Microemulsion: a novel alternative technique for edible oil extraction_a mechanistic viewpoint.

Microemulsions, as isotropic, transparent, nano size (<100 nm), and thermodynamically stable dispersions, are potentially capable of being used in food formulations, functional foods, pharmaceuticals, and in many other fields for various purposes, particularly for nano-encapsulation, extraction of bioactive compounds and oils, and as nano-reactors. However, their functionalities, and more importantly their oil extraction capability, strongly depend on, and are determined by, their formulation, molecular structures and the type, ratio and functionality of surfactants and co-surfactants. This review extensively describes microemulsions (definition, fabrication, thermodynamic aspects, and applications), and their various mechanisms of oil extraction (roll-up, snap-off, and solubilization including those by Winsor Types I, II, III, and IV systems). Applications of various food grade (natural or synthetic) and extended surfactants for edible oil extraction are then covered based on these concepts.

Solubilization of concentrated protein dispersion: Effect of hydrogen peroxide (H2O2) and sodium hexametaphosphate (SHMP).

In the present study, the functionality of H2O2 and sodium hexametaphosphate (SHMP) on solubilization of whey protein hydrolysate (WPH) and isolate (WPI), resistant to sterilization temperature at various concentrations, was investigated. The physical state of the treated WPH and WPI dispersions at the presence of various concentrations of H2O2 and SHMP was related to their colloidal structures and thermal stability. Using optimum concentration of H2O2, both dispersions stabilized against heat treatment likely because free SH groups blocked by H2O2. The solubilization range by SHMP was comparably low (up to 6 and 15% w/w for WPI and WPH, respectively). Moreover, the desirable stability was reached when H2O2 and SHMP were simultaneously used. The pH adjustment (7.2), prior to sterilization, also improved the stability range. This research highlights the potential of these substances to restrain the denaturation of whey proteins. Further investigations are still required to elucidate the accurate mechanism of solubilization.

Antidiabetic bio-peptides of soft and hard wheat glutens.

The effects of various purification techniques on kiwifruit enzyme characteristics (protease activity, kinetic parameters, and protein patterns) and production of wheat gluten bio-active peptides were investigated. The enzyme extract purified by ammonium sulfate precipitation method exhibited the highest protease activity (26), Km (0.04 ± 0.002 mM), Kcat /Km (40), and yield (96%). Using actinidin, the hard and soft wheat gluten subunit proteins produced antidiabetic inhibitory (α-glucosidase and α-amylase) peptides. The smallest Mw fraction of soft wheat gliadin peptide (<1 kDa) showed the highest inhibitory capacity against α-glucosidase (18.4 ± 0.7%) and α-amylase (53.3 ± 1.9%). The presence of high levels of amino acids with hydroxyl groups and proline in P3 sub-fraction had a critical role on α-glucosidase (47.2%) and α-amylase (71.2%) inhibitory activities. In conclusion, wheat gluten subunit peptides showed significant metabolic effects relevant to glucose and insulin control in vitro.

Growth, yield and quality of two guar (Cyamopsis tetragonoloba L.) ecotypes affected by sowing date and planting density in a semi-arid area.

The growth period, phenology, grain yield and gum content of two different guar ecotypes were studied in response to different sowing dates and plant densities. A two-year field experiment was conducted as a split-factorial in a randomized complete block design (RCBD) with three replicates in the research field of Tarbiat Modares University during 2016 and 2017 growing season. Main plots consisted of four sowing dates (May 21, June 4, June 21 and July 5 in 2016 and May 10, May 26, June 10 and June 26 in 2017), and subplots including three plant densities (13, 20 and 40 plants m-2) and two ecotypes (Pakistani and Indian). Based on findings, the phenological traits, plant height, grain yield and harvest index were significantly affected by plant density. The effect of ecotypes was statistically significant (p<0.05) on all traits except harvest index in the first year. Furthermore, the seed sowings on May 21 and May 26 with 13 plants m-2 led to highest grain yield (3004.8 and 2826.10 kg.ha-1 for two consecutive years). The high gum content (33.68 and 33.78% for two consecutive years) was also recorded for Pakistani ecotype while for gravity, Indian ecotype showed higher value in both crop years. By and large, the Pakistani ecotype showed better response compared to the Indian one in both years, especially in 1st and 2nd sowing dates.

Gum Tragacanth: Structure, characteristics and applications in foods.

Due to the high demand (consumers and regulatory authorities) on elimination or reduction of 'additives' in food and other health related products, there is increasing interest on natural macromolecules or hydrocolloids such as gums. Gum Tragacanth (GT) is a multifunctional exudate gum with unique thickening, emulsifying, viscosity improving, stabilizing, gelling and structuring capabilities. Owing to its distinctive functionality, it has been extensively used in low-fat or non-fat food formulations, colloid-based products, edible films and coatings and (nano) encapsulation of food ingredients. This review provides the comprehensive information on its physicochemical, structural and functional characteristics with a particular focus on its application in foods.

Microemulsion as nanoreactor for lutein extraction: Optimization for ultrasound pretreatment.

In the present study, the capability of microemulsion technique, as a novel technique for synchronous extraction and solubilization of lipophilic compounds, on lutein extraction from marigold petals was investigated. Under the optimized sonication (amplitude 100%, 120 s, 25°C), the extraction efficiency increased (85%) using SDS:ethanol (1:2)-based ME. Moreover, sonication led to smaller droplets (12-163 nm) with favorable thermodynamic stability. In addition, the developed MEs showed higher thermal and especially UV stability in comparison to organic solvent extracts which were fainted with first-order kinetics. It was also found that co-surfactant could be eliminated from formulation on the expense of the optimized sonication, was valuable output form industrial point of view. These findings revealed the high potential of ultrasound technique on the extraction and solubilization of lutein by ME technique which can be directly utilized in lutein-enriched functional foods and beverages. PRACTICAL APPLICATIONS: From applicability point of view, the solvent extracted compounds cannot be easily dissolved in food or pharmaceutical systems that are mostly hydrophilic. Therefore, microemulsions (MEs), as green and environmentally friendly food-grade systems, due to their potential capability for simultaneous extraction and solubilization of carotenoids are of great interest. Therefore, the present study confirmed the practical ability of MEs in lutein extraction and protection. All in all, the developed lutein MEs with high lutein extraction capacity and superior lutein chemical stability against thermal treatment and especially UV radiation is an original finding which allows design of new functional foods and could be potentially useful for enriching foods, pharmaceuticals, nutraceuticals, and supplement formulation.

Effect of cold plasma on essential oil content and composition of lemon verbena.

Cold plasma is known as a novel nonthermal processing method for decontamination of medicinal and aromatic plants (MAPs); however, there are little research studies about its effects on active ingredients of these plants. The aim of this research was to investigate the influence of low-pressure cold plasma (LPCP) treatments (1, 3, and 5 min) on the essential oil (EO) content and composition of lemon verbena leaves. The EO content was determined using hydro-distillation, and the composition of the extracted EOs was quantified using gas chromatography and gas chromatography-mass spectrometry techniques. The results showed that by increasing the LPCP treatment duration, the EO content was reduced from 1.2 to 0.9 (% v/w). The highest content of monoterpene hydrocarbons (e.g., limonene) and oxygenated sesquiterpenes (e.g., spathulenol and globulol) was also observed in LPCP-treated ones, whereas the oxygenated monoterpenes (e.g., citral) content of control was measurably higher than those treated with LCPC.

Formation of concentrated triglyceride nanoemulsions and nanogels: natural emulsifiers and high power ultrasound.

The fabrication of concentrated nanoemulsions provides potential advantages such as loading capacity enhancement, storage and transportation costs reduction, and creation of novel textures. The current study investigated the capability of high power ultrasound on nanoemulsification of high concentration triglyceride using various natural emulsifiers (saponin, whey protein isolate, lecithin and sucrose monopalmitate). The impact of the emulsifier concentration (up to 6 wt%), oil content (up to 60 wt%) and exposure to sonication (up to 33 min) on the droplet size distribution, physical stability and rheological properties were evaluated. Regarding the dilute nanoemulsion (10 wt% oil), droplet size was inversely correlated with the concentration of emulsifiers, however only by using saponin (2 wt%) the droplet size was in nano range (d < 200 nm). The concentrated nanoemulsions (20-50 wt%) were also fabricated under sonication (15 min at saponin-to-oil ratio 2 : 10 w/w%). They also presented shear-thinning behavior with relatively low consistency coefficients. Surprisingly, the one with 60 wt% oil was easily converted to viscoelastic gel upon 3 min sonication. Owing to such characteristics, they could have potential applicability in formulation of soft foods, creams, sauces, salad dressings, pastes, lotions, cosmetics and pharmaceuticals.

Extraction of lycopene using a lecithin-based olive oil microemulsion.

Incorporation of many water-insoluble nutraceuticals into aqueous formulations can present a real challenge for food industry. Hence, establishment of novel technologies for concurrent extraction and solubilisation of lipophilic compounds might be of a great interest. The main objective of the present study was to prepare olive oil microemulsions using different proportions of lecithin, 1-propanol, olive oil and water to examine their abilities to form microemulsion as well as extraction of lycopene from industrial tomato pomace. Lycopene extraction using 1 g tomato pomace and 4 extraction cycles applying 5 g microemulsion composed of lecithin: 1-propanol: olive oil: water (53.33:26.67:10:10 wt%) resulted in the highest extraction efficiency (88%). Such biocompatible and food-grade microemulsion containing lycopene can be applied in many food formulations where it can present a good solubility in aqueous and non-polar media and can improve the health-promoting properties of both lycopene and olive oil.

Ultrasonic-Assisted Fabrication of Concentrated Triglyceride Nanoemulsions and Nanogels.

In many food products such as gels, pastes, jellies, creams, sausages, and selected dressings or spreads, it is desirable to formulate concentrated triglyceride nanoemulsions so as to deliver lipophilic functional agents. In this study, the ability of ultrasonication to form nanoemulsions and nanogels containing high concentration of sunflower oil was investigated in the presence of sodium dodecyl sulfate (SDS) as a surfactant. The influence of SDS and oil concentration and duration of sonication on the physical stability, mean droplet diameter, and rheological properties of emulsions were determined. Ultrasonication for up to 9 min was highly effective on fabrication of stable nanoemulsions (an average droplet size of 158-171 nm) at low oil/surfactant ratio (10:0.7). The viscosity and storage modulus increased with decreasing the droplet size particularly at higher oil concentrations. The viscous nanoemulsions (containing 60, 50, and 40 wt % oil) transformed into viscoelastic gels when sonicated for 3, 9, and 30 min, respectively. On the basis of the findings of the present study, such textural and rheological modifications, resulted from droplet size decreasing, could be potentially useful in designing reduced fat gel-like products.

Stability assessment of lycopene microemulsion prepared using tomato industrial waste against various processing conditions.

BACKGROUND: Green separation techniques are growing at a greater rate than solvent extraction as a result of the constant consumer drive to 'go natural'. Considering the increasing evidence of the health benefits of lycopene and massive tomato industrial waste, in the present study, lycopene was extracted from tomato industrial waste using microemulsion technique and its mean droplet size and size distribution was determined. Moreover, the effects of pasteurization, sterilization, freeze-thaw cycles and ultraviolet (UV) irradiation on the thermodynamic stability, turbidity and lycopene concentration of the lycopene microemulsion were monitored. RESULTS: Freeze-thaw cycles, pasteurization and short exposure to UV irradiation showed no or negligible influence on lycopene content and turbidity of the microemulsion. However, long exposure to UV (260 min) reduced the lycopene content and turbidity by 34% and 10%, respectively. HHST (higher-heat shorter-time) and sterilization also reduced lycopene content (25%) and increased turbidity (32%). CONCLUSION: The lycopene microemulsion showed satisfactory stability over a process where its monodispersity and nanosize could be of potential advantage to the food and related industries. Regarding the carcinogenicity of synthetic colourants, potential applications of the lycopene microemulsion include in soft drinks and minced meat, which would result in a better colour and well-documented health-promoting qualities. © 2017 Society of Chemical Industry.

Solubilisation of Persian gum: Chemical modification using acrylamide.

Persian gum (PG), mountain almond tree (Amygdalus scoparia) exudate, is a transparent and natural edible gum which consists of soluble (SFPG, 25-30wt%) and insoluble (IFPG, 70-75wt%) fractions. Therefore, in the present study, using response surface methodology (RSM), the influence of concentration (0.64-7.36wt%), acrylamide (0.070-0.120mol), temperature (19.77-70.23°C), and time (0.32-3.68h) on solubilizing and some other properties of IFPG were investigated. Based on our findings, the highest solubility (64wt%) was achieved at the presence of 6wt% IFPG, and 0.08mol acrylamide at 60°C after 3h. Intrinsic viscosity and molecular weight determination also confirmed modification reaction which led to reduction in molecular weight. In addition, the effect of pH and electrolytes on rheological properties showed that the soluble part of IFPG which modified at optimum conditions had an anionic structure similar to conventional SFPG.

Food grade microemulsion systems: canola oil/lecithin:n-propanol/water.

In this study, the capability of a natural surfactant, lecithin, and the influence of ionic strength, pH, and temperature on some properties of a food grade microemulsion system were evaluated. For this purpose, the pseudoternary phase diagrams of canola oil/lecithin:n-propanol/water microemulsions in the presence of different salts (NaCl and CaCl2), ionic strengths, pHs, and temperatures were constructed. Our findings showed that the presence of salts slightly increased the W/O areas on the phase diagrams, whereas pH variation was not effective on the microemulsion formation. The expansion of microemulsion areas with temperature indicated the greater triglycerides solubilization capacity of lecithin based microemulsions at higher temperatures. These findings revealed the efficiency of lecithin-based microemulsion system for solubilization of triglycerides which can potentially be used for extraction of edible vegetable oils particularly canola oil.

Microemulsion-based lycopene extraction: Effect of surfactants, co-surfactants and pretreatments.

Lycopene is a potent antioxidant that has received extensive attention recently. Due to the challenges encountered with current methods of lycopene extraction using hazardous solvents, industry calls for a greener, safer and more efficient process. The main purpose of present study was application of microemulsion technique to extract lycopene from tomato pomace. In this respect, the effect of eight different surfactants, four different co-surfactants, and ultrasound and enzyme pretreatments on lycopene extraction efficiency was examined. Experimental results revealed that application of combined ultrasound and enzyme pretreatments, saponin as a natural surfactant, and glycerol as a co-surfactant, in the bicontinuous region of microemulsion was the optimal experimental conditions resulting in a microemulsion containing 409.68±0.68 µg/glycopene. The high lycopene concentration achieved, indicates that microemulsion technique, using a low-cost natural surfactant could be promising for a simple and safe separation of lycopene from tomato pomace and possibly from tomato industrial wastes.

Optimization of ultrasonic emulsification conditions for the production of orange peel essential oil nanoemulsions.

The aim of the present study was to investigate the influence of emulsifying conditions on some physical and rheological properties of orange peel essential oil (OPEO) in water nanoemulsions. In this regard, using the response surface methodology, the influence of ultrasonication conditions including sonication amplitude (70-100 %), sonication time (90-150 s) and process temperature (5-45 °C) on the mean droplets diameter (Z-average value), polydispersity index (PDI), and viscosity of the OPEO nanoemulsions was evaluated. In addition, the flow behavior and stability of selected nanoemulsions was evaluated during storage (up to 3 months) at different temperatures (5, 25 and 45 °C). Based on the results of the optimization, the optimum conditions for producing OPEO nanoemulsions (Z-average value 18.16 nm) were determined as 94 % (sonication amplitude), 138 s (sonication time) and 37 °C (process temperature). Moreover, analysis of variance (ANOVA) showed high coefficients of determination values (R (2) > 0.95) for the response surface models of the energy input and Z-average. In addition, the flow behavior of produced nanoemulsions was Newtonian, and the effect of time and storage temperature as well as their interactions on the Z-average value was highly significant (P < 0.0001).

Stabilization of biopolymer microgels formed by electrostatic complexation: Influence of enzyme (laccase) cross-linking on pH, thermal, and mechanical stability.

Biopolymer microgels formed by electrostatic complexation are often susceptible to disintegration when environmental conditions are changed, and so methods are required to improve their stability. In this study, microgels were formed by electrostatic complexation of a protein (type-B gelatin) and a polysaccharide (beet pectin). The impact of enzyme (laccase) crosslinking of the ferulic acid groups on the beet pectin was then studied as a method to improve microgel stability to environmental stresses. Gelatin-beet pectin (1:0.25w/w) microgels were formed at 35°C and pH4.4, and then the pH dependence of the ζ-potential, size, turbidity, and microstructure of the microgels was measured in the absence and presence of laccase cross-linking. Our results suggested that crosslinking occurred within the microgels (rather than between them) since no particle aggregation was observed after enzyme treatment. Enzyme crosslinking did not affect the ζ-potential of the microgels, but it did decrease their size. Both cross-linked and non-cross-linked microgels were stable to aggregation at low (2-3) and high (4.4-7) pH values, but not at intermediate values (3-4.4), which was attributed to their low surface charge. Cross-linking improved the resistance of the microgels to shearing-induced disruption (300rpm for 24h) and to thermal-induced disruption (50°C for 2min). These cross-linked biopolymer microgels may have applications for texture modification, encapsulation, or controlled release.

Histopathologic and sonographic analysis of laparoscopic removal ovarian nonendometriotic cyst: the evaluating effects on ovarian reserve.

Currently, laparoscopic cystectomy is the first-line therapy for ovarian benign cysts that are resistant to current therapies. There are different studies that point to ovarian reserve damage due to laparoscopic cystectomy. In this study, we evaluate the ovarian damage following laparoscopic cystectomy for non-endometriosis cysts using ultrasound and pathology findings. This is a prospective cohort study conducted between 7 rd month of 2011 and 10th month of 2012 in Women hospital affiliated to Tehran university of medical sciences.45 non-endometriosis cysts (17 teratoma,7 mucinous, 10 simple serous and 11 simple cysts) underwent laparoscopic cystectomy with stripping technique. Amount of excised parenchyma, number of lost oocytes and cyst wall fibrosis thickness were histopathologically studied. Before and 3 months after surgery antral follicle count was evaluated by ultrasound. AFC after cystectomy for teratoma and simple serous was significantly reduced P<0.05. By larger teratomas and more parenchyma inadvertently removed during their excision (1.64, 0.255) reduced AFC was seen and in simple serous cysts with more removed parenchyma amount (1.5) reduced AFC occurred. In our study simple cysts excision led to a loss in AFC that was not associated with any other cyst parameters. Mucinous cysts resection led to no specific ovarian reserve damage. Laparoscopic cystectomy for non-endometriosis leads to reduced ovarian reserve.

The effects of sonication and gamma irradiation on the inactivation of Escherichia coli and Saccharomyces cerevisiae in pomegranate juice.

BACKGROUND AND OBJECTIVES: Pomegranate fruit is a rich source of bioactive compounds. The serious concern over unprocessed fruit juices is microbial contamination, which effectively inactivated by thermal processing, but it significantly affects juice functional compounds. Therefore, the effect of gamma irradiation and ultrasonic on inoculated microbial to pomegranate juices was studied. MATERIALS AND METHODS: Two pomegranate cultivars were purchased from the Agricultural Research Center of Saveh, and their juices were extracted by a manual device and immediately centrifuged. Then the studied microorganisms were re-suspended in sterile pomegranate juices. The juices were continuously sonicated at amplitude levels of 50, 75 and 100% and times of 0, 3, 6, 9, 12 and 15 min at temperature of 25 ± 1 °C. Irradiation treatment was also carried out at various doses of 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3 kGy. RESULTS: The results showed that lower amplitude levels (50 and 75%) did not inactivate E. coli and S. cerevisiae significantly (<1.5 log reduction), while at 100% amplitude level for 15 min, their population reduced by 3.47 and 1.86 log cfu/mL, respectively. Gamma irradiation treatment at 1 kGy also reduced E. coli by 6.66 log cfu/mL, whereas at 3 kGy it reduced S. cerevisiae by 5.08 log cfu/mL. CONCLUSIONS: The low-dose gamma irradiation could potentially inactivate the studied microorganisms compared to the sonication, which had less destructive effects on their populations. Further research is needed to determine the effect of these methods on other fruit juices for industry purposes.

Performance of pregnant women on folic acid intake.

The cause of neural tube defects (NTDs) is multifactorial and in this case folic acid has an important role. Since the neural tube is closed during 21-28 days of pregnancy, most of women are not informed about their pregnancy at this time, and as a result the golden time of folic acid consumption is missed. The aim of this study was evaluating the performance of pregnant women attending to Tehran Women's Hospital in regard to folic acid intake during pre-conceptional period between 2011 and 2012. This cross-sectional study was conducted in 370 pregnant women attending the prenatal clinic of a hospital affiliate to Tehran University of Medical Sciences between 2011 and 2012. Data were collected through interview using a questionnaire. Although 70% of the pregnancies were planned, but 70.5% of pregnant women had not taken folic acid before conception or in necessary time. There was found a significant relationship between level of education, history of abnormalities in children and the number of abortions and taking folic acid before pregnancy (P=0.005, P=0.000 and P=0.000, respectively).

Influence of microwave-microencapsulated citric acid on some sensory properties of chewing gum.

Over the past few decades, microwave processing and its high potential capabilities have attracted food scientists. Application of microwave for microencapsulation is an innovative and new method in which the shell, due to having different dielectric constant, can fuse and cover core. In this research, the citric acid powder at various size ranges was microencapsulated by casein and inulin, using a domestic microwave oven. Then, for sensory evaluation purposes, they along with uncoated citric acid and commercial microcapsules were incorporated in chewing gum formulation. The qualitative and quantitative evaluations revealed the potential capability of this technique at micronized scales. Moreover, findings on some sensory characteristics showed practical and efficient applicability of inulin-coated microcapsules in chewing gum where its sensory scores were competitive and even much better than commercial ones. In addition, these observations elucidate a new approach for producing functional, nutritional and dietetic chewing gums.