Glucose fermentation in the presence of linoleic,oleic and stearic acids by a mixed culture

Long Chain Fatty Acid (LCFA) mixtures containing linoleic, oleic and stearic acids plus carbohydrates are found in a variety of effluents arising from fried food manufacture and milk processing. Accumulation of Volatile Fatty acids (VFAs) due to the presence of LCFAs may impair the operation of an anaerobic system treating effluents containing a mixture of triglycerides and carbohydrates. In this study, the effects of linoleic (C18:2), oleic (C18:1), and stearic (C18:0) acids on glucose fermentation were investigated at 21 °C using a culture acclimated to glucose. In cultures receiving ≥300 mg dm^?3 LCFAs, residual amounts of glucose remained after approximately 8 h and none was detected after 24 h. Acetate degradation was inhibited in the presence of 300 or more mg dm^?3 linoleic acid (LA), oleic acid (OA), or stearic acid (SA) with more acetate accumulation observed in cultures receiving LA. In comparison to the controls, similar amounts of propionate accumulation were observed in cultures receiving ≤100 mg dm^?3 of each LCFA. However, in cultures receiving ≥300 mg dm^?3 LCFAs, more propionate accumulated with complete removal observed within 20 days for only those cultures receiving oleic or stearic acids. Butyrate accumulation was observed only in cultures receiving ≥300 mg dm^?3 LA and none was detected after 10 days of incubation. Copyright © 2004 Society of Chemical Industry     

Use of thermostable Fusarium heterosporum lipase for production of structured lipid containing oleic and palmitic acids in organic solvent-free system

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

Chlorophyllase biocatalysis in an aqueous/miscible organic solvent medium containing canola oil

Chlorophyllase catalyzes the bioconversion of chlorophyll into chlorophyllide by replacing the phytol group with a hydrogen atom. There is an increased interest in the biotechnological application of chlorophyllase for the removal of green pigments from edible oil and its potential as an alternative to the use of the conventional bleaching technique. Partially purified chlorophyllase, obtained from the alga Phaeodactylum tricornutum, was assayed for its hydrolytic activity in an aqueous/miscible organic solvent system containing refined-bleached-deodorized (RBD) canola oil, using chlorophyll and pheophytin as substrate models. The results indicated that chlorophyllase biocatalysis could be successfully carried out in an aqueous/miscible organic system containing RBD canola oil. The presence of 20% RBD canola oil decreased the hydrolytic activity of chlorophyllase by 2.2 and 6.7 times, using chlorophyll and pheophytin as substrates, respectively. In addition, acetone acted as an activator of chlorophyllase activity at low concentrations and an inhibitor at higher ones. The optimal reaction conditions for chlorophyllase biocatalysis in the aqueous/miscible organic system were determined to consist of 20% RBD oil and 10% acetone at a 200 rpm agitation speed and at a temperature and substrate concentration of 35°C and 12.6 μM for chlorophyll, and 30°C and 9.3 μM for pheophytin.     

Phase separation phenomena of polysulfone/solvent/organic nonsolvent and polyethersulfone/solvent/organic nonsolvent systems

The precipitation values (PVs) of several organic nonsolvents in polysulfone (PSf)/solvent and polyethersulfone (PESf)/solvent systems were measured in temperatures ranging from 10 to 80°C by the direct titration method and compared with those of water in the same systems. The solvents used were N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAC); the organic nonsolvents employed were methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, ethylene glycol, and diethylene glycol as well as acetic acid and propionic acid. The compositions of nonsolvent, polymer, and solvent at the precipitation points for different polymer concentrations up to 10 wt % were also determined at 30°C with respect to both the polymers and six nonsolvents presented. These results were used to obtain the polymer precipitation curves in the polymer-solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent for a polymer. The results show that the precipitation value of nonsolvent in polymer/solvent systems depends on both the nature of polymer, solvent, and nonsolvent used and the temperature. The effect of temperature on the precipitation value was observed to be dramatically different for different polymer/solvent/nonsolvent systems. These results were explained on the basis of polar and nonpolar interactions of the polymer, solvent, and nonsolvent system. The results indicate that the precipitation values of the type presented in this paper not only give a relative measure of the nonsolvent tolerance of the polymer/solvent system involved and the strength of solvent and nonsolvent for the polymer, but also determine the relative location of the polymer precipitation curve in the triangular phase diagram. © 1993 John Wiley & Sons, Inc.     

The a-sulfonation of pelargonic,stearic, and substituted stearic acids

Direct sulfonation of higher fatty acids with sulfur trioxide or chlorosulfonic acid, without use of solvent, is possible, but the product must then be isolated as the sodium salt. Use of a chlorinated solvent permits isolation of the α-sulfo acid. Sulfonation with dioxane sulfur trioxide in place of sulfur trioxide gave a nearly colorless α-sulfostearic acid. Substituted stearic acids derived from oleic or elaidic acids (phenyl-, 9,10-dichloro-, and 9,10-dihydroxystearic acids) were α-sulfonated with dioxane sulfur trioxide. Solubility, detergent, and surface-active properties were examined and related to structure. The surface-active properties of sodium α-sulfopelargonic acid are not very evident, but the octyl ester, with a much lower critical micelle concentration (0.08% compared to 1.00%), was found to be a very efficient wetting agent. Presented at the fall meeting, American Oil Chemists’ Society, New York, N. Y., October 17–19, 1960. Eastern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Adsorption of dimer,trimer, stearic,oleic, linoleic,nonanoic and azelaic acids on ferric oxide

The adsorption isotherms of solutions of dimer, trimer, stearic, oleic, linoleic, nonanoic and azelaic acids in organic solvents, (mostly hexane) have been determined on an alpha ferric oxide with a surface area (B.E.T. N₂ adsorption) of 99 m² (99 × 10²⁰ A²) per gram. They all showed limiting adsorption as grams adsorbed per gram of iron oxide beyond a concentration of about 1 g/100 cc, analagous to the Langmuir type monolayer isotherm. Areas per molecule were calculated and compared with areas of close-packed models in positions parallel to and perpendicular to the surface. The calculated areas corresponded more closely to the flat or parallel positions. Heats of adsorption were determined and were in the range of 27–71 kcal/eq, suggesting chemisorption of the COOH group at the surface. The value of dimer acid suggests that both COOH groups are chemisorbed. Models show that the parallel position permits both COOH groups to touch the surface. The perpendicular position generally does not permit both COOH groups to touch the surface. Dimer acid showed a value (71 kcal/eq) higher than the monobasic acids (44–55 kcal/eq), possibly due to interaction of the ring structure (partly aromatic) with the surface. Azelaic acid from an 80–20t-butanol-hexane solvent showed a lower value of 27 kcal/eq, possibly due to adsorption of a hydrogenbonded alcohol-acid moiety as such. Journal Series No. 547, General Mills, Inc. Research Laboratories.     

Urethane foams from animal fats. II. Reaction of propylene oxide with fatty acids

Propylene oxide has been reacted with 9,10-dihydroxystearic acid to form polyol components for urethane foams. The alkali-catalyzed reaction proceeds slowly until the first mole of propylene oxide is absorbed and thereafter at a higher rate. For other substrates, the initial reaction proceeds most readily with alcohols and decreases in speed with increasing acidity of the hydroxyl group. Threo-anderythro-9,10-dihydroxystearic acids were reacted with approximately 1, 2, 4, 6 and 8 moles of propylene oxide. Both series of the resulting polyols were liquid, unlike corresponding oxyethylated derivatives, which were solids in theerythro series. A small amount of unsaturation was observed in the reaction products in accord with previous studies. The liquid polyols can be used conveniently in the preparation of rigid urethane foams.     

Phase equilibria of mixtures containing CO2 and organic acids using the UMR-PRU model

The UMR-PRU model, which has been successfully tested in the past to the predictions of different type of phase equilibrium and thermodynamic properties in binary and multicomponent systems, is applied in this work to phase equilibria in mixtures containing CO₂ and organic acids. New interaction parameters are determined by fitting only binary vapor–liquid equilibrium data and then they are used to predict the vapor–liquid, solid–gas and solid–liquid–gas equilibria in CO₂/organic acid systems. Furthermore, the UMR-PRU model with the newly derived interaction parameters is applied to the prediction of the phase equilibrium in ternary mixtures consisting of CO₂, organic acids and water. Satisfactory results are obtained in all cases.     

Hyperchlorinated fatty acids: II. Photochlorination of stearic acid in carbon tetrachloride,reaction study

The free radical chlorination of stearic acid in carbon tetrachloride was studied with variation of the chlorine flow rate, the active light intensity and the initial fatty acid concentration. In addition the variation of temperature with time was measured. The chlorine flow rate affects only the reaction time and modifies neither the chlorine content of the products obtained nor the yield, approximating 100%. On the other hand, the initial fatty acid concentration seems to be the prime factor determining the chlorine content of the products. Similarly, the onset of the polymerization of the chlorinated monomers depends essentially on the initial fatty acid concentration. These polymers are probably chlorinated polyesters. This behavior can be explained by the incursion of radical ions RCOO·⁺ resulting from irradiation of exciplexes formed by interaction between the more or less highly chlorinated fatty acid and the solvent. These interactions take place when the fundamental complex occupies a critical volume, which depends on the acid concentration.     

Metabolism in humans ofcis-12,rans-15-octadecadienoic acid relative to palmitic,stearic, oleic and linoleic acids

Mixtures of triglycerides containing deuterium-labeled hexadecanoic acid (16∶0), octadecanoic acid (18∶0),cis-9-octadecenoic acid (9c–18∶1),cis-9,cis-12-octadecadienoic acid (9c, 12c–18∶2) andcis-12,trans-15-octadecadienoic acid (12c,15t–18∶2) were fed to two young-adult males. Plasma lipid classes were isolated from samples collected periodically over 48 hr. Incorporation and turnover of the deuterium-labeled fats in plasma lipids were followed by gas chromatography-mass spectrometry (GC-MS) analysis of the methyl ester derivatives. Absorption of the deuterated fats was followed by GC-MS analysis of chylomicron triglycerides isolated by ultracentrifugation. Results were the following: (i) endogenous fat contributed about 40% of the total fat incorporated into chylomicron triglycerides; (ii) elongation, desaturation and chain-shortened products from the deuterated fats were not detected; (iii) the polyunsaturated isomer 12c,15t–18∶2 was metabolically more similar to saturated and 9c–18∶1 fatty acids than to 9c,12c–18∶2 (iv) relative incorporation of 9c,12c–18∶2 into phospholipids did not increase proportionally with an increase of 9c,12c–18∶2 in the mixture of deuterated fats fed; (v) absorption of 16∶0, 18∶0, 9c–18∶1, 9c,12c–18∶2 and 12c,15t–18∶2 were similar; and (vi) data for the 1- and 2-acyl positions of phosphatidylcholine and for cholesteryl ester fractions reflected the known high specificity of phosphatidylcholine acyltransferase and lecithin:cholesteryl acyltransferase for 9c,12c–18∶2. These results illustrate that incorporation of dietary fatty acids into human plasma lipid classes is selectively controlled and that incorporation of dietary 9c,12c–18∶2 is limited. These results suggest that nutritional benefits of diets high in 9c,12c–18∶2 may be of little value to normal subjects and that the 12c,15t–18∶2 isomer in hydrogenated fat is not a nutritional liability at the present dietary level.     

Dilatometric investigations of fats. VI. Melting dilation as a function of chain length in fatty acids and their glyceryl esters

Melting dilations have been determined for the even-numbered, saturatedn-fatty acids in the series lauric through stearic, and some of their glyceryl esters. These data have been correlated with data obtained previously to determine the relationship between melting dilation and the effective chain length of these compounds. The melting dilations of the mono-, di-, and triglyceryl esters of a fatty acid were found to be proportional to the acid residue content of each compound. The melting dilation of a monoglyceride was one-half that of the diglyceride and one-third that of the triglyceride of the same fatty acid. The increment of melting dilation of the fatty acids and glyceryl esters increased regularly with each addition of two methylene groups, with the end group components exerting a contant effect on the volume change. Equations were developed for calculating the melting dilation of then-fatty acids and their glycerides as a function of chain length of the fatty acid radical. The melting dilations of those compounds which are unsaturated, or have less than 10 carbon atoms, cannot be calculated by these equations.     

Thermoanalytical and infrared spectroscopy investigations of some mineral pastes containing organic polymers

The interaction in the presence of water between organic polymers [two polyvinyl alcohol acetate (PVA1 and PVA2)-, one polyvinyl acetate (PVAc)-, and one acryloethyl-metacrylomethyl (R)-type copolymers] and inorganic materials (3CaO·Al₂O₃+CaSO₄·2H₂O, 12CaO·7Al₂O₃, and CaO·Al₂O₃) was investigated using complex thermal analyses and infrared (IR) spectroscopy. The DTA curves of the 1-to 28-day-hydrated organo-mineral composite samples showed some significant differences in comparison with those of the hydrated inorganic materials. The most important differences consist in the presence of some exothermic peaks that are not attributable to the pure organic polymers. More than that, none of the specific effects of the pure organic polymers are evidenced on the DTA curves of the hydrated organo-mineral composite materials. This, in connection with their IR spectra, which clearly evidence the disappearance of some investigated polymers specific IR bands, can be considered as an indirect evidence of the cross-linking of polymer chains via metal ions.     

The solvent extraction of nickel from acidic solutions using synergistic mixtures containing pyridinecarboxylate esters. Part 2: Systems based on alkylsalicylic acids

The synergistic solvent extraction of nickel and cobalt by pyridinecarboxylate esters (2-, 3- or 4-C₅H₄N.CO.OR) in admixture with 3-bromo- or 3-nitro-derivatives of 5-alkylsalicylic acids was studied. Nickel is extracted more strongly than cobalt in all cases and, for systems containing a given pyridinecarboxylate, the pH₅₀ values (pH values for 50% extraction) of both metals decrease in the order: alkylsalicylic acid > bromo-derivative > nitro-derivative. For systems containing a given salicylic acid, the separation between the pH₅₀ values for nickel and cobalt was found to increase in the order: pyridine 2-ester < 4-ester ≈ 3-ester. The extractability of divalent base metals from sulphate solutions by mixtures of isodecyl 3- or 4-pyridinecarboxylate and 3-bromo- or 3-nitro-5-nonylsalicylic acid in Shellsol K decreases through the series: Cu > Ni > Co ≈ Zn > Ca > Mg. In single-stage batch extraction experiments with a simulated leach liquor containing Ni 2·2, Cu 0·5, Ca 0·4 and Mg 5·0 g dm⁻³ (and smaller amounts of other base metals), adjustment of the equilibrium pH value to between 3·3 and 4·0 with magnesium oxide gave extractions of nickel and copper of 97–100%, with co-extractions of calcium and magnesium of <0·5 and <0·1%, respectively. Amongst the metals present in lower concentrations, manganese (2–5%) and lead (5–10%) were extracted only slightly whereas cobalt (40–80%), zinc (15–65%) and iron (100%) were more strongly extracted.