Search

This study deals with lipase immobilization on micro- and mesoporous silica-based materials. The effects of the type of support (silica MCM-41, zeolite HZSM-5 (SAR 25), zeolite HZSM-5 (SAR 280), and the silica-aluminas Siral 10, Siral 20, and Siral 40) were investigated on the immobilization of lipase B from Candida antarctica (CALB) and lipase from Rhizomucor miehei (RML). The supports that allowed the highest immobilization efficiencies for the CALB were Siral 40 (91.4%), HZSM-5 (SAR 280) (90.6%), and MCM-41 (89.4%). Siral 20 allowed the highest immobilization efficiency for RML (97.6%), followed by HZSM-5 (SAR 25) (77.1%) and HZSM-5 (SAR 280) (62.7%). The effect of protein concentration on lipase immobilization was investigated, and the results adjusted well on the Langmuir isotherm model (R2 > 0.9). The maximum protein adsorption capacity of the support determined by the Langmuir model was equal to 10.64 and 20.97 mgprotein gsupport−1 for CALB and RML, respectively. The effects of pH (pH 7.0 and pH 11.0) and phosphate buffer solution concentration (5 and 100 mmol L−1) were also investigated on lipase immobilization. The immobilization efficiency for both lipases was similar for the different pH values. The use of 100 mmol L−1 phosphate buffer decreased the lipase immobilization efficiency. The biocatalysts (CALB-Siral 40 and RML-Siral 20) were tested in the ethyl oleate synthesis. The conversion of 61.7% was obtained at 60 °C in the reaction catalyzed by CALB-Siral 40. Both heterogeneous biocatalysts showed increased thermal stability compared with their free form. Finally, the reuse of the biocatalysts was studied. CALB-Siral 40 and RML-Siral 20 maintained about 30% of the initial conversion after 3 batches of ethyl oleate synthesis. Silica-aluminas (Siral 20 and 40) proved to be a support that allowed a high efficiency of immobilization of lipases and activity for esterification reaction. [ABSTRACT FROM AUTHOR]

Introduction Sweet Pepper (Capsicum annum) has a very important place among the vegetables produced in the world. Therefore, it is necessary to apply practical solutions to increase their sustainability to develop and improve production. The growing consumer rejection of chemical additives and the demand for more natural products have increased attention to some methods, including the drying method. One of the physical changes that occur during the drying of food is its reduction in volume. Vacuum drying is a method in which water and other solvents that have been absorbed into the volume or surface of the material are removed. Combining vacuum with heating can be an effective way to dry; because in this case, a high level of dryness can be achieved without the need for a large increase in temperature. A thermal process that is applied to vegetables and fruits as a pre-process step for freezing, drying and canning to inactivating enzymes, modifying texture, preserving flavor and nutrients, and extracting Interstitial air. Materials and Methods This study aimed to investigate the impact of various factors ethyloleate (concentrations 0,2,4%), sodium chloride(concentrations 0,2,4%) and blanching on the drying kinetics, physical properties, chemical composition and nutrients of green bell pepper, dried under vacuum at 60°C and pressure of 10 kpa using the response surface methodology. At the end of the drying time, 10 g of the treated samples were weighted to investigate the drying kinetics and the rest of the samples were kept for analysis. To achieve the drying kinetics, the samples were taken out of the oven (Behdad Company, model 3494, made in Iran) at 30 minute intervals and weighed by a digital scale, and dried down to moisture content of 12% ., and then for relevant analyzes on dried samples, the samples were stored in plastic packages until the day of experiments. Investigation of independent and interaction effects of immersion in different concentrations of sodium chloride and ethyloleate solution on the kinetics and drying time separately in blanching and non-blanching samples on the parameters of color, chlorophyll content, phenolic substances and vitamin C remaining in dried Sweet peppers were evaluated using minitab16 software and response level method (RSM). Results and Discussion The results showed that the drying process occur in the range of falling rate and also effect blanching in boiling water for 3 minutes and immersed in an alkaline solution of ethyloleate and sodium chloride with concentrations of 2 and 4% for 1 minute, significantly increase the drying rate. In blanching and treated samples with 4% ethyloleate and sodium chloride, the drying time was about 3.5 hours, while the control sample was dried under the same conditions for 7.5 hours. Pretreatment of samples, showed the chlorophyll content, phenolic compounds and vitamin C were higher than the control sample. Due to the effectiveness of ethyloleate in the protection of ascorbic acid, phenolic compounds and residual chlorophyll, the highest amount of ascorbic acid with a value of 39.77 was related to the samples treated in ethyloleate solution with a concentration of 4% and 4% NaCl and the minimum value of 17.98 was related to the control treatment. The highest amount of residual chlorophyll was 23.6 in the pretreated samples with a concentration of 4% ethyloleate and 4% NaCl and the lowest amount was related to the control sample with a concentration of 12.9%. The color of the dried samples showed that the lowest amount of color changes was related to the non-blanching sample with 4% ethyloleate and 4% NaCl with a value of 4.94. While the blanching and ethyloleate solution had no positive effect on the color of pepper and dried samples were dark. Comparison of blanching with non-blanching shows that blanching samples cause darkening of the primary color of the samples.The best sample in terms of quality and speed of drying, was belonged to the samples which blanched, treated with 4% solution of ethyloleate and sodium chloride. Conclusion In order to achieve the best quality in vacuum drying of pepper samples, pretreatments of blanching and using a concentration of 4% solution of ethyloleate and sodium chloride showed the most desirable quality. The best quality of dried samples were obtained when subjected to constant temperature and pressure during drying conditions. The benefits obtained using the pretreatment of ethyloleate and sodium chloride as an appropriate method of drying include increasing the absorption of water, keeping the chlorophyll, phenolic compounds and vitamin C content with time-saving in drying.

In this study, the performance and exhaust emissions of a direct injection (DI) diesel engine are compared using blended fuels consisting of cottonseed oil (CSO) and ethyl oleate (EO) at various diesel proportions. The uniqueness of this work lies in the fact that it utilizes engine emission and performance studies with blended fuel made from CSO and EO at a higher volume (%) composition than is typically used. Biodiesel reduces brake‐specific fuel consumption (BSFC) compared to CSO, even though it is higher than diesel due to viscosity and heating value. The brake thermal efficiency (BTE) was enhanced until 800 rpm and afterward reduced as the engine's speed continued to increase. Among all the blends, BTE was recorded as highest for CE20D and minimum for CSO. Because EO was unsaturated, culminating in a reasonably short ignition delay, NOx emissions in fused biofuel were marginally more significant than in diesel. The concentrations of UHC and CO reduced as the concentrations of CSO and EO increased, caused by a rise in the oxygen concentration by mass portion. The results of the combustion and emission tests suggest that CE20D has the potential to be a sustainable alternative fuel. [ABSTRACT FROM AUTHOR]

Long-term sustainability and decreasing amount of fossil oil reserves require a partial or complete transformation of traditional lubricating oils. The use of silica nanoparticles as a lubricant additive has a huge tribological potential, which has already been discussed in numerous articles. Nanosized silica shows excellent results in reducing friction and preventing wear, but they quickly aggregate and settle after homogenization in oils. For long-term stable dispersion of lubricating oils containing nanoceramics, the surface of the particles was modified with ethyl oleate. The surface modification, the ethyl oleate applied to the surface of the nanosilica, was confirmed by Fourier-transform infrared spectroscopy. Group III based lubricating oil was prepared using the surface-modified nanosilica. The particle size of the nanoparticles in the lubricating oil dispersion was examined by dynamic light scattering. Oscillating tribometer measurements were performed with different concentrations (0.1; 0.2; 0.3 wt%) of nanolubricants. Based on the tribological results, the friction coefficient of the surface-modified nanosilica is more stable, its wear is 15% lower compared to the reference. There is no significant change in the magnitude of the friction coefficient. It can be concluded that the ethyl oleate surface modification method may be suitable for tribological investigations of the acting mechanisms of nanoparticles. [ABSTRACT FROM AUTHOR]

The production of ethyl oleate was explored using novel metal-free Brønsted acid-functionalized porphyrin, grafted with benzimidazolium-based ionic liquid (BAPBIL) as a recyclable photocatalyst. The synthesized photocatalyst was characterized by FT-NMR and FT-IR spectroscopy techniques. The esterification reaction was carried out under a homemade photoreactor equipped with a 5 W LED as a visible light source. In this work, BAPBIL displayed as an efficient photocatalyst for esterification of oleic acid and levulinic acid using different alcohols such as methanol, ethanol, propanol, and octanol at ambient conditions. The mechanism of the photocatalyst was studied to confirm the role of the catalyst. Moreover, a scavenger study showed the effect of the scavenger on the rate of esterification of oleic acid. The heterogeneous recyclable photocatalyst (BAPBIL) presented recyclability up to five successive runs without losing its activity. The maximum conversion of the esterification product was achieved at 96% at optimized reaction conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mesoporous polymer ionic liquids for the immobilization of lipase demonstrated mesoporous properties. • Resultant systems were used as recyclable biocatalysts for ester production. • Lipase immobilization led to higher stability than that of the free enzyme. • The process can generate high-purity esters using lipase-immobilized mesoporous polymer ionic liquid. Herein, fatty acid esters were synthesized cost-effectively from various fatty acids using reusable lipase (L) immobilized with novel porous ionic polymer (PIP) (l –PIP). The functionalized mesoporous PIP was synthesized through Friedel–Crafts alkylation reaction of 1, 4-bis(bromomethyl) benzene in the presence of ferric chloride as catalyst, and lipase was completely immobilized with PIP at varied time, forming l –PIP–6 H , l –PIP–12 H , l –PIP–18 H , l –PIP–24 H , l –PIP–30 H , and l –PIP–36 H , which were applied in ester production. l –PIP–30 H was characterized using FT–IR, SEM, XPS, solid–state 13C NMR, and N 2 adsorption–desorption isotherms. The conversion of oleic acid reached 88.21 % under optimized conditions (12:1 ethanol/oleic acid molar ratio after 5 h at 45 °C with 250 wt% catalyst at 300 rpm). The stability and reusability of l –PIP–30 H were demonstrated by the sustained catalytic efficiency for at least six reaction cycles. Good catalytic activity during the esterification of various free fatty acids with ethanol was observed. This cost–efficient and effective lipase–immobilized PIP catalyst may have positive economic and environmental repercussions to inspire further academic and industrial research on biodiesel. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ethyl oleate (EO) and n -hexane (HEX) mixture is monopolar. • EO and ethanol mixture surface tension does not change linearly as a function of its composition. • HEX changes partial molar volume of EO in higher extant than vice versa. • Contact angle of EO + HEX mixture on PTFE can be described by Prigogine −Deffay equation. Due to the wide use of ethyl oleate (EO) in agriculture, medicine and automotive fuels, measurements of the surface tension, density, viscosity and contact angle of a mixture of ethyl oleate with ethanol (ET) and/or n -hexane (HEX) were made. The contact angle was measured on polytetrafluoroethylene (PTFE), poly(methyl methacrylate) (PMMA), glass and steel. The measurement results for the mixtures of EO + ET and EO + HEX were analyzed based on the properties of individual components of the mixtures. When considering the changes in the surface tension and contact angle on PTFE for the EO + ET and EO + HEX mixtures as a function of the mixture composition there were taken into account, not only the values of the total surface tension of the mixture components, but also the components and parameters of this tension. Based on the surface tension components and parameters of EO, ET, HEX, PTFE, PMMA, glass and steel, it was possible to predict changes in the surface tension of tested mixtures and the contact angle as a function of the mixture composition. [ABSTRACT FROM AUTHOR]

[Display omitted] • In many cases no correlation between total surface tension of liquid and contact angle occurs. • In contrary to ethanol (ET) and oleic acid (OA) ethyl oleate (EO) is a monopolar liquid. • Volumes of ET, OA and EO can be described by that of proper size cube. • Contrary to density EO viscosity is considerably different from those of ET and OA. Taking into account extensive practical application of ethyl oleate (EO) some of its physicochemical properties were determined and compared to those of ethanol (ET) and oleic acid (OA). For this purpose the surface tension, density, viscosity and contact angle of EO, ET and OA were measured. The contact angle was measured on the polytetrafluoroethylene (PTFE), poly(methyl methacrylate) (PMMA), steel and glass in the solid–liquid–air system. Based on the results of the surface tension and contact angle of ET, EO and OA on PTFE and PMMA the Lifshitz-van der Waals component as well as electron-acceptor and electron-donor parameters of the acid-base component of surface tension of these liquids were determined. For this determination the van Oss et al. method was applied. This method was carefully analyzed in terms of its usefulness for the systems studied by us. The components and parameters of the ET, EO and OA surface tension were analyzed with regard to their molecular structure. Based on the molecular structure and on the length of bonds and contact angle between them the size of the molecules and their contactable area were determined. [ABSTRACT FROM AUTHOR]

In this study, a bio-based ester was experimentally tested under a reciprocating contact in terms of the tribological performance to assess the potential of bio-based materials as boundary lubrication additives for low Sulphated Ash, Phosphorus, and Sulphur (SAPS) lubricants. A synergy in tribological performance has been observed when the ethyl oleate was used with a low concentration of ZDDP, showing both lower friction and wear loss, compared to only ethyl oleate or Zinc dialkyldithiophosphates (ZDDP) as single additives in base oil. SEM-EDX and ToF-SIMS analyses confirm that the additive combination of ester and low-concentration ZDDP generates a more evenly distributed tribo-film than that for only ZDDP as an additive. Although the tribo-film thickness of the ester/ZDDP lubricant combination, measured with AFM, issmaller than that for only low-concentration ZDDP, the combination shows superior wear protection ability over ZDDP. Mass spectra from ToF-SIMS show that the main component of the film formed by the additive combination is zinc polyphosphate, while the film generated from low-concentration ZDDP consists of short-chain iron phosphate. It is proposed that the ethyl oleate present in the additive combination alleviates severe shear in the contact, which promotes the formation of a uniform tribo-film composed of glassy zinc polyphosphate. The formed tribo-film enhances the adsorption of ester fragments, improving the tribological performance compared to using only ester as an additive. The obtained results demonstrate the potential of bio-based esters to reduce ZDDP usage and move towards greener lubricants. • Ethyl oleate is first investigated as a lubricant additive with ZDDP under reciprocating contacts. • Synergism for the additive combination is confirmed, with low friction and wear. • Ethyl oleate promotes the formation of uniformly distributed ZDDP tribo-film. • Ester molecular fragments deposited on ZDDP film improve tribology performance further. [ABSTRACT FROM AUTHOR]

The objective was to design and develop a drug-in-adhesive-type transdermal patch formulation of metoclopramide HCl, which is used as an effective antiemetic, dopaminergic antagonist agent. In DIA patches, drug is directly embedded in the polymeric adhesive layer and permeates through the skin to provide systemic effect, avoiding gastrointestinal tract complications, including the first-pass metabolism. Six different patch formulations were prepared by a solvent evaporation method using varying metoclopramide HCl concentrations using acrylate polymer DURO-TAK® 387/2510 for adhesive support. In vitro permeation profiles and parameters were obtained by using the skin of hairless albino Wistar rats. The influence of drug content on the rate of permeation was investigated, and patch formulation was optimized based on Q12, flux, and lag time. The effect of permeation enhancers (EO and PG) on the permeation rate of metoclopramide HCl was also studied. The skin irritation study was performed to observe the hypersensitivity against the patch component. Stability studies of the optimized formulation of a transdermal patch for three months at three different temperatures were investigated. The transdermal patch formulation containing 10% w/w metoclopramide HCl was capable of effectively delivering metoclopramide HCl for systemic effect without any skin irritation. It has Q12 of 3.892 ± 0.0043 mg/cm2, flux rate of 0.2501 mg/cm2 h, and the coefficient of permeability of 6.25E−02 cm/h with a lag time of 0.442 h. The stability data revealed that the optimized patch formulation could be stored at 4 °C in the refrigerator with a shelf life of 3.53 months. This newly developed metoclopramide transdermal DIA patch is an effective alternative to oral delivery with desirable antiemetic activity. [ABSTRACT FROM AUTHOR]

Objective: Lipases are often used in immobilized form, but commercial immobilized lipases are costly. An alternative is to produce lipases in solid-state fermentation, dry the solids and then use the "dry fermented solids" (DFS) directly. We produced DFS by growing Burkholderia contaminans on a mixture of sugarcane bagasse and sunflower seed meal and used the DFS to esterify oleic acid with ethanol in subcritical and supercritical CO2 at 40 °C. Results: Compared to a control without CO2 at atmospheric pressure, subcritical CO2 at 30 bar improved esterification activity 1.2-fold. Higher pressures, including supercritical pressures up to 150 bar, reduced activity to less than 80% of the control. At 30 bar, the esterification activity was improved a further 1.8-fold with the addition of 9% water (i.e. 9 g water per 100 g oleic acid) to the reaction medium. Conclusion: A subcritical CO2 atmosphere, with the addition of a small amount of water, improved the esterification activity of DFS containing lipases of Burkholderia contaminans. [ABSTRACT FROM AUTHOR]

Abstract Background Enzymatic ethanolysis of oils (for example, high oleic sunflower oil containing 90% of oleic acid) may yield two different reaction products depending on the regioselectivity of the immobilized lipase biocatalyst. Some lipase biocatalysts exhibit a 1,3-regioselectivity and they produced 2 mols of fatty acid ethyl ester plus 1 mol of sn2-monoacylglycerol (2-MAG) per mol of triglyceride without the release of glycerol. Other lipase biocatalysts are completely non-regioselective releasing 3 mols of fatty acid ethyl ester and 1 mol of glycerol per mol of triglyceride. Lipase from Thermomyces lanuginosus (TLL) adsorbed on hydrophobic supports is a very interesting biocatalyst for the ethanolysis of oil. Modulation of TLL regioselectivity in anhydrous medium was intended via two strategies of TLL immobilization: a. - interfacial adsorption on different hydrophobic supports and b.- interfacial adsorption on a given hydrophobic support under different experimental conditions. Results Immobilization of TLL on supports containing divinylbenezene moieties yielded excellent 1,3-regioselective biocatalysts but immobilization of TLL on supports containing octadecyl groups yielded non-regioselective biocatalysts. On the other hand, TLL immobilized on Purolite C18 at pH 8.5 and 30 °C in the presence of traces of CTAB yielded a biocatalyst with a perfect 1,3-regioselectivity and a very interesting activity: 2.5 μmols of oil ethanolyzed per min per gram of immobilized derivative. This activity is 10-fold higher than the one of commercial Lipozyme TL IM. Immobilization of the same enzyme on the same support, but at pH 7.0 and 25 °C, led to a biocatalyst which can hydrolyze all ester bonds in TG backbone. Conclusions Activity and regioselectivity of TLL in anhydrous media can be easily modulated via Biocatalysis Engineering producing very active immobilized derivatives able to catalyze the ethanolysis of triolein. When the biocatalyst was 1,3-regioselective a 33% of 2-monoolein was obtained and it may be a very interesting surfactant. When biocatalyst catalyzed the ethanolysis of the 3 positions during the reaction process, a 99% of ethyl oleate was obtained and it may be a very interesting drug-solvent and surfactant. The absence of acyl migrations under identical reaction conditions is clearly observed and hence the different activities and regioselectivities seem to be due to the different catalytic properties of different derivatives of TLL.

3-(N,N-dimethyldodecylammonium) propanesulfonic acid hydrogen sulfate ([SB3-12][HSO4]), a Brønsted acidic-surfactant-combined ionic liquid, was successfully prepared from cheap materials and applied to catalyze the esterification synthesis of ethyl oleate using oleic acid and ethanol as precursors. The produced condition of oleic acid ethyl ester was optimized including the amount of catalyst, reaction time, molar ratio and content of water. Under optimal condition (ethanol to oleic acid molar ratio, 3:1; amount of the catalyst, 5 wt% (based on the mass of oleic acid); reaction time, 3 h; reaction temperature, 78°C; and content of water, 0.4 wt%), the conversion of oleic acid was over 97%. Due to the reverse micelles formed by [SB3-12][HSO4], the micro-reactor not only promoted the esterification toward the desired side of the ester, but also avoided the hydrolysis of ester. Moreover, the [SB3-12][HSO4] could be reused by a simple decantation separating process and noticeable loss of catalytic activity was not observed even after being recycled for five cycles. The green system offers several advantages, such as excellent yield, efficient catalytic activity, free-solvent and simple operational procedure.

In human milk fat, the saturated fatty acids, namely palmitic acid, are located at the sn‐2 position of triacylglycerols (TAG) while unsaturated fatty acids (e.g. oleic acid) are esterified at position sn‐1,3. Thus, sn‐1,3‐dioleoyl‐2‐palmitoylglycerol (OPO) is the target TAG to be used as human milk fat substitutes (HMFS) in infant formulas. In this study, the noncommercial recombinant lipase/acyltransferase from Candida parapsilosis (CpLIP2) was immobilized in Accurel MP1000, and used as a biocatalyst for the interesterification of tripalmitin with ethyl oleate in a solvent‐free medium, to obtain structured lipids used as HMFS. Different molar ratios (MR) of ethyl oleate to tripalmitin (2:1–8:1) were used. After 4 h reaction at 60°C, about 30 mol% of oleic acid incorporation was already observed for all tested MR. An apparent equilibrium was reached after 8–24 h, with 32–51 mol% final incorporation, increasing with the MR. The incorporation of oleic acid into TAG was compared with the maximum predicted values when a random or a sn‐1,3‐regioselective biocatalyst was used. The obtained values are consistent with the maximum incorporation expected for a sn‐1,3‐regioselective enzyme. In fact, the amount of oleic acid at position sn‐2 was approximately 15% for all the MR tested, which is explained by the acyl migration phenomenon. CpLIP2 exhibited higher activity than most commercial immobilized lipases (e.g. faster reaction in solvent‐free media, low enzyme load, and low MR needed), and showed a recognized sn‐1,3 regioselective behavior. [ABSTRACT FROM AUTHOR]

Biodiesel is regarded as the most promising renewable biofuel which can satisfy the worldwide energy demand through its robust net energy output with less impact on environment and also an effective alternative or supplement for existing diesel fuel for powering Compression Ignition engines. This present study aims to compare the performance, combustion and emission characteristics of beef tallow biodiesel with its dominant fatty acid esters and their influence on these characteristics. Ethyl stearate, ethyl palmitate and ethyl oleate were identified as dominant fatty acid esters available in a composition of 14.78, 37.36 and 25.17%, respectively. Two set of samples were prepared for testing purpose and were classified as (i) blend samples and (ii) ester samples, with plain diesel as base fuel. The maximum cylinder pressure was found to be in the range between 67 and 71 bar for all the samples and heat release rate was found to be highest for B20 blend. Slight decrease in efficiency along with marginal increase in fuel consumption was a result of long chained fatty acid esters (stearate and oleate esters) whereas increase in CO2 emission and decrease in NOX emission were because of higher oxygen content, cetane number and degree of unsaturation in the ester molecule. [ABSTRACT FROM AUTHOR]

Abstract Apigenin has attracted a great interest in the food industry due to the wide range of its biological activities including antioxidant and anti-inflammatory. The encapsulation of apigenin in oil-in-water (O/W) emulsions could overcome its low solubility and lead to the development of new functional food products. The aim of this study is to formulate food-grade O/W submicron emulsions loaded with apigenin using high-pressure homogenization. Supersaturated solutions of 0.1 wt% apigenin in ethyl oleate were heated at 100 °C for 30, 60, or 120 min and the supernant after centrifugation were used as to-be-dispersed phases. An aqueous solution containing 1 wt% tween 20 was used as the continuous phase. We examined the effect of heating process of the ethyl oleate prior to emulsification and the homogenization-pressure (60–150 MPa) on the physico-chemical characteristics of the O/W emulsions immediately after formulation and during storage. Submicron O/W emulsions were formulated and the lowest average droplet diameter (d av) was 169 ± 2.082 nm with a polydispersity index (PDI) of 0.06 ± 0.002. After 30 days of storage at 4 °C, the O/W emulsion formulated remained physically stable with little change in their d av and PDI values. The preheat treatment of ethyl oleate, affected the initial loaded apigenin concentration but hardly affected the physico-chemical stability of O/W emulsions. However, HPLC analysis demonstrated that the emulsification pressure was a relevant parameter affecting apigenin retention during the storage of O/W emulsions. Apigenin degradation in ethyl oleate O/W emulsions followed zero order kinetics and about 91.5–93.5% of apigenin could be retained in O/W emulsions after 30 days of storage. Graphical abstract Unlabelled Image Highlights • Stable food grade O/W emulsions loaded with apigenin were formulated. • Heating pretreatment of ethyl oleate allowed higher loading of apigenin. • Homogenization pressure at 100 MPa retained better apigenin than higher pressure. • Degradation of apigenin in O/W emulsions followed zero order kinetics. [ABSTRACT FROM AUTHOR]

Blueberry belongs to the genus vaccinium, which is rich in a variety of biologically active components beneficial to the human body. Drying of blueberry is a slow and energy-intensive process because of its waxy skin, which has low permeability to moisture. Therefore, chemical pretreatment of ethyl oleate (AEEO) was adopted to accelerate moisture diffusivity. The results showed that the drying rate of blueberries was increased significantly by AEEO treatment, and the drying time can be shortened by 17.17-40.70%. After AEEO dipping, the effective diffusion coefficient increased from 5.461 × 10−9 to 1.067 × 10−8 m2/s at 60 °C. Six semi-theoretical thin-layer models were used to estimate the curves of air-drying of blueberry, and Wang-Singh model was found to perform better than other models. Besides, the rehydration and retention of nutritional contents were also improved by AEEO dipping. The total phenolics, total flavonoids, total anthocyanin content, and ABTS*+ scavenging activity of blueberry were increased by 37.74%, 21.01%, 47.83%, and 30.75%, respectively. The result of SEM observation and cell-membrane permeability indicated that AEEO could break down the wax layer of blueberry, change the crystal structure of wax layer, and increase cell permeability, which resulted in shorter drying time and higher quality of blueberry. [ABSTRACT FROM AUTHOR]

Highlights • TLL on C18 supports losses 1,3 regioselectivity and 99% of ethyl ester is released. • TLL on macroporous C-18 was 10-fold more active than TLL on mesoporous C-18. • TLL on C18 Purolite is 5-fold more stable than TLL on C18 Sepabeads. • Immobilized TLL is 20-fold more unstable in anhydrous oil than in anhydrous hexane. • PEGylation of immobilized TLL improves 10-fold its stability in anhydrous oil. Abstract Different immobilized biocatalysts of Thermomyces lanuginosus lipase (TLL) exhibited different properties for the ethanolysis of high oleic sunflower oil in solvent-free systems. TLL immobilized by interfacial adsorption on octadecyl (C-18) supports lost its 1,3-regioselectivity and produced more than 99% of ethyl esters. This reaction was influenced by mass-transfer limitations. TLL adsorbed on macroporous C-18 supports (616 Å of pore diameter) was 10-fold more active than TLL adsorbed on mesoporous supports (100–200 Å of pore diameter) in solvent-free systems. Both derivatives exhibited similar activity when working in hexane in the absence of diffusional limitations. In addition, TLL adsorbed on macroporous Purolite C-18 was 5-fold more stable than TLL adsorbed on mesoporous Sepabeads C-18. The stability of the best biocatalyst was 20-fold lower in anhydrous oil than in anhydrous hexane. Mild PEGylation of immobilized TLL greatly increased its stability in anhydrous hexane at 40 °C, fully preserving the activity after 20 days. In anhydrous oil at 40 °C, PEGylated TLL-Purolite C-18 retained 65% of its initial activity after six days compared to 10% of the activity retained by the unmodified biocatalyst. Macroporous and highly hydrophobic supports (e.g., Purolite C-18) seem to be very useful to prepare optimal immobilized biocatalysts for ethanolysis of oils by TLL in solvent-free systems. [ABSTRACT FROM AUTHOR]

• We produced methanesulfonic acid/ Chestnut shell activated carbon functional catalyst. • In the presence of 5 N HCL–MeOH, biomass treated with low temperatures is more porous. • The specific surface area of prepared CNS 300 –SO 3 H catalyst of 1198.12 m2/g−1. • Catalyst was successfully reused nine times without treatment for esterification cycles. By calcination and sulfurating Chestnut shell biomass (CNS), a solid acid catalyst was synthesized. In the preparation of the catalyst, a range of calcination temperatures (150 °C–350 °C) and time 2 h, a range of sulfonation temperatures (80 °C–160 °C), and a range of times (1–6 h) were examined in order to determine the effect on catalytic activity. The CNS 300 –SO 3 H catalyst was characterized by Brunauer-Emmett–Teller (BET), Fourier transforms infrared (FT–IR) spectroscopy, N 2 –adorption and desorption, and thermogravimetric analysis (TGA). A higher acid density (8.626 mmol/g–1) was found with the CNS 300 –SO 3 H catalyst, as well as a higher surface area (1198.12 m2/g–1). As part of the catalytic activity test, prepared catalysts were tested for their ability to catalyze the esterification of oleic acid with ethanol. Results revealed that a sulfonated activated carbon–CNS-derived acid catalyst is capable of esterifying oleic acid to about (95.25%) conversion. Chestnut-prepared catalysts showed better performance due to their high specific surface areas. Furthermore, the hydrophobic nature of the CNS 300 –SO 3 H catalyst made it stable for up to nine cycles of recycling. Catalyst is recyclable, and cheap feedstock makes the overall process more cost-effective and environmentally friendly. [Display omitted] [ABSTRACT FROM AUTHOR]

Grape growing in India is mainly confined to tropical peninsular regions of Maharashtra, Karnataka and Tamil Nadu. It is estimated that approximately 95% of total grapes are produced in Maharashtra and Karnataka alone. About 71 per cent of total grape production of the country is consumed as fresh and 27 per cent is processed into raisins. Grape drying is mainly concentrated in Sangli, Solapur and Nashik districts of Maharashtra and Vijayapura and Bagalkot districts of Karnataka. Generally, after dipping of grape bunches in solution of ethyl oleate and potassium carbonate (also known as Australian dip) the grape bunches are spread on nylon mesh inside grape drying shed and within 10-15 days drying process completed. There are several commercial products/substitutes for dip treatment available in the market. However, it has been reported that effectiveness of these products is variable. Therefore, present investigation was carried out to study effectiveness of a new commercial product for raisin production from Thompson Seedless grape variety in comparison to ethyl oleate. Grape bunches of Thompson Seedless were dipped in these solutions prior to drying inside raisin drying shed. Besides, the drying bunches were also sprayed with different concentrations of these products on 3rd and 5th days of drying. Observations were recorded on drying dynamics, browning index, colour intensity, content of phenols and tannins, sensory properties and quality parameters after storage for 4 months. It was observed that the dip treatment of Thompson Seedless grapes with a solution of 18 ml commercial product and 24 g potassium carbonate per litre of water for 2 minutes and sprays of 12 ml commercial product +16 g potassium carbonate per liter water on 3rd day and 6 ml commercial product + 8 g potassium carbonate per liter water on 5th day was found better than ethyl oleate for production of good quality raisins.

Ultrasonic velocity, density and viscosity of two liquid mixtures ethyl oleate with benzaldehyde have been determined at various temperatures in the range of 303.15 to 318.15 K. The ultrasonic velocity, viscosity and density data are used to estimate adiabatic compressibility, free length, molar volume and free volume along with their excess values. The observed variations of the said parameters with concentration and temperature are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. FT-IR spectra confirm the expected interactions. [ABSTRACT FROM AUTHOR]

Tetranychus cinnabarinus (Boisduval) is one of the most economically important and highly polyphagous herbivorous pests in fields and greenhouses worldwide. We previously reported that 2,4-di-tert-butylphenol (DTBP) and ethyl oleate (EO) showed significantly acaricidal, repellent and oviposition deterrent properties against T. cinnabarinus via an unknown mechanism. In this study, the acaricidal activities of DTBP and EO and their biochemical mechanisms in controlling T. cinnabarinus were investigated at different time points by assessing the associated changes in toxic symptoms, potential target-related enzyme activities and seven neurotransmitters belonging to the biogenic amines (BAs). The results showed that the median lethal times (LT) for DTBP and EO were 8 and 15 h after treatment, respectively. Using dynamic symptomatology observations, typical neurotoxic symptoms including excitation, convulsion and paralysis were observed in the mites treated with DTBP and EO. Furthermore, the two compounds exerted significant inhibitory activity on monoamine oxidase (MAO) in adult T. cinnabarinus females in vitro and in vivo and had little effect on acetylcholinesterase (AChE) activity. The content levels of the seven BAs analyzed by UPLC-3QMS were higher in the mites treated with DTBP and EO than in the controls, except for phenethylamine (PEA) (for DTBP and EO) and octopamine (OA) (for EO). These results demonstrate that both DTBP and EO exert effects on T. cinnabarinus that are possibly consequences of their preventive effects on the deamination of BAs in the nervous system, most likely through inhibitory effects on MAO or MAO-like enzymes and/or interactions with certain special biogenic amine G protein-coupled receptors. [ABSTRACT FROM AUTHOR]

Background: Enzymatic ethanolysis of oils (for example, high oleic sunflower oil containing 90% of oleic acid) may yield two different reaction products depending on the regioselectivity of the immobilized lipase biocatalyst. Some lipase biocatalysts exhibit a 1,3-regioselectivity and they produced 2 mols of fatty acid ethyl ester plus 1 mol of sn2- monoacylglycerol (2-MAG) per mol of triglyceride without the release of glycerol. Other lipase biocatalysts are completely non-regioselective releasing 3 mols of fatty acid ethyl ester and 1 mol of glycerol per mol of triglyceride. Lipase from Thermomyces lanuginosus (TLL) adsorbed on hydrophobic supports is a very interesting biocatalyst for the ethanolysis of oil. Modulation of TLL regioselectivity in anhydrous medium was intended via two strategies of TLL immobilization: a. - interfacial adsorption on different hydrophobic supports and b.- interfacial adsorption on a given hydrophobic support under different experimental conditions. Results: Immobilization of TLL on supports containing divinylbenezene moieties yielded excellent 1,3-regioselective biocatalysts but immobilization of TLL on supports containing octadecyl groups yielded non-regioselective biocatalysts. On the other hand, TLL immobilized on Purolite C18 at pH 8.5 and 30 °C in the presence of traces of CTAB yielded a biocatalyst with a perfect 1,3-regioselectivity and a very interesting activity: 2.5 µmols of oil ethanolyzed per min per gram of immobilized derivative. This activity is 10-fold higher than the one of commercial Lipozyme TL IM. Immobilization of the same enzyme on the same support, but at pH 7.0 and 25 °C, led to a biocatalyst which can hydrolyze all ester bonds in TG backbone. Conclusions: Activity and regioselectivity of TLL in anhydrous media can be easily modulated via Biocatalysis Engineering producing very active immobilized derivatives able to catalyze the ethanolysis of triolein. When the biocatalyst was 1,3- regioselective a 33% of 2-monoolein was obtained and it may be a very interesting surfactant. When biocatalyst catalyzed the ethanolysis of the 3 positions during the reaction process, a 99% of ethyl oleate was obtained and it may be a very interesting drug-solvent and surfactant. The absence of acyl migrations under identical reaction conditions is clearly observed and hence the different activities and regioselectivities seem to be due to the different catalytic properties of different derivatives of TLL. [ABSTRACT FROM AUTHOR]

3-(N,N-dimethyldodecylammonium) propanesulfonic acid hydrogen sulfate ([SB3-12][HSO4]), a Brønsted acidic-surfactant-combined ionic liquid, was successfully prepared from cheap materials and applied to catalyze the esterification synthesis of ethyl oleate using oleic acid and ethanol as precursors. The produced condition of oleic acid ethyl ester was optimized including the amount of catalyst, reaction time, molar ratio and content of water. Under optimal condition (ethanol to oleic acid molar ratio, 3:1; amount of the catalyst, 5 wt% (based on the mass of oleic acid); reaction time, 3 h; reaction temperature, 78°C; and content of water, 0.4 wt%), the conversion of oleic acid was over 97%. Due to the reverse micelles formed by [SB3-12][HSO4], the micro-reactor not only promoted the esterification toward the desired side of the ester, but also avoided the hydrolysis of ester. Moreover, the [SB3-12][HSO4] could be reused by a simple decantation separating process and noticeable loss of catalytic activity was not observed even after being recycled for five cycles. The green system offers several advantages, such as excellent yield, efficient catalytic activity, free-solvent and simple operational procedure. [ABSTRACT FROM PUBLISHER]

Ultrasonic velocity, viscosity and density of ethyl oleate in butanol have been determined at various temperatures in the range 303.15-318.15 K. These data are used to estimate adiabatic compressibility, intermolecular free length and acoustic impedance, molar volume and free volume along with their excess values. The observed variations in these parameters with different concentrations and temperatures are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. [ABSTRACT FROM AUTHOR]