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Natural lipids with nutritional or therapeutic benefits that also provide desired texture, melting and organoleptic appeal (mouthfeel, skin feel) are difficult to procure for the food and cosmetics industries. Natural Astrocaryum pulp oil (AVP) and kernel fat (AVK) from Guyana were blended without further modification to study the potential of extending the physical functionality of the blends beyond that of crude AVK and AVP. An evaluation of non-lipid components by ESI-MS indicated twenty-four (24) bioactive molecules, mainly carotenoids (90%), polyphenols (9%) and sterols (1%) in AVP, indicating important health and therapeutic benefits. Only trace-to-negligible amounts of these compounds were detected in AVK. The thermal transition phase behavior, solid fat content (SFC), microstructure and textural properties of five AVP/AVL blends were used to construct phase diagrams of the AVK/AVP binary system. Binary phase diagrams constructed from the cooling and heating DSC thermograms of the mixtures and description of the liquidus line indicated a mixing behavior close to ideal with a tendency for order, with no phase separation. Melting onsets, solid fat content and measurements of solid-like texture all predictively increased with increasing AVK content. The descriptive decay parameters obtained for SFC, crystal size, hardness, firmness and spreadability were similar and predictive and indicate the way the binary system structure approaches that of a liquid or a functional solid. The bioactive content of the blends was accurately calculated; the work provides a blueprint for the blending of AVP and AVK to deliver targeted bioactive content, stability, spreadability, texture, melting profile, organoleptic appeal and solid content. SFCs at 20 °C ranged from 9.1% to 39.1%, melting onset from −17.5 °C to 27.8 °C, hardness from 0.1 N to 3.5 N and spreadability from 3.3 N·s to 147.1 N·s; indicating a useful dynamic range of physical properties suitable for bioactive oils to bioactive butters. [ABSTRACT FROM AUTHOR]

The phase behavior of lipids extracted from Astrocaryum vulgare (AV) and Astrocaryum aculeatum (AA) pulp and kernels and their microstructural, thermal and flow properties were studied. The lipid profiles, crystal structures, microstructures, thermal stabilities and flow behaviors of these lipids provided important structure–function information that are useful to assess potential applications in the food, cosmetic and pharmaceutical industries. AV and AA fruits were sourced from the lowlands and rainforests, respectively, of Guyana. AV and AA pulp oils (AVP and AAP) were distinguished from each other in composition and unsaturation, with AVP oils being predominated by a di-unsaturated TAG (2-(palmitoyloxy)propane-1,3-diyl dioleate (POO)) and AAP oils predominated by propane-1,2,3-triyl trioleate (OOO); there were unsaturation levels of 65% and 80%, respectively. The main fatty acids in AVP oils were oleic, palmitic and stearic; for AAP, these were oleic, linoleic, palmitic and stearic. The kernel fats of AV and AA were similar in composition and had saturation levels of 80%, being mainly comprised of tri-saturated TAGs propane-1,2,3-triyl tridodecanoate (LLL) and 3-(tetradecanoyloxy)propane-1,2-diyl didodecanoate (LML). The onset of mass loss (T 5 % o n) of AV and AA pulp oils were similar at 328 ± 6 °C, which were 31 °C ± 9 higher compared to that of the kernel fats, which demonstrated similar T 5 % o n = 293 ± 7 °C. AA and AV pulp oils were liquid at room temperature, with melting points of −5 ± 1 °C and 3 ± 1 °C, respectively; both kernel fats were solid at room temperature, packing in β′ (90% of crystals) and β (10% of crystals) polymorphic forms and melting almost identically at 30 ± 1 °C. Pulp oils demonstrated sporadic nucleation at the onset of crystallization with slow growth into rod-shaped crystallites, leading to an approximately 50% degree of crystallization at undercooling of approximately 40K. Nucleation for kernel fats was instantaneous at undercooling of approximately 23K, demonstrating a spherulitic growth pattern incorporating crystalline lamella and a 90% degree of crystallization. Kernel fats and pulp oils demonstrated Newtonian flow behavior and similar dynamic viscosity in the melt, approximately 28.5 mPa·s at 40 °C. The lipid profiles of AVP and AAP oils were dominated by unsaturated TAGs, suggesting potential nutrition and health benefits, particularly compared to other tropical oils with higher saturation levels, such as palm oil. AAP oil in particular is as unsaturated as olive oil, contains high levels of beta carotene and provides a unique flavor profile. The AAK and AVK lipid profiles and phase transformation indicate potential for applications where a high solid fat content and medium-chain fatty acids are required. Their high lauric and myristic acid content makes them similar to industrially important tropical oils (coconut and palm kernel), suggesting their use in similar formulations. The melting point and plasticity of the kernel fats are similar to that of cocoa and shea butters, suggesting use as replacements in cosmetics, foods and confections. There is, however, the need to better understand their nutritional status and effects on health. [ABSTRACT FROM AUTHOR]

Ambient sun drying is the method most used by Indigenous communities for preserving fruits and seeds harvested from the forest. It is an effective method to increase the shelf-life of highly perishable foods and prevent spoilage until important bioactive compounds can be extracted at distant locations. The ambient sun drying kinetics and oil extraction of the pulp and seeds of commercially important oleaginous fruit directly obtained from the rainforests and swamps of Guyana, namely Astrocaryum vulgare (Awara), Astrocaryum aculeatum (Kuru), Oenocarpus bacaba (Turu), Mauritia flexuosa (Ite), Euterpe oleracea (Acai), Caryocar nuciferum (Souari), Attalea maripa (Kukrit), and Carapa guianensis (Crabwood), were studied. The fruits were dried under ambient conditions from initial moisture contents ranging from 24–71% to a final moisture content of 5%. Three models, the Lewis model, the modified Page model, and the standard logistic function (SLF) model, were utilized to model the drying kinetics and to estimate the parameters governing the drying process. These models were demonstrated to fit the experimental data with excellent goodness of fit (>0.98). The SLF, never used before to model drying kinetics, was observed to be the best-suited model overall, with the highest correlation coefficient and the least Chi-square (χ2). Depending on the fruit type, the estimated point where the maximum drying rate occurs varies from 35 min to 350 min for sun-dried fruit pulp and up to 4000 min for sun-dried kernels. The steepness of the drying curves varied from −0.5 to −3.5 g/min. The results of this work will aid in the design, development, optimization, and control of the ambient drying processes of economically and functionally important oleaginous forest fruits. This knowledge will assist in addressing the key challenge of spoilage faced by Indigenous communities in the preservation of tropical oleaginous fruits and seeds, possibly aiding in the preservation of functional characteristics of the extracted oils and adducing to the sustainable economic utilization of such fruit. [ABSTRACT FROM AUTHOR]

The seed oil of Carapa guianensis, known as crabwood oil (CWO), is distinguished for its medicinal and cosmetics applications, attributed to its bioactive components and lipid profile. CWO and its dry and solvent fractionation were studied, with a focus on physicochemical functionality and the partitioning of known bioactive compounds, such as limonoids and sterols. Important bioactive components, including limonoids and sterols, were partitioned depending on the fractionation method; in particular, there is a direct dependence on solvent polarity. There was a very strong solid fraction yield–solvent polarity with a high linear slope of −121.3%. The partitioning of the lipids is significant enough to drive measurable and predictable changes in the physical properties. Palmitic (P: C16:0) and oleic (O: C18:1) fatty acids account for about 60% of the total fatty acid composition of the TAGs of CWO and its fractions. The most abundant limonoid is methyl angolensate (from 28 to 39%), followed by Trichilin A (from 13% to 22%). Gedunin and Andirobin were more abundant in the liquid fractions, whereas Carapanolides (less than 1.3%) were more present in the olein fractions. The crystallization and melting temperatures of the solid fractions were up to 26 °C, compared to 11°C for CWO, and were particularly strongly correlated to the polarity of the solvents. The SFC profile indicated semi-solid fats, with the solid fractions showing up to 19% at 18 °C, twice the SFC in CWO. The fractions demonstrated a wide range of distinguishable microstructures. The shapes include well-organized spherulites and needle-like and rod-like crystals with sizes varying from 5 to 250 µ, suggesting that they are likely to have different flow characteristics and feel to the skin and mouth. There is a potential to make unique compositions with significantly different properties, with antimicrobial and antifungal efficacy due to the bioactive components of CWO through fractionation, using polarity as a predictive tool. [ABSTRACT FROM AUTHOR]

Vegetable oil (VO)-based lubricants are environmentally friendly replacements for mineral oils. This work critically reviews the literature and identifies the molecular structures in VO-based lubricants which have been used to improve performance. The specific roles that size, type, number, position, spatial arrangement, and symmetry play in determining lubricating functionality were highlighted. Data were systematically collected to identify the contributions of major structural components and relate them to specific physical functionality measurables. The relationships were presented to reveal structure–function trends. Empirical predictive relationships between flow and thermal transition properties and structures were established. Molecular mass was revealed to be a fundamental determinant of viscosity and transition temperatures, but these properties were shown to also be influenced by other structural factors such as polar functional groups, branching, and symmetry. Almost all the examined viscosity data plotted versus molecular mass are enclosed within the 95% prediction band of an exponential rise to a maximum function (R2 = 0.7897). Generally, for both flow and thermal transition, a given structure versus function follows simple linear or exponential functions with unbranched VO-based lubricants, lending themselves more easily to strong correlations. This review is a first step towards comprehensively relating structure to lubrication function. The revealed relationships of structural contributions to the lubricating functionality of VO-based lubricants provide insights that may be used to extend the ranges of chemical and physical properties of some molecular architectures examined. [ABSTRACT FROM AUTHOR]

Summary: One of the major shortcomings of current organic phase change materials (PCMs) is their relatively low melting points, typically below 80°C, which limits their integration into thermal energy storage (TES) systems. The present work was aimed at developing lipid‐derived PCMs with increased melting points which would be suitable for TES applications requiring higher melting points without compromising other key properties such as enthalpy. The introduction of an amide group into the structure of linear saturated fatty acids was used as a means to increase intermolecular interactions and therefore crystallization and melting points. A series of six linear monoamides with differing chain length and symmetry about the amide group were investigated for thermal stability, thermal transition, flow behavior, and crystal structure to establish the structure‐property relationships relevant to TES. The presence of the highly polar amide group in the aliphatic fatty acid–derived molecules resulted in notable improvement in performance compared with the analogous monofunctional molecules: Increases in melting points (79°C‐96°C) and high enthalpies of fusion (155‐201 J/g) were recorded. Fundamental relationships between structure, processing, and macroscopic physicochemical properties, never before elucidated, were revealed in the study. The study revealed a step‐like variation of macroscopic properties: a surprising outcome of the competition between intermolecular attractions, symmetry effects, and mass transfer limitations. The predictive structure‐function relationships established in this work will allow the straightforward engineering of monoamide architectures that can extend the range of organic PCMs and deliver thermal properties desirable for TES applications. [ABSTRACT FROM AUTHOR]

ABSTRACT: The product of 1‐butene metathesis of canola triacylglycerol (CMTAG), with shortened structures, terminal double bonds (50% of the total), and oligomers (40% dimer and trimer, and 10% higher oligomers) was used to synthesize novel polyols and polyurethane foams. A non‐chlorinated (Pol‐1) and a chlorinated polyol (Pol‐2) having OH value (170 and 190 mg KOH/g, respectively) were synthesized from CMTAG by epoxidation followed by hydroxylation, and epoxidation followed by hydrogenation, respectively. Both polyols remained liquid below ambient temperature and demonstrated physical characteristics such as viscosity which allowed for the facile preparation of polyurethane foams. The foam obtained with Pol‐1 was relatively soft (∼0.32 MPa at 10% strain) and very flexible (recovery ∼90%); whereas, the foam obtained with Pol‐2 was semi‐rigid (∼1.1 MPa at 10% strain and recovery of 64%). The higher strength and rigidity of Pol‐2 foam compared to Pol‐1 foam is chiefly attributable to the effect of the bulky chlorines on the crosslink density. Importantly, this work highlights that one can improve and control jointly the mechanical properties and deformation recovery ability of bio‐based foams by combining primary functional groups, oligomers, and high molar volume molecules in the polyols. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46616. [ABSTRACT FROM AUTHOR]

ABSTRACT Green Polyols were synthesized from a 1-butene cross metathesized palm oil (PMTAG) using a green, solvent free epoxidation and hydroxylation pathway. The synthetic strategy was adapted to control the degree of double bond epoxidation and ultimately the hydroxyl value of the polyols. The polyols comprised diol and tetrol monomers with terminal hydroxyl groups content as high as ∼18 mol %, and achieved hydroxyl values between 83 and 119 mg KOH g−1. Functional Rigid and highly flexible foams were prepared from two designer Green Polyols. The foams presented a high thermal stability ( Ton of degradation of ∼270 °C), suitable glass transition temperatures (∼−12 °C and ∼50 °C) and compressive strength (0.21 MPa at 10% strain and ∼1 MPa at 10% strain for the flexible and rigid foams, respectively) which are superior to existing lipid-based counterparts. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43509. [ABSTRACT FROM AUTHOR]

The crystal structure development of jojoba-like esters incorporating either 1-decenoic acid and/or 1-decenol, namely octadec-9-enyl dec-9-enoate (JLE-281), and its isomer dec-9-enyl oleate (JLE-282) was investigated to reveal the effect of symmetry about the ester group on crystallization of aliphatic fatty monoesters. The phase transformation path was investigated with temperature-time resolved X-ray diffraction during stepped isothermal crystallization, and while cooling from the melt at a fixed rate. Startling differences in phase behavior were uncovered between the isomers. When stepped isothermals were used, selective extinctions occurred at a transition temperature for JLE-281 but not for JLE-282. The extinctions, which are due to dramatic changes in the electronic density of certain families of planes, indicate a phase transition attributed to a brusque rearrangement of the oxygen atoms in the crystal subcell. The phase transition did not occur when the JLEs were cooled continuously. The crucial role played by the position of the alkyl chain and its orientation relative to the easy rotation site of the C-O bond in the phase trajectories of the JLEs was particularly highlighted. [ABSTRACT FROM AUTHOR]

Branched derivatives of waxy monoestersincorporating 9-decenoland 9-decenoic acid were synthesized using epoxidation and ring-openingesterification. The reactions were conducted at two different temperaturesand monitored over time. The crystallization, melting, and viscosityof the compounds were all controlled strongly as a function of incrementalbranching. Isomerism was shown to be critically important: an OH groupat the end of the hydrocarbon chain completely suppressed crystallization,whereas its isomer with a terminal acyl chain did not. The structureof the linear monoesters were shown to provide the templates for crystallization,melting, and flow behavior, whereas the branching effect extendedbut could not erase the effect of the base molecular architecture.These compounds present a large range of properties that are suitablefor a variety of applications ranging from waxes to lubricants. [ABSTRACT FROM AUTHOR]

ABSTRACT The physical properties of novel thermoplastic random copolyesters [-(CH2) n-COO-/-(CH2) n-COO-] x made of long ( n = 12) and medium ( n = 8) chain length ω-hydroxyfatty esters [HO-(CH2) n-COOCH3] derived from bio-based vegetable oil feedstock are described. Poly(ω-hydroxy tridecanoate/ω-hydroxy nonanoate) P(−Me13−/−Me9−) random copolyesters ( Mn = 11,000-18,500 g/mol) with varying molar ratios were examined by TGA, DSC, DMA and tensile analysis, and WAXD. For the whole range of P(−Me13−/−Me9−) compositions, the WAXD data indicated an orthorhombic polyethylene-like crystal packing. Their melting characteristics, determined by DSC, varied with composition suggesting an isomorphic cocrystallization behavior. TGA of the P(−Me13−/−Me9−)s indicated improved thermal stability determined by their molar compositions. The glass transition temperature, investigated by DMA, was also found to vary with composition. The crystallinities of P(−Me13−/−Me9−)s however, were unaffected by the composition. The stiffness (Young's modulus) of these materials was found to be related to their degrees of crystallinity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40492. [ABSTRACT FROM AUTHOR]

Three pure jojoba wax-like esters (JLEs), i.e., octadec-9-enyldec-9-enoate (JLE 281), dec-9-enyl oleate (JLE 282), and dec-9-enyl dec-9-enoate (JLE-20), were synthesized from fattyacids and fatty alcohols. Calorimetric, solid fat content evolution,and flow data were used to elucidate the phase behavior of the JLEs.It was clearly established that the length of the terminal alkyl chainand orientation of the linking group in the side chains of the bent-coremolecules play an important role in the phase development of the JLEsand ultimately their physical properties. Measurable differences inall physical properties investigated were detected between the isomersbased on the position of the ester group in the molecule, leadingto informed choices on what isomer should be synthesized for similarmonoesters for specific applications. [ABSTRACT FROM AUTHOR]

Seven model oligomers (from dimer to octamer) of thetriacylglycerol(TAG) triolein were synthesized from oleic acid and fully characterizedby 1H NMR, 13C NMR, mass spectroscopy, and gelpermeation chromatography (GPC). The thermal stability of the oligomersas determined by TGA was excellent, with degradation beginning at342 °C for the most thermally labile samples. The samples allpresented glass transitions at low temperatures, with Tgcontinuously shifting to higher temperatures with increasingnumbers of monomers. The crystallization and melting behavior scaledwith molecular size and relative number of double bonds in the trans-configuration. Flow behavior was investigated over a large range oftemperatures (−10 to 110 °C), and application of the Herschel–Bulkeymodel to shear stress versus shear rate data evidenced a flow behaviordependent on molecular size and temperature. The oligomers presenteda thinning to Newtonian flow transition temperature proportional tomolecular size. The viscosity versus temperature data, fitted witha generalized van Velzen equation, suggested that it is the competitionbetween the trans- character and size of the molecules which determinesthe rheology of these molecules. Overall, all the investigated propertiesplateaued at the hexamer, suggesting that no further marginal utilitycan be obtained with larger oligomers. [ABSTRACT FROM AUTHOR]

A comprehensive study of branched derivatives of fourpure jojobawax-like esters (JLEs), having 36, 40 (two isomers), and 44 carbonswas conducted to elucidate their crystallization and melting behavior.Crystallization and melting characteristics depended strongly on thenumber of branches, molar mass, and symmetry. The derivatives demonstrateda very strong tendency to form glassy liquids rather than crystalphases and remain liquid-like at very low temperatures. As the numberof branches increased, their crystallinity decreased drastically whiletheir glassy phase increased concomitantly with the depression ofthe onset of crystallization and/or glass transition temperature.A variety of possible transformation paths, ranging from very littlepolymorphic activity to extremely polymorphic behavior, dependingon number of branches, mass, and symmetry were revealed. It is shownthat asymmetry plays a large role in the low temperature behavior,rendering the branched derivatives of the asymmetrical JLEs much bettercandidates for lubricant formulations. [ABSTRACT FROM AUTHOR]

Abstract: The phase behavior of 1-palmitoyl-2,3-distearoyl-sn-glycerol (PSS)/tristearoylglycerol (SSS) binary system was investigated in terms of polymorphism, crystallization and melting behavior, microstructure and solid fat content (SFC) using widely different constant cooling rates. Kinetic phase diagrams were experimentally determined from the DSC heating thermograms and analyzed using a thermodynamic model to account for non-ideality of mixing. The kinetic phase diagram presented a typical eutectic behavior with a eutectic point at the 0.5PSS mixture with a probable precipitation line from 0.5PSS to 1.0PSS, regardless of the rate at which the sample was cooled. The eutectic temperature decreased only slightly with increasing cooling rate. PSS has a strong effect on the physical properties of the PSS–SSS mixtures. In fact, the overall phase behavior of the PSS–SSS binary system was determined, for a very large part, by the asymmetrical TAG. Moreover, PSS is a key driver of the high stability observed in crystal growth, polymorphism and phase development. Levels as low as 10% PSS, when cooled slowly, and 30% when cooled rapidly, were found to be sufficient to suppress the effect of thermal processing. [Copyright &y& Elsevier]

Abstract: Four pure jojoba wax-like esters (JLEs), having carbon chain length of 36, 40 (two isomers) and 44, were prepared by Steglish esterification of fatty acids (or acid chlorides) with fatty alcohols at room temperature. Calorimetric and diffraction data was used to elucidate the phase behavior of the esters. The primary thermal parameters (crystallization and melting temperatures) obtained from the DSC of the symmetrical molecules correspond well with the carbon numbers of the JLEs. However, the data also suggests that carbon number is not the only factor since the symmetry of the molecule also plays a significant role in the phase behavior. Overall, the JLEs show very little polymorphic activity at the experimental conditions used, suggesting that they are likely to transform the same way during melting as well as crystallization, a characteristic which may be useful in designing new waxes and lubricants. The XRD data clearly show that the solid phase in all samples consists of a mixture of a β-phase and a β′-phase; fully distinguishable by their characteristic diffraction peaks. Subtle differences between the subcell patterns and phase development of the samples were observed. Different layering of the samples was also observed, understandably because of the chain length differences between the compounds. The long spacings were perfectly linearly proportional to the number of carbon atoms. The length of the ester layers with n carbon atoms can be calculated by a formula similar to that used for the layers in linear alkane molecules. [Copyright &y& Elsevier]

Abstract: The kinetic phase behavior and phase transformation paths of purified tristearoylglycerol (SSS), 3-palmitoyl-1,2-distearoyl-sn-glycerol (PSS) and 1,2-dipalmitoyl-3-stearoyl-sn-glycerol (PPS) were investigated in terms of polymorphism, crystallization and melting. The details of the phase transformation paths were obtained using the heating cycles of two sets of experiments: (a) cooling rate was varied and heating rate fixed and (b) cooling rate was fixed and heating rate varied. Kinetic effects were manifest in all measured properties, underscoring the complexity of the phase transformation paths for each TAG, and the intricate thermodynamics–molecular relationships. For the first time, XRD data obtained for SSS, PSS and PPS TAGs, cooled at rates higher than 0.5°C/min, suggested the formation of a transient structure similar to the so-called α2-phase which has been observed in mixed saturated–unsaturated TAGs quenched from the melt. The more stable phases (β′ in PSS and PPS, and β in SSS) were only observed for cooling rates lower than 1.0°C/min. The kinetic and thermodynamic differences observed in the crystallization, structure and melting of SSS, PSS and PPS are proposed to be mainly due to the disturbances introduced at the “terrace” level via methyl-end group interactions, i.e., the missing of two or four CH2 groups compared to SSS. The symmetrical SSS with a relatively flat “terrace” crystallizes preferably in the most stable β-form. Two missing CH2 groups at the sn-1 position (PSS) introduces enough structural disturbances to promote the relative prevalence and persistence of the β′-phase, and four missing CH2 groups at the sn-1 and sn-2 positions (PPS) is relatively too large of a disturbance and therefore favors the α-form. [Copyright &y& Elsevier]

Abstract: A robust, well-defined and reproducible method to accurately measure the oil binding capacity (OBC) of structuring fats was developed. The method was validated using two oil/fat model systems, i.e., fully hydrogenated canola oil (FHCO) in canola oil (CO) (FHCO/CO) and fully hydrogenated soybean oil (FHSO) in CO (FHSO/CO). The mixtures were crystallized from the melt down to three different temperatures (15, 25 and 35°C) at constant rates of cooling and the OBC was measured after different periods of storage time. The critical concentration of hard fat at which the solid fat network is stable and effectively binds oil has been also measured for mixtures crystallized at temperatures close to room temperature, i.e., 25°C. Crystal structure, melting behavior, microstructure, and solid fat content of these binary systems have been investigated in relation to the OBC of the solid fat network using X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and wide-line pulsed nuclear magnetic resonance (pNMR) techniques. The two model systems exhibited similar trends in OBC over time, a behavior attributed to their similar TAG composition and polymorphism. However, relatively smaller OBC values were achieved by the CO/FHSO compared to CO/FHCO samples, largely due to differences in their solid network structure. Four successive decreasing linear segments, identifying successive mechanisms of oil migration/binding, were observed in the experimental OBC versus fat weight fraction curves. The critical concentration of hard fat, at which the solid fat network is effective in binding oil, was also determined and found to be ∼6wt% for both systems. [ABSTRACT FROM AUTHOR]

Abstract: The binary phase behavior of purified 1,3-dilauroyl-2-stearoyl-sn-glycerol (LSL) and 1,2-dilauroyl-3-stearoyl-sn-glycerol (LLS) was investigated at a slow (0.1°C/min) and a relatively fast (3.0°C/min) cooling rate in terms of melting and crystallization, polymorphism, solid fat content (SFC), hardness and microstructure. Much of the behavior of the system is explained by its polymorphism and the influence of thermal processing. The α-form and the β′-form of a double chain length structure were detected in the mixtures cooled at 3.0°C/min, whereas only the β′-form was detected in those cooled at 0.1°C/min. X-ray diffraction data as well as thermodynamic data propose that the most stable phases are promoted by the symmetrical LSL. The measured trends in structural characteristics, thermal properties, SFC, relative hardness and microstructure delimit three groups of mixtures which imply a competition between the stabilizing effect of LSL and disordering introduced by kinetic effects: (a) LLS-rich mixtures with LSL molar fractions (X LSL) less than 0.3, (b) mixtures with X LSL clustered around 0.5 and (c) LSL-rich mixtures with X LSL ≥0.7. The balance between ordering and kinetic effects determines the polymorphism of the mixtures, which in turn determines the behavior of the LSL/LLS system. The kinetic phase diagram of the LSL/LLS binary system constructed using heating differential scanning calorimetry thermograms displayed a singularity at the 0.5LSL molar fraction which delimits two distinct behaviors: eutectic behavior in one region and monotectic behavior in the other. The molecular interactions, as depicted by a non-ideality parameter of mixing obtained from a thermodynamic model based on the Hildebrand equation, suggests an almost ideal mixing behavior and a moderate tendency to the formation of unlike-pairs in the liquid state. [Copyright &y& Elsevier]

Abstract: The phase behavior of a binary system constituted of purified 1,3-dicaproyl-2-stearoyl-sn-glycerol (CSC) and 1,2-dicaproyl-3-stearoyl-sn-glycerol (CCS) was investigated at a very slow (0.1°C/min) and a relatively fast (3.0°C/min) cooling rate using differential scanning calorimetry (DSC), low resolution NMR, X-ray diffraction (XRD), and polarized light microscopy (PLM). Related forms of the β′ polymorph were detected for all mixtures as well as a β form for CSC-rich mixtures. A double chain length (DCL) stacking of the non-mixed CCS–CCS and CSC–CSC phases and a triple chain length (TCL) stacking of mixed CCS–CSC structure were detected for the different β′ forms. The kinetic phase diagram demonstrated an apparent eutectic at the 0.5CSC composition when cooled at 0.1°C/min and at the 0.25CSC composition when cooled at 3.0°C/min. The application of a thermodynamic model based on the Hildebrand equation suggests that compounds CSC and CCS are not fully miscible. In addition, the miscibility changes according to the structure of the growing solid phase which is dependent on CSC molar ratio as well as on the kinetics. It was also shown that the miscibility is concentration dependent and that the solid phase, which is growing at conditions well away from equilibrium, is determined kinetically. The molecular interactions were found to be strong and to favor the formation of CSC–CCS pairs in the liquid state. CSC and CCS were also shown to be immiscible in the solid state. Depressions in solid fat content (SFC) were observed for both rates. Relatively complex networks made of needle-like, spherulitic and granular crystals were observed in the CSC/CCS system. A pure CSC phase was found to be instrumental in promoting a higher SFC, and more stable polymorphic forms. The microstructure was shown to be strongly dependent on the cooling rate and was linked to the different polymorphic forms observed by DSC and XRD. Correlations between SFC and the eutectic behavior have been observed for the 3.0°C/min cooling rate, but not directly in the case of the 0.1°C/min cooling rate, where slower kinetics which favors the metastable to stable phase conversion processes prevented the same shifts in behavior. [Copyright &y& Elsevier]

Abstract: The phase behavior of the 1,3 propanediol dicaprylate/1,3 propanediol distearate (CC/SS) and the 1,3 propanediol dicaprylate/1,3 propanediol dipalmitate (CC/PP) binary systems were investigated using different techniques. The two systems presented essentially the same overall features. XRD measurements detected CC–CC, PP–PP and SS–SS bilayers which crystallized in β forms but no mixed bilayers for all mixtures. The phase diagrams of both systems were comparable and displayed a monotectic behavior. As strongly evidenced by XRD data, both phase diagrams suggested that CC, PP and SS formed largely separate phases but were probably not completely immiscible. Avrami analysis of SFC vs. time indicated heterogeneous nucleation and spherulitic crystal development from sporadic nuclei. However, noticeable differences in the manifestation of the molecular interactions have been detected at all levels of structure and confirmed by the interchange coupling determined by the enthalpy of melt, the final SFC and the hardness data. This was obviously related to the difference in chain size between SS and PP molecules. The effect on texture was highlighted by drastic microstructural differences between the two systems. Furthermore, the differences in nucleation and crystal growth, the more pronounced tendency for phase separation in the CC/SS system compared to the CC/PP system, and the relatively better crystallization of the CC/PP mixtures, particularly visibly for x CC ≤0.3 compared to the CC/SS mixtures were associated with the chain length difference. [Copyright &y& Elsevier]

Abstract: Polymorphic influences on the phase behavior of two types of binary mixtures of saturated monoacid 1,3-propanediol esters (PADEs), dipalmitate/distearate (PP/SS) and dimyristate/distearate (MM/SS) were examined by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and by solid fat content (SFC), hardness and microscopy measurements. Three stacking modes have been found in the PP/SS binary system. Mixed SS–PP bilayers were detected in all mixtures, SS–SS bilayers in x PP =0.0–0.4 mixtures and PP–PP bilayers in x PP =0.6–0.1 mixtures. Two different but close β polymorphs and one β′ polymorph were detected for this system. β′ was only detected in x PP =0.5–0.9 mixtures for the mixed bilayers. For the MM/SS binary system, only MM–MM and SS–SS bilayers were detected and both solid phases crystallized in two different β forms. XRD data evidenced clearly that the MM and SS components were completely immiscible in the solid state. The phase diagrams constructed using DSC data, exhibited a typical eutectic-type phase boundary. The presence of eutectics, the shape of the solidus lines as well as the analysis of the individual enthalpies of melting indicated typical phase separation for both systems. A thermodynamic study based on the Hildebrand equation and using the Bragg–Williams approximation for non-ideality of mixing confirmed the phase separation in the solid phase and suggested that the PP and SS were miscible in the liquid phase and that SS formed an ideal mixing with MM. Avrami analysis of SFC vs. time curves indicated heterogeneous nucleation and spherulitic crystal development from sporadic nuclei, and suggested that the nucleation rate was higher for the mixture at the eutectic composition. The relative hardness was correlated with the enthalpies, the final SFC and the microscopy measurements. [Copyright &y& Elsevier]

Abstract: A locally isolated (Perryvale, Alta., Canada) fungal genus, Mortierella ramanniana var. ramanniana, was evaluated as a potential industrial producer of γ-linolenic acid (GLA). Six growth variables (pH, temperature, carbon source, nitrogen source, and metal ions and oil supplementation) were systematically manipulated. The results indicated that the GLA production for this particular strain, could be maximized by using a basal growth medium consisting of 5% dextrose and 1% yeast extract, supplemented with 5mg/L Mn2+ with incubation at 20°C. The lipid yield under optimum conditions was 54.2% of the total dry biomass and consisted of 84.3% unsaturated fatty acids. The yield of GLA per gram biomass represented 13.3% of the total lipid content, slightly higher than that of the typical evening primrose oil GLA yield. The study establishes this variety as an effective intermediate fungal source of GLA. [Copyright &y& Elsevier]