Fatty Acid Ester Content Research Articles

Alginate Oligosaccharide Alleviated Cisplatin-Induced Kidney Oxidative Stress via Lactobacillus Genus-FAHFAs-Nrf2 Axis in Mice.

Alginate oligosaccharide is the depolymerized product of alginate, a natural extract of brown algae, which is associated with beneficial health effects. Here, we aimed to investigate the mechanism via which alginate oligosaccharides improve kidney oxidative damage and liver inflammation induced by cisplatin chemotherapy via the gut microbiota. C57BL/6J mice were treated with cisplatin were administered alginate oligosaccharide via gavage for 3 weeks. Compared to that observed in the cisplatin chemotherapy group without intragastric administration of alginate oligosaccharide, liver inflammation improved in the alginate oligosaccharide group, indicated by reduction in lipopolysaccharide and interleukin-1β (IL-1β) levels. This was accompanied by improvement in the oxidative stress of mice kidneys, indicated by the increase in the levels of superoxide dismutase (SOD), catalase (CAT) and nuclear NF-E2-related factor 2 (Nrf2) in renal tissue, and reduction in the levels of malondialdehyde (MDA) in renal tissue and serum creatinine (Cr) to the levels of the normal control group. Alginate oligosaccharide intervention increased the concentration of fatty acid esters of hydroxy fatty acids (FAHFAs). Alginate oligosaccharide regulated the composition of the intestinal microbial community and promoted Lactobacillus stains, such as Lactobacillus johnsonii and Lactobacillus reuteri. Spearman analysis showed that 5 members of FAHFAs concentrations were positively correlated with Lactobacillus johnsonii and Lactobacillus reuteri abundance. We observed that alginate oligosaccharide increased FAHFAs producing-related bacterial abundance and FAHFAs levels, enhanced the levels of SOD and CAT in kidney tissue, and reduced the levels of MDA via activating Nrf2, thereby ameliorating the renal redox injury caused by cisplatin chemotherapy.

Identification of age-markers based on profiling of Baijiu volatiles over a two-year maturation period: Case study of Lu-flavor Baijiu

Baijiu is a highly-valued traditional Chinese distilled alcoholic liquor and maturation markedly improves its sensory qualities and market value. Identification of age-markers is challenging because of the complexity of the endogenous chemical profile and the absence of exogenous components added during maturation. Here, freshly-distilled raw Lu-flavor Baijiu samples were stored for two years and non-targeted screening for age-markers based on the volatile profile characterized by solid-phase micro-extraction assisted GC-MS. The resulting volatile datasets were analyzed by partial least-squares discriminant analysis, Spearman's correlation and Random-forest decision-tree, to identify potential age-markers. The contents of long chain fatty acid ethyl esters varied the most during maturation, mostly being absent in freshly-distilled Baijiu, but appearing at different times. Similar behavior was observed in bottled samples matured up to four years. In addition, a slight increase in short/medium chain fatty acid ester content was observed. Unsupervised PCA analysis, applied only to the fatty acid ethyl ester dataset, was able to distinguish between bottled Baijiu samples matured for one, two, three, or four years. These age-markers may help establish a reliable model for verifying the maturation time of Lu-flavor Baijiu. This screening approach should be adaptable to other alcoholic liquors, for quality assessment and authenticity testing.

Garlic Allelochemical Diallyl Disulfide Alleviates Autotoxicity in the Root Exudates Caused by Long-Term Continuous Cropping of Tomato.

Continuous cropping obstacles seriously affect the sustainable production of tomatoes (Solanum lycopersicum L.). Researchers have found that intercropping with garlic (Allium sativum L.) could alleviate tomato continuous cropping obstacles. Diallyl disulfide (DADS) is the main allelochemical in garlic. However, the mechanism of DADS in alleviating tomato continuous cropping obstacles is still unknown. In this research, aqueous extracts of tomato continuous cropping soil were used to simulate the continuous cropping condition of tomato. Our results showed that DADS increased root activity and chlorophyll content and improved the activity of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and phenylalanine ammonia-lyase (PAL)) and the metabolism of nonenzymatic antioxidants (glutathione (GSH) and oxidized glutathione (GSSG)) in tomato plants. DADS treatment reduced the content of fatty acid esters in tomato root exudates (e.g., palmitate methyl ester, palmitoleic acid methyl ester, oleic acid methyl ester) and increased the level of substances such as dibutyl phthalate and 2,2'-methylenebis(6-tert-butyl-4-methylphenol). The higher concentrations of palmitate methyl ester inhibited tomato hypocotyl growth, while oleic acid methyl ester inhibited tomato root growth. Moreover, the application of DADS significantly inhibited the secretion of these esters in the root exudates. Therefore, it suggests that DADS may increase tomato resistance and promote tomato plant growth by increasing root activity and photosynthetic capacity and development to reduce autotoxicity of tomato.

Aroma compound profile of mature coconut water from tall variety through thermal treatment

Mature coconut water has inferior flavor characteristics compared to young coconut water. Thermal treatment can potentially be used not only to prolong the shelf life of coconut water, but also to alter its aroma compound profile. Therefore, the effect of heating on aroma compound profile of mature coconut water from tall variety was investigated in this study. Thermal treatment was performed at 85 °C for 15 min, 90 °C for 10 min, and 95 °C for 10 min. Volatile aroma compounds were extracted with solvent extraction and HS-SPME and analyzed with GC-TOFMS. The results showed that heat treatment affected the concentration of volatile aroma compounds in mature coconut water. Major changes were in esters, especially fatty acid esters that increased by 2–20%, and ketones that decreased by 2–21%, which mostly consisted of acetoin. Further analysis with descriptive sensory evaluation showed that heat treatment could reduce the undesirable ferment aroma attribute, most likely due to the decreased concentration of acetoin. Moreover, heat treatment also led to a slight increase in the intensity of sweet, floral, and creamy attributes, which could be related to the increased concentration of fatty acid esters. Heating at 85 °C for 15 min had slightly higher intensity for sweet and creamy characteristics compared to the other heat treatments. Thus, this study has shown that heat treatment could alter the aroma compound profile of mature coconut water.

Transformation of naturally occurring (3R,3′R,6′R)-lutein and its fatty acid esters to (3 R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin

The objective of this study was to develop straightforward processes that could be applied to the large-scale production of β-cryptoxanthin in an attempt to facilitate investigation of its biological activity. An oleoresin obtained from crude extracts of marigold flowers (Tagetes erecta) with approximately 24% total lutein fatty acid ester content was directly used as starting material for partial synthesis of (3 R)-β-cryptoxanthin under mild reaction conditions at ambient temperature. Therefore, acid-catalyzed deoxygenation of lutein esters from marigold oleoresin followed by hydrogenation in the presence of catalytic amount of platinum (Pt) supported on alumina (5%) at ambient temperature gave a mixture of (3 R)-β-cryptoxanthin fatty acid esters (major) and (3 R,6′R)-α-cryptoxanthin fatty acid esters (minor). Saponification and Z-to-E isomerization of the product followed by crystallization gave a mixture of (3 R)-β-cryptoxanthin as the major product. Similarly, acid-catalyzed hydrogenation of unesterified (3 R,3′R,6′R)-lutein with Pt/alumina in ethyl acetate gave a mixture of (3 R,6′R)-α-cryptoxanthin acetate (minor) in a one-pot reaction. Alkaline hydrolysis and Z-to-E isomerization of the mixture followed by crystallization provided (3 R)-β-cryptoxanthin.

Experimental investigation of the effects of turkey rendering fat biodiesel on combustion, performance and exhaust emissions of a diesel engine

In this study, turkey rendering fat biodiesel (TRFB) was produced by two-step reactions (esterification and transesterification). Fatty acid ester content and yield in methyl ester were found 96.7% and 88.5% respectively. TRFB was blended with diesel fuel (DF) at 10%, 20%, and 50% (v/v) proportion to obtain fuel blends named TRFB10, TRFB20 and TRFB50, respectively. The effects of TRFB blends on the combustion, performance and exhaust emissions of a direct injection single cylinder diesel engine were systematically investigated under different engine loads, at the constant engine speed of 2000 rpm. The results show that the maximum cylinder pressure (CPmax) and maximum heat release rate (HRRmax) values of the TRFB blends were higher than those of DF for all engine loads because of the low cetane number of the TRFB and the rapid burning of the fuel accumulated in the combustion chamber during the long ignition delay. It was observed that the DF has a higher exhaust gas temperature than the biodiesel blends at high loads because of the longer combustion duration of the DF. The brake thermal efficiency (BTE) values of the TRFB blends were found to be lower than those of DF at all loads. Since the heating value of the biodiesel is lower than that of DF, it was observed that the brake specific fuel consumption (BSFC) values of TRFB blends are higher compared to those of DF. In addition, TRFB10, TRFB20 and TRFB50 blends reduce smoke opacity approximately 20%, 25% and, 40%, respectively, and cause a slight increase in nitrogen oxide (NOx) emissions.

Supercritical production and fractionation of fatty acid esters and acylglycerols

The production of biodiesel or fatty acid esters (FAE) from lipids with supercritical methanol (scMeOH) has gained interest in the last decade because it allows the direct transesterification of crude oils and fats. The reaction should be carried out above 593K in order to achieve complete conversion. When milder conditions are set, also monoglycerides (MG) and diglycerides (DG), together with glycerol, are obtained as byproducts of the transesterification process. Acylglycerols are common food emulsifiers and surface active agents in many industrial cleaning products.The main goal of this work is to study the fractionation of FAE and acylglycerols by using CO2 as a green solvent. Mixtures of FAE, MG and DG were produced by partial transesterification of sunflower oil with scMeOH in a temperature range of 556–605K and using different methanol to oil molar ratios (between 20 and 50). Then, experimental data on phase equilibria of reaction products+CO2 were measured at 298K and 313K in a variable volume cell with windows. The measured data were used to test the predictive capability of the Group Contribution with Association Equation of State (GCA-EoS). The acylglycerols can be purified by near critical extraction of the FAE with CO2. The simulation of the extraction process working with CO2, in liquid or supercritical state, gives a concentration of acylglycerols higher than 99.8wt.% in the raffinate phase with a concentration of FAE above 97wt.% in the extract phase.

Spectroscopic and Chromatographic Fingerprint Analysis of Composition Variations inCoffea arabicaLeaves Subject to Different Light Conditions and Plant Phenophases

Fingerprints of self-shaded and sunlight-exposed leaves of the same Coffea arabica plant were obtained to determine metabolic concentration changes owing to different light environments and phenological stages. Leaf extract yields of the ethanol, acetone, dichloromethane and hexane solvents, as well as their statistical design mixtures, are reported. Highest yields are obtained with binary 1:1 ethanol-acetone mixtures for all sun-exposed and self-shaded leaves. Principal component analysis (PCA) of Fourier transform infrared (FTIR) spectra of leaf extracts indicate spectral differences between 2962-2828, 1759-1543 and below 1543 cm-1 that can be attributed to higher concentrations of fatty acid esters or the ester group in triglycerides, caffeine, chlorogenic acids and carbohydrates that are more prevalent in leaves of flowering plants. High-performance liquid chromatography with UV diode array detector (HPLC-UV-DAD) spectra of the chromatographic peaks for the extracts showed that sun-exposed samples contain stronger absorptions for caffeine, chlorogenic acid and theobromine. Confirmatory experiments carried out with reference UV calibration curves determined caffeine contents for sun-exposed leaves that are about double those for self-shaded leaves of flowering plants. Knowledge of leaf caffeine content in Coffea arabica is of ecological importance since sun-exposed conditions seem more stressful than self-shading ones for this species. Lipid concentrations in self-shaded leaves are almost double those that were sun-exposed.

Influence of cold stabilisation and chill membrane filtration on volatile compounds of apricot brandy

The aim of this research was to evaluate the influence of cold stabilisation treatment and chill membrane filtration on apricot brandy's stability and its volatile compounds. Cold stabilisation treatment included exposure of the brandy to the temperature of −1°C during 24h. Membranes with pore sizes of 200, 450 and 800nm were used in this study. The content of fatty acid esters (ethyl palmitate, ethyl laurate), the main causes of chill haze in strong alcoholic drinks, was efficiently reduced by all tested membranes. Content of alcohols, aldehydes and terpenes (except nerol) was not significantly influenced by applied treatments. All the brandy samples were stable after the re-exposure to lower temperatures. The sample filtered through the 800nm pore size membrane showed the best sensory characteristics, most similar to the control sample.

APOC3 and PNPLA3 in non‐alcoholic fatty liver disease: Need to clear the air

See article in J. Gastroenterol. Hepatol. 2012; 27: 951–956.

Biochemical label-free tissue imaging with subcellular-resolution synchrotron FTIR with focal plane array detector

The critical questions into the cause of neural degeneration, in Alzheimer disease and other neurodegenerative disorders, are closely related to the question of why certain neurons survive. Answers require detailed understanding of biochemical changes in single cells. Fourier transform infrared microspectroscopy is an excellent tool for biomolecular imaging in situ, but resolution is limited. The mid-infrared beamline IRENI (InfraRed ENvironmental Imaging) at the Synchrotron Radiation Center, University of Wisconsin-Madison, enables label-free subcellular imaging and biochemical analysis of neurons with an increase of two orders of magnitude in pixel spacing over current systems. With IRENI's capabilities, it is now possible to study changes in individual neurons in situ, and to characterize their surroundings, using only the biochemical signatures of naturally-occurring components in unstained, unfixed tissue. We present examples of analyses of brain from two transgenic mouse models of Alzheimer disease (TgCRND8 and 3xTg) that exhibit different features of pathogenesis. Data processing on spectral features for nuclei reveals individual hippocampal neurons, and neurons located in the proximity of amyloid plaque in TgCRND8 mouse. Elevated lipids are detected surrounding and, for the first time, within the dense core of amyloid plaques, offering support for inflammatory and aggregation roles. Analysis of saturated and unsaturated fatty acid ester content in retina allows characterization of neuronal layers. IRENI images also reveal spatially-resolved data with unprecedented clarity and distinct spectral variation, from sub-regions including photoreceptors, neuronal cell bodies and synapses in sections of mouse retina. Biochemical composition of retinal layers can be used to study changes related to disease processes and dietary modification.

Nonalcoholic Fatty Liver Disease: is It All in the Genes?

Abstract Background: Nonalcoholic fatty liver disease is associated with hepatic insulin resistance and type 2 diabetes mellitus. Whether this association has a genetic basis is unknown. Methods: In 95 healthy Asian Indian men, a group known to have a high prevalence of nonalcoholic fatty liver disease, we genotyped two single-nucleotide polymorphisms (SNPs) in the gene encoding apolipoprotein C3 ( APOC3 ) that are known to be associated with hypertriglyceridemia (rs2854116 [T-455C] and rs2854 117 [C-482T]). Plasma apolipoprotein C3 concentrations, insulin sensitivity, and hepatic triglyceride content were measured. We also measured plasma triglyceride concentrations and retinyl fatty acid ester absorption as well as plasma triglyceride clearance after oral and intravenous fat-tolerance tests. Liver triglyceride content and APOC3 genotypes were also assessed in a group of 163 healthy non-Asian Indian men. Results: Carriers of the APOC3 variant alleles (C-482T, T-455C, or both) had a 30% increase in the fasting plasma apolipoprotein C3 concentration, as compared with the wild-type homozygotes. They also had a 60% increase in the fasting plasma triglyceride concentration, an increase by a factor of approximately two in the plasma triglyceride and retinyl fatty acid ester concentrations after an oral fat-tolerance test, and a 46% reduction in plasma triglyceride clearance. The prevalence of nonalcoholic fatty liver disease was 38% among variant-allele carriers and 0% among wild-type homozygotes (P<0.001). The subjects with nonalcoholic fatty liver disease had marked insulin resistance. A validation study involving non-Asian Indian men confirmed the association between APOC3 variant alleles and nonalcoholic fatty liver disease. Conclusions: The polymorphisms C-482T and T-455C in APOC3 are associated with nonalcoholic fatty liver disease and insulin resistance.

Apolipoprotein C3 Gene Variants in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease is associated with hepatic insulin resistance and type 2 diabetes mellitus. Whether this association has a genetic basis is unknown. In 95 healthy Asian Indian men, a group known to have a high prevalence of nonalcoholic fatty liver disease, we genotyped two single-nucleotide polymorphisms (SNPs) in the gene encoding apolipoprotein C3 (APOC3) that are known to be associated with hypertriglyceridemia (rs2854116 [T-455C] and rs2854117 [C-482T]). Plasma apolipoprotein C3 concentrations, insulin sensitivity, and hepatic triglyceride content were measured. We also measured plasma triglyceride concentrations and retinyl fatty acid ester absorption as well as plasma triglyceride clearance after oral and intravenous fat-tolerance tests. Liver triglyceride content and APOC3 genotypes were also assessed in a group of 163 healthy non-Asian Indian men. Carriers of the APOC3 variant alleles (C-482T, T-455C, or both) had a 30% increase in the fasting plasma apolipoprotein C3 concentration, as compared with the wild-type homozygotes. They also had a 60% increase in the fasting plasma triglyceride concentration, an increase by a factor of approximately two in the plasma triglyceride and retinyl fatty acid ester concentrations after an oral fat-tolerance test, and a 46% reduction in plasma triglyceride clearance. The prevalence of nonalcoholic fatty liver disease was 38% among variant-allele carriers and 0% among wild-type homozygotes (P<0.001). The subjects with nonalcoholic fatty liver disease had marked insulin resistance. A validation study involving non-Asian Indian men confirmed the association between APOC3 variant alleles and nonalcoholic fatty liver disease. The polymorphisms C-482T and T-455C in APOC3 are associated with nonalcoholic fatty liver disease and insulin resistance.

Synthesis of Rapeseed Biodiesel Using Short-Chained Alkyl Acetates as Acyl Acceptor

In this study, we conducted experiments using a response surface methodology to determine the optimal reaction conditions for the enzymatic synthesis of biodiesel from rapeseed oil and short-chained alkyl acetates, such as methyl acetate or ethyl acetate, as the acyl acceptor at 40 degrees C. Based on our response surface methodology experiments, the optimal reaction conditions for the synthesis of biodiesel were as follows: methyl acetate as acyl acceptor, catalyst concentration of 16.50%, oil-to-methyl acetate molar ratio of 1:12.44, and reaction time of 19.70 h; ethyl acetate as acyl acceptor, catalyst concentration of 16.95%, oil-to-ethyl acetate molar ratio of 1:12.56, and reaction time of 19.73 h. The fatty acid ester content under the above conditions when methyl acetate and ethyl acetate were used as the acyl acceptor was 58.0% and 62.6%, respectively. The statistical method described in this study can be applied to effectively optimize the enzymatic conditions required for biodiesel production with short-chained alkyl acetates.

A Supercritical Fluid‐Assisted, Integrated Process for By‐Products from Fat and Lipid Production

AbstractAn integrated process for the enzymatic alcoholysis of lipids and the separation of the products by supercritical fluid extraction has been designed and tested with a commercial vegetable oil. The optimization of the reaction conditions and the fractionated separation in a cascade of three separators, which were operable at different temperatures and pressures, have been tested. The fractions were analyzed by HPLC for their content of fatty acid esters and different acylglycerides.

Structural characterization of natural rubber based on recent evidence from selective enzymatic treatments

A structural characterization of natural rubber (NR) was carried out by a combination of selective enzymatic treatment and high-resolution characterization techniques. The nitrogenous groups in NR from Hevea brasiliensis have been regarded as an important factor governing cured rubber properties, although there is no structural evidence to prove that relationship. The nitrogenous compounds in highly purified NR were characterized to determine the origin of the nitrogenous groups in NR. The rubber particles of fresh latex were purified by washing, i.e., a successive dilution of the cream fraction and concentration by centrifugation in the presence of a surfactant. The nitrogen content of the NR formed from the washed rubber particles decreased from 0.281% to 0.015% after washing 3-5 times; this content was similar to that of NR deproteinized by a proteolytic enzyme. The presence of 1-2 nitrogen atoms per rubber chain was estimated on the basis of nitrogen content and number-average molecular weight (Mn). The nitrogen content of fractionated rubber fractions from rubber particles washed for five times increased with increasing Mn. The nitrogenous groups in rubber chains are postulated to mostly originate from phospholipids associating with branch points and functional groups formed by oxidation and successive reactions in NR latex. An analysis of the structure of the chain end group (alpha-terminal) was carried out by treating the deproteinized NR (DPNR) latex with lipase, phosphatase, and phospholipases A(2), B, C and D. The enzymatic treatment of DPNR latex significantly decreased the long-chain fatty acid ester content in DPNR, and also the Mn and Higgins'k' constant, except for phospholipase D treatment. This indicates the presence of phospholipid molecules in NR, which connect rubber molecules together. (1)H-NMR results of rubber obtained from DPNR latex showed weak signals due to monophosphate, diphosphate and phospholipids at the alpha-terminal. Treating DPNR latex with lipase and phosphatase decreased the relative intensity of the (1)H-NMR signals corresponding to phospholipids; however, with the same treatment, no change in the signals due to mono- and diphosphates was observed. The presence of mono- and diphosphates as well as some phospholipid signals after lipase and phosphatase treatment indicates that mono- and diphosphate groups are directly linked to the modified structure at their alpha-terminals; such connections are considered to be due to the association or linkage of such groups with phospholipid.

An infrared spectroscopic method for quantitative analysis of fatty alcohols and fatty acid esters in machinery oils

A new infrared spectroscopic method suitable for determining total fatty alcohol and fatty acid ester concentrations in industrial oils has been developed. Oil samples were diluted with toluene (1:3 w/w), the toxicity and volatility of which are relatively low compared with more commonly used IR solvents, like carbon tetrachloride or carbon disulfide. Mixture standards were prepared from dodecanol, tetradecanol, octadecanol, methyl stearate and methyl palmitate. Some analytical and statistical tests were performed on the developed method. The recoveries and the repeatability of the method proved to be sufficient for the quantitative determination of fatty alcohol and fatty acid ester additives in industrial oils. Reproducibility testing in another laboratory also produced satisfactory results. The developed method also proved to be relatively quick and simple. This method was developed to satisfy industry's need to determine the concentrations of these oil additives, and it has already been applied successfully in machinery oil analysis.

Synthesis of fatty acid esters from acid oils using lipase B from Candida antarctica

AbstractEsterification of corn and sunflower acid oils with straight‐ and branched‐chain alcohols were conducted using lipase B from Candida antarctica (Novozym 435) in n‐hexane. Sunflower acid oil consisted of 55.6% free fatty acids and 24.7% triacylglycerols, while the free fatty acids and triacylglycerols contents of corn acid oil were 75.3% and 8.6%, respectively. After 1.5 h of methanolysis of sunflower acid oil, the highest fatty acid methyl ester content (63.6%) was obtained at 40 °C and the total fatty acid/methanol molar ratio was 1/1, using 15% enzyme based on acid oil weight. The conversion of both acid oils with straight‐ and branched‐chain alcohols was not significantly affected by the chain length of the alcohols. However, the lowest fatty acid methyl ester content (50%) was obtained in the reaction of corn acid oil with methanol. Sunflower acid oil was converted to fatty acid esters using primer alcohols such as n‐propanol, i‐ and n‐butanol, n‐amylalcohols, n‐octanol, and a mixture of amylalcohol isomers, resulting in a fatty acid ester content of about 70% at 40 °C.

Postmenopausal estrogen therapy and serum estradiol fatty acid esters in women with and without previous intrahepatic cholestasis of pregnancy

BACKGROUND. Fatty acid esters of 17β‐estradiol (E2) are estrogen metabolites associated with lipoproteins in blood.AIM. To study the effects of estrogen therapy on concentrations of serum E2 fatty acid esters in postmenopausal women with a history of an estrogen‐related liver disorder, intrahepatic cholestasis of pregnancy (ICP), and in healthy women in a double‐blind, crossover fashion.METHOD. ICP (n = 10) and control women (n = 10) received increasing doses of E2 valerate orally 2–4 mg/day, or transdermal E2 50–100 μg/day for 6 weeks. After a 4‐week wash‐out period, the subjects crossed over to the alternate E2 treatment. Concentrations of serum E2 fatty acid esters were quantified after saponification by fluoroimmunoassay.RESULTS. Oral E2 administration increased median serum E2 fatty acid ester concentrations from 57 to 73 pmol/L in the ICP and from 56 to 74 pmol/L in the control group, in association with elevations in serum E2, estrone and sex hormone‐binding globulin levels. Transdermal E2 treatment did not increase serum E2 ester levels.CONCLUSIONS. The increase in serum E2 fatty acid esters during oral E2 administration may be attributed, at least partly, to the higher estrogen dose during oral compared with transdermal therapy. A history of ICP did not affect esterification of E2 during estrogen therapy.

Kinetics on the hydrolysis of fatty acid esters in subcritical water

Hydrolysis of fatty acid esters with different acyl and alkyl chains in subcritical water was examined over a temperature range of 483–543 K in a batch reactor. The concentrations of fatty acid esters were sufficiently low to assume a homogeneous reaction at every temperature. The hydrolysis of every fatty acid ester at any temperature obeyed first-order kinetics. The rate constant was observed at various temperatures, and the apparent activation energy and frequency factor were evaluated according to the Arrhenius equation for each fatty acid ester. Steric hindrance of the acyl and alkyl chains was found to increase the activation energy of the hydrolysis. The enthalpy–entropy compensation held in the hydrolysis of the fatty acid esters tested.