Autoxidized Soybean Oil Research Articles

Physical, biological and chemical characterisation of wood treated with silver nanoparticles

Nowadays, environmentally friendly processes are of great interest and are considerably needed due to the environmental pollution seems to be a problem worldwide. For this reason, in this study, silver nanoparticles were synthesized using environmentally-friendly methods and their effectiveness as wood preservatives was investigated. Scots pine (Pinus sylvestris L.) samples were impregnated with an autoxidized soybean oil polymer containing Ag nanoparticles (Agsbox). Samples characterised by Fourier transform infrared spectroscopy (FTIR) were tested against brown rot (Coniophora puteana) and wood-destroying insects (Hylotrupes bajulus). In addition, decay tests were applied to mini-block samples leached according to the EN 84 standard. Results demonstrated that Agsbox increased decay resistance in the unleached samples. However, low efficacy was exhibited against newborn H. bajulus larvae. As a results of FTIR measurement, impregnated with the nanocomposites showed significant changes at the 2910 cm−1 (C–H) and 1712 cm−1 (C=O) peaks.

Fungal inhibition and chemical characterization of wood treated with novel polystyrene-soybean oil copolymer containing silver nanoparticles

In this study, Scots pine (Pinus sylvestris L.) samples were impregnated with autoxidized soybean oil polymer containing Ag nanoparticles (Agsbox) and polystyrene-soybean oil copolymer (AgPSsb) in order to inhibit white-rot fungus (Trametes versicolor). Chemical changes of the impregnated specimens were characterized by FTIR techniques. The higher concentration of nano preservative resulted in higher weight percent gain (WPG) in the impregnated samples. The samples impregnated with 1.5% of Agsbox, had the highest WPG (2.98%). The silver nanocomposite-impregnated wood specimens improved the anti-fungal properties. In addition, treatment with 0.4% AgPSsb resulted in the lowest moisture content (23.4%) after decay tests. In the samples, the lowest weight loss (0.87%) due to fungal decay was observed with the use of 0.4 wt% of AgPSsb. Mass losses of Agsbox impregnated specimens at 1.5% and 0.04% were 2.86% and 4.61% respectively. The FTIR spectra of the specimens impregnated with the nanocomposites showed the impregnated components at the peaks of 2910 cm−1 and 1714 cm−1 in particular.

High fluorescence emission silver nano particles coated with poly (styrene-g-soybean oil) graft copolymers: Antibacterial activity and polymerization kinetics

Autoxidation of poly unsaturated fatty acids makes negative effect on foods. In this work, this negative effect was turned to a great advantage using autoxidized soybean oil as a macroperoxide nanocomposite initiator containing silver nano particles in free radical polymerization of vinyl monomers. The synthesis of soybean oil macro peroxide was carried out by exposing soybean oil to air oxygen with the presence of silver nanoparticles (Ag NPs) at room temperature. Autoxidized soybean oil macroperoxide containing silver nanoparticles (Agsbox) successfully initiated the free radical polymerization of styrene in order to obtain Polystyrene (PS)-g-soybean oil graft copolymer containing Ag NPs. Both autoxidized soybean oil and PS-g-sbox with Ag NPs showed a surface plasmon resonance and high fluorescence emission. Overall rate constant (K) of styrene polymerization initiated by autoxidized soybean oil macroperoxide with Ag NPs was found to be K=1.95.10−4Lmol−1s−1 at 95°C. Antibacterial efficiency was observed in the PS-g-soybean oil graft copolymer film samples containing Ag NPs. 1H NMR and GPC techniques were used for the structural analysis of the fractionated polymeric oils.

Efficiency of Gold Nano Particles on the Autoxidized Soybean Oil Polymer: Fractionation and Structural Analysis

AbstractPolyunsaturated plant oils have gained great interest as monomers to produce biodegradable polymers obtained from renewable resources due to the limited existing sources of petroleum oil and environmental issues. Soybean oil was autoxidized by exposure to atomospheric oxygen at room temperature with or without the presence of gold nanoparticles (Au NPs) 5–41 days. When the autoxidation process was catalyzed with Au NPs, the molecular weight of the oxidized oil was increased in 5 days. In contrast to this, without Au NPs, the oxidized oil was still a fluidized liquid. Autoxidized soybean oil polymer in toluene solution with gold NP showed a surface plasmon resonance at λmax = 540 nm in a UV–VIS spectrometer and a fluorescence emission spectrum at λmax = 450 nm, when it was irradiated at λmax = 390 nm. The higher molecular weight of the polymeric oils was successively fractionated by the extraction from the solvent‐non‐solvent mixture CHCl3/petroleum ether with the volume ratio of 5:15. Three polymeric oils fractions with different molecular weight (ca 1000, 4000, and 40,000 g/mol) were obtained. GC–MS analysis, 1H‐NMR and GPC techniques were used in the structural analysis of the fractionated polymeric oils.

Synthesis of Segmented Polyurethane Based on Polymeric Soybean Oil Polyol and Poly (Ethylene Glycol)

Polyurethane (PUR) plastic sheets were prepared by reacting hydroxylated polymeric soybean oil (PSbOH) synthesized from autoxidized soybean oil with polyethylene glycol (PEG) in the presence of isophorone diisocyanate (IPDI). FTIR technique was used to identify of chemical reactions. These polyurethanes have different valuable properties, determined by their chemical composition. The effect of stoichiometric balance (i.e., PSbOH/PEG-2000/IPDI weight ratio) on the final properties was evaluated. The polyurethane plastic sheets with the PSbOH/PEG-2000/IPDI weight ratio 1.0/1.0/0.67 and 1.0/0.3/0.3 had excellent mechanical properties indicating elongation at break more than 200%. Increase in IPDI and decrease in PEG weight ratio cause the higher stress–strain value. The properties of the materials were measured by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), stress–strain measurements and FTIR technique.

Adaptation of the AOCS official method for measuring hydroperoxides from small‐scale oil samples

AbstractAn adaptation of the American Oil Chemists' Society Official Method Cd 8–53 for determining peroxides in fats and oils using a 0.5‐g sample is described. Comparisons of the Official Method and the small‐scale method were performed by analyzing soybean oil samples spiked with t‐butyl hydroperoxide and autoxidized soybean oil samples. A linear relationship between the Official Method and the small‐scale method was obtained with an R2 of 0.998. The small‐scale method is sensitive, precise, and suitable for small sample sizes and uses only about 10% of the chemicals necessary for the Official Method.

Effects of filtration through activated carbons on peroxide, thiobarbituric acid and carbonyl values of autoxidized soybean oil

AbstractEffects of filtration bleaching on peroxide value (PV), thiobarbituric acid value (TAV) and carbonyl value (CV) of autoxidized soybean oil were investigated by using twenty‐three kinds of activated carbon in order to improve oil quality. From the decreases in PV, TAV and CV and from the physical and chemical properties of activated carbons, it was suggested that hydroperoxides, aldehydes and ketones were adsorbed on the acid sites distributed over the surface or within the pores of the activated carbons while the autoxidized soybean oil flowed through the packed column. The residual tocopherols in autoxidized soybean oil and treated soybean oil were determined during storage. The decrease in oxidative stability of treated soybean oil seemed to be caused by elimination ofα‐,β‐andγ‐tocopherols.δ‐Tocopherol was chemically more stable thanα‐,β‐ andγ‐tocopherols in autoxidized soybean oil.

Effects of filtration through bleaching media on thiobarbituric acid and carbonyl values of autoxidized soybean oil

Effects of filtration bleaching on thiobarbituric acid values (TAV) and carbonyl values (CV) of autoxidized soybean oil were investigated by using sixteen kinds of bleaching media in order to improve oil quality. The standard activated clay was the most effective in reducing the amounts of aldehydes and ketones in autoxidized soybean oil. From the decreases in TVA and CV and physical and chemical properties of media, it was concluded that decreases of TAV and CV are mainly dominated by the acidity over the highest range, +1.5∼−5.6, rather than the acidity over the lower acid strength ranges, total acidity or specific surface area of media. From the results of chemical composition and acidity over the highest range (+1.5∼−5.6) of the clays and TAV or CV reduction by using the heattreated clays, it was suggested that the acidity over the highest range originated from the water contained between layers and bound water in the clay.

The Effect of Rancid Oils on Lymphoid Tissues

Among the oxidation products of edible fats and oils, lipid hydroperoxides and the low-molecular-weight compounds containing short-chain aldehydes such as 4-hydroxynonenal are absorbed from the intestinal wall and carried into the internal organs with oral administration to rodents. Oral intake of lipid hydroperoxides or the low-molecular-weight compounds causes significant cytotoxic damage to the lymphoid tissues. The DNA synthesis of thymocytes is remarkably depressed and lymphocyte necrosis is observed in the thymus and intestinal Peyer's patches. In these cases, the mitogenic response to concanavalin A of splenocytes is increased. With long-term (90 d) feeding of slightly autoxidized soybean oil (peroxide value ; 150 meq/kg) in mice, the same symptoms as those mentioned above are observed. These findings indicate that oral intake of rancid oils give significant effects on immunocompetent cells and causes depression of the DNA synthesis of thymocytes, which would be one of the major cause for impairing immunocompetent systems in animals.

Effects of Filtering through Bleaching Media on Decrease of Peroxide Value of Autoxidized Soybean Oil

ABSTRACTThe effects of filtering through bleaching media on decrease of peroxide value (PV) of autoxidized soybean oil were investigated to improve its quality. Sixteen kinds of filtering and bleaching media were employed. The standard activated clay was the most effective in decreasing the peroxides in autoxidized soybean oil. The relations between the decrease of PV and the physical or the chemical properties of the media were examined. It was found that peroxides are reduced in proportion to the amount of acid at the highest acid strength range + 1.5–5.6 rather than amount of acid at the lower acid strength range, total amount of acid or specific surface area of medium.

The effect of dietary autoxidized oils on immunocompetent cells in mice

Effects of dietary autoxidized oil on immunocompetent cells, such as splenocytes and thymocytes, were studied in mice. When the autoxidized methyl linoleate was administered orally to male C57BL/6 mice in a single dose, the DNA synthesis of thymocytes was remarkably depressed 1 day after the treatment, and then the mitogenic response to concanavalin A of splenocytes was increased 3 days after the dose. With long-term (90 days) feeding of slightly autoxidized soybean oil (with a peroxide value of 150 mequiv/kg) in mice, the DNA synthesis of thymocytes was depressed and the mitogenic response to concavanalin A of splenocytes was increased. No effect was observed on plasma glutamic acid-oxaloacetic acid transminase and glutamic acid-pyruvic acid transaminase levels, nor on liver thiobarbituric acid reactants due to the dose of autoxidized soybean oil. These findings indicate that oral intake of autoxidized oil effects immunocompetent cells and causes depression of the DNA synthesis of thymocytes in mice.

Effect of Dietary Vitamin E on the Toxicity of Autoxidized Oil to Rats

Tocopherol, one of the antioxidants in vegetable fats and oils, was added to the autoxidized diet of male rats at the same tocopherol level as soybean oil before autoxidation. Autoxidized soybean oil was used as the test lipid; fresh soybean oil was the control. The diet containing autoxidized oil depressed the body weight gains and increased the tissue ratios to body weight, with the exception of testicle. Parallel with those, increased hemolysis, peroxide value and carbonyl value in the tissue lipids, and a decrease in linoleic or arachidonic acid was observed. The effect of dietary vitamin E on the tissue lipid peroxidation was different among the individual organs. From the results obtained by chemical analyses, the lipid peroxidation caused in the liver, heart and intestine was recognized to be suppressed effectively when the same tocopherol level as fresh soybean oil was added to the diet.

Bitter Taste of Oxidized Fatty Acids

A strong bitter taste was reported previously in highly autoxidized soybean oil, especially in the free fatty acid fraction. In the present study, for the elucidation of bitter substances in autoxidized oils, autoxidized linoleic acid was fractionated by silicic acid column chromatography, and the fraction with maximum peroxide value was treated with cysteine-ferric trichloride, reduced with sodium borohydride, oxidized with chromic acid and esterified with diazomethane. The results indicated that the bitter substances of autoxidized linoleic acid possessed a particular structure between the carboxyl group and other functional groups. To verify this fact, four oxidized fatty acids [ricinoleic(12-hydroxyoctadecenoic), 12-oxooctadecenoic, 9,12-dioxooctadecenoic, and dihydroxyoctadecenoic acids] were synthesized from castor oil, and their correlation to the bitter taste was investigated. The results showed that ricinoleic acid had a strong bitter taste, along with a strong stimulation, but this bitter taste was greatly reduced by methyl esterification. On the other hand, 12-hydroxy- and 9,10-dihydroxystearic acids were tasteless. From these results we conclude that the presence of an unsaturated bond, a carboxyl, a hydroxyl and/or peroxyl groups is a requisite for the bitterness of ricinoleic and autoxidized fatty acids.

Studies on the nature of the taste of lipids. Part VII. for Part VI, see ref. 1. Bitter taste of oxidized fatty acids.

A strong bitter taste was reported previously in highly autoxidized soybean oil, especially in the free fatty acid fraction. In the present study, for the elucidation of bitter substances in autoxidized oils, autoxidized linoleic acid was fractionated by silicic acid column chromatography, and the fraction with maximum peroxide value was treated with cysteine-ferric trichloride, reduced with sodium borohydride, oxidized with chromic acid and esterified with diazomethane. The results indicated that the bitter substances of autoxidized linoleic acid possessed a particular structure between the carboxyl group and other functional groups. To verify this fact, four oxidized fatty acids [ricinoleic(12-hydroxyoctadecenoic), 12-oxooctadecenoic, 9,12-dioxooctadecenoic, and dihydroxyoctadecenoic acids] were synthesized from castor oil, and their correlation to the bitter taste was investigated. The results showed that ricinoleic acid had a strong bitter taste, along with a strong stimulation, but this bitter taste ...

Studies on Nature of the Tastes of Lipids. VI.

Many flavor deteriorations in lipid-containing foods are attributable to autoxidation of their lipids.. It is well known that autoxidized oils show unpleasant taste and odor. However, little reserch has been made on their taste. This paper deals with the taste of autoxidized soybean oil, and the elucidation of contributing matters to bitter taste. The oil with peroxide value of 2212 was used for the experiments, , because it had the strongest bitter and stimulant taste and astrigency characteristic among autoxidized oils. After the systematic fractionation as shown in Fig.-1, each fraction was added to the fresh oil on the basis of yields or acid value, and tested organoleptically. A strong bitter taste was detected in both free fatty acids and deacidified glyceride fractions. During several chromatographic analysis, the bitter substance in the former was supposed to be polar oxidized fatty acids rich in functional groups. The volatile compound fraction had a strong astrigency, which may be caused by carbonyl compounds.

Studies on the flavor of autoxidized soybean oil.

AbstractThe flavor components of soybean oil in the early stages of autoxidation were isolated by distillation in a molecular still. The distillate consisted of an aqueous layer and an oily film. The oily film did not reproduce the autoxidized flavor when added to freshly deodorized oil. Gas chromatographic and organoleptic analysis indicated that the oily film contained hexanal, vinylamyl ketone, andtrans,cis‐2,6‐nonadienal. The aqueous layer reproduced the autoxidized flavor when added to freshly deodorized oil, and the flavor had a retention time on butandiol succinate columns between those of pentanal and hexanal. Mixtures of vinylethyl ketone and pentanal gave a flavor to freshly deodorized oil similar to the flavor of oil in the early stages of autoxidation. Vinylethyl ketone was identified in the distillate from autoxidized soybean oil as the 2,4‐dinitrophenylhydrazone.

CHEMICAL REACTIONS INVOLVED IN THE CATALYTIC HYDROGENATION OF OILS. II. IDENTIFICATION OF SOME VOLATILE BY-PRODUCTS.

AbstractGas chromatography of the volatile by‐products produced during the catalytic hydrogenation of an autoxidized soybean oil with a peroxide number of 11.2 meq/kg yielded approx 41 peaks. Twenty‐one of the gas chromatographic fractions were collected and rechromatographed, and their chemical identity studied with micro‐iR and mass spectrophotometry. These volatile by‐products, according to peak area of gas chromatogram, showed a predominance of hydrocarbons and alcohols.The fractions which have been identified aren‐octane,n‐nonane,n‐decane,n‐heptadecane,n‐hexanol,n‐heptanol,n‐decanol,n‐hexanal,n‐decanal and 3‐nonanone. Among the gas chromatographic fractions collected,n‐decanol has an odor most reminiscent of that of catalytic hydrogenation.

Polarographic studies of fat oxidation

SummaryThe polarograms of autoxidized soybean oil indicated the presence of a peroxide, which was formed in considerably larger proportion in soybean oil than in methyl esters of similar composition. This peroxide was reduced at more positive potentials than the hydroperoxide at the dropping mercury electrode. In solvent fractionation, using mixtures of Skellysolve F and acetone, this peroxide associates with the polymerized fraction. Hydrogenated soybean oil samples and olive oil also showed the presence of this peroxide in considerable concentrations in the period that they began to give turbid solutions in Skellysolve F. Soybean oil oxidized in the presence of cobalt catalyst contained negligible proportions of peroxides normally reduced at the dropping mercury electrode. Attempts to concentrate the peroxides from methyl oleate oxidized in a similar manner did not succeed.

Volatile cleavage products of autoxidized soybean oil

SummaryVolatile odor principles of reverted soybean oil collected at very low temperature have been fractionated into rancidity and reversion components by adsorption on silica gel. These principles apparently contain aldehyde groups since they can no longer be detected organoleptically after the addition of aldehyde reagents.Isolations of individual aldehydes within the rancid and reverted fractions were made by forming the 2,4‐dinitrophenylhydrazones and chromatographically separating these colored derivatives. Identifications were based upon melting points, ultimate analyses, and adsorption data.The following aldehydes were identified: acetaldehyde, propionaldehyde, α‐pentenal, and hexanal. There is strong evidence that crotonaldehyde is also present although not completely resolved from propionaldehyde as dinitrophenylhydrazones.