Showing 67 results for Emulsion
Volume 2, Issue 2 (9-2018)
Abstract
Methyl Tert-butyl Ether(MTBE) has been used as a booster in gasoline octane numbers in many countries, but after a short time due to the high absorption in water and the possibility of entry into groundwater, its use in developed countries is prohibited. In this work, for the first time, to reduce the adverse environmental effects, MTBE was encapsulated, and release control was considered. For this purpose, the inverse mini-emulsion polymerization of monomer methylmethacrylate(MMA) was performed in the presence of MTBE and in the cyclohexane medium by oil/water/oil. Poly methyl methacrylate/MTBE nanocapsules were synthesized in 0.5, 1, 2 ratios of MTBE to methyl methacrylate (R = MTBE / MMA).
The effect of changing R values on conversion polymerization, on encapsulation efficiency of MTBE and on the morphology of capsules was investigated. For this purpose, TGA and TEM were used. Changing the R ratio from 0.5 to 2 allowed the capsule to be controlled in the range of 50-500 nm. The start of the MTBE degradation range of 130 ° C increased to 250 ° C due to the presence of the MTBE inside the capsule, and it was possible to start controlling the release of the nucleus by heating and starting at a temperature of 250 ° C. By addition of 1.5% of the capsules to the gasoline, the octane number increased by 5 units.
According to the results inverse mini-emulsion polymerization is a suitable method for encapsulating and reducing the environmental effects of MTBE by limiting its contact with the environment.
Volume 4, Issue 12 (4-2007)
Abstract
Mass transfer between packaging and its contents during the storage mainly affects physical and chemical properties of foods. Possible interaction between HDPE container and soft drink basis was studied in this work. GC-HS analysis was applied to identify the possible reactants of HDPE. Basis packaged in HDPE containers was stored at different storage temperatures; 4, 25 and 48˚C. Specific migration of n-Octane as possible reactant was determined by headspace chromatography coupled with mass spectrometer. Quality parameters of basis were measured during storage time at different temperatures. N-Octane was not detected in the samples stored at 4 and 25˚C, and at 48˚C was 0.7ppb, which is much smaller than permitted level of FDA (300ppm). The best storage condition was recognized at HDPE container and darkness condition in 4˚C. So the temperature was recognized as an important attribute in basis storage.
Volume 6, Issue 1 (6-2017)
Abstract
The effects of adding refined cod liver oil- rich in omega 3- in three forms (fish oil, O/W emulsion, gelled oil-in-water emulsion) to sausage from silver carp (Hypophthalmichthys moltrix) was investigated. In this regard, such properties of the sausage as its physicochemical, sensory, microbiological, texture, color, cooking loss and oxidative stability of enriched sausages were assessed. The results of proximate composition analyses showed that there was no difference between enriched formulated fish sausage (p> 0.05). pH ranged from 6.52 to 6.72 and decreased during storage. Enrichment of fish sausage caused to higher ω-3 PUFAs content, especially EPA and DHA, and decreasing significantly the ω-6/ω-3 ratio from 22.3 to 9.85. The control and fish oil treatments showed significantly higher thiobarbituric acid value during storage (p<0.05). Cooking loss was lower in gelled emulsion than other formulations. Texture analysis results showed higher hardness in gelled emulsion sausages than the others. Sensorial tests showed that the gelled emulsion sausages had higher acceptability scores. As a result, gelled emulsion was demonstrated to be a suitable delivery system in fortification of fish sausage.
Volume 6, Issue 1 (6-2022)
Abstract
Abstract
Research subject: In recent years, toner-based printers have found many applications for ease of use, economical, high speed and quality. Therefore, many attempts have been made to produce toner by various methods such as suspension polymerization and emulsion aggregation. But in all these methods, despite the proper color properties and particle size, the reaction conversion is low.
Research approach: In the present study, in situ emulsion polymerization method based on styrene and butyl acrylate monomers in the presence of carbon black has been used to produce toner with a conversion above 75%. In this regard, the effect of polymerization reaction temperature and stirrer speed on conversion at different times, particle size and particle size distribution, thermal and color properties of the final product were investigated. Color measurement was performed to evaluate the color characteristics. Also, the microstructure of the synthesized toners was evaluated using scanning electron microscopy.
Main results: The results show that in situ emulsion polymerization method while having the proper conversion of the reaction in the range of 75-90% is well able to create the suitable color characteristics and particle size distribution for the toner. All toners produced had a particle size distribution and a spherical shape that was unaffected by the reaction temperature and stirrer speed. By increasing the polymerization temperature from 70℃ to 80℃, resulted in a higher conversion, but the increase in stirrer speed had a dual effect on the conversion. Sticking of spherical particles with each other was observed by increasing the temperature to 90℃. The sudden addition of a monomers to the reaction media and using batch process resulted in the observation of two glass transition temperatures. This type of toner synthesis can be a guide for future research to produce toner with the highest conversion.
Volume 7, Issue 2 (7-2018)
Abstract
In recent years, different formulations such as nanoemulsions have been widely used for the target delivery, and enhanced biological functions of pesticides combinations. In this study, contact toxicity of
Mentha longifolia L. essential oil compared with its nanoemulsion on
Ephestia kuehniella Zeller has been investigated. The experiments were conducted and executed at 27 ± 1 °C,
and 75 ± 5% relative humidity under dark conditions. Chemical composition of this plant extract was also studied. The main constituents were
pulegone (28.84%), 1,8-cineol (19.6%), p-menthan-3-one-cis (8.2%), β-pinene (6.46%) and p-menthan-3-one-trans (5.86%). Results indicated that the mortality rate of 5
th instar larva of
E. kuehniella increased with rising concentrations (10000-40000ppm) for oil and (8000-20000 ppm) for nanoemulsion, respectively. The essential oil LC
50 was 21352ppm, while this value for nanoemulsion was 14068ppm. According to the results, nanoemulsion was more effective than essential oil.
M. longifolia oil had lower durability and the 50% persistent time (PT
50) was 2.39 day compared to the nanoemulsion (PT
50 = 17.13 day) in the highest concentration of essential oil. The nanoparticle size was 14-36 nanometers (nm) when the transmission electron microscope (TEM) was applied. The surface morphology of nanoemulsion was also studied by TEM. The average size of the particles was estimated 234nm by using laser
light scattering apparatus. The overall results of this study show that by using nanoemulsion formulation, the effect of essential oil contact toxicity and its durability increases. Hence, the nanoemulsion slow-release formulation may represent a new category of biopesticides and this should be considered in the integrated pest management program.
Volume 8, Issue 1 (1-2019)
Abstract
The efficiency of neem based insecticides have been assessed by many studies however, there is scanty information on the cost:benefit ratio of their use vis-a-viz synthetics, particularly, in watermelon production. In this study, thirty-six 5 m long x 8 m wide plots were arranged in Randomized Complete Block Design in 4 replications of weekly spray of; 0.5% Cyper-diforce® (CD); 1, 3 and 5% Neem Oil Emulsion (NOE); 0.25% CD + 1, 3 and 5% NOE; 1% soap solution and, Control (unsprayed plots). Arthropods were sampled on 5 m length of row using Suction Sampler and Yellow Sticky Board. Severity of leaf damage and aphid colony size was also assessed. At harvest, marketable fruits were weighed and used to compute cost-benefit ratio. The prevalent pests were five species of leaf-beetles, Aphis gossypii Glover, Bemisia tabaci (Gennadius), Bactrocera cucurbitae (Coquillett) and Helicoverpa armigera (Hubner). The beneficials included; Apis mellifera L., Cardiochiles niger Szépligeti and Cheilomenes sulphurea (Olivier). The 0.5% CD was ineffective against Aphids but 3 and 5% NOE were. Overall, insecticide treatments reduced infestation by 2.9-95.3%. Though, combination of 0.25% CD with NOE treatments suppressed pest infestation relative to sole neem oil treatments, leaf injury and yields were statistically comparable. Sole NOE treatments were observed not to significantly suppress populations of beneficials when compared to 0.25% CD or their combinations. 0.25% CD + 5% NOE consistently gave the highest yield/season (39192-44642 kgha-1). Monetary benefits exceeded US$3724 ha-1. The insignificant differences in yield among the insecticide treatments showcased neem’s potential in managing watermelon pests. The ineffectiveness of Cyper-diforce® against A. gossypii suggests resistance development.
Volume 9, Issue 3 (8-2020)
Abstract
Controlled delivery technology of protein/peptide drugs from biodegradable particles has emerged as one of the eminent areas to overcome problems related to macromolecules formulation. The goal of the present study was to develop protein-loaded micro-particles using biodegradable polymer, polycaprolactone (PCL) and hydrogel from beluga cartilage. Bovine serum albumin (BSA) was used as a model for protein/ peptide molecules such as GnRH. The double emulsion (W/O/W) technique was selected as one of the most appropriate methods for preparing a drug delivery system for soluble proteins in water. The first emulsion was prepared using ultrasonic and the mechanical agitator was used for achieving the second emulsion. The hydrogel prepared by enzymatic digestion was used in the first aquatic solution. At the present investigation, three groups were considered as the drug delivery system: G1; (PCL/hydrogel/BSA), G2; (PCL/BSA) and G3; (PCL/Alginate/BSA). Findings showed that the morphology of particles was spherical and non-conglomerated in all groups. The comparison of average particle size among groups was also indicated that the particles.
Volume 10, Issue 3 (6-2021)
Abstract
Pistachio psylla, Agonoscena pistaciae Burkhardt & Lauterer (Hem.: Psyllidae) is one of the most important pests of pistachio orchards in Iran. The application of chemical pesticides early in the growing season until harvest has affected farmers’ and consumers’ health. In this research, the efficacy of arugula Eruca sativa cold press seed oil, methanolic spinach Spinacia oleracea seed extract, and dayabon® (SL 10%) was studied against nymphs and adults of pistachio psylla in a laboratory at 26 ± 2 °C, 65 ± 5% RH, and photoperiod of 16: 8 (L: D) h. LC50 values of nanoemulsion formulation (NEF) of spinach seed extract and its nonformulated extract on the early nymphal stage were 468 and 4381 mg/l, respectively. In contrast, the LC50 value of arugula seed oil and dayabon was 2281 and 4380 mg/l, respectively. NEF of spinach seed extract (LC50 = 124 mg/l) was significantly more toxic than other compounds against the 5th nymphal stage. There was no significant difference in nonformulated spinach seed extract (LC50 = 3946 mg/l), arugula seed oil (LC50 = 3189 mg/l) and dayabon (LC50 = 3930 mg/l) against 5th instars. The efficiency of dayabon and arugula seed oil and a chemical pesticide fenitrothion was studied in the field located in Dehmolla County, Shahrood, Iran. Sampling was carried out before and after treatment. There were no significant differences between days after treatments. It means that the botanicals were effective until 21 days after treatment. Findings indicated that botanical pesticides used in this study could be effective against pistachio psylla.
Volume 12, Issue 48 (9-2015)
Abstract
The purpose of this study was to investigate the effect of lyophilized Alyssum homolocarpum seed gum–whey protein concentrate (with the ratio of 1:1, 1:3 and 3:1) on physicochemical properties of corn oil–in–water emulsions. Interfacial tension and emulsion characteristics such as particle size distribution, zeta potential, flow behavior, viscosity and creaming were investigated. The results showed that with the increasing gum ratio in the mixture, the interfacial tension increased, but the difference was not statistically significant. In emulsions stabilized with gum–protein mixture, increasing gum content, increased the particles size, negative charge on droplets surface, consistency coefficient, yield stress and hysteresis between the forward and the backward diagrams. The particle size distribution curve was monomodal and emulsions stabilized with this mixture showed non–newtonian and psedoplastic behavior. No creaming was observed in all emulsions.
Volume 12, Issue 48 (9-2015)
Abstract
In this research, the production of low fat butter, as a novel product, based on full-fat soy flour and sodium caseinate was studied. Water : butter ratio, soy flour : sodium caseinate ratio and emulsifier content were the designed factors and their effects on rheological properties of low-fat butter such as hardness, spreadability, adhesiveness, elasticity and consistency were evaluated. The Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed as experimental design and statistical analysis. By increasing water to butter ratio, as a principal factor affecting on product characteristics, hardness, adhesiveness, elasticity, consistency and spreadability were reduced. The final product was w/o emulsion which was low-calorie, had functional and nutritional effects due to protein components and also its properties could be compared with ordinary butter. Based on final results, the optimum formulation for low-fat butter were: water : butter ratio as 1.03 (50% water and 48.5% butter), soy flour : sodium caseinate as 1.57 (5% soy flour and 3.2% sodium caseinate) and 0.66% emulsifier.
Volume 13, Issue 0 (11-2015)
Abstract
Volume 13, Issue 2 (11-2024)
Abstract
The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae) is one of the important ornamental plant pests in urban regions. In this study, the microemulsion system was developed using cypermethrin insecticide as the active ingredient, xylene as the solvent, and surfactants including Tensiofix 8427 + SDS, and Tensiofix 8427 + SLS, and 1-butanol (cosurfactant), as stabilizer. The optimal microemulsion formulation was determined using a pseudo-ternary phase diagram using the water titration method. The microemulsions mean droplet sizes were in the range 11.2–22.8 nm. The droplets of all three formulations were spherical and uniformly dispersed in water. The mortality percentage was 66.66, 56.66, and 55.00% 24 h after aphids exposure to C1-250 (cypermethrin: Tensiofix 8427 + SDS + 1-butanol: water, at the ratio of 10:20:70), C2-250 (cypermethrin: Tensiofix 8427 + SLS + 1-butanol: water, at the ratio of 10:20:70), and C3-250 (cypermethrin: Tensiofix 8427 + SLS + 1-butanol: water, at the ratio of 15:30:55), which increased to 92.86, 89.29, and 83.94%, 48 h after exposure, respectively. The results revealed that the microemulsion formulation containing cypermethrin 250 g/L was more effective in controlling A. gossypii than cypermethrin technical material and 150 g/L cypermethrin-based microemulsion.
Volume 13, Issue 52 (4-2016)
Abstract
Previous studies have shown that Astragalus Gossypinus species of gum tragacanth are able to stabilize oil in water emulsion. Today, irradiation is used to disinfect many polymers. Results have shown that irradiation treatment has a significant effect on molecular weight and functional properties of Gums, especially Gum tragacanth. The aim of this study is to investigate the effect of irradiated Gum tragacanth at doses 0, 1/5, 3, 5 kGy on the emulsion stability index of oil in water emulsion which contain 0.5% w/w gum tragacanth and 10% w/w sun flower oil was studied by measuring creaming index. In order to monitor the mechanism of stabilization, rheological properties and particle size distributing parameters were measured. Rheological properties were measured by using rheometer and particle size distribution was determined using laser diffractometry. All treatments were performed three times and the data were analyzed by one way ANOVA. Significant differences between means were identified (P values < 0.05) using Duncan test. Results indicated thatrheological properties, particle size distributing and the stability of oil in water emulsion has been affected by irradiation. These changes are dependent on irradiation dose. Results show that irradiation treatment at 1.5 kGy created the most stable system by changing the studied parameters.
Volume 13, Issue 55 (9-2015)
Abstract
The effect of xanthan gum (0-0.3%) on corn oil-in-water (pH=7) emulsions prepaired by 0.5% grass pea (Lathyrus sativus) protein isolate was studied. Particle size, PDI, zeta-potential, emulsion capacity, emulsion stability and creaming index of emulsions were measured inorder to find the effect of xanthan gum on the stability of emulsion. Results showed that increasing concentrations of gum caused depletion flocculation and thus increased the particle size but had no significant effect on the zeta potential. Study on creaming index, emulsion capacity and stability also showed that with increasing xanthan gum, emulsion capacity and stability increased, while, creaming index decreased. Therefore, after 28 days of storage at 4˚C, no changes were observed in the emulsions containing xanthan gum.
Volume 13, Issue 60 (0-0)
Abstract
In the present study, the influence of various emulsifiers (Tween 80, Tween 60, Tween 20, Sodium caseinate, WPC and WPI), ratio of emulsifier (Tween 80) to oil phase (orange peel essential oil) at eight levels (1, 1.5, 1.75, 2, 2.25, 2.5, 2.75, and 3:1), and the possibility of using complete form, soluble and insoluble fractions of the two native gums (Persian gum and gum tragacanth) individually and combined in the formulations on the formation and some properties of orange peel essential oil nanoemulsions was evaluated. Ultrasonic emulsification technique was used to produce nanoemulsions and the mean droplet diameter (Z-average), polydispersity index, viscosity, flow behavior, physical stability of selected formulations during storage (up to 90 days at 25˚C), as well as the total input energy during process was evaluated. Our results showed that surfactant-to-oil ratio (SOR) had a significant effect on the mentioned properties (P< 0.0001) where the lowest Z-average was observed at SOR=2. Meanwhile, none of the local gums and proteins were able to form nanoemulsions in the absence of emulsifier (Tween 80). Moreover, their soluble fractions (individually and combined at reasonably low concentration) showed significant effect (P< 0.0001) on the measured properties in the presence of emulsifier. Furthermore, the flow behavior of nanoemulsions was Newtonian, and the effect of storage time on the Z-average value was significant (P< 0.0001).
Volume 14, Issue 63 (6-2016)
Abstract
Volume 14, Issue 64 (6-2016)
Abstract
Effects of Lepidium perfoliatum seed gum (LPSG) concentration (0, 0.3 and 0.6 wt%) and different processing treatments (freezing, pasteurization and sterilization) on physical and stability of oil-in- water emulsion prepared by whey protein (6 wt%) was investigated. For this purpose, particle size distribution, creaming index, microscopic characteristics, viscosity and flow behavior of emulsions were studied. Results showed that thermal processing increased the particle size of dispersed phase. Results also showed that the damage of membrane surface at high temperature such as sterilization was higher than other temperatures. At low Lepidium perfoliatum seed gum concentration, the emulsions were somewhat more resistant to thermal processes. However, at higher gum concentrations (0.3 and 0.6%), thermal processing did not have a negative effect on the emulsion stability. The viscosity and consistency coefficients also increased with increasing gum concentration. Shear thinning behavior for emulsions at all thermal treatments were also observed. Therefore, adding LPSG to the emulsion could increase its stability to the thermal processing.
Volume 14, Issue 64 (6-2016)
Abstract
Increasing manufacturers demand to replacing synthetic gums with natural and native intergradient, created the idea of this study. The aim of this research is to evaluate the properties of oil in water emulsions in the presence of the Lepidiumsativum seed gum and its stability and/or emulsifying behavior. Surface and interfacial tension, particle size, zeta potential, creaming index and rheological properties such as viscosity, consistency coefficient and flow behavior index were measured.Lepidiumsativum seed gum used as 0-1% (w/v) proportions.The lowest surface and interfacial tension were obtained for the concentrations of 1 and 0.5% respectively.Particle size decreased with increasing quantities of gum expect for 1% concentration. At 0.25% concentration for aqueous solutions and 1% for emulsions, zeta potential showed the most negative values. Non-Newtonian and shear thinning behavior for all emulsions containing gum were observed. Every emulsions were stable during 28 days.
Morteza Alizadeh, Mohammad Taeibi Rahni, Mohammad Eftekhari Yazdi,
Volume 15, Issue 4 (6-2015)
Abstract
Emulsion consists of drops of one liquid dispersed into another immiscible liquid, is a novel technique for producing monodisperse droplets. The aim of this research is using the Lattice Boltzmann Method (LBM) to simulate two-phase flows in micro-channels to access the emulsification process. To this approach, The Index-Function Model proposed by He, is used to simulate drop formation in emulsification process in a co-flowing micro-channel with a complex geometry and three inlets. The simulation is performed to investigate the mechanism of drop generation due to dripping and jetting modes and the mode between them. Index function model, which is a new reliable model to evaluate two-phase flows, is applied to track the motion and deformation of the interface between the two immiscible fluids. Accuracy of our results is examined by two well-known basic analytical models including Relaxation of a rectangular drop and coalescence of two static droplets. Our results indicate good agreements with analytical data. The dimensionless numbers such as Capillary and Velocity ratio were used. The Capillary number is one of the most important dimensionless numbers in determination of fluid flow characteristics in micro-channels. The simulations reproduce dripping, widening jetting and narrowing jetting simultaneously in a coflowing microchannel in agreement with the experimental ones. This indicates that index function LBM model has a good accuracy and high stability to simulate this kind of flow.
Volume 15, Issue 84 (2-2019)
Abstract
In this study, the feasibility of fabrication of nanoemulsions containing garlic extract to hide the unpleasant odor and keeping functional properties of them in order to promote their applications in food formulation was considered. For this purpose, the various formulations of nanoemulsions containing garlic extract using high energy method (water bath type ultrasonic) were produced and also, the effect of various ratios of garlic extract on droplet size, encapsulation efficiency, antioxidant and antimicrobial activity, viscosity, electrical conductivity and turbidity of nanoemulsions was evaluated. Droplet size of various nanoemulsions ranged from 62 to 302 nm for water in oil nanoemulsions based on the dispersed phase ratio. The results of gas chromatography showed that the produced nanoemulsions were covered the volatile compounds of garlic extracts by a relatively high performance, but with an increase in the percentage of dispersed phase (garlic extract) from 5 to 25 percent, encapsulation efficiency was dropped from 89 to 80 % in water-in-oil nanoemulsion. Results from microbial test showed that water-in-oil nanoemulsions have a relatively low antimicrobial activity and they have only an inhibitory effect in high percent of garlic extract (25 %). Results of antioxidant activity by DPPH method cleared that water-in-oil nanoemulsions have a high free radical scavenging power. Also, the electrical conductivity of water-in-oil nanoemulsions was very low due to the oily continuous phase of nanoemulsions.
