Low VOC self-crosslinking waterborne acrylic coatings incorporating fatty acid derivatives

Acrylic waterborne coatings free of volatile coalescing agents were produced and characterized. The film-formers used in the coatings were resins incorporating an allylic fatty acid derivative (AFAD) and an acrylic fatty acid derivative (AcFAD), either as reactive (non-volatile) coalescing agents or as co-monomers. The minimum film-forming temperatures of the new coatings were lower than the reference, confirming that AFAD and AcFAD act as coalescing agents. On the other hand, the observed reductions in through drying-time and increase in scrub resistance, more evident for AcFAD, indicating that reaction between the conjugated double bonds in the fatty acid derivatives and atmospheric oxygen–oxidative cure–took place and provided an effective self-crosslinking drying mechanism.     

Pro- and Antioxidative Effect of α-Tocopherol on Edible Oils, Triglycerides and Fatty Acids

Using advanced electron paramagnetic resonance techniques (EPR), oxidation of crude vegetable oils and their components (fatty acids and triglycerides) by radicals generated from hydrogen peroxide was investigated. The correlation rotational times were determined allowing us to characterize radicals formed during edible oils oxidation. Additionally ¹H- and ¹⁴N-hyperfine coupling constants differentiate the fatty acids dependently on their unsaturation. The acids with a higher number of unsaturated bonds exhibit higher A_N values of PBN/·lipid adduct. The waste oil with high free fatty acids content underwent the oxidation reaction more efficiently, however due to saturation and the high content of the fatty acids the carbon-centered radicals formed (upon hydrogen peroxide radicals) and their PBN (N-tert-butyl-α-phenylnitrone) adducts were less stable. The antioxidant effect was dependent on the amount of α-tocopherol added. In small amounts of up to 0.35 mg/1 g of fatty acid or triglyceride, it inhibited the creation of PBN/·lipid adducts while with higher amounts it intensified adduct formation. The α-tocopherol (AT) addition influence was also studied as spin scavenging dependence and indicated that any addition of the antioxidant in the investigated samples led to free radical scavenging and the effect increased with the increase in AT content.     

Competitive adsorption among sesame oil components in a concentrated miscella system

Competitive adsorption of free fatty acids and carotenoids adsorption from sesame oil miscellas on vegetable carbon was studied by regression analysis. The equations obtained indicated that unsaturated carbonyls, free fatty acids (FFA₀), and carotenoids interacted to determine fatty acid and carotenoid adsorption. The driving force for carotenoid adsorption, the carotenoid concentration (C₀), was affected by a quadratic function of free fatty acid concentration [i.e., (FFA₀/C₀)²]. As FFA₀/C₀ increased, carotenoid adsorption efficiency was reduced, possibly because the accessible adsorption sites for carotenoids were occupied by fatty acids. Unsaturated carbonyls promoted free fatty acid adsorption, probably in the pores that were readily accessible for fatty acids. However, when the carbonyl concentration increased in the oil miscella, carbonyls were adsorbed instead of fatty acids. The results indicated how different oil molecules interact and affect adsorption (i.e., free fatty acids and carotenoids). Therefore, the adsorption process of vegetable oils (i.e., bleaching) has to be considered a multicomponent adsorption system.     

Effect of physical refining on selected minor components in vegetable oils

The final quality of vegetable oils is largely determined by the deodorization process. From an organoleptic point of view, oils should be light in color with a bland taste and a good cold and/or oxidative stability. Today, however, more and more attention is paid to the real nutritional quality. Oils should contain low trans fatty acid levels, low polymeric triglycerides, and secondary oxidation products and at the same time being rich in natural antioxidants. In order to comply to these new quality requirements, the deodorization technology has been modified substantially. Mathematical models were established describing the influence of different process parameters (time, temperature, steam, and pressure) on trans fatty acid formation, tocopherol stripping, and production of oxidized and polymeric triacylglycerides during physical refining of soybean oil. Trans fatty acid (TFA) formation was influenced only by time and temperature. No significant influence of pressure or sparging steam could be observed. Models expressing the relative degree of cis/trans-isomerization of linoleic (DI_18:2) and α-linolenic acid (DI_18:3) could be extrapolated to other oils and deodorizer designs. Tocopherol removal was mainly influenced by process temperature and sparging steam. Additionally, tocopherol retention seemed to be dependent on the deodorizer design (steam injection geometry and sparging steam distribution). During physical refining, oxidized and polymerized triacylglycerols were not significantly influenced by any of the investigated process parameters. Industrially, process conditions are adapted to minimize trans fatty acid formation and maximize tocopherol retention. These goals can be achieved in a so-called DUAL TEMP^copy; deodorizer.     

A colorimetric determination of fatty acids as a new assay of lipases in reverse micelles

A new simple spectrophotometric method is described for the determination of the free fatty acid content in triglyceride oils or other lipophilic samples. The method utilizes phenol red as fatty acid indicator, which is solubilized phenol red as fatty acid indicator, which is solubilized in reverse micelles formed by AOT [sodiumbis(2-ethylhexyl) sulfosuccinate] in isooctane. Fatty acid determinations in vegetable oils can be carried out rapidly with oil samples of less than 100 mg. The acid value of three different oils tested agreed quite well with the acid value obtained for the same samples with another colorimetric determination using cupric acetate. The method can be extended to a continuous determination of fatty acids which are released during the initial stage of a lipase catalyzed hydrolysis of triglyceride substrates in reverse micelles. This new sensitive lipase assay has been applied for a lipase ofPseudomonas bacteria with lipase concentrations as low as 0.1 μg/ml. Using trioctanoylglycerol as substrate in 50 mM AOT/isooctane with w_o=[H₂O]/[AOT]=11.1 (pH 9.0), the apparent overall Michaelis-Menten constant (K_m′app,ov) is 27 mM and the turnover number (k_cat) 44 sec⁻¹.     

Optimization of biodiesel production from edible and non-edible vegetable oils

The non-edible vegetable oils such as Jatropha curcas and Pongamia glabra (karanja) and edible oils such as corn and canola were found to be good viable sources for producing biodiesel. Biodiesel production from different edible and non-edible vegetable oils was compared in order to optimize the biodiesel production process. The analysis of different oil properties, fuel properties and process parameter optimization of non-edible and edible vegetable oils were investigated in detail. A two-step and single-step transesterification process was used to produce biodiesel from high free fatty acid (FFA) non-edible oils and edible vegetable oils, respectively. This process gives yields of about 90-95% for J. curcas, 80-85% for P. glabra, 80-95% for canola, and 85-96% for corn using potassium hydroxide (KOH) as a catalyst. The fuel properties of biodiesel produced were compared with ASTM standards for biodiesel.     

Purity assessments of major vegetable oils based on δ13C values of individual fatty acids

The fatty acid compositions and δ¹³C values of the major fatty acids of more than 150 vegetable oils were determined to provide a database of isotopic information for use in the authentication of commercial maize oil. After extraction of oils from seeds, nuts or kernels, and methylation, fatty acid compositions were determined by capillary gas chromatography. All compositions were within the ranges specified by the Codex Alimentarius. Gas chromatography combustion-isotope ratio mass spectrometry was employed to determine the δ¹³C values of the major fatty acids of the oils. A large number of pure maize oils and potential adulterant oils from various parts of the world were studied to assess the sources of variability in δ¹³C values. Such information is vital to establishing the compound specific isotope technique as a reliable means of assessing vegetable oil purity. Variability in δ¹³C values was related to the geographical origin of the oil, year of harvest, and the particular variety of oil. This suggests that the ultimate δ¹³C values of fatty acids are determined by a combination of environmental and genetic factors.     

Density estimation for fatty acids and vegetable oils based on their fatty acid composition

The liquid density of fatty acids can be accurately estimated by the modified Rackett equation over a wide range of temperatures. The modified Rackett equation requires the critical properties and an empirical parameter,Z _RA , for each acid as the basis for computing density as a function of temperature. The liquid density of vegetable oils can be estimated by using mixture properties corresponding to the fatty acid composition and a correction for the triglyceride form. The density prediction is explicitly temperature-dependent.     

Hematological and lipid changes in newborn piglets fed milk replacer diets containing vegetable oils with different levels of n−3 fatty acids

To test if linolenic acid (18∶3n−3) from vegetable oils would affect bleeding times and platelet counts in new-borns, piglets were used as a model fed milk replacer diets containing 25% (by wt) vegetable oils or oil mixtures for 28 d and compared to sow-reared piglets. The oils tested included soybean, canola, olive, high oleic sunflower (HOAS), a canola/coconut mixture and a mixture of oils mimicking canola in fatty acid composition. All piglets fed the milk replacer diets showed normal growth. Bleeding times increased after birth from 4–6 min to 7–10 min by week 4 (P<0.001), and were higher in pigs fed diets containing 18∶3n−3, as well as in sowreared piglets receiving n−3 polyunsaturated fatty acids (PUFA) in the milk, as compared to diets low in 18∶3n−3. Platelet numbers increased within the first week in newborn piglets from 300 to 550×10⁹/L, and remained high thereafter. Milk replacer diets, containing vegetable oils, generally showed a transient delay in the rise of platelet numbers, which was partially associated with an increased platelet volume. The oils showed differences in the length of delay, but by the third week of age, all platelet counts were >500×10⁹/L. The delay in rise in platelet counts appeared to be related to the fatty acid composition of the oil, as the effect was reproduced by a mixture of oils with a certain fatty acid profile, and disappeared upon the addition of saturated fatty acids to the vegetable oil. There were no alterations in the coagulation factors due to the dietary oils. Blood plasma, platelets and red blood cell membranes showed increased levels of 18∶3n−3 and long-chain n−3 PUFA in response to dietary 18∶3n−3. The level of saturated fatty acids in blood lipids was generally lower in canola and HOAS oil-fed piglets as compared to piglets fed soybean oil or reared with the sow. The results suggest that consumption of milk replacer diets containing vegetable oils rich in 18∶3n−3 does not represent a bleeding risk, and that the transient lower platelet count can be counterbalanced by the addition of saturated fatty acids to the vegetable oils.     

Effect of citric acid and blanching pre-treatments on drying and rehydration of Amasya red apples

Drying behaviour of red apples was experimentally examined in a laboratory dryer at drying temperatures of 55, 65 and 75 °C and a constant air velocity of 2.0 m/s. Two pre-treatments (blanching and 0.5% citric acid) were applied to prior to drying process. It was observed that both the drying temperature and pre-treatment affected the drying time. The shortest drying times were obtained from pre-treated samples with citric acid solution. Blanched samples have higher rehydration ratios than other samples. Five mathematical models namely, Newton, Henderson and Pabis, Page, Logarithmic and Parabolic models were evaluated in the kinetics research. The fit quality of the proposed models was evaluated by using the determination of coefficient (R²), reduced chi-square (χ²), root means square error (RMSE) and mean relative percent error (P). The Parabolic model provided the best representation of data. Effective moisture diffusivity (D_eff) computed on the basis of Fick's second law. D_eff value of pre-treated samples with citric acid solution was higher than the other samples.     

Characterization of Trimethylolpropane‐Based Biolubricant

The oxidative stability index (OSI) of fatty acid methyl esters (FAME) and trimethylolpropane (TMP) esters or TMPE produced from five vegetable oils (Brassica rapa L., Linum usitatissimum L., Zea mays L., Brassica napus L., Camelina sativa L.) are compared. The highest stability is observed in vegetable oils while the processed products are less stable. The major causes in loss of OSI are attributed to excess FAME in the crude product and the loss of natural antioxidants due to refinement with silica and celite. The low‐temperature flow properties of TMPE produced from four different vegetable oils (B. juncea L., L. usitatissimum L., B. rapa L., and C. sativa L.) are investigated by proton nuclear magnetic resonance (¹H‐NMR). The T2 relaxations of different TMPE are measured to observe how the mobility of oil changed as temperature decreased. Increased oil mobility (represented by T2) is correlated with rising temperature. The Gaussian widths of the singlet in ¹H‐NMR spectra of each oil demonstrated increased molecular mobility as temperature increased. Extrapolation of the relation of T2 signals of these four oils indicates that T2 approached zero between 232 K and 239 K, suggesting the molecular motion leading to a T2 relaxation has largely ceased. Practical Applications: The OSI is determined for four vegetable oils as well as the product FAME and TMPE. The vegetable oils are more stable than their products. The loss of natural antioxidants during purification of FAME and TMPE contributes to the lower OSI compared to vegetable oil. The low‐temperature flow behavior of TMP‐based biolubricants is determined between 238 K and 298 K using T2 relaxation. As temperature decreases, a singlet resonance in ¹H‐NMR spectra attributed to TMP protons broadens until it disappears. The results suggest that the log of the spin‐spin relaxation time is linearly correlated with rising temperature and oil mobility.     

Influence of blanching treatment and drying methods on the drying characteristics and quality changes of dried sardine (Sardinella gibbosa) during storage

The aim of this study is to examine the drying characteristics of blanched and unblanched sardine during indoor and open sun drying processes. Changes in temperature and relative humidity of the air during drying were recorded. The color, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA) content, fatty acid composition, and sensory attributes of dried samples were also evaluated once a month for 5 months of storage. High drying rates were obtained in all samples at the start of drying and then decreased with increasing drying time. The highest drying rate and effective water diffusivity (D_eff) were observed in blanched sardine during open sun drying. Blanching treatment slowed down the FFA progression during product storage but adversely affected the color, PV, and TBARS content as well as sensory properties. Although sardine dried for a longer time under indoor drying conditions, it attained a stable moisture ratio that was lower than in open sun-dried samples. Indoor drying produced a quality stable product with less lipid oxidation and the desired moisture content, higher polyunsaturated fatty acids and sensory properties. Blanching treatment negatively affected the fish quality and is therefore not recommended for commercial sardine drying.     

Lipid and fatty acid biosynthesis by Rhodotorula minuta

Demand for fatty acids is increasing at an annual rate of 17%, due to their increased use in the oleochemical and transport industries. Presently, vegetable oils are the major source of fatty acids, whereas lipids with fatty acids similar to those of some vegetable oils have been reported to be synthesized by oleaginous microorganisms. In the present study, the culturing conditions for the oleaginous yeast Rhodotorula minuta IIP-33 have been optimized. In contrast to the lipid accumulation characteristics of most oleaginous yeasts, a carbon-to-nitrogen ratio of 30 was favorable for maximal accumulation of lipids (48%) with 22.5% conversion of glucose as carbon substrate. The lipids contained fatty acids in the C₇–C₁₈ range, the relative composition of which varied with culture temperature.     

A novel method for the determination of acid value of vegetable oils

The voltammetric behavior of naphthoquinone in the presence of free fatty acids (FFA) at the polypyrrole (PPy)‐modified electrode was investigated in an ethanol/1,2‐dichloroethane (3 : 1) solution containing 0.1 M LiClO₄. A well‐defined new reduction peak appeared at a more positive potential and was higher than that obtained at the bare Pt electrode. Based on the fact that the new reduction peak current showed a good correlation with the concentration of fatty acids, an electroanalytical method for the acid value (AV) of vegetable oils was developed using the PPy‐modified electrode in linear potential sweep voltammetry. The experimental parameters were optimized to obtain a sensitive voltammetric response in this work. A linear calibration graph was obtained in the concentration range of 5.0×10^–6–6×10^–3 M for FFA (R = 0.993), with a sensitivity of 2.41×10^–2 A L/mol and a detection limit of 1.2×10^–6 M (S/N = 3). Each assay of vegetable oil sample took about 80 s. The developed method is applied to the AV determination of six commercial vegetable oils. The results well agreed with those obtained by the titration method. Compared to the conventional titration method, the proposed method is superior in sensitivity and accuracy and requires a small amount of vegetable oil sample, with no pretreatment.     

Sunflower Acid Oil-Based Production of Rhamnolipid Using Pseudomonas aeruginosa and Its Application in Liquid Detergents

Utilization of industrial waste as substrates for the rhamnolipid synthesis by Pseudomonas aeruginosa is a worthy alternative for conventionally used vegetable oils and fatty acids to reduce the production cost of rhamnolipid. Sunflower acid oil (SAO), a by-product of the oil industry, contains 70% 18:0 fatty acid, with oleic acid as a major component. In this scope, production and analysis of rhamnolipid was successfully demonstrated using SAO as a new substrate. Pseudomonas aeruginosa produced rhamnolipid (a glycolipid biosurfactant) at a maximum concentration of 4.9 g L⁻¹ with 60 g L⁻¹ of SAO in the medium. Structural properties of rhamnolipid biosurfactant are confirmed using thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and fourier transformed infrared spectroscopy (FTIR) analysis. Further surface-active properties of the crude rhamnolipid were evaluated by measuring surface tension and emulsification properties. The synthesized rhamnolipid reduced the surface tension of water to 30.12 mN m⁻¹ and interfacial tension (against heptane) to 0.52 mN m⁻¹. Moreover, rhamnolipid shows the highest emulsification index (above 80%) for vegetable oils. This study confirms the use of SAO as a potential substrate for rhamnolipid production. The synthesized rhamnolipid was incorporated in liquid detergent formulation along with alpha olefin sulfonate (AOS) and sodium lauryl ether sulfate (SLES). The performance properties including foaming and cleaning efficiency of liquid detergent were compared.     

Fatty acid methyl ester as reactive diluent in thermally cured solvent-borne coil-coatings—The effect of fatty acid pattern on the curing performance and final properties

Four different fatty acid methyl esters (FAMEs): rape seed methyl ester (RME), tall oil methyl ester (TOME), and two types of linseed oil methyl ester (Linutin) have been studied as reactive diluents in thermally cured solvent-borne coil-coatings. The purpose was to evaluate the effect of fatty acid methyl ester structure on the curing performance and final properties of the coating. The permanent incorporation of the reactive diluent via transesterification reaction has been followed with ¹H NMR analysis of model systems. Dynamic mechanical analysis (DMA) measurements, of free-standing films, show that the glass transition temperature (T_g) decreases upon addition of the reactive diluent. Both the amount of incorporated reactive diluent and the final film properties are affected by the number and placement of alkene-bonds in the FAME.     

Density and viscosity of vegetable oils

A generalized method was developed to estimate the liquid density of vegetable oils and fatty acids. The correlation for vegetable oils was based on fatty acid critical properties and composition of the oil. The correlations predicted the density of vegetable oils and fatty acids with an average absolute deviation of 0.21 and 0.77%, respectively. The present method is slightly more accurate in predicting vegetable oil density and simpler than the method of Halvorsen et al. Also, a method is introduced that predicts viscosity from density data, thus relating two key properties of vegetable oils.     

Investigation of Conjugated Soybean Oil as Drying Oils and CLA Sources

Better sources of drying oils for coatings and conjugated linoleic acid (CLA) for potential health benefits are of continuing interest. Iodine under photochemical conditions in hexanesB at reflux temperatures was investigated as a catalyst for conjugating soybean oil (SBO) for use as drying oils and as a potential source of CLA. Variations in catalyst loading, SBO, light source, free radical catalyst, solvent and temperature strongly affected the efficiency of the process. Changes in fatty acid isomer distributions in conjugated SBO (CSBO) influenced drying properties of CSBO. Conjugated dienes formed were predominantly trans-9,trans-11, which contrasts distributions found with catalysts such as strong base and metal compounds. Drying times of some of the CSBOs were superior to that of raw linseed oil. Iodine was partially recovered.     

The decomposition of secondary esters of castor oil with fatty acids

In this study, thermal splitting of secondary fatty acid esters of castor oil was investigated to determine the reaction kinetics under various conditions. Zinc oxide,p toluenesulfonic acid and sulfuric acid were used as catalysts. Reactions were carried out at 260, 270, and 280°C. Experimental data fitted the first-order rate equation for the catalyzed and noncatalyzed reactions. In addition to the kinetic investigation, the splitting (pyrolysis) mixture was evaluated in the preparation of a synthetic drying oil. For this purpose, the mixed fatty acids of linseed, sunflower andEcballium elaterium seed oils were used in the esterification stage of the process. Pyrolysis mixtures were converted to drying oils by combining the liberated acids with equivalent amounts of glycerol. The oils thus obtained show good drying oil properties.     

Die katalytische Metathese von ungesättigten Fettsäureestern

Catalytic Metathesis of Esters of Unsaturated Fatty Acids Several active and selective catalysts have been developed for the metathesis of unsaturated hydrocarbons in homogeneous medium. These are based on WCl₆ and MoCl₅ with Sn(CH₃)₄, Sn(C₆H₅)₄ and Pb(C₆H₆)₄ as the most important co-catalysts. These catalyst systems also permit the metathesis of compounds having functional groups, such as esters of fatty acids and halogenated hydrocarbons. The metathesis of esters of fatty acids enables the synthesis of numerous compounds, which so far were either unknown or difficult to synthesize. Such compounds are, for instance, certain long chain unsaturated dicarboxylic acids which are derived from monoenoic fatty acids, such as oleic acid and erucic acid. From technological viewpoint the unsaturated dicarboxylic acids might be significant as raw material for the preparation of unsaturated polyesters and polyamides, as well as for the synthesis of certain flavoring agents. The metathesis of fatty oils (glycerides) leads to the formation of high molecular weight compounds. The metathesis of semi-drying and drying oils offers the possibility to prepare stand oils having good drying properties.