EFFECT OF INTERMITTENT FRYING ON FATTY ACIDS, VITAMIN E, LIPID OXIDATION AND ACRYLAMIDE IN OILS AND PLANTAIN CHIPS COLLECTED FROM SMALL- SCALE PRODUCERS IN CAMEROON

Deep-fat frying is susceptible to induce the formation of undesirable products as lipid oxidation products and acrylamide in fried foods. Plantain chips produced by small-scale producers are sold to consumers without any control. The objective of this study was to evaluate the quality of plantain chips from local producers in relation to production process parameters and oils, and to identify the limiting factors for the production of acrylamide in plantain chips. Samples of frying oils and plantain chips prepared with either palm olein or soybean oil were collected from 10 producers in Yaoundé. Quality parameters determined in this study were: fatty acid composition of the oils, determined by gas chromatography (GC) of free acid methyl ester; trans fatty acids, determined by Fourier transform infra-red spectroscopy; Tocopherols and tocotrienols as markers of nutritional quality were analyzed by High Performance Liquid Chromatography in isocratic mode. Free fatty acids and acylglycerols as markers of lipid hydrolysis were analyzed by GC of trimethylsilyl derivatives of glycerides. Conjugated dienes, Anisidine value and viscosity as markers of lipid oxidation and thermal decomposition of the oils; acrylamide which is formed through Maillard reaction and identified as a toxic compound in various fried products. Asparagine content of the raw fresh plantain powder was also determined. Fatty acid composition of palm oleins was stable within a day of intermittent frying. In soybean oils, about 57% and 62.5% of linoleic and linolenic acids were lost but trans fatty acids were not detected. Soybean oils were partly hydrolysed leading to the formation of free fatty acids, monoacylglycerols and diacylglycerols. In both oils, tocopherols and tocotrienols contents decreased significantly by about 50%. Anisidine value (AV) and polymers contents increased slightly in fried palm oleins while conjugated hydroperoxides, AV and polymers greatly increased in soybean oils. Acrylamide was not detected in the chips. This is explained by the absence of asparagine in the raw plantains, the other acrylamide precursors being present. This study shows that the plantain chips prepared at the small-scale level in Yaounde with palm olein are of good quality regarding oxidation and hydrolysis parameters and the absence of acrylamide. In contrast, oxidation developed with soybean oil whose usage for frying should be questioned. Considering that asparagine is the limiting factor for the formation of acrylamide in plantain chips, its content depending on several factors such as production parameters and maturity stage should be explored.

Impacto da utilização de ácido gálhico, ácido ferúlico e eugenol em modo contínuo na suscetibilidade de Pseudomonas aeruginosa

Dissertação de Mestrado, Biologia Molecular e Microbiana, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

UV-Vis, FTIR and antioxidant study of Persea Americana (Avocado) leaf and fruit: A comparison

El aguacate (Persea americana Miller) es una conocida fruta arb´orea con un alto contenido nutricional que crece en varias partes del mundo. El presente estudio compara los espectros del UV-Vis y del espectr´ometro infrarrojo con transformada de Fourier (FTIR) de la fruta y de la hoja de aguacate (c´ascara, pulpa y aceite) cultivado en Ecuador y posteriormente eval´ua su actividad antioxidante empleando el 1,1-difenil-2-picrilhidrazil (DPPH•). El estudio de los espctros UV-Vis y FTIR revel´o que el aguacate tiene predominantemente flavonoides. Entre la hoja y el fruto del aguacate, se comprob´o mediante el ensayo DPPH• (captura de radicales libres), que la hoja tuvo una mayor actividad antioxidante, la que oscila entre 84,46% y 80,12%, con valores de 32.60-32.73 μg equivalentes de ´acido g´alico por mL. Se demostr´o que el orden de la actividad antioxidante de los extractos es: hoja de aguacate > c´ascara > aceite > pulpa. La actividad antioxidante tuvo una correlaci´on positiva con el contenido total de flavonoides y estos extractos de plantas (especialmente de las hojas del aguacate) son ´utiles para el desarrollo de futuros productos antioxidantes.

Determination of antioxidant activity, phenolic contents and antiviral potential of methanol extract of Euphorbia spinidens (Euphorbiaceae)

Purpose: This study was aimed to evaluate the antioxidant activity of the methanol extract of Euphorbia spinidens (Euphorbiaceae) and its effect on Herpes simplex virus type-1 (HSV-1) replication. Methods: The methanol extract of aerial parts of E. spinidens collected from Khorasan State in North- Eastern part of Iran was used in this study. Total phenolic, flavonoid contents and the antioxidant activity were evaluated using Folin-Ciocalteu method, aluminum chloride colorimetric method and β- carotene-linoleate model system, respectively. Both the cytotoxic and antiviral effects of the crude extract on Vero cell line were determined by quantifying the viability of Vero cells using 3-(4,5- dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium (MTS) assay. Results: Total phenolic and flavonoid contents of E.spinidens were 70 ± 1 mg of gallic acid equivalent/g of dry extract (mg GAE/g extract) and 49.66 ± 1.00 mg rutin equivalent/g of dry extract (mg RTN/g extract), respectively. Antioxidant activity was 44 ± 1 % compared with the standard, buthylated hydroxytuloene (BHT). The 50 % cytotoxic concentration (CC50) of the extract on Vero cells was 5.072 ± 0.063 mg/ml and its antiviral concentration of 50 % effectiveness (EC50) value was 0.34 ± 0.003 mg/ml. Conclusion: The findings of this study show that the methanol extract of E. spinidens has high content of phenolic and flavonoid compounds with good antioxidant activity. Furthermore, this extract has significant antiviral effect on HSV-1 probably due to the inhibition of viral replication.

Anti-cancer and antioxidant properties of phenolics isolated from Toona sinensis A Juss acetone leaf extract

Purpose: To investigate the antioxidant and anticancer activities of phenolics from the leaf extract of Toona sinensis (TS). Methods: Acetone leaf extract of TS was screened for total phenolic and flavanoid contents, and the flanonoids were subjected to high performance liquid chromatographic (HPLC) analysis. Antioxidant properties were assessed via oxygen radical absorbance capacity (ORAC), peroxyl radical scavenging capacity (PSC) and cellular antioxidant activity (CAA), while anti-proliferative activity ins HepG2 cell line was assessed using methylene blue assay. Results: The extract contained 36.02 ± 0.24 mg of gallic acid equiv/g dry weight (DW) and 20.24 ± 1.73 mg of catechin equiv/g DW of total phenolic and total flavonoid, respectively. The levels of rutin and quercitrin were 0.51 and 19.55 mg/g, respectively. Epicatechin, gallic acid, quercitin, isoquercetin were not detected. The extract showed significant antioxidant potential and high anti-proliferation capacity with low cytotoxicity against HepG2 cell in vitro. The underlying mechanism of anti-proliferative effect was induction of apoptosis. Conclusion: TS leaf extract possesses significant in vitro antioxidant properties and anti-proliferative effect against HepG2 cells, which make it a potential anticancer drug source.

Anticonvulsant and sedative effect of Fufang Changniu pills and probable mechanism of action in mice

Purpose: To investigate the anticonvulsant and sedative effects of Fufang Changniu Pills (FCP) and its probable mechanism of action in mice. Methods: The water decoction of FCP was prepared and the main constituents were determined by high performance liquid chromatography (HPLC). The anticonvulsant activities of FCP were evaluated by maximal electroshock (MES) and pentylenetetrazole (PTZ)-induced seizures in mice. Pentobarbital sodium-induced sleeping time and locomotor activity measurements were performed to evaluate the sedative effects of FCP in mice. Finally, PTZ-induced chronic seizures were established, and expressions of gamma-aminobutyric acid A receptor (GABA-A) and glutamic acid decarboxylase 65 (GAD65) in the brains of the mice were assayed by western blot in order to explore the probable mechanisms of action of the drug. Results: Gallic acid, liquiritin, cinnamyl alcohol, cinnamic acid and glycyrrhizic acid were detected in FCP decoction. FCP (50, 100 and 200 mg/kg) showed significant anticonvulsant and sedative effects on epileptic mice induced by MES (p < 0.05) and PTZ (p < 0.05). Moreover, pentobarbital sodium-induced sleeping time and locomotor activity tests showed that FCP possesses sedative effect (p < 0.05). Western blot data indicate that FCP significantly up-regulated GABA-A and GAD 65 in the brains of chronic epileptic rats (p < 0.05). Conclusion: FCP has significant anticonvulsant and sedative effects, and the mechanism of its action may be related to the up-regulation of GABA-A and GAD 65 in mice brain.

Engineered zeolitic materials: synthesis and application

Les zéolithes étant des matériaux cristallins microporeux ont démontré leurs potentiels et leur polyvalence dans un nombre très important d’applications. Les propriétés uniques des zéolithes ont poussé les chercheurs à leur trouver constamment de nouvelles utilités pour tirer le meilleur parti de ces matériaux extraordinaires. Modifier les caractéristiques des zéolithes classiques ou les combiner en synergie avec d’autres matériaux se trouvent être deux approches viables pour trouver encore de nouvelles applications. Dans ce travail de doctorat, ces deux approches ont été utilisées séparément, premièrement avec la modification morphologique de la ZSM-12 et deuxièmement lors de la formation des matériaux de type coeur/coquille (silice mésoporeuses@silicalite-1). La ZSM-12 est une zéolithe à haute teneur en silice qui a récemment attiré beaucoup l’attention par ses performances supérieures dans les domaines de l’adsorption et de la catalyse. Afin de synthétiser la ZSM-12 avec une pureté élevée et une morphologie contrôlée, la cristallisation de la zéolithe ZSM-12 a été étudiée en détail en fonction des différents réactifs chimiques disponibles (agent directeur de structure, types de silicium et source d’aluminium) et des paramètres réactionnels (l’alcalinité, ratio entre Na, Al et eau). Les résultats présentés dans cette étude ont montré que, contrairement à l’utilisation du structurant organique TEAOH, en utilisant un autre structurant, le MTEAOH, ainsi que le Al(o-i-Pr)3, cela a permis la formation de monocristaux ZSM-12 monodisperses dans un temps plus court. L’alcalinité et la teneur en Na jouent également des rôles déterminants lors de ces synthèses. Les structures de types coeur/coquille avec une zéolithe polycristalline silicalite-1 en tant que coquille, entourant un coeur formé par une microsphère de silice mésoporeuse (tailles de particules de 1,5, 3 et 20-45 μm) ont été synthétisés soit sous forme pure ou chargée avec des espèces hôtes métalliques. Des techniques de nucléations de la zéolithe sur le noyau ont été utilisées pour faire croitre la coquille de façon fiable et arriver à former ces matériaux. C’est la qualité des produits finaux en termes de connectivité des réseaux poreux et d’intégrité de la coquille, qui permet d’obtenir une stéréosélectivité. Ceci a été étudié en faisant varier les paramètres de synthèse, par exemple, lors de prétraitements qui comprennent ; la modification de surface, la nucléation, la calcination et le nombre d’étapes secondaires de cristallisation hydrothermale. En fonction de la taille du noyau mésoporeux et des espèces hôtes incorporées, l’efficacité de la nucléation se révèle être influencée par la technique de modification de surface choisie. En effet, les microsphères de silice mésoporeuses contenant des espèces métalliques nécessitent un traitement supplémentaire de fonctionnalisation chimique sur leur surface externe avec des précurseurs tels que le (3-aminopropyl) triéthoxysilane (APTES), plutôt que d’utiliser une modification de surface avec des polymères ioniques. Nous avons également montré que, selon la taille du noyau, de deux à quatre traitements hydrothermaux rapides sont nécessaires pour envelopper totalement le noyau sans aucune agrégation et sans dissoudre le noyau. De tels matériaux avec une enveloppe de tamis moléculaire cristallin peuvent être utilisés dans une grande variété d’applications, en particulier pour de l’adsorption et de la catalyse stéréo-sélective. Ce type de matériaux a été étudié lors d’une série d’expériences sur l’adsorption sélective du glycérol provenant de biodiesel brut avec des compositions différentes et à des températures différentes. Les résultats obtenus ont été comparés à ceux utilisant des adsorbants classiques comme par exemple du gel de sphères de silice mésoporeux, des zéolithes classiques, silicalite-1, Si-BEA et ZSM-5(H+), sous forment de cristaux, ainsi que le mélange physique de ces matériaux références, à savoir un mélange silicalite-1 et le gel de silice sphères. Bien que le gel de sphères de silice mésoporeux ait montré une capacité d’adsorption de glycérol un peu plus élevée, l’étude a révélé que les adsorbants mésoporeux ont tendance à piéger une quantité importante de molécules plus volumineuses, telles que les « fatty acid methyl ester » (FAME), dans leur vaste réseau de pores. Cependant, dans l’adsorbant à porosité hiérarchisée, la fine couche de zéolite silicalite-1 microporeuse joue un rôle de membrane empêchant la diffusion des molécules de FAME dans les mésopores composant le noyau/coeur de l’adsorbant composite, tandis que le volume des mésopores du noyau permet l’adsorption du glycérol sous forme de multicouches. Finalement, cette caractéristique du matériau coeur/coquille a sensiblement amélioré les performances en termes de rendement de purification et de capacité d’adsorption, par rapport à d’autres adsorbants classiques, y compris le gel de silice mésoporeuse et les zéolithes.

Production de biodiesel à partir de microalgues par catalyses homogène et hétérogène

Résumé : Au Canada, près de 80% des émissions totales, soit 692 Mt eq. CO[indice inférieur 2], des gaz à effet de serre (GES) sont produits par les émissions de dioxyde de carbone (CO[indice inférieur 2]) provenant de l’utilisation de matières fossiles non renouvelables. Après la Conférence des Nations Unies sur les changements climatiques, COP21 (Paris, France), plusieurs pays ont pour objectif de réduire leurs émissions de GES. Dans cette optique, les microalgues pourraient être utilisées pour capter le CO[indice inférieur 2] industriel et le transformer en biomasse composée principalement de lipides, de glucides et de protéines. De plus, la culture des microalgues n’utilise pas de terre arable contrairement à plusieurs plantes oléagineuses destinées à la production de biocarburants. Bien que les microalgues puissent être transformées en plusieurs biocarburants tels le bioéthanol (notamment par fermentation des glucides) ou le biométhane (par digestion anaérobie), la transformation des lipides en biodiesel pourrait permettre de réduire la consommation de diesel produit à partir de pétrole. Cependant, les coûts reliés à la production de biodiesel à partir de microalgues demeurent élevés pour une commercialisation à court terme en partie parce que les microalgues sont cultivées en phase aqueuse contrairement à plusieurs plantes oléagineuses, ce qui augmente le coût de récolte de la biomasse et de l’extraction des lipides. Malgré le fait que plusieurs techniques de récupération des lipides des microalgues n’utilisant pas de solvant organique sont mentionnées dans la littérature scientifique, la plupart des méthodes testées en laboratoire utilisent généralement des solvants organiques. Les lipides extraits peuvent être transestérifiés en biodiesel en présence d’un alcool tel que le méthanol et d’un catalyseur (catalyses homogène ou hétérogène). Pour la commercialisation du biodiesel à partir de microalgues, le respect des normes ASTM en vigueur est un point essentiel. Lors des essais en laboratoire, il a été démontré que l’extraction des lipides en phase aqueuse était possible afin d’obtenir un rendement maximal en lipides de 36% (m/m, base sèche) en utilisant un prétraitement consistant en une ébullition de la phase aqueuse contenant les microalgues et une extraction par des solvants organiques. Pour l’estérification, en utilisant une résine échangeuse de cations (Amberlyst-15), une conversion des acides gras libres de 84% a été obtenue à partir des lipides de la microalgue Chlorella protothecoïdes dans les conditions suivantes : température : 120°C, pression autogène, temps de réaction : 60 min, ratio méthanol/lipides: 0.57 mL/g et 2.5% (m/m) Amberlyst-15 par rapport aux lipides. En utilisant ces conditions avec une catalyse homogène (acide sulfurique) et une seconde étape alcaline avec de l’hydroxyde de potassium (température : 60°C ; temps de réaction : 22.2 min; ratio catalyseur microalgue : 2.48% (m/m); ratio méthanol par rapport aux lipides des microalgues : 31.4%), un rendement en esters méthyliques d’acides gras (EMAG) de 33% (g EMAG/g lipides) a été obtenu à partir des lipides de la microalgue Scenedesmus Obliquus. Les résultats démontrent que du biodiesel peut être produit à partir de microalgues. Cependant, basé sur les présents résultats, il sera necessaire de mener d’autre recherche pour prouver que les microalgues sont une matière première d’avenir pour la production de biodiesel.

Propolis components accountable for bactericidal accomplishment and antibiofilm activity

This study aimed at evaluating antimicrobial and antibiofilm activity of phenolic compounds present in propolis ethanol extracts (PEE). Seventy per cent ethanol extracts from seven types of propolis, one Green, two Red and four Brown collected in four Brazilian States were prepared and total phenolics, flavonoids, tannins and anthocyanins were assessed by high-performance liquid chromatography (HPLC). Minimum bactericidal concentration (MBC) and inhibitor effect on Staphylococcus aureus biofilm formation and capacity to disrupt established biofilms were assessed towards eight S. aureus isolates from milk of small ruminants with mastitis, one methicillin-resistant S. aureus (MRSA) and S. aureus ATCC 25923. To evaluate different propolis components accountability for bactericidal accomplishment and antibiofilm activity, the results were analysed by the non-parametric Spearman coefficient. Results of phenolic compounds were 216,21 to 312,08 gallic acid milligram equivalent per extract gram (mg EGA/g) of total phenolics, 55,08 to 140,6 quercetin milligram equivalent per extract gram (mg EQ/g) of flavonoids, 118,51 to 3766,16 catechin milligram equivalent per extract gram (mg EC/g) of tannins and 1,03 to 8,39 milligram per extract gram (mg/g) of anthocyanins. Red1 and Red2 showed higher tannin contents, while Red2 exhibited superior amount of anthocyanins and total phenolics. Brown3 presented higher flavonoid quantity. Green, Red1 and Red2 PEE showed the lowest levels of flavonoids, but the higher antimicrobial activity. Most PEE exhibit bactericidal activity at a concentration of 1.6 mg/mL. Brown4 PEE showed the worst capacity to inhibit S. aureus. Green PEE showed to be the most efficient in both preventing and disrupting biofilm. All PEE studied exhibited a better inhibitory activity prior-to than post-biofilm formation. According to non-parametric Spearman correlation analysis, there seems to be a significant negative correlation between the ability to disrupt biofilm and both tannins and anthocyanins contents.

Effects of nitrogen level on purslane antioxidant activity.

The high antioxidant activity of purslane, Portulaca oleracea L., gives it a high nutritional and functional value. The commercial production of purslane has increased in Portugal, making it necessary to know the effects of inputs, mainly nitrogen, on the antioxidant activity. The main goal of this study was to evaluate the influence of nitrogen application on purslane antioxidant activity. The experiment was carried out with for treatments: 30, 60 and 90 kg/ha of nitrogen. Plants of golden-leaf purslane were grown in Styrofoam-boxes filled with substrate and fertigated two times per week, over four weeks with ammonium nitrate solution (16.9% NO3-N and 16.7 NH4+-N). The increase in the nitrogen level decreased the water-soluble proteins content. However the ascorbate, phenols content as well as antioxidant activity measured by FRAP method was not affected by nitrogen level. Plants shoot antioxidant activity, measured by DPPH method decreased significantly in the treatment with 90 kg N/ha (26.20 g/g gallic acid). On the other hand, plant shoot antioxidant activity mediated by peroxidases was higher in treatment 30 kg N/ha (0.459 µmol min-1/mg prot.). Application of 60 kg N/ha allowed a vigorous plant growth without disturb its antioxidants and conservation properties.

Biodiesel production from waste cooking oil over sulfonated catalysts

Biodiesel production from waste cooking oil with methanol was carried out in the presence of poly(vinyl alcohol) with sulfonic acid groups (PVA-SO3H) and polystyrene with sulfonic acid groups (PS-SO3H), at 60°C. The PVA-SO3H catalyst showed higher catalytic activity than the PS-SO3H one. In order to optimize the reaction conditions, different parameters were studied. An increase of waste cooking oil conversion into fatty acid methyl esters with the amount of PVA-SO3H was observed. When the transesterification and esterification of WCO was carried out with ethanol over PVA-SO3H, at 60°C, a decrease of biodiesel production was also observed. The WCO conversion into fatty acid ethyl ester increased when the temperature was increased from 60 to 80°C. When different amounts of free fatty acids were added to the reaction mixture, a slight increase on the conversion was observed. The PVASO3H catalyst was reused and recycled with negligible loss in the activity.

An ESR and NMR study of the gamma radiolysis of a bisphenol-A based polycarbonate and a phthalic acid ester

A study of the gamma-radiolysis of the commercial polymers U-polymer, UP (Unitake) and polycarbonate, PC, (Aldrich) has been undertaken using ESR spectroscopy. The G-value of radical formation at 77 K has been found to be 0.31 +/- 0.01 for UP and 0.5 +/- 0.02 for PC. By using thermal annealing and spectral subtraction, the paramagnetic species formed on irradiation has been assigned. The effect of radiation on the chemical structure of UP and PC has been investigated at ambient temperature and at 423 K. The NMR results show that a new phenol type chain end is formed in the polymers on exposure to gamma-radiation. The G-value of formation of the new phenol ends was estimated to be 0.7 for PC (423 K) and 0.4 for UP (300 K). (C) 1998 John Wiley & Sons, Ltd.

Synthesis, identification, characterization, stability, solubility, and protein binding of ester derivatives of salicylic acid and diflunisal

O-Acyl esters were prepared from salicylic acid and diflunisal by esterification with the appropriate acyl anhydride (in the presence of sulfuric acid at 80 degrees C) or acyl chloride (in the presence of pyridine at 0 degrees C). Synthesis, identification and characterization of these compounds is described. In vitro hydrolysis, solubility and protein binding studies of these O-acyl esters were performed. For the diflunisal esters, the melting points fell as the side chain was increased from ethyl to pentyl. The melting points showed no significant difference as the length of the side chain was increased from pentyl to heptyl. The aspirin analogues showed a similar trend, The relationship between solubility and carbon chain length agreed closely with that for the melting points with carbon chain length. In vitro non-enzymatic hydrolysis studies concluded that: (1) hydrolysis rate constants generally decreased with carbon chain length; (2) the diflunisal esters have shorter half lives compared with their salicylate counterparts; and (3) the in vitro hydrolysis of these compounds was retarded by the presence of bovine serum albumin. Protein binding experiments showed that the strength of binding of the aspirin and diflunisal analogues to bovine serum albumin increased with carbon chain length. (C) 1997 Elsevier Science B.V.

Esterification of oleic acid catalayzed by an Aspergillus niger strain. Influence of water activity and alcohol concentration

Effects of water activity and 1-propanol concentration on synthesis of propyl oleate from oleic acid using Aspergillus niger cell-bound lipases in isooctane are described. A. niger produces lipases (EC 3.1.1.3) which partly bind to the mycelium during growth. Ester production was monitored for 72 hours at different 1-propanol concentrations and water activities. Aliquots were sequentially withdrawn and propyl esters were quantified using GC and methyl palmitate as an internal standard. In all assayed conditions A. niger cell-bound lipases catalysed propyl oleate synthesis, but at different degrees.

Reversible flow of cholesteryl ester between high-density lipoproteins and triacylglycerol-rich particles is modulated by the fatty acid composition and concentration of triacylglycerols

We determined the influence of fasting (FAST) and feeding (FED) on cholesteryl ester (CE) flow between high-density lipoproteins (HDL) and plasma apoB-lipoprotein and triacylglycerol (TG)-rich emulsions (EM) prepared with TG-fatty acids (FAs). TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18% and 14%, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001) and a negative correlation from EM to HDL (r = -041, P = 0.0088). Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7%, 20.7%, and 20%, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7%, 51.2%, and 46.3%, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.