Separation Behavior of Octadecadienoic Acid Isomers and Identification of <i>cis</i>‐ and <i>trans</i>‐Isomers Using Gas Chromatography

Shibamoto, Shigeaki; Gooley, Andrew A.; Yamamoto, Kouhei

doi:10.1007/s11745-014-3966-8

Cited by 6 publications

(4 citation statements)

References 44 publications

(64 reference statements)

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“…1). In support of this identification, Shibamoto et al [20] synthesized c9, t15-18:2, which identified it using dimethyl disulfide derivatization and GC/MS. They determined its elution order relative to a number of 18:2 isomers by analyzing them isothermally on a 100 m BPX90 capillary GC column.…”

Section: Resultsmentioning

confidence: 87%

Non‐conjugated cis/trans 18:2 in Beef Fat are Mainly Δ‐9 Desaturation Products of trans‐18:1 Isomers

Vahmani

Rolland

Gzyl

et al. 2016

Lipids

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Human liver cells (HepG2) were cultured with individual trans (t) 18:1 including t6-, t12-, t13-, t14-, t15- and t16-18:1, and retention times of their Δ-9 desaturation products were determined using 100-m biscyanopropyl-polysiloxane and SLB-IL111 columns. Corresponding peaks were found in beef adipose tissues known to have different delta-9 desaturase activities. Further lines of evidence indicating the presence of Δ-9 desaturation products of t-18:1 isomers in beef fat were developed by analysis of fatty acid methyl esters (FAME) fractionated using Ag-TLC, and by GC/MS. Some of the Δ-9 desaturation products of t-18:1 have been previously identified in ruminant fat (c9, t12- and c9, t13-18:2). Some of the Δ-9 desaturation products of t-18:1 (c9, t14- and c9, t15-18:2) have been previously tentatively identified as different fatty acids, and for the first time we provide evidence of the presence of c9, t16-18:2, and where t6, c9-18:2 may elute during analysis of FAME from beef fat.

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Section: Resultsmentioning

confidence: 87%

Non‐conjugated cis/trans 18:2 in Beef Fat are Mainly Δ‐9 Desaturation Products of trans‐18:1 Isomers

Vahmani

Rolland

Gzyl

et al. 2016

Lipids

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“…A cis ‐ to trans ‐isomerization reaction at 105 °C for 15 min (Snyder & Scholfield, ) was carried out by adding 10 mL of p ‐toluenesulfinic acid/1,4‐dioxane solution (20 mg/mL) to 18:2( c , c ) (20 mg). The mixture was neutralized by adding 5 mL of 1 mol/L NaOH aqueous solution monitored with phenolphthalein, extracted into n ‐hexane, dehydrated by adding anhydrous sodium sulfate (until aggregation disappeared), and after cooling, purified by thin‐layer chromatography using Merck 5721 thin‐layer silica gel plates with n ‐hexane/diethyl ether/acetic acid (70:30:1, v/v/v) (Shibamoto et al, ; Snyder & Scholfield, ).…”

Section: Methodsmentioning

confidence: 99%

“…To remove the residual iodine, the mixture was loaded onto a pre‐prepared column packed with Extrelut® NT to which a saturated Na 2 S 2 O 3 aqueous solution (0.8 mL) was added. After elution with 10% diethyl ether/ n‐ hexane (1 mL, four times), the eluate was evaporated to dryness, made up to 1 mL with n‐ hexane, and then analyzed using GC/EI‐MS (Buser et al, ; Carballeira et al, ; Christie, ; Dunkelblum et al, ; Francis, ; Scribe et al, ; Shibahara et al, , , , ; Shibamoto et al, , ; Vincent et al, ; Yamamoto et al, , , ).…”

Section: Methodsmentioning

confidence: 99%

“…However, the derivative method has its weak point in that the difference of fragment ion intensity is weak and only the samples in which the target components can be perfectly separated on the chromatogram are available. Recently, the dimethyl disulfide (DMDS) adduct method is widely used to determine the double‐bond positions (Buser, Arn, Guerin, & Rauscher, ; Carballeira, Shalabi, & Cruz, ; Christie, ; Dunkelblum, Tan, & Silk, ; Francis, ; Scribe, Guezennec, Dagaut, Pepe, & Saliot, ; Shibahara, Yamamoto, Kinoshita, & Anderson, ; Shibahara, Yamamoto, Nakayama, & Kajimoto, , ; Shibahara, Yamamoto, Shinkai, Nakayama, & Kajimoto, ; Shibamoto, Gooley, & Yamamoto, ; Shibamoto, Murata, & Yamamoto, ; Vincent, Guglielmetti, Cassani, & Tonini, ; Yamamoto, Shibahara, Nakayama, & Kajimoto, , , ). One of the advantages of the DMDS method is that the methylthio group is added to each double‐bond carbon, and the characteristic ions in which cleavage occurs between the double‐bond carbons in the mass spectrum can be used to determine the double‐bond positions simply.…”

Section: Introductionmentioning

confidence: 99%

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Preparation of Dimethyl Disulfide Adducts from the Mono‐Trans Octadecadienoic Acid Methyl Esters

Shibamoto

Murata

et al. 2018

Lipids

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The dimethyl disulfide (DMDS) adduct method is one of the more effective methods for determining double bond positions of dienoic acid. The DMDS method can be simply used to obtain the characteristic ions in which cleavage occurs between the methylthio group-added double-bond carbons as can be seen in the mass spectrum obtained using gas chromatography/electron ionization-mass spectrometry. In the case of the methylene-interrupted di-cis type and di-trans type dienoic acid, the DMDS addition reaction only occurs at one double-bond position, and cannot occur at the remaining double-bond position due to steric hindrance. As a result, two types of adducts are produced in the addition reaction. However, in the case of the methylene-interrupted mono-trans (mono-cis) type dienoic acid, the DMDS addition reaction only occurs at the cis-double bond. As a result, one type of adduct is produced in the addition reaction. In this report, we investigate the cause of the reaction selectivity by focusing on the addition reaction time.

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Eskin¹,

Clough²,

List³

2015

Lipid Technology

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A process for the interesterification of fatty materials is disclosed. The steps consist of a prior purification step followed by introduction of soap into the fatty material to form a soap-containing fatty mixture, homogenizing of the mixture by mixing, contacting the said mixture with lipase to produce a soap containing interesterified fatty material and finally removing soaps to yield interesterified material. The soap may be formed in situ by addition of aqueous alkali to the fatty material or introduced directly to the fatty material. /gl Kellens, 2014, US Patent 8 697 393.Effect of vacuum-combined baking of cookies on acrylamide content, texture and colorThe effects of vacuum-combined baking on the acrylamide content, texture and color of cookies was investigated. Baking studies were carried out at 205°C under atmospheric pressure (101 kPa ) or under partially reduced pressure (40-60 kPa). Baking times were adjusted to yield cookies with similar moisture contents, and surface and internal temperatures were monitored to aid in interpretation of the results. Acrylamide content was determined by a liquid chromatography/mass spectrometry (LC/MS) method. Texture measurements were made on a texture analyzer instrument and color by digital image analysis. Sensory tests were also conducted. The results showed that the combined baking process yielded cookies with lower acrylamide contents as baking time was reduced at atmospheric pressure (11 minutes, 57 ng/gm; 7.5 minutes, 32 ng/ gm). Further reductions in acrylamide content were observed at reduced pressures (40-60 kPa, 2.5 minutes, 27 ng/gm). Baking at reduced pressures produced cookies with lighter surface colors, lower hardness, but similar eating qualities as conventional baking. /gl Palazoglu et al., Eur. Food Res. Technol. 2015, 240, 243-249. Separation behavior of octadecadienoic acid isomers and identification of cis-and tran-isomers using gas chromatography A strongly polar cyanopropyl capillary column was used to determine the separation behaviors of 24 octadecadienoic acid methyl esters (18 : 2 ME), which were compared to saturated methyl stearate (18 : OME) and arachidic methyl esters and the dependency of GC column temperature was assessed. The 24 isomers were obtained by performing cis-to trans-isomerization of six regioisomers. There are no reference standards commercially available for the C18 : 2 ME and the elucidation of their elution orders will aid the future identification of cis-trans isomers of C : 18 : 2 ME. The use of equivalent chain lengths was used to identify C : 18 : 2 isomers from partially hydrogenated canola oil. /gl Shibamoto et al., Lipids 2015, 50, 85-100.Low temperature chemical synthesis of high-purity diacylgylcerols (DAG) from monoacylgylcerols (MAG) A chemical method for the low-temperature synthesis of DAG from MAG is reported as well as a simple purification step for preparation of high purity DAG. Reactions were carried out in both solventassisted and solvent-free conditions. Catalysts studied included sodium methoxid...

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Separation Behavior of Octadecadienoic Acid Isomers and Identification of cis‐ and trans‐Isomers Using Gas Chromatography

Cited by 6 publications

References 44 publications

Non‐conjugated cis/trans 18:2 in Beef Fat are Mainly Δ‐9 Desaturation Products of trans‐18:1 Isomers

Non‐conjugated cis/trans 18:2 in Beef Fat are Mainly Δ‐9 Desaturation Products of trans‐18:1 Isomers

Preparation of Dimethyl Disulfide Adducts from the Mono‐Trans Octadecadienoic Acid Methyl Esters

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