Oxidative stability of soybean oil products obtained by regioselective chemical interesterification

Konishi, Hiroaki; Neff, W. E.; Mounts, T. L.

doi:10.1007/bf02546217

Cited by 15 publications

(11 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Antioxidant addition could prolong the induction period and reduce PV, but it was not possible to restore the stability of SL to pre-modification values. When comparing the oxidative stability of products from soybean oil and methyl stearate, it was observed that SL had the best stability in comparison with the RL and soybean oil [24]. That was ascribed to incorporation of stearic acid in sn-1,3 positions, which stabilized linoleic acid.…”

Section: Discussionmentioning

confidence: 99%

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Timm‐Heinrich

Nielsen

et al. 2003

Euro J Lipid Sci & Tech

View full text Add to dashboard Cite

Oxidative stability of structured lipids produced from sunflower oil and caprylic acidTraditional sunflower oil (SO), randomized lipid (RL) and specific structured lipid (SL), both produced from SO and tricaprylin/caprylic acid, respectively, were stored for up to 12 wk to compare their oxidative stabilities by chemical and sensory analyses. Furthermore, the effect of adding a commercial antioxidant blend Grindox 117 (propyl gallate/citric acid/ascorbyl palmitate) or gallic acid to the SL was investigated. The lipid type affected the oxidative stability: SL was less stable than SO and RL. The reduced stability was most likely caused by both the structure of the lipid and differences in production/purification, which caused lower tocopherol content and higher initial levels of primary and secondary oxidation products in SL compared with RL and SO. Grindox 117 and gallic acid did not exert a distinct antioxidative effect in the SL oil samples during storage.

show abstract

Section: Discussionmentioning

confidence: 99%

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Timm‐Heinrich

Nielsen

et al. 2003

Euro J Lipid Sci & Tech

View full text Add to dashboard Cite

show abstract

“…The oxidation processes of SO and SSO were both carried out in duplicate for 45 days. Three hundred mg of each individual Table 1 Total and positional fatty acid profiles (peak area %), acid value, peroxide value (POV) and tocopherol contents of soybean oil (SO) and structured soybean oil (SSO) All values are means ± SD; Mean values with different superscripts within the row of SO and SSO (a, b) are significantly different (P < 0.05) 3 , which contained 0.1 % tetramethylsilane as an internal standard, and this mixture was placed into a 5-mm diameter NMR tube. The acquisition parameters were spectral width 12,335.5 HZ, number of scans 16, acquisition time 2.656 s. The experiment was carried out at 28 °C.…”

Section: Oxidation Processmentioning

confidence: 99%

“…However, the results are controversial [1]. Some researchers indicated that a linoleic (L) acyl moiety located at the sn-2 position of TAG molecule is more stable to oxidation than when it exists at the sn-1(3) position [2,3]. Furthermore, TAG shows higher resistance to oxidation when docosahexaenoic acid exists at the sn-2 position than that at the sn-1(3) position [4].…”

Section: Introductionmentioning

confidence: 99%

Effect of Positional Distribution of Linoleic Acid on Oxidative Stability of Triacylglycerol Molecules Determined by ¹H NMR

Wang

Yang

Gan

et al. 2015

J Americ Oil Chem Soc

View full text Add to dashboard Cite

1H nuclear magnetic resonance (1H NMR) was used to determine the effect of positional distribution of linoleic acid (L) on the oxidative stability of triacylglycerols. For this purpose, structured soybean oil (SSO), which had a similar total fatty acid composition but a different L positional distribution than soybean oil (SO), was produced by interesterification reaction. The SO and SSO were oxidized in the dark at 40 °C. Afterwards, 1H NMR was used to monitor the oxidation process and quantify the main polyunsaturated fatty acid, Z,E‐ and E,E‐conjugated forms, hydroperoxides, and aldehydes at different oxidation periods in a single run. After 45 days of oxidation, SSO showed lower L content than SO (9.9 ± 1.1 and 16.8 ± 0.5 %, respectively). Additionally, secondary oxidation products in SSO were shown to be more abundant than in SO (82.3 ± 4.9 and 43.6 ± 0.9 mmol/L oil, respectively). This study indicated that SO, which contains a higher distribution of L at the sn‐2 position, was more resistant to autoxidation than SSO.

show abstract

“…A similar method using benzidine instead of anisidine has been reported 20 but does not appear to be used to any significant extent. Several methods to measure volatile aldehydes in closed system headspace have been reported 61,65,71 .…”

Section: Secondary Oxidation Productsmentioning

confidence: 99%

Characterization of Biodiesel Oxidation and Oxidation Products

2005

View full text Add to dashboard Cite

This report must be reproduced in full,unless SwRI approves a summary or abridgement. iii EXECUTIVE SUMMARY Stability Chemistry FundamentalsChemical reactivity of fatty oils and esters can be divided into oxidative and thermal instability. Both of these types of instability are determined by the amount and configuration of the olefinic unsaturation on the fatty acid chains. Many of the plant-derived fatty oils, including soy and rapeseed, contain polyunsaturated fatty acid chains that are methylene-interrupted rather than conjugated. This structural fact is key to understanding both oxidative and thermal instability.In oxidative instability, the methylene carbons between the olefinic carbons are the sites of first attack. After hydrogen is removed from such carbons oxygen rapidly attacks and a hydroperoxide is ultimately formed where the polyunsaturation has been isomerized to include a conjugated diene. This reaction is a chain mechanism that can proceed rapidly once an initial induction period has occurred. The greater the level of unsaturation in a fatty oil or ester, the more susceptible it will be to oxidation. Once the hydroperoxides have formed, they decompose and inter-react to form numerous secondary oxidation products including aldehydes, alcohols, shorter chain carboxylic acids, and higher molecular weight oligomers often called polymers. Another polymerization mechanism, vinyl polymerization, has been proposed as being part of the degradation process of fatty oils and esters. However, conventional understanding of oxidation chemistry would imply that such processes would not be significant when oxygen was abundant, so its precise level of importance has not been determined.Metals, free fatty acids, acidic fuel additives, the size of the alcohol group (for mono-esters), and the presence of natural antioxidants can all impact the oxidative stability of fatty oils and/or esters. Oxidation can also be catalyzed by light, but such photo-oxidation should not be a significant factor for the manufacture and transportation of biodiesel fuel.Thermal polymerization of fatty oils and esters does not become important until temperatures of 250-300°C are reached. This is because the methylene-interrupted polyunsaturated structure cannot participate in such reactions until it isomerizes into a conjugated configuration, and such isomerization will not occur until that temperature range is reached. Thermal polymerization occurs by the Diels Alder reaction, and two fatty acid chains are linked by a cyclohexene ring. Higher order oligomers are also possible, although the exact mechanism is still not established. Certain thermal polymerization products in used cooking oils may carry over to non-distilled biodiesel. The verification of such compounds and their impact on fuel quality has not been determined. Thermal polymerization may be of limited importance in biodiesel fuel that is repeatedly heated by the engine and recycled to the fuel tank before actual combustion. However, thermal polymerization will not impact stor...

show abstract

Oxidative stability of soybean oil products obtained by regioselective chemical interesterification

Cited by 15 publications

References 27 publications

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Effect of Positional Distribution of Linoleic Acid on Oxidative Stability of Triacylglycerol Molecules Determined by ¹H NMR

Characterization of Biodiesel Oxidation and Oxidation Products

Contact Info

Product

Resources

About

Oxidative stability of soybean oil products obtained by regioselective chemical interesterification

Cited by 15 publications

References 27 publications

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Effect of Positional Distribution of Linoleic Acid on Oxidative Stability of Triacylglycerol Molecules Determined by 1H NMR

Characterization of Biodiesel Oxidation and Oxidation Products

Contact Info

Product

Resources

About

Effect of Positional Distribution of Linoleic Acid on Oxidative Stability of Triacylglycerol Molecules Determined by ¹H NMR