Sunflower Oil Fatty Acids Research Articles

Synthesis and evaluation of new hyperbranched alkyds for coatings

Novel hyperbranched alkyd resins (HBAs) were synthesized by reacting the hydroxyl end-groups of the prepared hyperbranched polyesters, based on 1,3,5-tris(2-hydroxyethyl) cyanuric acid (THECA) as a trifunctional core, with different oil fatty acids, namely, linseed, soya and sunflower oil fatty acids. Resins of different compositions of HBAs were prepared by changing either the fatty acid or the generation of the hyperbranched polyester. Their molecular structures were identified using IR and 1H and 13C NMR spectroscopy. The thermal stability, glass transition temperatures and rheological properties were investigated. All of the alkyd resins exhibited initial decomposition temperature at values >300 °C. The decreased Tg values of LG3, SG3 and SFG3 render them suitable for use as coatings that are applied at ambient temperature. All HBAs show Newtonian behaviour and the viscosity was ranging between 1.2 and 5.2 Pa s. Film properties of the prepared alkyd resins using different driers were determined and it has been found that all samples exhibited good adhesion, bending, impact, ductility, and high gloss, but show low hardness.

Capillary gas chromatographic analysis of complex phytosteryl/-stanyl ester mixtures in enriched skimmed milk-drinking yoghurts

The capillary gas chromatographic (GC) separation of complex mixtures of plant steryl and stanyl fatty acid esters was achieved using a medium polar trifluoropropylmethyl polysiloxane as stationary phase. An approach allowing the facile synthesis of steryl/stanyl fatty acid esters was developed, thus creating the basis for a calibration of the method for the different types of ester mixtures to be expected in enriched foods. The usefulness of the approach for the rapid authentication of enriched low-fat products via qualitative and quantitative analysis of intact steryl and stanyl fatty acid esters was demonstrated by analysis of two skimmed milk-drinking yoghurts commercially available on the European market. Combining the extraction of lipids under acidic conditions with the GC separation step showed that one of the products contained a steryl/stanyl ester mixture obtained from long-chain sunflower oil fatty acids and sterols/stanols from tall oil. The other product, however, was shown to contain the rather unusual steryl/stanyl esters of the medium-chain octanoic and decanoic acid as ingredients.

Alkyd resins synthesized from postconsumer PET bottles

Simultaneous glycolysis and neutral hydrolysis of waste PET flakes obtained from grinding postconsumer bottles was carried out in the presence of xylene and an emulsifier at 180 °C. The product was separated from EG, water and xylene by filtration and was extracted by water at boiling point three times. The remaining solid was named water insoluble fraction (WIF). The filtrate was cooled to 4 °C and the crystallized solid obtained by filtration was named water-soluble crystallizable fraction (WSCF). These fractions were characterized by acid value (AV), hydroxyl value (HV) determinations. WSCF and WIF were used for preparation of the alkyd resins. Three long oil alkyd resins were prepared from phthalic anhydride (PA) (reference alkyd resin) or depolymerization product of the waste PET (PET-based alkyd resin), glycerin (G), sunflower oil fatty acids (SOFA) and glycol (EG) (reference alkyd resin) or depolymerization product of the waste PET (PET-based alkyd resin). Film properties and thermal degradation stabilities of these alkyd resins were investigated. Physical properties (drying times, hardness and abrasion resistance) and thermal degradation stabilities of the PET-based alkyd resins are better than these properties of the reference alkyd resin.

A high oleic sunflower oil fatty acid esters of plant sterols mixed with dietary diacylglycerol reduces plasma insulin and body fat accumulation in Psammomys obesus

BackgroundMetabolic syndrome is associated with subsequent development of cardiovascular diseases and type 2 diabetes. It is characterized by reduced response to insulin, central obesity, and dyslipidemia. Intake of plant sterols (PS) has been shown to confer a healthier lipid profile and ameliorate cardiovascular disease risk factors in experimental animals and humans. In this study we used an animal model of type 2 diabetes to assess the effects of a preparation of PS esterified to high oleic sunflower oil fatty acids mixed with dietary diacylglycerol (PS-HOSO) on diabetic related metabolic parameters. Psammomys obesus (P. obesus) were fed high energy (HE) diet supplemented by either PS-HOSO or control oil. Following 4.5 weeks of intervention, animals were divided into fasting and non-fasting modes prior to outcome measurements. Glucose and insulin levels as well as blood lipid profile, body weight, and fat accumulation were evaluated in fasting and non-fasting modes.ResultsP. obesus fed with a HE diet displayed a characteristic heterogeneity in their blood glucose and insulin levels with a subset group displaying type 2 diabetes symptoms. PS-HOSO treatment significantly reduced total cholesterol (24%, P < 0.001) and non-HDL cholesterol (34%, P < 0.01) compared to the control diet. Among fasting animals, body weight at end point and epididymal fat-to-liver weight ratio were significantly (P < 0.05 each) reduced (7% and 16%, respectively) compared to controls. Interestingly, fasting blood glucose levels were similar between groups, whereas plasma insulin level at end point was 44% lower in the PS-HOSO group compared to control group (P < 0.0001)ConclusionPS-HOSO supplementation to diabetes-prone gerbils counteracts the increase in body weight and epididymal fat accumulation, and also results in a drop in circulating insulin levels. These effects are pointing out that PS-HOSO may serve as a functional ingredient for metabolic syndrome or diabetic sufferers, which not only influences body weight, but also prevents or reverses insulin resistance and hyperlipidemia.

P-cresol/Formaldehyde-Based Sunflower Epoxy Esters for Surface Coatings

Epoxy esters were prepared by reacting sunflower oil fatty acids with epoxy resins which were prepared by the epoxidation of P-cresol/formaldehyde resins (1:1, 3:2, 2:1). The epoxy esters were blended with alkyd resin and the film characteristics of these blends were studied at different pigmentation level. It was found that the cured films showed excellent resistance to water and solvents (acetone, ethanol, methanol, ethylmethylketone, toluene), while the resistance to alkali (10% NaOH) was poor. It was also found that increasing the ratio of P-cresol/formaldehyde increase the acid resistance and no significant difference was observed with these tests. All the coating films exhibited a very good adhesion to metallic substrate, good impact, scratch hardness, and flexibility.

Esterification of free fatty acids in sunflower oil over solid acid catalysts using batch and fixed bed-reactors

The esterification of free fatty acids (FFA) found in vegetable oils with CH3OH using a solid catalyst is a promising method to convert FFA into valuable fatty acid methyl ester (FAME, biodiesel) and obtain a FFA-free oil that can be further transesterified using alkali bases. The present work aimed at determining active and durable solid catalysts for the esterification of palmitic acid (PA, C16H32O2) dissolved in commercial sunflower oil with methanol. Contrary to the case of experiments realized at high dilution in solvents or in pure FFA medium, in which methanol is fully soluble, a lack of full miscibility occurred in the present case. Both a stirred batch reactor and, for the first time to our knowledge, a recirculating system using a fixed bed-reactor were used to investigate this system. A silica-supported Nafion® resin (SAC-13) appeared as the most promising catalyst, requiring no activation, contrary to sulfated zirconia (SZ) that must be activated above 400 °C. The SZ material could not be fully regenerated after use because of sulfate group leaching and the fact that the adsorbed oil decomposed to form carbonaceous deposits at the higher temperatures needed to activate the sample by dehydration. The poisoning of SAC-13 by water was mild and simply reversed using a moisture-free feed or purging with a dry gas. The activity of SAC-13 measured with the batch reactor was essentially equal to that obtained using a fixed bed-reactor in a recirculating system and no rate difference was observed whether an extrudate or a powder form of the sample was used. No rate differences were also observed at various stirring rates. These observations stress that no mass transport limitations were taking place. The TOF (based on the number of sulfur atoms) obtained over the SAC-13 was about seven times lower than that obtained using concentrated sulfuric acid. The possibility to use a fixed bed reactor paves the way for simplified studies of similar systems in terms of (1) the separation of the catalyst and product and (2) the mechanical stability of the catalyst particles. The combination of SAC-13 and a fixed bed-reactor system could lead to a practical and cost-effective FFA removal unit in front of typical oil transesterification units.

Olive oil containing olive oil fatty acid esters of plant sterols and dietary diacylglycerol reduces low-density lipoprotein cholesterol and decreases the tendency for peroxidation in hypercholesterolaemic subjects

Plant sterols (PS) and MUFA are well-documented cholesterol lowering agents. We aimed to determine the effect of PS esterified to olive oil fatty acids (PS-OO) on blood lipid profile and lipid peroxidation in hypercholesterolaemic subjects. Twenty-one moderately overweight, hypercholesterolaemic subjects consumed three consecutive treatment diets, each lasting 28 d and separated by 4-week washout periods, using a randomized crossover design. Diets contained 30 % energy as fat, 70 % of which was provided by olive oil (OO), and differed only in the treatment oils: OO, PS esterified to sunflower oil fatty acids (PS-SO), and PS-OO. Both PS-SO and PS-OO treatments provided 1.7 g PS /d. PS-OO and PS-SO consumption resulted in a decrease (P = 0.0483) in LDL-cholesterol (LDL-C) concentrations compared with the OO diet. Although total cholesterol and apo B-100 levels were not significantly affected, PS-SO and, to some extent, PS-OO reduced the total:HDL-cholesterol (HDL-C) ratio (P = 0.0142) and the apo B-100:apo A-I ratio (P = 0.0168) compared with the OO diet. There were no differences across diets in lipoprotein(a) (Lp(a)) and lipid peroxidation levels. However, following consumption of OO and PS-SO, Lp(a) concentrations increased (P = 0.0050 and 0.0421, respectively), while PS-OO treatment did not affect Lp(a) levels. Furthermore, there was a decrease (P = 0.0097) in lipid peroxidation levels with PS-OO treatment during the supplementation phase. Our results suggest that supplementing an OO-rich diet with PS-OO favourably alters the plasma lipid profile and may decrease the susceptibility of LDL-C to lipid peroxidation in hypercholesterolaemic subjects.

Effects of Saline and Sodic Stress on Yield and Fatty Acid Profile in Sunflower Seeds

Among the objectives concerned in this research, much importance has been attached to the assessment of the influence of soil type, irrigation water quality and leaching requirement on the production and composition in fatty acids of sunflower oil. The trial was run in 2001 on a sunflower crop (cv. HS 90) grown in cylindrical pots at the Campus of Bari University (Italy). 36 treatments obtained from the factorial combination of two clay soils with nine types of brackish water and two leaching fractions (10 and 20%) were compared. The nine types of irrigation water were obtained by dissolving the proper amounts of NaCl and CaCl2 in de-ionized water, according to the factorial combination of three salt concentration levels (0.01, 0.032 and 0.064 M) with three sodium levels (SAR = 5, 15 and 45). At ripening the main yield traits, oil yield and acid composition of seeds were analysed. At the highest salinity level about 70% yield reduction, in terms of seeds per plant was observed. The oil yield and the final acid composition of seeds were significantly affected by soil type, leaching requirement, salinity and the SAR levels of irrigation water. A progressive decline in oil yield was recorded as the salt concentration and sodium level of irrigation solutions increased. As to the fatty acid composition, a gradual increase in oleic and linolenic acid content and a corresponding decrease in the other fatty acids were found as the salinity and sodium levels of irrigation water increased. The oleic/linoleic acid ratio too increased as the salinity increased. The salt and sodium-induced stresses of irrigation water reduced the seed and oil yields while still favouring a progressive increase in the oleic acid content and a slight decrease of linoleic, palmitic and stearic acids, thus improving oil quality. The results point out both the influence of the soil and the positive effect of sodium and salt stress and of the leaching fraction on the food quality of sunflower oil.

Application of Ethyl Esters and d3-Methyl Esters as Internal Standards for the Gas Chromatographic Quantification of Transesterified Fatty Acid Methyl Esters in Food

Ethyl esters (FAEE) and trideuterium-labeled methyl esters (d3-FAME) of fatty acids were prepared and investigated regarding their suitability as internal standards (IS) for the determination of fatty acids as methyl esters (FAME). On CP-Sil 88, ethyl esters of odd-numbered fatty acids eluted approximately 0.5 min after the respective FAME, and only coelutions with minor FAME were observed. Depending on the problem, one or even many FAEE can be added as IS for the quantification of FAME by both GC-FID and GC-MS. By contrast, d3-FAME coeluted with FAME on the polar GC column, and the use of the former as IS requires application of GC-MS. In the SIM mode, m/z 77 and 90 are suggested for d3-methyl esters of saturated fatty acids, whereas m/z 88 and 101 are recommended for ethyl esters of saturated fatty acids. These m/z values give either no or very low response for FAME and can thus be used for the analysis of FAME in food by GC-MS in the SIM mode. Fatty acids in sunflower oil and mozzarella cheese were quantified using five saturated FAEE as IS. Gravimetric studies showed that the transesterification procedure could be carried out without of loss of fatty acids. GC-EI/MS full scan analysis was suitable for the quantitative determination of all unsaturated fatty acids in both food samples, whereas GC-EI/MS in the SIM mode was particularly valuable for quantifying minor fatty acids. The novel GC-EI/MS/SIM method using fatty acid ethyl esters as internal standards can be used to quantify individual fatty acids only, that is, without determination of all fatty acids (the common 100% method), although this is present. This was demonstrated by the exclusive quantification of selected fatty acids including methyl-branched fatty acids, erucic acid (18:1n-9trans), and polyunsaturated fatty acids in cod liver oil and goat's milk fat.

Boundary Lubrication Performance of Free Fatty Acids in Sunflower Oil

Free fatty acids are released over time in vegetable oils, primarily through the hydrolysis of the triglyceride base. In mineral oils, fatty acids are considered to be one of the classical boundary lubrication additives, but they may not have the same impact in vegetable oils, due to the vast difference in chemistry between the base oils. The purpose of this study was to evaluate the influence of free fatty acids on the boundary lubrication performance of sunflower oil, with particular focus on the impact of unsaturation within the fatty acid and assessing the effect of elevated temperatures. The results obtained suggest stearic acid can effectively reduce both the wear and friction of sunflower oil formulations under boundary lubrication conditions, although performance is limited when bulk oil temperatures approach 150°C.

Wild helianthus annuus, a potential source of reduced palmitic and stearic fatty acids in sunflower oil

The current trend in human diets is to decrease consumption of the saturated palmitic and stearic fatty acids. Healthy diets restricting not only total fat, but the saturated portion of that fat, would decrease blood serum cholesterol and the risk of coronary heart diseases. Edible vegetable oils are the principal source of fats in many diets. Sunflower oil, which is fifth in production among edible vegetable oils in the world, contains 65 g kg-1 saturated palmitic and 45 g kg-1 saturated stearic acids. These concentrations are high compared to rapeseed oil with 40 g kg-1 palmitic and 20 g kg-1 stearic acids. A reduction of saturated fats in traditional sunflower oil would lead to a healthier edible oil. The objective of this preliminary study was to search the vast genetic diversity available from wild Helianthus annuus, the closest relative of the cultivated sunflower, for potential sources of reduced saturated fatty acids; less than 70 g kg-1 combined palmitic and stearic fatty acids. Achenes of eighty-two populations of wild H. annuus were collected from the central Great Plains of the USA. Composited 20-achene samples from each population were analyzed for saturated fatty acids using organic base-catalyzed transesterification of fatty acid methyl esters and capillary gas chromatography. The average palmitic acid concentration ranged from 39 to 65 g kg-1 for the populations. Average stearic acid concentrations ranged from 19 to 37 g kg-1. Achene oil of one population of wild H. annuus from Holmquist, South Dakota, USA had a palmitic acid concentration averaging 39 g kg-1, while stearic acid averaged 19 g kg-1. The combined 58 g kg-1 palmitic and stearic acids is almost 50% lower than the present level of these fatty acids in sunflower oil. The level of saturated fatty acids observed in the population remained low when plants were grown in the greenhouse under uniform conditions. In the greenhouse palmitic acid concentration of this population averaged 40 g kg-1, while stearic acid averaged 19 g kg-1. Crosses between this population and an inbred cultivated line produced F1 plants with an achene oil that averaged 39 g kg-1 palmitic and 21 g kg-1 stearic acid. In comparison, the inbred cultivated parent averaged 61 g kg-1 palmitic and 51 g kg-1 stearic acid. F2 plants produced achene oil that averaged 45 g kg-1 palmitic and 23 g kg-1 stearic acid, for a total of 68 g kg-1. When F1 plants were backcrossed to the cultivated inbred, BC1F1 plants produced an achene oil that averaged 45 g kg-1 palmitic and 26 g kg-1 stearic acid for a total of 71 g kg-1. In comparison, the inbred cultivated parent averaged 65 g kg-1 palmitic and 42 g kg-1 stearic acid, for a total of 107 g kg-1. Preliminary information indicates that palmitic and stearic fatty acids in sunflower oil can be reduced by introducing genes from a wild annual population into cultivated sunflower. Further research will be needed to determine the inheritance of these fatty acids. Other agronomic traits will also have to be monitored during introgression of the fatty acids genes.

Wild perennial sunflower as a potential source of reduced palmitic and stearic fatty acids in sunflower oil

The trend in healthier human diets is to decrease the consumption of the saturated fatty acids. Sunflower oil, which is fourth in production among edible vegetable oils in the world, contains 65 g kg-1 palmitic and 45 g kg-1 stearic acids, both saturated fatty acids. These levels are high compared with rapeseed (Brassica napus L) oil with 40 g kg1 palmitic and 20 g kg-1 stearic acids. A reduction of saturated fats in traditional sunflower oil would lead to a healthier edible oil. The objective of this preliminary study was to search the vast genetic diversity available from wild ancestors of cultivated sunflower for potential sources of reduced palmitic and stearic fatty acids. Achene oil of one population of wild H. giganteus L. (GIG-102) from INRA, Montpellier, France, had 47 g kg-1 palmitic acid and 18 g kg-1 stearic acid. The combined 65 g kg-1 palmitic and stearic acids is 40% lower than the present level of these fats in sunflower oil. The level of saturated fatty acids observed in the population remained low when plants were grown in the greenhouse under uniform conditions. In the greenhouse, palmitic acid averaged 48 g kg-1, while stearic acid averaged 16 g kg-1. This would indicate that palmitic and stearic acid concentrations are under genetic control with potential for incorporation into cultivated sunflower. Crossing this population with an inbred cultivated line produced F1 plants with an achene oil that averaged 39 g kg-1 palmitic and 26 g kg-1 stearic acid. The inbred cultivated parent averaged 55 g kg-1 palmitic and 51 g kg-1 stearic acid. F2 plants produced an achene oil that averaged 47 g kg-1 palmitic and 29 g kg-1 stearic acid, for a total of 76 g kg-1. When F1 plants were back-crossed to the cultivated inbred, BC1F1 plants produced an achene oil that averaged 47 g kg-1 palmitic and 28 g kg1 stearic acid for a total of 75 g kg-1. The inbred cultivated parent averaged 54 g kg-1 palmitic and 56 g kg-1 stearic acid, for a total of 110 g kg-1. Preliminary information indicate that palmitic and stearic fatty acids in sunflower oil can be reduced by introducing genes from a wild perennial progenitor into cultivated sunflower. Further research will be needed to determine the inheritance of these fatty acids. Other agro-nomic traits will also have to be monitored during the introgression of genes for reduced saturated fatty acids into cultivated sunflower.

Glycolipids of the smut fungus Ustilago maydis from cultivation on renewable resources

When grown on vegetable oils and their derivatives, the smut fungus Ustilago maydis (DSM 4500 and ATCC 14826) produces several glycolipids under nitrogen-limiting conditions. With 45 g l−1 sunflower oil fatty acids (technical grade) a yield of 30 g l−1 glycolipid was achieved. The resulting mixture contained predominantly mannosylerythritol lipids together with smaller amounts of cellobiose lipids. The production of the more polar cellobiose lipids was enhanced when glucose was used as carbon source. The molecular structure of the main components of the glycolipid mixture were elucidated by a combination of NMR spectroscopic and mass-spectrometric techniques.

Production of glycerides from glycerol and fatty acids by native lipase ofNigella sativa seed

The possible application of native lipase ofNigella sativa seed in the esterification of fatty acids to glycerol was investigated, and the effect of process parameters and the enzyme selectivity on the reaction were determined. For this aim, the esterification of oleic acid, sunflower oil fatty acids, and coco oil fatty acids with glycerol were studied.

Effects of antioxidants on the stability of triacylglycerols and methyl esters of fatty acids of sunflower oil

The autoxidation of kinetically pure triacylglycerols and methyl esters of sunflower oil (TGSO and MESO) in the presence of four different concentrations of 3,4-dihydroxybenzoic, ferulic, sinapic and caffeic acids, and in the absence of metal ions, at 100 °C was studied. It was established that the effectiveness and strength of the phenolic acids was greater in TGSO than in MESO. The interpretation of the results by kinetic and computational methods allowed the mechanism of action of the antioxidants to be elucidated. In both lipid substrates the molecules of the phenolic acids participate in one side reaction. The rate constants of this reaction in TGSO and MESO are practically the same, which shows that the binding of the fatty acids to the triacylglycerol structure of the sunflower oil does not change the mechanism of phenolic acid consumption in side reactions. The phenolic acids participate in reactions of chain initiation, which have a three to six times higher rate in MESO than in TGSO. The radicals of 3,4-dihydroxybenzoic, sinapic and caffeic acids in MESO, and of 3,4-dihydroxybenzoic and caffeic acids in TGSO, take part in one reaction of chain propagation (with the lipid substrate). The radicals of ferulic acid in MESO, and of ferulic and sinapic acids in TGSO, participate in more than one reaction of chain propagation. The effectiveness and strength of the phenolic acids are higher in TGSO than in MESO because, during the oxidation of TGSO, the contribution of the inhibitor radicals and molecules to chain initiation and propagation is smaller than in the case of MESO oxidation.