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The crystallization behavior of 1,2,3-tripalmitoyl glycerol or PPP using differential scanning calorimetry (DSC), thermo-optical polarized light microscopy and in situ synchrotron radiation X-ray diffraction (SR-XRD) techniques was precisely examined under static isothermal and dynamic thermal treatments, and the results were compared with preceding studies. PPP was rapidly (15 °C min−1) cooled to target temperatures (from 40 to 59 °C) to determine the precise moment at which crystallization was initiated. Once crystallization ceased, polymorphic transformation and melting were analyzed during subsequent heating. α form was crystallized during isotherms from 40 to 46 °C, temperature at which it coexisted with β′ phase. The latter was solely formed from 47 to 53 °C, and polymorphic crystallization was directed to obtain exclusively most stable β at 54 °C and higher temperatures. Nucleation time values for the α, β′ and β polymorphs exhibited exponential growth type, and a good correlation was found between data obtained by DSC and SR-XRD. Dynamic experiments were based on the use of high (15 °C min−1), intermediate (2 °C min−1) and low (0.5 and 0.1 °C min−1) cooling and heating rates. Thermo-optical polarized light microscopy experiments also provided valuable information on microstructural changes occurring during polymorphic modifications. Less stable forms predominated at high cooling rates, whereas lower velocities leaded the polymorphic crystallization to obtain more stable forms. [ABSTRACT FROM AUTHOR]

Abstract There is an increasing imperative to explore safer alternatives for pesticides due to their indiscriminate use and consequential health impacts on the environment and humans. Nanoformulations of pesticides are being developed as potential alternatives due to their beneficial properties, including enhanced solubility, targeted delivery to the site of action, improved stability and efficacy and reduced non-target effects. Nevertheless, a comprehensive assessment is necessary for these emerging nanopesticides compared to existing formulations, aiming to ascertain whether their "nano" characteristics exacerbate toxicity for non-target organisms. This study investigated the toxicity of tebuconazole (TBZ) in different formulations, including nanoformulations (poly-ε-caprolactone [PCL] and nanostructured lipid carrier [NLC] loaded with TBZ), as well as a commercial formulation, on the reproduction of the nematode Caenorhabditis elegans in both aqueous and soil matrices. Additionally, the impact of the correspondent nanocarriers without TBZ on C. elegans was examined. In water, TBZ in the form of nano and commercial formulations exhibited higher toxicity on the nematodes' reproduction than the TBZ (a.s.) attributable to higher freely dissolved concentrations of TBZ, which resulted in a toxicity order, ranging from the most to the least toxic as follows: NLC-TBZ > PCL-TBZ > commercial formulation > TBZ (a.s.). For NLC-TBZ, the excess toxicity could be clearly explained by combined toxicity of TBZ (a.s.) and nanocarriers, with the effect addition of the separate single compounds matching the observed effects of the nanoformulation. For PCL-TBZ, effects were stronger than expected from the effect addition of TBZ (a.s.) and PCL nanocarriers, potentially due to enhanced bioavailability of encapsulated TBZ in the gut of the nematodes. In soil, NLC with and without loaded TBZ showed higher toxicity than other tested compounds, while PCL nanocarriers without TBZ did not exhibit negative effects on the reproduction of C. elegans. Microcosm experiment, where long-term effects on native soil nematode fauna were tested, confirmed that TBZ-nanoformulations act via combined toxic effects of TBZ and nanocarriers. These findings contribute valuable insights to understanding nanopesticides' ecotoxicity and underscore the need for harmonized regulatory assessments to evaluate these novel formulations adequately.

There is an increasing imperative to explore safer alternatives for pesticides due to their indiscriminate use and consequential health impacts on the environment and humans. Nanoformulations of pesticides are being developed as potential alternatives due to their beneficial properties, including enhanced solubility, targeted delivery to the site of action, improved stability and efficacy and reduced non-target effects. Nevertheless, a comprehensive assessment is necessary for these emerging nanopesticides compared to existing formulations, aiming to ascertain whether their "nano" characteristics exacerbate toxicity for non-target organisms. This study investigated the toxicity of tebuconazole (TBZ) in different formulations, including nanoformulations (poly-ε-caprolactone [PCL] and nanostructured lipid carrier [NLC] loaded with TBZ), as well as a commercial formulation, on the reproduction of the nematode Caenorhabditis elegans in both aqueous and soil matrices. Additionally, the impact of the correspondent nanocarriers without TBZ on C. elegans was examined. In water, TBZ in the form of nano and commercial formulations exhibited higher toxicity on the nematodes' reproduction than the TBZ (a.s.) attributable to higher freely dissolved concentrations of TBZ, which resulted in a toxicity order, ranging from the most to the least toxic as follows: NLC-TBZ > PCL-TBZ > commercial formulation > TBZ (a.s.). For NLC-TBZ, the excess toxicity could be clearly explained by combined toxicity of TBZ (a.s.) and nanocarriers, with the effect addition of the separate single compounds matching the observed effects of the nanoformulation. For PCL-TBZ, effects were stronger than expected from the effect addition of TBZ (a.s.) and PCL nanocarriers, potentially due to enhanced bioavailability of encapsulated TBZ in the gut of the nematodes. In soil, NLC with and without loaded TBZ showed higher toxicity than other tested compounds, while PCL nanocarriers without TBZ did not exhibit negative effects on the reproduction of C. elegans. Microcosm experiment, where long-term effects on native soil nematode fauna were tested, confirmed that TBZ-nanoformulations act via combined toxic effects of TBZ and nanocarriers. These findings contribute valuable insights to understanding nanopesticides' ecotoxicity and underscore the need for harmonized regulatory assessments to evaluate these novel formulations adequately. [ABSTRACT FROM AUTHOR]

Abstract Donepezil-HCl is a member of the acetylcholinesterase inhibitors that is indicated for the symptomatic treatment of Alzheimer’s disease (AD) and has many side effects. In this study, to reduce the side effects of Donepezil-HCl and increase the penetration of the drug through the blood-brain barrier, we aimed to design a solid lipid nanoparticle (SLN) formulation. The effects of the different formulation parameters, such as homogenization speed, sonication time, lipid and drug concentration, surfactant type and concentration, and volume of the aqueous phase, were assessed for optimization. The particle size and PDI increased with increasing lipid concentration but decreased with increasing amounts of surfactant (Tween 80) and co-surfactant (lecithin). When the homogenization rate and sonication time increased, the particle size decreased and the encapsulation efficiency increased. The optimized formulation exhibited particle size, PDI, encapsulation efficiency, and zeta potential of 87.2±0.11 nm; 0.22±0.02; 93.84±0.01 %; -17.0±0.12 mV respectively. The in vitro release investigation revealed that approximately 70% of Donepezil-HCl was cumulatively released after 24 hours. TEM analysis proved that spherical and smooth particles were obtained and formulations had no toxic effect on cells. The final optimized formulation could be a candidate for Donepezil-HCl application in Alzheimer’s treatment with reduced side effects and doses for patients.

[Display omitted] • Identification of measurable structural hierarchy levels of crystalline lipids. • Mechanistic understanding of lipid crystallization from molecule to bulk material. • Shear rate dependent lamellar height distribution of lipids. • Morphology-rheology correlation using polarized light microscopy and laser diffraction spectroscopy. • Topography of crystal clusters and crystallites using scanning electron and atomic force microscopy. The crystallization behavior of lipids is relevant in many fields such as adipose tissue formation and regeneration, forensic investigations and food production. Using a lipid model system composed of triacylglycerols, we study the formation of crystalline structures under laminar shear flows across various length scales by polarized light-, scanning electron-, and atomic force microscopy, as well as laser diffraction spectroscopy. The shear rate during crystallization γ ̇ cryst influences the acyl-chain length structure and promotes domain growth into the flow direction thereby transforming the crystallites from oblate into prolate particles. Concentration dependent aggregation of crystallites into clusters is the rate limiting step for floc and floc network formation. At high γ ̇ cryst , fast crystallite cluster formation at smaller equilibrium diameters is promoted. The high crystallite cluster concentration induces their aggregation into flocs which form weak networks. At low γ ̇ cryst , floc generation is limited by the low amount of crystallite clusters leading to slow growth of larger flocs and forming of strong networks. The findings in this work have potential implications ranging from the design of injectable soft tissue fillers for adipose tissue regeneration, to the crystalline network formation in microorganism derived lipids, up to a more energy-efficient production of chocolate confectionery. [ABSTRACT FROM AUTHOR]

Background: Zidovudine (Azidothymidine, AZT) is widely used in the treatment of Acquired Immuno Deficiency Syndrome (AIDS) and related conditions, either alone or in combination with other antiviral agents to combat HIV. AZT is a Biopharmaceutical Classification System (BCS) class III drug and has various disadvantages. Thus, AZT is a potential candidate for delivery via lipid-based drug delivery system. Materials and Methods: In the present work, solid lipid microparticles (SLMs) of Zidovudine were developed for sustaining the drug release, to overcome or to reduce the hepatic metabolism and to ensure optimal bioavailability. A total of sixteen formulations of Zidovudine loaded solid lipid microparticles in two groups viz., one with tripalmitin and another with trimyristin were prepared by emulsion-solvent evaporation method. Results: The average particle size and entrapment efficiency of the prepared SLM varied between 5.48 µm-10.64 µm and 46.92 % and 58.39% respectively. The release of zidovudine from the SLM varied between 70.47% and 100% at the end of 24 hrs. 80% of the drug release which is required for obtaining the optimal therapeutic concentration was achieved by SLM 8. Conclusion: Formulation SLM 8 was considered best with maximum sustainability in the drug release along with maintaining therapeutic optimum. The formulation was found stable under stressed conditions. [ABSTRACT FROM AUTHOR]

In this research work, we hypothesized to predict the nanoparticulate system, best suited for targeted delivery of filgrastim. Significance: Targeted delivery of filgrastim to bone marrow is required to decrease the incidence of neutropenia/febrile neutropenia. This is achieved by nanoparticulate systems, duly designed by bioinformatics approach. The targeted delivery of filgrastim in nanoparticulate system was achieved by molecular dynamics (MD) simulation studies. Two matrices comprising PLGA and SLN (tripalmitin, core component of SLN system) were modeled separately with proposed drug filgrastim. Energy minimization of all systems was done using the steepest descent method. PLGA and tripalmitin systems were equalized at 310 °C, at 1 bar pressure with Berendsen barostat for 200 ps using a v-rescale thermostat for 100 ps. Atomistic MD simulations of four model system and mass density of interacting systems were calculated. The mass density maps of each nanoparticle system, that is, PLGA and tripalmitin showed an increase in density toward the end of the simulation. The contact numbers attained equilibria with the average number of approx.. 1500 contacts in case of tripalmitin–filgrastim system. While PLGA–filgrastim system shows lesser contacts as compared to tripalmitin with average contacts of approx. 1000.The binding free energy was predicted to be −1104 kJ/mol in tripalmitin–filgrastim complex and −421 kJ/mol in PLGA–filgrastim system. Findings of study revealed that both nanoparticle systems assumed to be good model for drug-carrier systems. Though SLN systems were thought to be more appropriate than PLGA, still the in vivo findings could ascertain this hypothesis in futuristic work. [ABSTRACT FROM AUTHOR]

Normal-phase high-performance liquid chromatography (HPLC) is widely used in combination with evaporative light scattering detection (ELSD) for separating and detecting lipids in various food samples. ELSD responses of different lipids were evaluated to elucidate the possibilities and challenges associated with quantification by means of HPLC-ELSD. Not only the number and type of polar functional groups but also the chain length and degree of unsaturation of (free or esterified) fatty acids (FAs) had a significant effect on ELSD responses. Tripalmitin and trilinolein yielded notably different ELSD responses, even if their constituting free FAs produced identical responses. How FA structure impacts ELSD responses of free FAs is thus not predictive for those of triacylglycerols and presumably other lipids containing esterified FAs. Because ELSD responses of lipids depend on the identity of the (esterified) FA(s) which they contain, fully accurate lipid quantification with HPLC-ELSD is challenging and time-consuming. Nonetheless, HPLC-ELSD is a good and fast technique to semi-quantitatively compare the levels of different lipid classes between samples of comparable FA composition. In this way, lipid profiles of different flours from near-isogenic wheat lines could be compared.

• Polymorphic structures adopted by deuterated tripalmitin on cooling have been characterised using neutron diffraction. • For shear studies, simultaneous rheological data from a Couette cell was collected with neutron diffraction data. • Tripalmitin was observed to directly transform from a liquid phase to a β polymorph under the influence of shear. • Temperature at which β transition occurs is independent of shear rate, but shear forces influence crystalline order. This neutron diffraction study of deuterated tripalmitin has provided further insight into a forensic observation of the crystallisation of lipids under high-shear conditions. To achieve this, an experimental set up was designed to enable simultaneous rheological data from a Couette cell to be recorded with neutron powder diffraction, enabling the influence of shear on the polymorph transformation on cooling to be monitored in real time. Tripalmitin was observed to directly transform from a liquid phase to a β polymorph under the influence of shear. Although the liquid to β transition was not observed to be influenced by shear rate, the degree of crystallinity, qualitatively denoted by an increase in the sharpness of the diffraction peaks, was observed at higher shear rates. Evidence is also presented that the rate of cooling influences the ordering in the β-polymorph produced in zero shear conditions. [ABSTRACT FROM AUTHOR]

This work investigates the molecular interactions within the main triacylglycerols constitutive of palm oil, all having a key role in the multi-step dry fractionation process. Identification of these interactions is possible thanks to the establishment of binary and ternary phase diagrams, using differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD) at variable temperature. The following systems were selected: PPP-POP, PPP-OPP, PPP-POO, POP-OPP, POP-POO, OPP-POO, PPP-POP-POO and PPP-OPP-POO (P: palmitic acid and O: oleic acid), and analyzed in direct mode (heating at 5 °C/min., after melting and quenching at −60 °C), and after tempering for three months at 20 °C (tempered mode). DSC makes it possible to bring out crystallization and melting phenomena associated to polymorphic transitions, which are further characterized (crystalline forms) by XRD. The results show that unsaturated are poorly soluble in fully saturated triacylglycerols, that the intersolubility decreases in proportion to the number of unsaturated fatty acids, that positional isomerism (POP/OPP) has a major impact, that OPP may induce formation of molecular compounds and that co-crystallization properties are highly modified by tempering depending on the polymorphic properties of the systems. This provides a better understanding and allows for effective control of the palm oil dry fractionation process.

Background: α-Cyclodextrin (α-CD), a soluble dietary fiber, may improve abnormal plasma lipids and promote weight loss. Preliminary evidence suggests that it may exert these effects by binding dietary fat and reducing absorption; this has not been tested in humans.Objective: The primary objective was to test whether supplemental α-CD increases fecal content of dietary lipid in humans.Methods: This was a randomized, double-blind, placebo-controlled, crossover study completed at the Mayo Clinic. Eight healthy volunteers, 5 premenopausal women and 3 men ages 23-54 y with body mass index (BMI; kg/m2) 18-27, underwent 2 separate study visits with a ≥2-wk washout period. The first morning of each visit volunteers consumed a standardized breakfast (14.5% protein, 27.5% fat, 60% carbohydrate, and 1.5 kcal/mL) containing [14C]tripalmitin and [3H]triolein with 2 g of α-CD or placebo, followed by 2 g of α-CD or placebo per meal for 2 more days. Volunteers consumed 100 g/d of dietary fat. Feces were collected for 72 h after the labeled breakfast to measure radiotracer content and total fecal fat. Radiotracer appearance in plasma TGs was measured at intervals after the labeled meal as a secondary outcome.Results: Virtually no 3H radiotracer, but an average of ∼20% of the 14C radiotracer was recovered in fecal lipids, with no difference between α-CD and placebo. Total fecal fat content and radiotracer appearance in postprandial plasma TGs did not differ between the α-CD and placebo treatments. Plasma appearance of 14C-TG was 37% ± 14% less (P < 0.0001) than 3H-TG.Conclusions: α-CD supplementation did not increase loss of dietary lipid in stool or total fecal fat compared with placebo in healthy adults. Greater stool loss and lesser appearance in plasma TGs of tripalmitin-derived [14C] compared with triolein-derived [3H] TGs imply different metabolic handling of these 2 dietary fat tracers. This trial was registered at www.clinicaltrials.gov as NCT03002168. [ABSTRACT FROM AUTHOR]

There is still ambiguity surrounding the application of the Avrami model to estimate kinetic parameters and growth dimension of crystallizing fats. In order to overcome this ambiguity, adjustments to the Avrami model are proposed. This research shows that isothermal palm oil (PO) crystallization is a stepwise process characterized by different consecutive kinetic segments, when dividing the Avrami equation into sub-domains following the study by Narine, Humphrey, and Bouzidi (2006) for an extended Avrami model. Thus, the Avrami model needs to be applied to each step separately. These sub-domains were merged to derive an average global rate constant that demonstrates the crystallization rates of fats follow bell-shaped curves depending on temperature, corroborating the fundamental crystallization literature. Applying this extended Avrami model to three different geographic origins of PO (Ghana, Colombia and Ecuador), the progression and maximum of these bell-shaped curves were found to be highly correlated with the tripalmitin to triolein (PPP/OOO) ratio of PO. Thus, we were able to advance the findings of Narine et al. (2006) and show the applicability of the Avrami model to describe the crystallization process of POs of different geographic origins and its blends with palm stearin. [ABSTRACT FROM AUTHOR]

High lipid heterotrophic microalgae (HM) Schizochytrium limacinum is a good dietary source of long‐chained polyunsaturated fatty acids. HM biomass has successfully been used in aquafeeds. However, the high saturated fatty acid content of the triacylglycerol (TAG) could limit the applications of HM as a main feed lipid source. Enzymatic interesterification of HM oil with unsaturated oils may increase the utilization efficiency and remove the technical challenges in using such oils. In the present study, extracted oil from HM biomass (Alltech Inc.) with rapeseed oil are mixed, and interesterified enzymatically with either Lipozyme RM IM or Lipozyme 435 in reactions with no, addition or 5% addition, of distilled water. The experimental oil mixes are formulated to target a total fatty acid profile similar to fish oil. No addition of water to the reaction mixture leads to more efficient TAG recovery after interesterification. Overall, enzymatic interesterification of HM and rapeseed oils with Lipozyme RM IM produces oils with lower levels of tri‐saturated TAG isomers, higher content of TAG isomers with unsaturated fatty acids and a lower slip melting point. Animal studies need to be performed to evaluate the biological effects of interesterified against unprocessed highly unsaturated oils. Practical Applications: Heterotrophic microalgal oil as a pure product could have limited application in feeds and foods due to its structural content of triacylglycerol (TAG) with saturated fatty acids in all three positions, due to both nutritional and practical reasons. Enzymatic interesterification of HM oil with rapeseed oil is in the present study shown to be an efficient technology to produce oils with more desirable TAG composition and reduced melting point for feed and food applications compared to the original raw material. Content of selected triacylglycerol (TAG) isomers in rapeseed oil (RO), extracted heterotrophic microalgae (HM) oil, and oil mixtures following enzymatic interesterification in reaction with no addition of water (Trial 2) by the use of Lipozyme 435 or Lipozyme RM IM. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of adding monoacylglycerols (MAGs) to triacylglycerols (TAGs) on the crystallisation properties in a fat system. Differential scanning calorimetry (DSC) and polarised light microscopy (PLM) methods were used for the analysis. Different MAGs (monoolein--O, monopalmitin--P, and monolaurin--L) were added at 1, 3, and 5% (w/w) to TAG samples, namely (triolein--OOO, tripalmitin--PPP, and tristearin--SSS). DSC results showed that the addition of MAGs changed the crystallisation of the TAGs (PPP, SSS, and OOO). The same MAG may exhibit different behaviours (induction or retardation of crystallisation) depending on the proportion added. The addition of 5% (w/w) of MAG to TAG (PPP and SSS) delayed the crystallisation process, while the best proportion of added MAGs to promote crystallisation was 3% (w/w). [ABSTRACT FROM AUTHOR]

The objective of this study was to formulate and characterize properties of solid lipid nanoparticle (SLN) dispersion containing quercetin. SLN was prepared by ultrasonication method using tripalmitin and lecithin as lipid core and then the surface was coated with chitosan. Entrapment efficiency was greater than 99%, and mean particle size of SLN was 110.7 ± 1.97 nm with significant increase in the coated SLN (c-SLN). Zeta potential was proportionally increased and reached plateau at 5% of chitosan coating with respect to tripalmitin. Differential scanning calorimetry showed disappearance of endothermic peak of quercetin in SLNs, indicating conversion of crystalline state to amorphous state. FTIR study of SLNs showed no change in the spectrum of quercetin, which indicates that the lipid and chitosan were not incompatible with quercetin. When coating amount was greater than 2.5% of tripalmitin, particle size and zeta potential were very stable even at 40°C up to 90 days. All SLN dispersions showed significantly faster release profile compared to pure quercetin powder. At pH 7.0, the release rate was increased in proportion to the coating amount. Interestingly, at pH 3.0, chitosan coating of 5.0% or greater decreased the rate. Cellular uptake of quercetin was performed using Caco-2 cells and showed that all SLN dispersions were significantly better than quercetin dispersed in distilled water. However, cellular uptake of quercetin from c-SLN was significantly lower than that from uncoated SLN. [ABSTRACT FROM AUTHOR]

Solvent systems are not readily available for the separation of very nonpolar compounds by countercurrent chromatography (CCC). In this study we therefore evaluated the suitability of room temperature ionic liquids (IL) in organic solvents for the CCC separation of the extremely nonpolar lipid compounds tripalmitin (PPP) and cholesteryl stearate (CS). The four IL tested were [C 10 mim][OTf], [C 2 mim][NTf 2 ], [P66614][NTf 2 ], and [P66614][Cl]. Search for a CCC-suited solvent system started with solubility studies with fourteen organic solvents. Following this, combinations were made with one organic solvent miscible and one organic solvent immiscible with IL (147 combinations). Twenty-four initially monophasic mixtures of two organic solvents became biphasic by adding IL. Several unexpected results could be observed. For instance, n- hexane and n- heptane became biphasic with [P66614][Cl]. Further nine systems became biphasic although the IL was not miscible in any of the two components. These 33 solvent systems were investigated with regard to phase ratio, settling time, share of IL in the upper phase and last not least the K U/L values of PPP and CS, which were 8.1 and 7.7 respectively. The most promising system, n- heptane/chloroform/[C 10 mim][OTf] (3:3:1, v/v/v ) allowed a partial separation of PPP and CS by CCC which was not achieved beforehand. [ABSTRACT FROM AUTHOR]

In the course of their day, sample environment professionals can be confronted by numerous technical challenges applicable to a range of scientific questions. This paper presents three successful outcomes from user-posed sample environment challenges for in situ neutron scattering experiments undertaken at the Australian Centre for Neutron Scattering (formerly the Bragg Institute). The sample environments presented here have nothing in common other than their novelty. They may not be the best solution but have been constrained by time, resources and ability. The questions the users posed were: Can we mount a cylinder in cylinder (CIC) rheometer, more regularly used on a small angle scattering instrument, on a diffraction instrument and obtain usable data? Can we supply high-voltage (up to 10 kV) across a sample within the Paris-Edinburgh press while mounted on a powder diffraction instrument? And finally can a Lakeshore 340 and an in-house built liquid conductivity cell do the job of a commercial liquid conductivity meter? This paper presents the engineering and equipment solutions that were used to answer these questions, and in each case the scientific users left with useful, intriguing and, hopefully, publishable data. [ABSTRACT FROM AUTHOR]

Context:Lipid-polymer hybrid nanoparticles (LPNPs) are polymeric nanoparticles enveloped by lipid layers, which have emerged as a potent therapeutic nanocarrier alternative to liposomes and polymeric nanoparticles. Objective:The aim of this work was to develop, characterize and evaluate LPNPs to deliver a model protein, lysozyme. Materials and methods:Lysozyme-loaded LPNPs were prepared by using the modified w/o/w double-emulsion-solvent-evaporation method. Poly-ɛ-caprolactone (PCL) was used as polymeric core material and tripalmitin:lechitin mixture was used to form a lipid shell around the LPNPs. LPNPs were evaluated for particle size distribution, zeta potential, morphology, encapsulation efficiency,in vitrodrug release, stability and cytotoxicity. Results:The DLS measurement results showed that the particle size of LPNPs ranged from 58.04 ± 1.95 nm to 2009.00 ± 0.52 nm. The AFM and TEM images of LPNPs demonstrate that LPNPs are spherical in shape. The protein-loading capacity of LPNPs ranged from 5.81% to 60.32%, depending on the formulation parameters. LPNPs displayed a biphasic drug release pattern with a burst release within 1 h, followed by sustained release afterward. Colloidal stability results of LPNPs in different media showed that particle size and zeta potential values of particles did not change significantly in all media except of FBS 100% for 120 h. Finally, the results of a cellular uptake study showed that LPNPs were significantly taken up by 83.3% in L929 cells. Conclusion:We concluded that the LPNPs prepared with PCL as polymeric core material and tripalmitin:lechitin mixture as lipid shell should be a promising choice for protein delivery. [ABSTRACT FROM AUTHOR]

Calcium sulfate (CS) formulations are frequently implanted as antibiotically impregnated bone substitutes in orthopedic and trauma surgery to prevent or treat bone infections. Calcium ions have been discussed as candidates to accelerate blood coagulation. The goal of this study is to evaluate substance-specific influences of CS formulations on blood coagulation. Specific ELISAs were conducted to determine markers of activated blood coagulation after incubation of human blood with CS beads. Additionally, wettability with freshly drawn human blood was measured. Three different types of CS bone substitute beads were compared (CS dihydrate with tripalmitin, containing Gentamicin (Herafill®-G: Group A) or Vancomycin (CaSO4-V: Group B); and a CS hemihydrate with Tobramycin (Osteoset®: Group C)). Examinations were performed by ELISA assays for F1+2, FXIIa and C3a. Our results prove that none of the CS preparations accelerated single specific assays for activated coagulation markers. This allows the conclusion that neither Herafill®-G (CaSO4-G) nor CaSO4-V alter haemostasis negatively. Blood samples incubated with Osteoset® display an elevated F1+2-activity. The addition of tripalmitin in Herafill®-G shifts the original into a significantly hydrophobic formulation. This was additionally proven by contact angle examination of the three substances with freshly drawn human blood, showing that acceleration of plasmatic coagulation is hindered by lipids and induced by surface effects caused by presence of rapidly soluble calcium ions in the Osteoset® preparation.

The crystallization behavior of lipids has important implications in industrial processing of food products, whose physical characteristics depend largely on crystallized fats. The study of the crystallization behavior and polymorphism of a pure lipid system is of great scientific importance as a means of gaining an understanding of the phenomena involved, serving as basic knowledge to help guide the addition or removal of these compounds in different raw materials. The crystallization behavior and polymorphism of pure tripalmitin (PPP) and tristearin (SSS) were investigated by Polarized Light Microscopy (PLM) and Differential Scanning Calorimetry (DSC) under different crystallization conditions. The polymorphic forms (β′ and β) of PPP and SSS exhibited different morphologies depending on how they were obtained, either from α form recrystallization or from isotropic melt. Crystallization in the β form was faster in SSS than in PPP, indicating that the process occurs faster in TAGs composed of longer fatty acid chains. Both β′ and β polymorphic forms were obtained from α form recrystallization, albeit with predominance of the β form. [ABSTRACT FROM AUTHOR]

The kinetic study of crystallization in purification process has not been well, because the models has not adjusted the experimental data. In the system, tripalmitin - triolein with higher molar fractions at upper 40º C. Only crystallized tripalmitin. It uses two models, called Avrami and D. The model D adjusted very well the experimental data, the Avrami was not. At molar fraction 1, were not differences between two models, thus at this point, the nuclei formation was simultaneous, and in molar fractions lower than 1, the nuclei formation was continuous.

Abstract: In the brain, astrocytes play an essential role with their multiple functions and sophisticated structure, as surrounded by a fractal environment which has not been available in our traditional cell culture. Water-repellent fractal tripalmitin (PPP) surfaces can imitate the fractal environment in vivo, so the morphology and biochemical characterization of astrocytes on these surfaces are examined. Water-repellent fractal PPP surface can induce astrocytes to display sophisticated morphology with smaller size of cell area, longer and finer filopodium-like processes, and higher morphological complexity. The super water-repellent fractal PPP surface with water contact angle of 150°∼160° produces the maximal effects compared with other surfaces at lower water contact angles. The trends of characteristic protein expression, including that of nestin, vimentin, GFAP and glutamine synthetase, for astrocytes cultured on super water-repellent fractal PPP surfaces approximate more to in vivo pattern. The super water-repellent PPP surface also render astrocytes to perform more pronounced promotion of neurogenesis by increasing the release of nerve growth factor in a co-culture system. Altogether, our results suggest that the super water-repellent fractal PPP surface facilitates the astrocytes to mimic their in vivo performance, thus provides a closer-to-natural culture environment for experimental assessment of glial structure and functions. [Copyright &y& Elsevier]

Abstract: The objective of this study was to investigate the effects of blending triacylglycerols (TAGs) and diacylglycerols (DAGs) on the melting and crystallization properties in a fat system. To this end, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and polarized light microscopy (PLM) methods were used. Different DAGs (diolein—OO, dipalmitin—PP and distearin—SS) were added at 5% to each TAG (triolein—OOO, tripalmitin—PPP and tristearin—SSS). DSC results showed that the addition of DAGs delayed the onset of crystallization of saturated TAGs (PPP and SSS). By contrast, the addition of DAGs to unsaturated TAG (OOO) accelerated the onset of crystallization, with the appearance of an extra crystallization peak upon the addition of SS and PP. PLM results revealed that the addition of OO affected the polymorphic transition of the TAGs studied findings were consistent with DSC melting curves and XRD results. [Copyright &y& Elsevier]

Highlights: [•] We study the effects of starting mode on deposition of fats on cooled surfaces. [•] Deposition induced by surface temperature exhibited three stages of fouling. [•] Strong subcooling condition caused spalling of deposits. [•] Fouling of low concentration PPP solutions exhibited sigmoidal Rf –t behaviour. [ABSTRACT FROM AUTHOR]

Structured lipids (SLs) containing palmitic, oleic, and docosahexaenoic acids for possible use in infant formulas were synthesized by enzymatic acidolysis reactions. The substrates used were tripalmitin, extra virgin olive oil free fatty acids (EVOOFFA), and docosahexaenoic acid single cell oil free fatty acids (DHASCOFFA) in 1:1:1, 1:2:1, 1:3:2, 1:4:2, and 1:5:1 molar ratios. Reactions were carried out at 65 °C for 24 h using Lipozyme TL IM lipase. The products were analyzed for total and positional fatty acids by GC-FID, triacylglycerol (TAG) molecular species by HPLC-ELSD, and thermal behavior by DSC. The SLs, SL132, SL142, and SL151 had desirable fatty acid distribution for infant formula use with nearly 60 mol% palmitic acid at the sn-2 position and oleic acid predominantly at the sn-1,3 positions. The total DHA content of SL132, SL142, and SL151 were 7.54, 6.72, and 5.89 mol%, respectively. The major TAG molecular species in the SLs were PPP, OPO, and PPO. The melting completion temperature of SL132 was 37.1, 35.2 °C in SL142, and 32.9 °C in SL151. The SLs synthesized in this study have potential use in infant formulas. [ABSTRACT FROM AUTHOR]

Morphologies and tensile properties of polybutene-1 (PB)/tripalmitin (TP) blend and PB/micro fibrous cellulose (MFC)/TP composite were studied. The scanning electron microscope observation showed that the PB(70 %)/TP(30 %) had a microphase-separated structure. The DSC measurement showed that the crystallization of the PB part was affected by the TP existence. A new crystal structure was observed in the X-ray diffraction pattern of the PB(70 %)/TP(30 %). Quicker saturation of the PB crystal phase transformation from the metastable tetragonal (II) to the stable hexagonal (I) phase was observed in the PB(70 %)/TP(30 %) under the aging at r.t. The saturation controlled the Young's modulus increment of the PB(70 %)/TP(30 %) in the aging process. The elongation at break value of the PB/TP increased by the loading of the TP, suggesting that the TP worked as the plasticizer. The thermogravimetry measurement of the PB(70 %)/TP(30 %) suggested that there existed an interaction between them. The TP addition provided a good dispersibility and ductility enhancement for PB/MFC composite. It was found that the TP worked as a good compatibilizer for the composite. [ABSTRACT FROM AUTHOR]

Solid-lipid nanoparticles (SLNs) are an interesting nanoparticulate delivery system. The present work was carried out with the aim to develop a prolonged release solid-lipid nanoparticulate system for the drug using aceclofenac. Aceclofenac-loaded solid-lipid nanoparticles (ACSLNs) was prepared by hot high pressure homogenization technique. Tripalmitin was used as the lipid core. Surfactants (Poloxamer 188, Tween 80, and soya lecithin) and co-surfactant (sodium tauro glycholate) were used in the formulations. The prepared ACSLN formulations were characterized for encapsulation efficiency (EE), photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), and x-ray diffraction (XRD). From these studies, mean particle diameter of the formulation prepared with combination of surfactants (Poloxmer 188 and Tween 80) was about 200 nm with spherical morphology and amorphous nature. Higher EE was obtained with SLNs prepared using combination of soya lecithin and poloxmer 188. The organization and distribution of the ingredients in the nanoparticulate system were studied by differential scanning calorimetry (DSC) and the results showed that the drug is incorporated into the solid matrix. The prepared formulations demonstrated favorable in vitro prolonged release characteristics. Experimental in vitro release data were substituted in available mathematical models to establish the release kinetics of ACSLNs and it was found to follow first-order kinetics and Higuchi diffusion mechanism. Our results suggest that these SLN formulations could constitute a promising approach for the drug delivery of aceclofenac. [ABSTRACT FROM PUBLISHER]

The impact of surfactant type and carrier oil type on the phase behavior and physical stability of emulsified tripalmitin was investigated. Solid lipid nanoparticles (SLNs) were prepared by homogenizing lipid and aqueous phases at a temperature (≈80 °C) above the melting point of tripalmitin, and then cooling the resulting oil-in-water emulsion to induce lipid droplet crystallization. When stored at 37 °C, tripalmitin particles had good long-term stability ( d < 150 nm) when coated with Tween 20, but were prone to aggregation and gelation when coated with modified starch (MS). Conversely, when stored at ≤20 °C tripalmitin particles coated by MS were more stable to aggregation/gelation than those coated by Tween 20. Blending tripalmitin with low melting point lipids (either medium chain triglycerides or orange oil) prior to homogenization led to a considerable alteration in the SLN phase behavior and stability. DSC measurements indicated that the presence of the carrier oils reduced the crystallization temperature, melting temperature, and melting enthalpy of tripalmitin. In addition, the carrier oils improved the stability of SLNs to particle aggregation and gelation, although some particle coalescence still occurred. These results have important implications for formulating colloidal delivery systems for utilization within the food and other industries. [ABSTRACT FROM AUTHOR]

We investigated the shearing effect in the thermo-mechanical properties of candelilla wax (CW) and candelilla wax-tripalmitin (CW-TP) organogels developed using safflower oil as the liquid phase. A shear rate of 600 s was applied during cooling (1 °C/min) of 3% CW and 3% CW-1% TP solutions, until reaching nucleation (i.e., 47 °C) or metastable conditions (i.e., 52 °C) then allowing the development of the organogel under quiescent conditions at 15 °C. The thermal and rheological properties of these organogels were compared with the ones of organogels developed under static conditions. The X-ray results showed that under static conditions the CW crystallized in an orthorhombic $$ \left( {{{\hbox{O}}_{ \bot }}} \right) $$ subcell packing with a lateral stacking with a length ( L) equivalent to the hydrocarbon chain's length. During organogelation of the 3% CW-1% TP solution, CW and TP co-crystallized in a $$ {{\hbox{O}}_{ \bot }} $$ subcell packing with TP in a 2 L stacking organization. The application of shearing did not modify the molecular packing of the crystals or the melting properties of the organogels. However, the CW and CW-TP organogels developed with shearing showed the formation of larger crystals (i.e., fiber-like or plate-like) in comparison with the ones developed under static conditions. The presence of 1% TP increased the solid fat content, and thus the CW-TP organogels showed higher elasticity ( G′) than CW organogels. The organogels developed with the application of shearing until reaching metastable conditions (i.e., CW 52 °C and CW-TP 52 °C) had the highest G′ and yield stress of all organogels investigated. In the same way, creep and recovery analyses showed that CW 52 °C and CW-TP 52 °C organogels had the highest resistance to deformation, lowest instantaneous recovery, and highest extended recovery of all organogels studied. We concluded that application of shear and the extent of its application as a function of supercooling determine crystal size and the proportion of transient to junction zones throughout the three-dimensional crystal network and, therefore, the organogels' rheological properties. [ABSTRACT FROM AUTHOR]

The C18 unsaturated fatty acid (UFA) selectivity of three immobilized lipases, namely, Lipozyme TL IM from Thermomyces lanuginosa, Lipozyme RM IM from Rhizomucor miehei, and Novozym 435 from Candida antarctica, was determined in acidolysis conducted in hexane. Tripalmitin with a mixture of equimolar quantities of C18 UFAs was used as the substrate. Significantly different incorporation rates were observed for C18 UFAs used ( p < 0.05). The highest incorporation was obtained for all three C18 UFAs with Novozym 435 followed by Lipozyme RM IM and Lipozyme TL IM catalyzed acidolysis under default conditions (substrate mole ratio 1:1; temperature 50 °C; reaction time 6 h; enzyme dosage 10%). Incorporation of the equimolar quantities of C18 UFAs was in the order C18:3 > C18:2 > C18:1 which also reflects C18 UFAs preferences of the lipases. The effects of operating variables on incorporation or UFA selectivity of lipases were also investigated. Among the experimental parameters including the mole ratio of fatty acid to triolein, temperature, enzyme dosage, and time on incorporation, the effect of the substrate mole ratio on UFA selectivity was greater than those of the others. [ABSTRACT FROM AUTHOR]

In this study, in situ and mapping Raman spectroscopic measurements were used to investigate the physical structure of solid lipid extrudates and relate the structure to dissolution behaviour. Theophylline anhydrate was extruded with tripalmitin, with and without the water-soluble polymer, polyethylene glycol 10000. Raman mapping of the extrudate cores revealed that drug particles of diverse size were dispersed in a continuous lipid phase with or without polyethylene glycol. At the surface, there was evidence of more mixing between the components. Previous characterisation by other methods suggested that the extrudate surface is covered predominantly by lipid, and the Raman mapping suggested that such a layer is in general less than a few micrometres thick. Nevertheless, the lipid layer dramatically reduced the drug dissolution rate. The extrudate cores were also mapped after a period of dissolution testing, and there was no evidence of a uniformly receding drug boundary in the extrudates during drug release. In situ Raman spectroscopy analysis during dissolution testing revealed that the drug distribution in the extrudate affected the formation of theophylline monohydrate. However, the drug release rate was primarily determined directly by drug distribution, with the solid-state behaviour of the drug having a smaller influence. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 1464–1475, 2010 [ABSTRACT FROM AUTHOR]

Using the CO2-and N2-assisted atomization processes, the production of ibuprofen/lipid composite microparticles is investigated, in which the lipid includes myristic acid and tripalmitin. The produced composite particles show similar morphology to that of the purelipids obtained by the same process. In the case of the N2-assisted process, the average size of composite particles is slightly larger than that of the pure lipid particles due to the difficulty of solidification when using N2. In the case of the CO2-assisted process, the average size of composite particles is slightly smaller than that of the pure myristic acid particles, but slightly larger than that of the pure tripalmitin particles. The dissolution study reveals that the drug release from the ibuprofen/myristic acid particles is enhanced in comparison with that of the unprocessed ibuprofen. For the particles produced by the N2-assisted process, the X-ray diffraction (XRD) patterns clearly indicate the encapsulation of ibuprofen into myristic acid. The obtained ibuprofen/tripalmitin composite particles with 5% or 20% of ibuprofen (in mass) evidently show the controlled drug release: only about 20% of the drug is released in 500 min from the ibuprofen/tripalmitin composite particles consisting of 20% ibuprofen prepared by the CO2-assisted process, and the same release is obtained from the ibuprofen/tripalmitin composite particles containing 5% ibuprofen prepared by the N2-assisted process. [ABSTRACT FROM AUTHOR]

Exchange of molecules between liquid and solid components of a triacylglycerol (TAG) system is an important process in the degradation of many food components as well as for many industrial processes such as fractionation. NMR is a technique that can be used to measure the exchange between solid and liquid phases. In this work we show that monoacylglycerols (MAG) and diacylglycerols (DAG) have a retarding effect on the rate of exchange between solid and liquid TAG. In particular dipalmitoylglycerol significantly retards the rate of exchange. It is postulated that this result suggests that exchange occurs primarily through certain hotspots, probably kinks and defects on the crystal surface. MAG and, in particular, DAG can block these hotspots. It is suggested that because of their molecular structure they can partially co-crystallize with the TAG crystal during the exchange process and then block further exchange. [ABSTRACT FROM AUTHOR]

The structure of triacylglycerols in vegetable oil blends was enzymatically modified, and the blends were incorporated into skim caprine milk to produce goat milk-based infant formula analogs, homologous to human milk. A modified lipid containing palmitic, oleic, and linoleic acids, resembling the composition of human milk fat, was synthesized by enzymatic interesterification reactions between tripalmitin and a vegetable oil blend containing a 2.5:1.1:0.8 ratio of coconut, safflower, and soybean oils. A commercial sn-1,3-specific lipase obtained from Rhyzomucor miehei, Lipozyme RM IM, was used as the biocatalyst. The effects of substrate molar ratio and reaction time on the incorporation of palmitic, oleic, and linoleic acids at the sn-2 position of the triacylglycerols were investigated. The fatty acid composition and sn-2 position of the experimental formulas were analyzed using gas chromatography. Results showed that the highest incorporation of palmitic acid was obtained at 12 h of incubation at 55°C with a substrate molar ratio of 1:0.4 of tripalmitin to vegetable oil blend. However, the modified milk interesterified for 12 h at a 1:1 molar ratio had a greater resemblance to human milk compared with the other formulas. The level of oleic acid incorporation at the sn-2 position increased with the molar ratio of tripalmitin to vegetable oil blend. It was concluded that, unlike the original goat milk and other formulas, the formulated caprine milk with a molar ratio of 1:1 and a 12-h incubation was similar to the fatty acid composition of human milk. [ABSTRACT FROM AUTHOR]

The spray-freezing of two food fats, tripalmitin (PPP) and cocoa butter (CB) and mixtures thereof, has been modeled experimentally using a novel single droplet freezing apparatus configured so that temperature profiles or samples for microstructure analysis can be obtained. For 2 mm diameter droplets suspended in a cold air flow at temperatures around 2-15°C, initial cooling rates were on the order of 10 K s-1 and the temperature profiles could be correlated directly to DSC data collected at 20 K min-1 indicating that minimal supercooling of the materials occurred in the droplet form. Microstructure analysis confirmed that PPP crystallized preferentially in mixtures, and that the surface structure was very, sensitive to storage conditions. The bulk structure was much less sensitive, and the internal microstructure of the PPP droplets revealed distinct nucleation sites, which were absent from the CB: These persisted in the mixtures up to 50 wt%. X-ray analysis indicated that the fats crystallized in their more stable forms, namely, β for PPP and Form V/VI in CB. [ABSTRACT FROM AUTHOR]

Abstract: A conventional method was used to measure the melting points of the natural lipid tripalmitin and of the coenzyme ubiquinone (coQ10) under high pressure carbon dioxide. The pressure–temperature behavior of the binary three-phase solid–liquid–gas (SLG) equilibrium for these and other systems, namely naphthalene and biphenyl with carbon dioxide, ethylene and ethane, were investigated using the Peng–Robinson equation of state (PR-EoS) with the van der Waals one fluid (vdw-1) mixing rules and with the NRTL equation to calculate the solute activity in the liquid phase. When the interaction parameter in the vdw-1 mixing rules could be determined by the PR-EoS through the correlation of the solid–fluid phase equilibrium data, the two NRTL parameters were used as adjustable parameters. The results showed that fairly good correlations could be achieved for the experimental pressure–temperature data of all the asymmetric systems studied here, indicating that the NRTL parameters are crucial for describing the pressure–temperature behavior but have little effect on the phase compositions at the SLG equilibrium. [Copyright &y& Elsevier]

Aims/hypothesis: Long-term exposure of beta cells to lipids, particularly saturated fatty acids in vitro, results in cellular dysfunction and apoptosis (lipotoxicity); this could contribute to obesity-related diabetes. Our aims were to relate cell death to intracellular triglyceride concentration, composition and localisation following incubation of INS1 cells in saturated and unsaturated NEFA in high and low glucose concentrations. Materials and methods: In sulin-producing INS1 cells were cultured (24 h; 3 and 20 mmol/l glucose) with palmitic, oleic or linoleic acids and the resulting intracellular lipids were analysed by gas chromatography and microscopy. Cell death was determined by quantitative microscopy and 3-(4,5-dimethlthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and glucose-stimulated insulin secretion by ELISA. Results: All NEFA (0.5 mmol/l, 0.5% albumin) inhibited glucose-stimulated (20 mmol/l) insulin secretion. Cytotoxicity was evident only with palmitic acid (p«0.05), in which case intracellular triglyceride consisted largely of tripalmitin in angular-shaped dilated endoplasmic reticulum. Cytotoxicity and morphological disruption were reduced by addition of unsaturated NEFA. Triglyceridecontent (control cells; 14.5 ng/μg protein) increased up to 10-fold following incubation in NEFA (oleic acid 153.2 ng/μg protein; p«0.05) and triglyceride and phospholipid fractions were both enriched with the specific fatty acid added to the medium (p«0.05). Conclusions/interpretation: In INS1 cells, palmitic acid is converted in the endoplasmic reticulum to solid tripalmitin (melting point »65C), which could induce endoplasmic reticulum stress proteins and signal apoptosis; lipid-induced apoptosis would therefore be a consequence of the physicochemical properties of these triglycerides. Since cellular triglycerides composed of single species of fatty acid are not likely to occur in vivo, destruction of beta cells by saturated fatty acids could be predominantly an in vitro scenario. [ABSTRACT FROM AUTHOR]

Abstract: Acyl migration in the glycerol backbone often leads to the increase of by-products in the enzymatic production of specific structured lipids. Acyl migration is a thermodynamic process and is very difficult to stop fully in actual reactions. The objective of this study was to investigate the feasibility of suppressing acyl migration by a programmed change of reaction temperature without loss of reaction yield. The model reactions were the acidolysis of tripalmitin with conjugated linoleic acid (CLA) or with caprylic acid (CA) targeted for human milk fat substitutes. Acyl migration was considerably inhibited in the temperature-programmed acidolysis of PPP with CLA or CA, with only slight reduction of acyl incorporation, the reaction leading to the required products. Acyl migration was reduced by 29% (35 h) and 45% (48 h), respectively, in the acidolysis of PPP with CLA under solvent and solvent-free systems, in comparison with 37% (35 h) and 61% (48 h), respectively, for the acidolysis of PPP and CA. Acyl migration in the acidolysis of PPP with CA was, in general, lower than the acidolysis of PPP with CLA in both systems. Temperature programming was more prominent in solvent-free systems for the reduction of acyl migration. Acyl incorporation was not significantly affected by temperature programming. The study suggests that it is feasible to reduce acyl migration by programmed change of acidolysis temperature without significant loss of reaction yield. [Copyright &y& Elsevier]

Etoposide-incorporated tripalmitin nanoparticles with negative (ETN) and positive charge (ETP) were prepared by melt emulsification and high-pressure homogenization techniques. Spray drying of nanoparticles led to free flowing powder with excellent redispersibility. The nanoparticles were characterized by size analysis, zeta potential measurements, and scanning electron microscopy. The mean diameter of ETN and ETP nanoparticles was 391 nm and 362 nm, respectively, and the entrapment efficiency was more than 96%. Radiolabeling of etoposide and nanoparticles was performed with Technetium-99m (99mTc) with high labeling efficiency and in vitro stability. The determination of binding affinity of99mTc-labeled complexes by diethylene triamine penta acetic acid (DTPA) and cysteine challenge test confirmed low transchelation of99mTc-labeled complexes and high in vitro stability. Pharmacokinetic data of radiolabeled etoposide, ETN, and ETP nanoparticles in rats reveal that positively charged nanoparticles had high blood concentrations and prolonged blood residence time. Biodistribution studies of99mTc-labeled complexes were performed after intravenous administration in mice. Both ETN and ETP nanoparticles showed significantly lower uptake by organs of the reticuloendothelial system such as liver and spleen ( P<.001) compared with etoposide. The ETP nanoparticles showed a relatively high distribution to bone and brain (14-fold higher than etoposide and ETN at 4 hours postinjection) than ETN nanoparticles. The ETP nanoparticles with long circulating property could be a beneficial delivery system for targeting to tumors by Enhanced Permeability and Retention effect and to brain. [ABSTRACT FROM AUTHOR]

Human milk fat contains 20-25% palmitic acid (16:0) and 30-35% oleic acid (18:1). More than 60% of the palmitic acid occurs at the sn-2 position of the glycerol backbone. Palm oil is a rich source of both palmitic and oleic acids. The structured lipid 1,3-dioleoyl-2-palmitoylglycerol (OPO)is an important ingredient in infant formula. OPO was synthesized from palm oil by a three-step method. In the first step, low-temperature fractionation was applied to palm oil FA, yielding a palmitic acid-rich fraction (87.8%) and an oleic acid-rich fraction (96%). The palmitic acid content was further increased to 98.3% by transforming palmitic acid into ethyl palmitate. In the second step, esterification of ethyl palmitate and glycerol catalyzed by lipase Novozym 435 under vacuum (40 mm Hg) was employed for the synthesis of tripalmitin. Finally, OPO was obtained by the reaction of tripalmitin with oleic acid catalyzed by Lipase IM 60. In this final step, the TAG content in the product acylglycerol mixture was 97%, and 66.1% oleic acid was incorporated into TAG. Analysis of the FA composition at the sn-2 position of TAG showed 90.7 mol% of palmitic acid and 9.3 mol% of oleic acid. OPO content in the product TAG was ca. 74 mol%. Thus, an efficient method was developed for the synthesis of OPO from palm oil. [ABSTRACT FROM AUTHOR]

The soiling of unplasticized PVC with solid and liquid oily agents was studied with tripalmitin, palmitic acid, and triolein as model compounds. Deposition was made by spin coating technique. Quantification of the soiling agent on the PVC surface was done by FTIR spectroscopy, by determining the area of the ν(C&z.dbnd;O) vibrations as a function of the concentration of the coating solution. The C&z.dbnd;O stretching was characteristic for each model compound. Optical microscopy in normal and polarized light and noncontact atomic force microscopy (AFM) were used to study the structure of the model compounds and their dispersion on the PVC surface. Noticeable differences in topography were seen in comparisons of the clean PVC surface with soiled surfaces. The three model compounds formed different structures on the PVC surface. [Copyright &y& Elsevier]

The aim of this work was to investigate the catalytic functions of a new immobilized Thermomyces lanuginosa lipase in interesterification and to optimize the conditions of interesterification for the production of human milk fat substitutes (HMFS) containing n−3 PUFA by response surface methodology (RSM). Thermomyces lanuginosa lipase had an activity similar to that of immobilized Rhizomucor miehei lipase (Lipozyme RM IM) in the glycerolysis of sunflower oil, but the former had higher activity at a low reaction temperature (5°C). Thermomyces lanuginosa lipase was found to have much lower catalytic activity than Lipozyme RM IM in the acidolysis of sunflower oil with caprylic acid. However, the activity of T. lanuginosa lipase was only slightly lower than that of Lipozyme RM IM in the ester-ester exchange between tripalmitin (PPP) and the ethyl esters of EPA and DHA (EE). For this reason, the new immobilized T. lanuginosa lipase was used to produce HMFS from PPP by interesterification with EE. The optimization of major parameters was conducted with the assistante molar ratio of 5 (EE/PPP), a lipase load of 20 wt% (on substrates), and a reaction time of 20 h, with acyl incorporation up to 42%. The model generated significantly represented real relationships between the response (incorporation) and reaction parameters. [ABSTRACT FROM AUTHOR]

The problems of low reaction rate and cis–trans isomerization encountered in the gas–liquid catalyzed hydrogenation of vegetable oils can be overcome by using a supercritical fluid to bring the reactive mixture into a homogeneous phase. For that purpose, experimental phase equilibrium data on mixtures of high molecular weight substrates with hydrogen and a supercritical fluid are needed in order to evaluate optimum process conditions. In this work vapor–liquid and liquid–liquid equilibria in mixtures of hydrogen+propane+tripalmitin have been measured. A temperature region between 323 and 453 K, and pressures up to 15 MPa were covered. [Copyright &y& Elsevier]

In developing compositional models for biomass-based diesel fuel extenders, volatility properties of medium- and long-chain saturated triglycerides are essential to predict the impact of low levels of these compounds in mixtures with short-chain triglycerides. A thermogravimetric analysis (TGA) method for rapid measurement of boiling points and vapor pressure was used to obtain data for four pure medium- and long-chain triglycerides. Normal boiling points at 1 atm and the temperature dependence of vapor pressure from 760 mm down to 25 mm Hg were obtained for trilaurin (C12:0), trimyristin (C14:0), tripalmitin (C16:0), and tristearin (C18:0). The data showed good agreement with the Clausius–Clapeyron model for temperature dependence of vapor pressure up to 1 atm pressure. The results of this study were consistent with those obtained using differential scanning calorimetry (DSC) and with data previously reported for reduced pressure. [Copyright &y& Elsevier]

A newly developed 1,3-positionally specific thermostable lipase from Fusarium heterosporum (named R275A lipase) was immobilized on Dowex WBA for the production of structured lipid by acidolysis of tripalmitin (PPP) with oleic acid (OA). The immobilized catalyst was fully activated by pretreatment at 50°C in a PPP/OA mixture containing 2% water. The pretreatment caused concomitant hydrolysis, but the hydrolysis was repressed using a substrate without water in the subsequent reactions. The optimal reaction conditions were determined as follows: A mixture of PPP/OA (1∶2, w/w) and 8% immobilized lipase catalyst was incubated at 50°C for 24 h with shaking at 130 oscillations/min. The acidolysis reached 50% under these conditions, and the contents of triolein, 1,3-dioleoyl-2-palmitoyl-glycerol, 1(3),2-dioleoyl-3(1)-palmitoyl-glycerol, 1(3),2-palmitoyl-3(1)-oleoyl-glycerol, 1,3-dipalmitoyl-2-oleoyl-glycerol, and PPP in the reaction mixture were 8, 36, 4, 28, 1, and 6 mol%, respectively. The stabilities of immobilized R275A lipase catalyst and two immobilized catalysts containing Rhizopus delemar or Rhizomucor miehei lipases were compared under the conditions mentioned above, with the catalysts being transferred to fresh substrate every 24 h. The half-life of the R275A lipase catalyst was 370 d, which was significantly longer than those of Rhizopus and Rhizomucor lipase catalysts. [ABSTRACT FROM AUTHOR]

Canola oil is generally a clear oil which does not require winterization. However, sediment formation has become an increasing problem in Australian canola oil. Canola oil stored at temperatures between −5 and 21°C formed sediment more rapidly at lower temperatures. The sediment and clear fractions of a group of sedimenting canola oils were analyzed and compared. Both fractions contained wax esters of carbon number C42–C52, the sediment fractions containing between 0.37 and 3.09 mg g−1 and clear fractions containing between 0.12 and 0.85 mg g−1. The triacylglycerol profiles of sediment fractions contained four compounds, PPO, PPP, PSO and PPS (where P is palmitoyl, O is oleoyl, and S stearoyl), that were not detected in clear fractions. The contents of palmitic acid and total saturated fatty acids were higher in the sediment fraction than the clear fraction. Added PPP clouded a clear oil as effectively as stearyl behanate and more than OOO or lauryl arachidate. Sedimentation may be linked to environmental conditions, as seed grown in 1997, a dry year, produced more problem oils than seed grown in previous years that had more nearly average rainfall. [ABSTRACT FROM AUTHOR]

A model system with a heterogenous composition of triacylglycerides (TG), in which the component with the highest melting temperature crystallized independently, was developed. Thus, tripalmitin solutions in sesame seed oil (0.98, 1.80 and 2.62% w/v) with ideal crystallization behavior, evaluated through differential scanning calorimetry and the Hildebrand equation, were utilized as a model system to investigate the effect of supercooling and viscosity (η) on the development of polymorph states of TG crystals, their crystal growth mechanism, crystal growth rate constant (z), and activation energy associated with the crystallization process (Ea). Results indicated that a modification of the Avrami equation, as suggested by Khanna and Taylor, provides reliable values of z and, subsequently, correct estimates of Ea. This was not the case when the original Avrami equation was used. Subse quent analysis indicated that nucleation and crystal growth, as well as the polymorph states devel oped by the TG, depend mainly on η and the extent of supercooling. The latter is a function of the concentration of the TG with the highest melting temperature in the system (e.g. tripalmitin). In conclusion, it is feasible to model the combined effect of supercooling, the viscosity of the liquid phase, and the concentration of the component to crystallize, through multiple variable regression to predict the size, number and polymorph state of the crystals developed during the industrial process of fractional crystallization of vegetable oils and fats. This would allow us to establish process condi tions where a higher yield and separation efficiency of the crystal fraction could be achieved. [ABSTRACT FROM PUBLISHER]

Surplus fats and oils were reacted with several lipases under supercritical fluid conditions for the purpose of obtaining value-added products. Lipases, however, require sufficient moisture content to act as effective biocatalysts. An immobilized lipase from Candida antarctica was chosen to examine the rate of enzyme moisture loss under laboratory ambient conditions and also under supercritical fluid conditions. A more important aspect was to determine the effect of lipase moisture content on the hydrolysis of triacylglycerols under the same supercritical fluid conditions. Under ambient conditions at constant air flow, the immobilized lipase lost water at the rate of 4 to 5%/h, from 48.3% moisture to a final moisture content of 0.2%. Water is known not to be very soluble in supercritical carbon dioxide (SC-CO2). Nevertheless, under supercritical fluid conditions of 60°C, 4000 psi, and carbon dioxide flow rates of 0.5 or 1 L/min measured as expanded gas, the enzyme moisture loss was approximately 2 to 6%/h. To determine the effect of moisture loss on enzymatic hydrolysis, lipase beds in a tubular reactor with moisture contents of 1.5 to 23.5% were reacted with tripalmitin under supercritical conditions. A lipase with an initial moisture content of 1.5% gave little evidence of hydrolysis whereas those containing 5.4 to 23.5% moisture content resulted in products that contained only palmitic acid and unreacted tripalmitin. Thus, optimal parameters for continuous lipase hydrolysis of tripalmitin require: enough enzyme moisture to compensate for complete substrate hydrolysis; sufficient enzyme moisture for losses due to water solubility in SC-CO2; temperature and pressure sufficient to solubilize the tripalmitin; high carbon dioxide total flow to solubilize all the tripalmitin; and a relatively large enzyme bed volume to increase the solubilized substrate contact time with the enzyme. [ABSTRACT FROM AUTHOR]

Crystallization of tripalmitin (TP) in sesame oil was investigated under isothermal conditions at a cooling rate similar to the one achieved in industrial crystallizers (1 K/min). The results obtained indicated that, at TP concentrations <0.98%, triacylglycerides of sesame oil developed mixed crystals with TP. However, at concentrations within the interval of 0.98 to 3.44%, tripalmitin crystallized independently from sesame oil. Within this concentration interval, discontinuities were observed in the behavior of the induction time of TP crystallization ( T i) in sesame oil as evidenced by differential scanning calorimetry, polarized microscopy studies, and determination of the Avrami index ( n). In general, the discontinuities in T i were associated with different polymorph states developed by TP in sesame oil as a function of its concentration and crystallization temperature. Thus, TP crystals obtained at temperatures above 296 K with 1.80 and 2.62% TP solutions had n values close to 3 and developed lamellar-shaped crystals that are characteristic of β tripalmitin. In contrast, the crystals obtained at temperatures of 296 K and below with 1.80% and 2.62% TP solutions provided n values close to 3. Axialite-shaped β′ TP crystals were obtained under these conditions. For the 0.98% TP solution, simultaneous production of α and β′ crystals occurred below 291 K. However, at temperatures above 291 K, a crystallization process with n=3 was obtained, and it developed a different polymorph state, i.e., β, with lamellar-shaped TP crystals. [ABSTRACT FROM AUTHOR]

The phase behavior of the sn-1,3-dipalmitoyl-2-oleoylglycerol (PPP-POP) binary mixture system was studied by powder X-ray diffraction with synchrotron radiation and by differential scanning calorimetry. The results showed that the immiscible phases were observed in metastable and in the most stable forms. In particular, synchrotron X-ray diffraction enabled us to reveal the monotectic nature of α as a kinetic phase behavior. The equilibrium phase diagram of the PPP-POP mixture is divided into two regions. In POP concentration ratios below 40%, solid-state transformation from α to β was observed, indicating that the α-β transition of PPP was promoted in the presence of POP. By contrast, the polymorphic transition proceeds from α to β through the occurrence of the intermediate β′ form at POP concentration ratios above 50%. [ABSTRACT FROM AUTHOR]