stabilize the nanosystems. All formulations were obtained by a high energy method, using an ultrasonic device (Labsonic U, an ultrasound homogenizer). Variations in the emulsification parameters were tested, including surfactants concentration, pre-emulsification time, ultrasound power and sonication time. On the basis of statistical analysis (experimental design, cluster analysis, classification and regression trees) the best emulsification process parameters were determined. In order to verify the results of statistical analysis, once more an experimental study was conducted. The results obtained confirmed that statistical analysis can be a useful method in determining the conditions for obtaining stable nanoemulsions with desired properties. Formulations obtained with the use of Silybum marianum seed oil were characterized by long-term stability, a low polydispersity index, low viscosity and an average droplet size less than 200 nm.     

Rheology and stability of phospholipid-stabilized emulsions

Lecithin in cosmetic emulsions produces a unique “skin feel,” which can be related to its rheological properties. In this study, water-in-oil (w/o) and oil-in-water (o/w) emulsions were made from a cosmetic-grade caprylic/capric triglyceride with deoiled lecithin and hydroxylated lecithin. Synthetic surfactants commonly used in commercial cosmetic products were used as controls. Optical light microscope investigation showed significant differences in the structures of the w/o and o/w emulsions made with the lecithins. Freeze/thaw tests were conducted to evaluate emulsion stability. The o/w emulsion (oil/water = 20:80) was stable with 3% hydroxylated lecithin at room temperature. However, 4% hydroxylated lecithin was needed for stabilizing the emulsion with an oil-to-water ratio of 20:80 or 30:70 through the freeze/thaw treatments. With 4% deoiled lecithin, the w/o emulsion showed a water-holding capacity up to 80%, which was also stable through two freeze/thaw cycles. All emulsions in this study exhibited pseudoplastic flow, in which a minimum shearing stress, a yield value, was required before flow became linear. In general, the emulsion viscosity increased as lecithin content increased. Changing the oil-to-water ratio also affected the emulsion viscosity. The deoiled lecithin-based w/o emulsions had higher yield values than hydroxylated lecithin-based o/w emulsions. Therefore, more force was needed to spread the w/o emulsions. In addition, because w/o emulsions had more viscous continuous phases and a greater volume of internal phases, the w/o emulsions were more viscous than the o/w emulsions.     

Development and evaluation of oil in water nanoemulsions based on polyether silicone as demulsifier and antifoam agents for petroleum

Oil in water (o/w) nanoemulsions were synthesized in order to be evaluated as an alternative to petroleum emulsions destabilization processes and inhibition of foam formed in the crude oil. The nanoemulsions were prepared by the high energy method through High Pressure Homogenizer (HPH), utilizing poly(propylene glycol) (PPG) and xylene solvent as oil phase and different polarity polyether silicone surfactants samples. These nanoemulsions were evaluated in respect to their efficiency in the petroleum demulsification process. The results of these tests showed that nanoemulsions performance on the destabilization of petroleum emulsions is influenced by the utilized surfactant's polarity. The nanoemulsions and pure samples of PPG and xylene solvent were evaluated concerning capacity of formed foam inhibition in petroleum (antifoam test), and the results showed no significant influence of samples on foam stability. Petroleum/saline water added interfacial tension measurements, added or not the nanoemulsions were executed and showed that the additives adsorption in the interface is related to the surfactant's polarity and nanoemulsion drop size. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40889.     

Krill Lecithin as Surfactant for Preparation of Oil/Water Nanoemulsions as Curcumin Carriers

Curcumin is a component in Curcuma longa L. with documented bioactive properties but has low bioavailability. To overcome this problem, curcumin nanoemulsions are prepared employing omega-3-rich phospholipids from krill oil as a surfactant and serve as curcumin carrying systems. The phospholipids are obtained through aqueous (LAD) and ethanolic (LED) degumming processes. The data obtained shows that LAD has a recovery of 70.7 ± 0.51% (w/w) phospholipids, being more efficient than LED with 45.97 ± 1.27% (w/w). Also, a higher content of omega-3 fatty acids is found in LAD with 36 ± 2.14% (w/w). From the critical micellar concentration (CMC) as an assessment of emulsifying capability, it is found that the krill oil (KO), LAD, and LED has a CMC in the range 0.666–0.700 g L⁻¹. Two formulations with different surfactant levels are developed: experiment A with 9.5% and experiment B with 4.75% (w/w) of krill lecithin are obtained by aqueous degumming. In the formulation of nanoemulsions average particle sizes of 139 ± 2.5 and 142 ± 5.3 nm are produced for experiments A and B, respectively. These results indicate that krill lecithin is an omega-3 rich good surfactant which can be employed to encapsulate curcumin. Practical applications: An interest has emerged in the food industry to develop surfactants with nutritional value. Phospholipids are natural emulsifiers that are widely used to form nanoemulsions because of their elevated interfacial activity. Krill oil has been reported to be an important source of phospholipids and omega-3 fatty acids, which are mainly esterified to phospholipid moieties. Because of these properties, krill oil phospholipids could form micelles and function as carrier systems for bioactive compounds, thus increasing their permeability in the intestine. Consequently, the present work focused on obtaining a nanostructure using a natural surfactant that possesses fatty acids with nutritional value such as omega-3 fatty acids. This will provide an added value to the product obtained, as well as improve the bioavailability of non-polar bioactive compounds. The results obtained could justify the use of krill oil as a useful functional food additive.     

Enlargement of Nanoemulsion Region in Pseudo-ternary Mixing Diagrams for a Drug Delivery System

The purpose of this research was to develop the pseudo-ternary mixing diagrams for a potential drug delivery system consisting of vitamin E (potential drug) + soybean oil + surfactant + co-surfactant (anhydrous glycerol) + water. The potential drug (vitamin E) was loaded in the oil phase. The effects of different surfactants (pure and mixed) on the mixing diagrams, especially on the nanoemulsion region, were investigated. The influence of the drug loading level on the mixing diagrams was also determined. The surfactants studied were polyethoxylated (20) sorbitan monolaurate, polyethoxylated (20) sorbitan monooleate, polyethoxylated (35) castor oil and their mixtures. The size (area) of the nanoemulsion region of the mixing diagrams was found to be dependent on the type of surfactant used and the loading level of the drug (vitamin E).     

Some characteristics of polyoxyethylene sorbitol tetra-oleate: Oligomer type emulsifier

Polyoxyethylene (P) sorbitol tetra-oleates with molecular weights of 2000 to 4000 were synthesized. They may be regarded as tetramers of those ordinary surfactants that consist of one hydrophilic and one hydrophobic group. Some emulsifying properties of the tetrameric surfactants were investigated including the phase inversion temperature (PIT, HLB-temperature). These surfactants are effective at relatively low concentration, they are stable for coalescence, and they are less irritating than conventional surfactants. Specifically, they proved to be good emulsifiers for unsaturated triglycerides such as olive oil. The mean droplet diameter of the emulsion was small, 1.5 microns. The emulsifying activity of these oligomer type surfactants for olive oil was improved markedly by the addition of 0.2–0.9 wt % of sodium oleate. Such effective performances of these surfactants have not been recognized in ordinary surfactants. It is expected that these oligomer type surfactants may find applications in various industrial fields.     

Quality characteristics of olive leaf‐olive oil preparations

Olive leaf‐olive oil preparations were obtained by vigorous mixing at various levels of addition (5, 10, 15%w/w) of new or mature leaves. After removal of the plant material via centrifugation, quality and sensory characteristics of the preparations were determined. Oxidative stability (120°C, 20 L/h) and DPPH radical scavenging were increased ～2–7 fold depending on the level of leaves used due to enrichment with polar phenols, mainly oleuropein, and a‐tocopherol. The extraction process affected the chlorophyll content and organoleptic traits as indicated by acceptability and preference tests (n = 50). Forty‐four % of the panelists identified a strong pungency in preparations with 15% w/w new leaves. Fifty‐four % of them identified a bitter taste in those with 15% w/w mature leaves, which was attributed to high levels of oleuropein (～200 mg/kg oil). Olive leaf‐olive oil preparations had interesting properties regarding antioxidants present that can attract the interest of a functional product market. Practical applications: The wider use of olive oil and derived products is highly desirable. In this sense, the current study presents data that support introduction to the market of a new specialty olive oil based solely on olive tree products (olive oil and leaves). Thus, in addition to olive oil and olive paste, a new product, that is an olive oil enriched with olive leaf antioxidants, especially oleuropein produced via a “green” technique (mechanical means instead of extraction with organic solvent) can be made available for consumers.     

Development of Nanoemulsion of Silicone Oil and Pine Oil Using Binary Surfactant System for Textile Finishing

Nanoemulsions of silicone oil and pine oil using a binary surfactant system were prepared. Silicone oil and pine oil were used to achieve softness and mosquito repellency and antibacterial activity respectively when the nanoemulsion was applied on the fabric. A silicone surfactant (AG-pt) and a hydrocarbon surfactant (TDA-6) were used in different proportions to obtain stable nanoemulsions at the lowest possible droplet size. The various emulsification process variables such as ratio of hydrocarbon to silicone surfactant, surfactant concentration, ratio of silicone oil to pine oil, oil weight fraction and sonication time have been studied. The optimal variables include the ratio of hydrocarbon to silicone surfactant of 80:20, surfactant concentration of 8%, ratio of silicone oil to pine oil of 80:20, oil weight fraction of 20% and 15 min of sonication time at 40% of the applied power. Nanoemulsions were found to be very stable with emulsion droplet size around 41 nm. In order to compare different emulsification techniques, emulsions were also prepared using the conventional method. Emulsions analyzed using SEM showed spherical droplets ranging from 40 to 120 nm. Atomic force microscopy was used to evaluate the bounciness, fluffiness and softness of fabric. From this study, it was found that stable nanoemulsion with a lowest possible droplet size of silicone and pine oil could be prepared by ultrasonic emulsification technique in order to deliver multiple properties when applied to fabric.     

Evaluation of nanoemulsions based on silicone polyethers for demulsification of asphaltene model emulsions

Asphaltenes are considered the main agents responsible for stabilizing petroleum emulsions. However, due to the complex chemical nature of crude oil, it is necessary to extract these molecules and prepare model solutions to investigate the effects of the various asphaltenes separately. In this study, the demulsification efficiency of oil‐in‐water (O/W) nanoemulsions based on silicone polyethers was evaluated using asphaltene model emulsions. The interfacial properties of the model emulsions were evaluated, with and without the presence of the nanoemulsions, by interfacial tension and inerfacial rheology measurements and correlating them with the ability and/or speed of diffusion to the interface. Dispersion/flocculation tests of the asphaltenes were performed to assess whether the nanoemulsions were modifying the aggregation state of the asphaltenes during the process of destabilizing the model emulsions. Through the interfacial rheology tests of the model asphaltene/saltwater system, with or without addition of the systems used in the demulsification tests, it was possible to determine the influence of the nanoemulsions on the mechanical properties of the interfacial film. The results of the water/oil gravitational separation tests showed that the nanoemulsions had separation efficiency between 80 and 95%, depending on the composition of the water/surfactant/oil/asphaltene system. The nanoemulsions containing xylene as the oil phase destabilized the emulsions the fastest. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44174.     

Evaluation of MALDI-TOF/MS Technology in Olive Oil Adulteration

Adulteration of extra virgin olive oil (EVOO) by addition of other vegetable oils or lower-grade olive oils is a common problem of the oil market worldwide. Therefore, we developed a fast protocol for detection of EVOO adulteration by mass spectrometry fingerprinting of triacylglycerol (TAG) profiles based on MALDI-TOF/MS. For that purpose, EVOO TAG profiles were compared with those of edible sunflower oil and olive oil composed of refined olive oil and virgin olive oils. Adulteration of EVOO was simulated by addition of sunflower and mixture of refined olive oil and virgin olive oils at 1, 10 and 20% w/w. Results of mass spectrometry TAG profiling were compared with routinely assessed K values for identification of adulteration. MALDI-TOF/MS technology coupled with statistical analysis was proven as useful for detection of adulteration in EVOO at a rate down to 1%. In contrast, standard spectrophotometric methods failed to identify minor adulterations. In addition, the ability of MALDI-TOF/MS in detection of adulteration was tested on EVOO samples from different geographical regions. Results demonstrated that MALDI-TOF/MS technology coupled with statistical analysis is able to distinguish adulterated oils from other EVOO.     

用均匀设计的方法进行阳离子型重油乳化剂的研究

采用均匀设计与调优软件进行了重油乳化剂配方实验方案的设计和实验结果的优化。通过两次优化设计的方法 ,较快地取得了最佳配方。实验结果表明 ,阳离子表面活性剂与阴离子表面活性剂复配容易生成不具有表面活性的物质 ,故不宜一同使用。阳离子表面活性剂与非离子表面活性剂复配制得的乳化剂性能较好。乳化剂最佳配方为氯化十八烷基二甲基苄基铵 70mg,聚氧乙烯失水山梨醇单月桂酸酯 7mg ,失水山梨醇单硬脂酸酯 7mg ,乳酸乙酯 36mg(共占乳化油总质量的 0 12 % )。可使燕山石油化工公司产运动黏度ν10 0 =12 0mm2 /s的重油在油水质量比为 70∶30时形成的油包水型乳化重油在 80℃下稳定 3d(72h)以上 ,常温下稳定 1a以上。不同重油乳化稳定性的差别较大。     

Palm‐based functional lipid nanodispersions: Preparation,characterization and stability evaluation

The objective of the present study was to investigate the effect of high‐pressure homogenization conditions, namely pressure (20–80 MPa) and number of cycles (1–3 cycles), on the properties of palm‐based functional lipids. Nanodispersions prepared with palm‐based functional lipid and Tween 20 were characterized by monitoring their physicochemical and morphological properties. The results showed that high‐pressure homogenizer was an efficient emulsification technique producing small emulsion droplets with narrow size distribution. In general, the results showed that different homogenization conditions had significant (p < 0.05) effect on the size distribution of prepared nanodispersions. Average particles ranging from 95 to 130 nm and 140 to 210 nm were obtained for the nanoemulsions containing palm‐based tocopherol–tocotrienol and carotenoid, respectively. However, this study indicated that increasing the energy input beyond moderate pressures (20–80 MPa) and cycles (1–3) led to “over‐processing” of droplets. The nanodispersions proved to be physically stable and showed good stability during 12 weeks of storage.     

Facile Formation of Medium-Chain-Length Poly-3-Hydroxyalkanoates (mcl-PHA)-Incorporated Nanoparticle Using Combination of Non-Ionic Surfactants

The assembly of nanoparticles incorporating bacterial medium-chain-length poly-3-hydroxyalkanoates (mcl-PHA) via phase inversion emulsification (PIE) was investigated. Sequential addition of water into an agitated mixture of carrier oil (jojoba oil), nonionic surfactants (Cremophor EL and Span 80) and melted mcl-PHA triggered phase inversion of water-in-oil (W/O) to oil-in-water (O/W) emulsion. The emulsion inversion point (EIP) at 30% w/w of water content was determined by abrupt changes in viscosity and conductivity of the suspension. Concurrently, infrared transmittance of the O–H group of water, the C–O–C group of surfactants and the C–H group of alkane chain were practically identical while Small Angle X-ray Scattering indicated the presence of a bi-continuous/lamellar structure. The morphology of the emulsion changed, with increasing water content, from W/O to bi-continuous/lamellar structure and finally to O/W. mcl-PHA appears to form a bridging polymeric network, covering the nanoparticle with a protective layer for enhanced protection of the encapsulated compound. A hypothetical mechanism for the mcl-PHA-based nanoparticle assembly is also proposed.     

Studies on applications of lipolytic enzyme in detergency I. Effect of lipase fromCandida cylindracea on removal of olive oil from cotton fabric

To investigate the effect of lipolytic enzyme on removal of triglyceride soils in laundry, the removal of olive oil from cotton fabric was examined by washing with an aqueous solution of lipase fromCandida cylindracea with and without surfactants at various washing temperatures and times. It was proved that, at optimum conditions, the removal of olive oil with the addition of lipase was 15 to 20% higher than without lipase. Therefore, it might be expected that lipase will be applied in the laundry detergents in practice.     

Preparation of water-soluble polyurethane surfactants

A novel series of water-soluble polyurethane surfactants has been prepared by the addition polymerization of 2,4 and 2,6-toluene diisocyanate 80 : 20%, respectively (TDI) to polyethylene glycol (PEG) and/or castor oil and ethylene glycol (EG). These water-soluble polyurethane surfactants have been found to exhibit excellent surface active properties including surface tension, foaming and wetting tendency, and formation of stable emulsions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1531–1536, 1998     

Evaluation of the influence of polyoxide‐based surfactants on the separation process of model emulsions of asphaltenes using the FTIR‐ATR technique

During extraction of crude oil, water is generally present in the oil. This water‐in‐oil (w/o) mixture undergoes turbulent flow that promotes sheer forces, resulting in the appearance of emulsions. These emulsions can be highly stable due to the presence of compounds with polar characteristics such as asphaltenes, which act as natural emulsifiers and form resistant films at the oil–water interface. Nonionic surfactants based on polyoxides are widely used to prevent the formation or to break down w/o emulsions. To shed more light on the destabilization mechanism of w/o emulsions promoted by these surfactants, in this study the techniques of tensiometry and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR‐ATR) were applied to study the interface formed by poly(ethylene oxide)‐poly(propylene oxide) (PEO‐PPO) block copolymers and asphaltenic petroleum fractions. Initially, the critical micelle concentration of the copolymers in aqueous solution was determined. The results agreed with those found by tensiometry. The bottle test was used to evaluate the break‐down of the w/o emulsions in the presence of the PEO‐PPO block copolymers, and the results presented good agreement with those obtained by tensiometry and FTIR‐ATR. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

A laboratory study of the bleaching process in stigmasta-3,5-diene concentration in olive oils

The bleaching effect was simulated in pilot plant by measuring the influence of temperature (40, 50, 60, 70, 80, and 90°C), time (5, 10, 15, 20, 25, and 30 min), and concentration of solid adsorbent [1.5 and 8% (w/w) of Tonsil supreme NFF] on stigmasta-3,5-diene (STIG) obtained by dehydration of steroidal compounds. Conditions were chosen to simulate those used in industrial operations. The presence of refined oils in extra virgin olive oil can be detected by these newly formed steroid hydrocarbons. Experimental results indicated that STIG did not exceed an imposed limit of 0.15 mg/kg in extra virgin olive oil, when oils were bleached with 1.5% earth at temperatures ≤80°C for 30 min in admixed to oils sold as virgin. A large proportion of the adulterations were not detectable by the official methods. Color determinations (CIE-1931) chromatic coordinates) were replicated on a refined oil and in admixed extra virgin olive oil. Color of olive oil was not significantly affected by mixing with refined oil (≤20%).     

Microencapsulated Fish Oil Powder Formulation with Improved Resistance to Oil Leakage During Powder Compression

The effects of the addition of pectin to a primary fish oil emulsion stabilized by a heated milk protein–carbohydrate mixture, and heat treatment of emulsion at low pH (with or without the addition of pectin) on the properties of final emulsions (pH 7) and powders (~42 % w/w/fat) prepared from these emulsions were examined. Either the addition of pectin (without the additional heat treatment at pH 3), or additional heat treatment step at pH 3 (with or without pectin) reduced the surface oil and free oil of spray dried powders, and also reduced oil leakage on powder compression. However, the extra heat treatment step at low pH to the emulsion (without pectin) resulted in a greater susceptibility to oxidation of EPA and DHA in the powder. A judicious choice of ingredients for formulating and processing emulsions prior to spray drying enables the application of food‐grade microencapsulated fish oil powders in directly compressible tablet applications.     

Effect of temperature and type of food simulant on antioxidant stability

Additive migration levels in food simulants from polimeric materials that are intended to be into contact with food can be affected by additive stability under the migration test conditions. In this work, the stability of some phenolic antioxidants and one oxidized phosphite antioxidant was studied in four food simulants: distilled water, 3% (w/v) acetic acid, 10% (v/v) ethanol, and the fatty food simulant olive oil, under different temperatures 5, 40, and 70°C, during ～20 days. Samples were analyzed by reversed‐phase high performance liquid chromatography (HPLC) with UV diode‐array detector. In general, antioxidants appeared to be more stable in olive oil than in the aqueous simulants. Among aqueous simulants, water and 10% ethanol allowed the highest stability of antioxidants at low temperatures. The 3% acetic acid allowed good stability for the lowest phenolic compounds even at high temperatures, but the highest molecular weight compounds decomposed very fast even at low temperatures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 656–663, 2006