Fatty acid ethyl esters study

Fatty acid ethyl esters may be clinically important, independent of whether FAEEs induce cytotoxicity, because they can serve as a marker for ethanol intake. We performed a study to determine the clinical utility of FAEE in the blood as a short-term confirmatory marker for ethanol intake and as a long-term marker for ethanol intake after ethanol is no longer detectable (Doyle, 1996), To isolate FAEEs from plasma for quantitation by gas chromatography-mass spectrometry (GC-MS) in these clinical studies, we developed a two-step method using solid-phase extraction with a recovery of 70 3%, using ethyl oleate as a recovery marker (Bernhardt, 1996). 

The preparation of DHA-enriched concentrates from fish oil triglycerides often involves the formation/processing of ethyl ester derivatives as well as free fatty acid forms. Comparative studies have been reported in the literature on the digestibility and bioavailability of DHA when consumed in the form of triglyceride, free fatty acid, or ethyl ester in human volunteers. These studies have indicated that DHA is readily absorbed as a free fatty acid form with higher apparent digestibility/absorption... 

The production of the higher alcohols, the acetates of isoamyl alcohol and phenylethyl alcohol, and the ethyl esters of the C6-C10 fatty acids has been studied in semiaerobic sugar fermentations by strains of . cerevisiae and S. uvarum. S. cerevisiae generally produced more esters than S. uvarum. Isoamyl acetate was the main ester produced by >. cerevisiae. and others, in decreasing order, were ethyl caprylate, ethyl caproate, ethyl caprate and phenylethyl acetate(39). Several unusual thio compounds have been produced by Saccharomvces in model anaerobic fermentations using amino acids such as methionine as the sole carbon source(21). These model fermentations produce methylthiopropanal and traces of other sulfur containing compounds, such as methionyl acetate and 2-methyltetrahydrothiophene-3-one. 

Experimental Diets. The three experimental diets used were based on the AIN-93 (35) formulation with several modifications to obtain the extremely low n-3 fatty acid level required in this study (Table 1). The custom-pelleted diets were obtained commercially and employed a cold pelleting process to preserve unsaturated fats (Dyets, Bethlehem, PA). The dependent variable in the two artificially reared groups was the substitution of a-linolenic acid ethyl ester for oleic acid ethyl ester in the n-3 Adq diet. The maternal diet contained a fatty acid composition similar to that of the n-3 Adq diet but made up with a mixture of safflower and flax oils due to the greater quantity of diet to be consumed. All three diets contained 10 wt% fat and had a similar Unoleic acid content. The rats were fed these diets until they were sacrificed. 

Another reactive separation processes studied for ethyl lactate production is the catalytic extractive reaction (Figure 20.4.7). In this case, the esterification is performed in a biphasic liquid solvent system composed by a reactive polar liquid phase which contains the esterification constituents lactic acid, eflianol and catalyst, and an extractive organic solvent selective of the ester. Therefore, ethyl lactate should preferably be dissolved in the extractive organic phase shifting, in this way, the reaction equilibrium to ester formation. The immiscible extractive solvent is an aromatic or other solvent like toluene, benzene or diethyl ether, among others. Nevertheless, it has also been used an immiscible solvent based on fatty acid methyl ester, but in this case, the procedure represents a method to produce an organic biosolvent and not just ethyl lactate as solvent. 

The ability to disperse the calcium soap formed from a given amount of sodium oleate has been studied for a number of a-sulfo fatty acid esters with 14-22 carbon atoms [28,30]. In principle, the lime soap dispersion property increases with the number of C atoms and the dissymmetry of the molecule. Esters with 14 C atoms have no dispersion power and in the case of esters with 15-17 carbon atoms the least symmetrical are the better lime soap-dispersing agents. However this property does not only depend on the symmetry but on the chain length of the fatty acid group. For example, methyl and ethyl a-sulfomyristate have better dispersing power than dodecyl propionate and butyrate. The esters with 18 and more carbon atoms are about equal in lime soap dispersion power. Isobutyl a-sulfopalmitate is the most effective agent under the test conditions. 

Jennings et al (228) fractionated an extract from Bartlett pears into 32 volatile components of which five were found to contribute significantly to the characteristic pear aroma. Later studies indicated that esters of trans-2 cis-4 decadienoic acid and hexyl acetate were significant components of the Bartlett pear aroma (229, 230). More recently, numerous volatiles of Bartlett pears were separated and identified including esters of methyl, ethyl, propyl, butyl, and hexyl alcohols, and Cio to Ci8 fatty acids (231, 232). 

In order to expand the worldwide market, considerable efforts are being devoted to improve the image of Madeira wine. Consequently, their characteristics have to be well defined. So, in order to define and describe the particular characteristics and the authenticity of the product, secondary metabolites of grape and wines mainly linked to a specific variety, must be deeply studied. In Madeira wine, these compounds are mainly included in the chemical classes of mono and sesquiterpenoids C13 norisoprenoid higher alcohols, ethyl esters, volatile fatty acids, carbonyl compounds, sulfur compounds, furanic compounds, lactones, and polyphenols. 

This case study investigates the possibility of applying reactive distillation to the synthesis of fatty-acid esters as a generic multiproduct process. As representative species we consider the lauric (dodecanoic) acid and some alcohols the series Q-C8, such as methanol, n-propanol and 2-ethyl-hexanol (isooctanol). The generic reversible chemical reaction is ... 

Conflicting results have been reported about the absorption of EPA and DHA either as an ethyl ester (EE) or in a triglyceride (TG) formula. Based on a randomized double-blind study on the effects of EE and TG on plasma fatty acids, platelet function and haemostasis, it has been concluded that TG and EE fish oils are well incorporated... 

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