Single cell oil production by a novel yeast Trichosporon mycotoxinivorans for complete and ecofriendly valorization of paddy straw

Background: Oleaginous yeasts can be grown on different carbon sources, including lignocellulosic hydrolysate containing a mixture of glucose and xylose. However, not all yeast strains can utilize both the sugars for lipogenesis. Therefore, in this study, efforts were made to isolate dual sugar-utilizing oleaginous yeasts from different sources. Results: A total of eleven isolates were obtained, which were screened for their ability to utilize various carbohydrates for lipogenesis. One promising yeast isolate Trichosporon mycotoxinivorans S2 was selected based on its capability to use a mixture of glucose and xylose and produce 44.86 ± 4.03% lipids, as well as its tolerance to fermentation inhibitors. In order to identify an inexpensive source of sugars, nondetoxified paddy straw hydrolysate (saccharified with cellulase), supplemented with 0.05% yeast extract, 0.18% peptone, and 0.04% MgSO4 was used for growth of the yeast, resulting in a yield of 5.17 g L−1 lipids with conversion productivity of 0.06 g L−1 h−1 . Optimization of the levels of yeast extract, peptone, and MgSO4 for maximizing lipid production using Box­Behnken design led to an increase in lipid yield by 41.59%. FAME analysis of single cell oil revealed oleic acid (30.84%), palmitic acid (18.28%), and stearic acid (17.64%) as the major fatty acids. Conclusion: The fatty acid profile illustrates the potential of T. mycotoxinivorans S2 to produce single cell oil as a feedstock for biodiesel. Therefore, the present study also indicated the potential of selected yeast to develop a zero-waste process for the complete valorization of paddy straw hydrolysate without detoxification

Characterization of residual oils for biodiesel production

Background: Residual oils were characterized according to their physicochemical properties, i.e. acidity, iodine value, peroxide value and saponification number, to evaluate the degradation level and viability for biodiesel production. Results: The methyl esters of fatty acids (FAME) from samples of residual bovine, chicken and soybean oils were quantified by using four transesterification methods, using acidic and basic catalysis and, gas chromatography with flame ionization detector (GC-FID). Methods that used acidic catalysis at a lower temperature were the most efficient. Methyl biodiesel samples were synthesized by basic catalysis (KOH) for all quantified oils and the physicochemical properties of the biofuel were evaluated, i.e. viscosity, flash and fire points, density, water content, iodine and acidity numbers. Conclusions: The obtained results suggesting that it is possible to take advantage of these residues for biodiesel production as the obtained products were approved according to the rules established by the National Association of Petroleum (ANP); the bovine samples were the exception regarding moisture and acidity.

Changes in food caused by deep fat frying - A review

Deep-fat frying is widely used in food industries because of its low cost and high demand, since it produces convenient food of high acceptability. The process is based on the oil-food interaction at high temperatures, which cooks and dehydrates the food, leading to physical and chemical changes, such as starch gelatinization, protein denaturation, flavoring and color production via Maillard reaction. Some food and oil compounds are lost in the frying process, and potentially toxic compounds are developed in the oxidized oil. Although widely studied, many of these compounds have not been fully identified. The purpose of this study was to review literature findings on changes in food caused by the frying process.

Alterações nos alimentos causados pelo processo de fritura- Revisão. O processo de fritura é amplamente utilizado em indústria de alimentos devido ao baixo custo e alta demanda pela praticidade e grande aceitação. O processo é baseado na interação óleo-alimento a altas temperaturas, que cozinha o alimento e desidrata, levando a alterações físicas e químicas assim como a gelatinização do amido, desnaturação de proteínas, aroma e produção de cor através da reação de Maillard. Alguns compostos presentes nos alimentos e no óleo são perdidos no processo de fritura, e componentes potencialmente tóxicos são desenvolvidos nos óleos oxidados. Embora diversos tenha havido avanços na identificação desses componentes, muitos ainda não foram identificados. A proposta desse trabalho foi avaliar as alterações nos alimentos causadas pelo processo de fritura.

Numerical simulation of oil spill behavior in the Persian gulf

The aim of this research is to simulate oil spill behavior in the Persian Gulf due to the wind and tidal currents. This is achieved by coding an oil spill mathematical model consisting of several major submodels including hydrodynamic model, oil slick dynamic model and oil weathering model. The base of all of them is Eulerian approach and they are coupled together to simulate spill incident in the Persian Gulf. The hydrodynamic model provided to simulate the tidal current is based on two dimensional depth averaged equations of shallow water discretized by finite volume method that is applied on rectangular structured mesh. The tidal current in the Gulf is made by imposing tidal fluctuation to the main open boundary at the Hormuz Strait. This model verification is carried out by comparison the resultant predictions of model with the available measured data and it shows a good agreement. Oil slick transport on the sea surface is simulated by an advection-diffusion model. Also, the most effective natural processes on oil fate and their effect on oil properties are estimated by an oil weathering model. Then, a test case including analytical solution is chosen to ensure the model capability on oil spill simulation. Finally, the model is implemented for a spillage event in the Persian Gulf. By explanation of the presented results, oil fate, the slick transport and other predicted data are demonstrated. The results show the model capability on modelling of an oil spill incident in marine environment

Microemulsão: um promissor carreador para moléculas insolúveis / Microemulsion: a promising carrier system for insoluble compounds

Microemulsão (ME) é um sistema que foi descoberto por Hoar e Schulman no ano de 1943 e que é termodinamicamente estável e isotropicamente translúcido de dois líquidos imiscíveis (óleo/água), estabilizados por um filme interfacial de tensoativos. O estudo de sistemas microemulsionados se baseia nas suas três teorias de formação: (1) teoria da solubilização, (2) teoria da tensão interfacial e (3) teoria termodinâmica. A estrutura formada é influenciada pelas propriedades físico-químicas dos componentes utilizados e da razão entre os componentes. O objetivo desta revisão foi avaliar o estado da arte de sistemas microemulsionados enfatizando uma abordagem teórica. Além disso, os recentes avanços sobre a aplicabilidade clínca e utilização como carreador de moléculas insolúveis foram discutidas.

Microemulsions (ME) are thermodynamically stable and isotropic systems of two immiscible liquids (oil/water), stabilized by an interfacial film of surfactants, discovered by Hoar and Schulman in 1943. The study of ME formation is based on three areas of theory: (1) solubilization, (2) interfacial tension and (3) thermodynamics. ME structures are influenced by the physicochemical properties and proportions of their ingredients. The goal of this review is to assess the state of the art of microemulsified systems, from a theoretical viewpoint. Also, recent progress on their clinical application and use as carriers for insoluble compounds is discussed.

Bonding agent underneath sealant: shear bond strength to oil-contaminated

This study evaluated in vitro the shear bond strength of a resin-based pit-and-fissure sealant (Fluroshield - F) associated with either an ethanol-based (Adper Single Bond 2 - SB) or an acetone-based (Prime & Bond - PB) adhesive system under conditions of oil contamination. Mesial and distal enamel surfaces from 30 sound third molars were randomly assigned to 2 groups (n=30): I - no oil contamination; II - oil contamination. Contamination (0.25 mL during 10 s) was performed after 37 percent phosphoric acid etching with an air/oil spray. The specimens were randomly assigned to subgroups, according to the bonding protocol adopted: subgroup A - F was applied to enamel without an intermediate bonding agent layer; In subgroups B and C, SB and PB, respectively, were applied, light-cured, and then F was applied and light-cured. Shear bond strength was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. Means (± SD) in MPa were: IA-11.28 (±1.84); IIA-12.02 (±1.15); IB-9.73 (±2.38); IIB-9.62 (±2.29); IC-28.30 (±1.63); and IIC-25.50 (±1.91). It may be concluded that the oil contamination affected negatively the sealant bonding to enamel and the acetone-based adhesive system (PB) layer applied underneath the sealant was able to prevent its deleterious effects to adhesion.

Este estudo avaliou in vitro a resistência ao cisalhamento (RC) de um selante resinoso [Fluroshield (F); Dentsply/Caulk] em associação com um sistema adesivo com solvente a base de etanol [Adper Single Bond 2 (SB); 3M/ESPE] ou a base de acetona [Prime & Bond (PB); 3M/ESPE] após contaminação com óleo do esmalte. Superfícies mesiais e distais de esmalte de 30 terceiros molares hígidos foram aleatoriamente alocadas em 2 grupos (n=30): I - contaminação com óleo; II - sem contaminação. A contaminação foi realizada (0,25 mL;10 s) com um jato de ar/óleo após o condicionamento do esmalte com ácido fosfórico a 37 por cento. Os espécimes foram aleatoriamente alocados em subgrupos, de acordo com a técnica adesiva empregada: A - F foi aplicado sobre o esmalte condicionado sem sistema adesivo; B - SB + F; C - PB + F. RC foi testada em uma máquina universal de ensaios (0,5 mm/min; 50 kgf) e os dados analisados por ANOVA e t-teste (α=0,01). As médias de RC em MPa foram: IA-11,28 (±1,84); IIA-12,02(±1,15); IB-9,73 (±2,38); IIB-9,62 (±2,29); IC-28,30 (±1.63); e IIC-25,50 (±1,91). Conclui-se que a contaminação com o óleo afetou a adesão do selante resinoso ao esmalte e o sistema adesivo com solvente a base de acetona (Prime & Bond) aplicado sob o selante foi capaz de impedir os efeitos deletérios da contaminação com óleo.

Effect of oil types and concentration on ultrasonic measurements of alkyl polyglucosides liquid crystal phases

Phase diagrams for the ternary systems of Glucopone, Water and several hydrocarbons are reported. Four different types of hydrocarbon are used namely; heptane, octane, dodecane and tetradecane. Small angle X-ray scattering [SAXS] and polarizing microscope are used for phase identification and structure characterization. The ternary systems are shown to form different liquid crystalline phases with the Increase of concentration in the following order - cubic, hexagonal, and lamellar. An optical isotropic gel phase with strong elastic properties is found in these systems and Identified as cubic phase. The cubic phase is optically isotropic, transparent and highly viscous phase with three-dimensional structure. The cubic samples showed several diffraction peaks and can be assigned to the la3d space group. The rheological study on the cubic phase is performed. All cubic samples behave as solid-like material with storage modulus G 0.7x10[6] Pa typical of cubic lyotropic materials. The effect of oil concentration in the ultrasonic measurements for the three different liquid crystalline phases is studied. The effect of different types of oil on the ultrasonic measurements is also investigated. The ultrasonic measurements showed that the ultrasonic velocity of the cubic samples Increased as the oil concentrations increased. The ultrasonic measurements showed that the ultrasonic velocities of the lamellar phases decreased with increase in the chain lengths of the hydrocarbon, while the ultrasonic velocities were almost similar for hexagonal phases

Evaluation of specific biological heat potential of oily wastewater in an autothermal thermophilic aerobic treatment system.

This study focuses on the specific biological heat potential (h(b)) of oil and grease wastewaterin an autothermal thermophilic aerobic treatment (ATAT) system. A novel experimental device was applied to evaluate h(b) by using heat balance model under steady state. In the study the treatment system was daily fed with realistic and artificial wastewater at 11250 and 17420 mg COD l(-1), respectively. The wastewater was rich in oil and grease at 1220 and 600 mg l(-1), respectively. The sludge retention time (SRT) was controlled at 5 days. The results showed that the average values of h(b) were 3.7 and 3.1 kcal g(-1) COD removed and the true growth yield (Y0) were 0.10 and 0.13 mg MLSS mg(-1) COD for realistic and artificial wastewater respectively. These two systems could maintain reactoroperating temperatures at 43 degrees C and 48 degrees C, respectively. The COD removal efficiency was as high as 90 to 97%. The oil and grease reduction was 68 to 72%. The high organic matter removal capacity and low sludge yield of ATAT process have been demonstrated.

Solubilization characteristics of paraffin oil in different types of surfactants

Solubilization characteristics of paraffin oil in water were studied in presence of three types of surface active agents at 25°C. The solubilization process was discussed based on several factors including chemical structure of the used surfactants, chemical structure of solubilizate [carbon distribution of the used paraffin oil], and surface activities of the tested surfactants including critical micelle concentration [cmc] and aggregation number [n]. The solubilization time relationship showed that the chemical structure of surfactant molecules was the most effective factor influencing the solubilization process. In addition, the steps of solubilization process were discussed using the paraffin-surfactants solubilization extent profile

Efecto de alcoholes lipofílicos en el reparto de surfactantes nonilfenol polietoxilados en sistemas aceite/microemulsión/agua / Effect of lipophilic alcohols in the partitioning of nonylphenol polyethoxylated surfactants in oil/microemulsion/water systems

El comportamiento de fases en un sistema surfactante-agua-aceite se afecta por las llamadas variables de formulación, por ejemplo, por la naturaleza de los componentes o su ambiente fisicoquímico. Una de estas variables es la presencia del tipo y concentración de alcohol en el sistema. Para estudiar este efecto se realizaron barridos de formulación variando el número de óxido de etileno (EON) del sistema, por medio de la mezcla de un surfactante lipofílico con otro hidrofílico con el fin de hallar el sistema de máxima solubilidad (Winsor III óptimo) e incorporar en este sistema los alcoholes a diferentes concentraciones para observar el cambio de transición. El reparto se determinó por cromatografía líquida de alta resolución (HPLC). La adición de alcoholes lineales lipofílicos a estos sistemas proporciona mayor polaridad a la fase oleica y por ende mayor fraccionamiento hacia la misma. Se encontró que si la cadena alquílica del co-surfactante está por encima de un número de átomos de carbono promedio del alcohol (ACAN, acrónimo del inglés “alcohol carbon atom number”) igual a 4,5 el 50 por ciento del fraccionamiento no se ve afectado por el incremento de la concentración ni por el tipo de alcohol lipofílico.

Phase behavior in surfactant-water-oil systems is affected by the so-called formulation variables, for example, thenature of the components or their physiochemical environment. One of these variables is the presence of the type and concentration of the alcohol in the systems. The formulation scan varying the ethylene oxide number (EON) of the system were carried out, by means of the mixture of a lypophilic surfactant with another hydrophylic with the purpose of finding the maximum solubility system (Winsor III optimum) and to incorporate in this system the different alcohols with different concentrations to observe the transition change. The partititon coefficient was determined by high performance liquid cromatografic (HPLC). The addition of lineal lipophilics alcohols to these systems provides more polarity to the oil phase in consequence more fractionation towards it same one. It was found that if the alkyl chain of the co-surfactant is above an ACAN (alcohol atom carbon number) equal to 4,5 the 50 percent of fractionation is not affected by the increment of the concentration neither for the type of alcohol.

Etude comparee des acides gras des huiles d'olives Tunisiennes

The acidic composition of extracted 1995-1996 olive oils have been studied according to the main varietes existing in Tunisia. Our results show that different oils have the same acidic composition. However, oils extracted from northern varietes are more rich in oleic acids [mean 66,72% VS, 52,43% in the south], but less rich in palmitic acid [11,93% VS 19,85% in the south]. The ratio saturated fatty acids/insaturated fatty acids increases from north to south [0,175 VS 0,291] leading to blood oils in the latter region

Composition triglycerique des huiles d'olives Tunisienne.

Triglycerides composition of Tunisien olive oils from 1995-1996 [oleicol campaign] was studied according their main varietes Our results show that triglycerides of the studied olive oil had portion numbers [equivalent carbon numbers = ECN] ranging from 42 to 50. In addition, triglyceride composition was closely clinked to the acidic composition, trilinolein [LLL] was higher than the european norm [less than 0.5%]. The difference between theoritical and practical ECN42 did not exceed 0.3%. These results are in agreement with the C.O.l. norms

Investigation of the fixed oil isolated from the roots of echinops kebericho mesfin

The investigation of the fixed oil of the roots of Echinops kebericho Mesfin [Family Compositae] was carried out for the first time. This study revealed the presence of the following fatty acids: Lauric myristic, myristoleic, palmitic, palmitoleic, stearic, oleic, linoleic, linolinic, arachidic and behenic acids in the saponifiable fraction. The unsaponifiable fraction was found to contain beta-sitosterol, stigmasterol, campesterol, beta-amyrin, lupeol and ursolic acid. The identification of ursolic acid was carried out by spectroscopic methods [H-NMR, 13C-NMR and MS]. The chemotaxonomic value of this study has been discussed

Modified release matrix prepared by compaction of spheres containing waxy material

In this study, chlorpheniramine maleate spheres were prepared by the extruder/marumerizer. A new waxy material, Gelucire 50/02 at three levels (10 per cent , 30 per cent and 50 per cent ) was added and Avicel PH-101 was used as spheronizing material. The drug was incorporated into the waxy material by two methods. The first was the direct method, in which the drug (10 per cent ), wax and Avicel PH-101 were mixed together. The second was the fusion method, in which the drug was dispersed in the melted wax and the solidified mass was milled and mixed with Avicel PH-101. The data obtained indicated that simple addition of waxy material into chlorpheniramine maleate-Avicel PH-101 spheres interrupted matrix formation and increased drug release. Also in this study, a multiparticulate delivery system was prepared successfully by compaction of spheres into tablets. Tablets compacted from spheres prepared by fusion method gave less drug release than those compacted from spheres of the same composition but prepared with direct method. As the level of wax was increased in tablet formulation, drug release was decreased