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1.
Koji Masuda Kosuke Abe Yoshihiro Murano 《Journal of the American Oil Chemists' Society》2021,98(1):21-29
Triacylglycerol (TAG) isomers have been reported to have differing physical and nutritional properties. The analysis of TAG isomers is therefore important for understanding the physical properties of lipids as well as their digestion and absorption. However, methods for the quantitative analysis of TAG regioisomers and enantiomers in vegetable oils and biological samples are still under development. Recently, methods using recycle high-performance liquid chromatography (HPLC) and silver ion column-HPLC have been reported. However the recycle HPLC method requires more than 1 hour, in general, for each sample that is analyzed. Furthermore, existing methods are unable to quantify regioisomers and enantiomers simultaneously. Thus, we aimed to develop a practical method to simultaneously quantify regioisomers and enantiomers of TAG. Three isomers of sn-POO, OPO, and OOP were separated by supercritical fluid chromatography coupled with triple quadrupole mass spectrometer (SFC/MS/MS) using a CHIRALPAK® IG-U column with acetonitrile and methanol as mobile phase. The separation was completed in 40 min, which is a shorter run time than the conventional techniques published to date. Linear calibration curves with standards were obtained and used to quantify sn-OPO, sn-POO, and sn-OOP in extra virgin olive oil, refined olive oil, palm oil, palm olein, and interesterified palm olein. 相似文献
2.
Vera Samburova Mark S. Lemos Sage Hiibel S. Kent Hoekman John C. Cushman Barbara Zielinska 《Journal of the American Oil Chemists' Society》2013,90(1):53-64
To assess the suitability of microalgal strains for biodiesel production the lipid content and composition, especially individual triacylglycerols (TAG) and free fatty acids (FFA) must be determined. In this study, the compositions and concentrations of TAG and FFA were analysed in four halophytic algal species, Dunaliella salina, D. tertiolecta, D. bardawil, and D. granulata. These species were selected as part of a larger screen to identify species suitable for biofuel feedstocks. An accelerated solvent extraction instrument was used for lipids and fatty acid extraction using a dichloromethane–hexane solvent system. Ultra-performance liquid chromatography coupled with mass spectrometry (MS) detection was optimized and applied to the quantitative analysis of TAG and FFA in the different algal extracts. Individual TAG were characterized structurally using direct electrospray ionization (ESI) MS and MS/MS techniques. Cationic adducts (NH4 +) of TAG were detected and quantified in the positive ESI MS and MS/MS modes, while the negative ESI mode was used for FFA analysis. Over 20 TAG were identified and quantified in the four Dunaliella strains. Analysis of FFA compositions demonstrated that the most abundant FFA in these four algal species were palmitic, linolenic, linoleic, and oleic acids. 相似文献
3.
Hiromi Yoshida Yuka Tomiyama Masayuki Saiki Yoshiyuki Mizushina 《Journal of the American Oil Chemists' Society》2007,84(11):1031-1038
The positional distribution of fatty acids (FA) of triacylglycerols (TAG) and major phospholipids (PL) prepared from four
cultivars of peas (Pisum sativum L.) were investigated as well as their tocopherol contents. The lipids extracted from these peas were separated by thin-layer
chromatography (TLC) into seven fractions. The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while the
other components were also present in minor proportions (5.6–9.2%). γ-Tocopherol was present in the highest concentration,
and α- and δ-tocopherols were very small amounts. The main PL components isolated from the four cultivars were phosphatidylcholine
(42.3–49.2%), followed by phosphatidylinositol (23.3–25.2%) and then phosphatidylethanolamine (17.7–20.5%). Small but significant
differences (P < 0.05) in FA distribution existed when different pea cultivars were determined. However, the principal characteristics of
the FA distribution in the TAG and the three PL were evident among the four cultivars; unsaturated FA were predominantly located
in the sn-2 position, and saturated FA primary occupied the sn-1 or sn-3 position in the oils of the peas. These results suggest that the regional distribution of tocopherols and fatty acids in
peas is not dependent on the climatic conditions and the soil characteristics of the cultivation areas during the growing
season. 相似文献
4.
Takahiro Hayasaka Naoko Goto-Inoue Nobuhiro Zaima Yoshishige Kimura Mitsutoshi Setou 《Lipids》2009,44(9):837-848
Imaging mass spectrometry (IMS) has been developed as a method for determining and visualizing the distribution of proteins
and lipids across sections of dissected tissue. Although lipids play an important role in mammal development, their detailed
distributions have not been analyzed by conventional methods. In this study, we tried to determine and visualize lysophosphatidylcholine
(LysoPtdCho) and triacylglycerol (TAG) in a mouse embryo by matrix-assisted laser desorption/ionization (MALDI) hybrid quadrupole
time-of-flight (TOF) mass spectrometer. Many peaks were detected from a raster scan of the whole embryonic sections. The peaks
at m/z 496.33, 524.36, 879.72, 881.74, and 921.74 were identified by MS/MS analyses as [LysoPtdCho (16:0) + H]+, [LysoPtdCho (18:0) + H]+, [TAG (16:0/18:2/18:1) + Na]+, [TAG (16:0/18:1/18:1) + Na]+, and [TAG (16:0/20:3/18:1) + K]+, respectively. The ion images constructed from the peaks revealed that LysoPtdCho were distributed throughout the body and
TAGs were distributed around the brown adipose tissue and in the liver at embryo day 17.5. Thus, IMS system based on MALDI
hybrid quadrupole TOF MS revealed the distribution of LysoPtdCho and, more importantly, the organ-specific distribution of
TAGs in the embryonic stages of mammals for the first time. We can conclude that this technique enables us to analyze the
roles of various lipids during embryogenesis and gives insight for lipid research. 相似文献
5.
Daniela Gastaldi Claudio Medana Valeria Giancotti Riccardo Aigotti Federica Dal Bello Claudio Baiocchi 《European Journal of Lipid Science and Technology》2011,113(2):197-207
Triacylglycerols (TAG) from milk‐fat from different sources (cow, goat and human milks) were characterised using non‐aqueous reversed phase high‐performance liquid chromatography–atmospheric‐pressure chemical ionisation, coupled to MS/MS (RP HPLC‐APCI MS/MS). The fatty‐acid content of all samples was also established by methyl transesterification and GC‐MS analysis. Optimisation of the HPLC gradient, combined with APCI tandem MS, enables TAGs complex mixtures to be analysed without prior separation. More than 160 different glycerides were identified; between 50 and 70 compounds were identified in the chromatograms of each sample. This method also enabled the principal TAG regioisomers to be recognized. The study focused on the investigation of the structure of TAGs containing very‐long‐chain PUFA, namely all cis‐ 4,7,10,13,16,19‐ DHA (DHA, C22:6, n‐3) and all cis‐5,8,11,14,17‐eicosapentaenoic acid (EPA, C20:5, n‐3), both in human and in n‐3‐enriched cow's milks. Ten TAGs containing DHA were identified in human milk and only one in milk from cows fed an n‐3 enriched diet. 相似文献
6.
Hiromi Yoshida Naoko Yoshida Yuka Tomiyama‐Sakamoto Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2012,114(7):787-793
Extracted lipids obtained from Jack beans (white and red) were fractionated by TLC into nine subfractions. The major components were TAGs (TAG: 43.8–45.7 wt%) and phospholipids (PL: 46.7–47.0 wt%), while other components were also present in minor proportions (0.3–2.7 wt%). The principal fatty acids (FA) are generally palmitic (18.8–28.8%), stearic (0.7–6.8%), oleic (42.0–51.8%), linoleic (16.2–22.8%), and α‐linolenic (3.0–8.2%) acids, the distribution of which differs according to these lipid classes. There were no significant differences (p>0.05) in the positional distribution of FA in the TAG; unsaturated FA (97.5%) were predominantly concentrated in the sn‐2 position while saturated FA (33.3%) primarily occupied the sn‐1 position or sn‐3 position. However, significant differences (p<0.05) in FA distribution existed when the individual PL were compared between the white and red beans. Based on the FA composition of these lipids, it seems that the two cultivars of Jack beans are very similar to each other with a few exceptions. The results could be useful to both producers and consumers for our daily diet to improve value of the Japanese diet. Practical applications : The lipid composition suggests that these beans could be a good source of nutraceuticals with providing heath benefits. The white and red beans may be well incorporated into our daily Japanese diets to improve nutritional value. The data obtained in this study provide valuable information for manufacturing functional drinks such as Jack bean tea in Japan. 相似文献
7.
A simple, fast and reproducible reversed‐phase high performance liquid chromatography (HPLC) method coupled to electrospray ionization mass spectrometry (ESI‐MS) for the analysis of triacylglycerols (TAGs) species in the commercial edible oils has been developed. The TAGs species were separated using isocratic 18% isopropanol in methanol and a Phenomenex C18 column. The ESI‐MS conditions were optimized using flow injection analysis of standard TAG. Fifteen, fourteen, and sixteen TAGs were separated and identified in corn oil, rapeseed oil, and sunflower oil, respectively. The presence of intense protonated molecular (M + H+), ammonium (M + ${\rm NH}_{4}^{ + } $ ), and sodium (M + Na+) adducts ions and their respective diacylglycerols ions in the ESI‐MS spectra showed correct identification of TAGs. Some minor potassium adducts (M + K+) were also found. In addition, the identity of the fatty acid, position of each fatty acid, and the location of the double bond in the fatty acid moiety were explained. It was found that this isocratic method is useful for fast screening and identification of triacylglycerols in lipids. 相似文献
8.
Madeira laurel oil was fractionated by liquid extraction combined with TLC, and TAGs were analyzed by HPLC coupled with atmospheric
pressure chemical ionization-MS (APCI-MS). Eluted molecular species compositions of the eluted TAG in the complex natural
mixture were determined by GC identification of FAME and byLC-atmospheric pressure chemical ionization (APCI)-MS analysis
of the lipid. The APCI-MS spectra of most TAG exhibited [M+H]+ and [M−RCOO]+ ions, which defined the M.W. and the molecular association of fatty acyl residues, respectively. Despite the relatively high
degree of saturation, with a saturated/unsaturated ratio of 0.70, no totally saturated TAG nor mixed asymmetric TAG with two
saturated FA (SSM or SSU, where S is saturated, M is monounsaturated, and U is unsaturated) were found. This type of molecular
structure provides a possible explanation for the relatively low m.p. (12–15°C) and also the high oxidative resistance observed. 相似文献
9.
Tandem mass spectrometry based on ammonia negative ion chemical ionization and sample introduction via direct exposure probe was applied to analysis of regioisomeric structures of octanoic acid containing structured triacylglycerols
(TAG) of type MML, MLM, MLL, and LML (M, medium-chain fatty acid; L, long-chain fatty acid). Collision-induced dissociation
of deprotonated parent TAG with argon was used to produce daughter ion spectra with appropriate fragmentation patterns for
structure determination. Fatty acids constituting the TAG molecule were identified according to [RCO2]− ions in the daughter ion spectra. With the standard curve for ratios of [M-H-RCO2H-100]− ions corresponding to each [RCO2]− ion, determined with known mixtures of sn-1/3 and sn-2 regioisomers of structured TAG, it was possible to determine the proportions of different regioisomers in unknown samples.
The method enabled quantification of MML- and MLM-type structured TAG. In the case of MLL- and LML-type TAG, it was possible
to determine the most abundant regioisomer in the unknown mixture and estimate the proportions of regioisomers when there
were more than 50% MLL-type isomers in the mixture. 相似文献
10.
For the purpose of synthesizing standards to be used in the quantification of TAG hydroperoxides, three TAG (1,2-dioleoyl-3-palmitoylglycerol,
1-oleoyl-2-linoleoyl-3-palmitoylglycerol, and triolein) monohydroperoxides were chemically synthesized as authentic specimens.
TAG were prepared by using a simple condensation in pyridine of glycerol and the corresponding acid chlorides. These TAG were
then converted into monohydroperoxides by a photosensitized peroxidation. The synthesized monohydroperoxides were analyzed
by normal-phase and RP-HPLC. The results of normal-phase HPLC analysis showed that monohydroperoxides from a corresponding
TAG were a mixture of regioisomers. In RP-HPLC, however, the regioisomers of monohydroperoxides were not separated and gave
a single peak, which may improve the sensitivity for the detection of TAG monohydroperoxides. In this study TAG monohydroperoxide
standards were synthesized; these will be useful for the study of yet unknown biological and pathological roles of TAG hydroperoxides. 相似文献
11.
Ozan Nazim Ciftci Roman Przybylski Magdalena Rudzińska 《European Journal of Lipid Science and Technology》2012,114(7):794-800
Composition of fatty acids, tocopherols, sterols, and TAGs in the lipids of flax, perilla, and chia seeds were investigated where lipid content was at 45, 40, and 35%, respectively. α‐Linolenic acid (ALA) dominated among fatty acids in all oils and accounted for 58.2, 60.9, and 59.8% in flax, perilla, and chia, correspondingly in these three oils trilinolenin was the main TAG found at 19.7, 22.6, and 21.3%. Triunsaturated TAGs accounted for 77.9, 77.5, and 74.5% of the total amounts in flax, perilla, and chia oils. Contents of tocopherol were at 747 in flax, 734 in perilla, and 446 mg/kg in chia seed lipids. γ‐Tocopherol was the dominating isomer contributing 72.7% in flax, 94.3% in perilla, and 94.4% in chia to the total amount of tocopherols. Flaxseed lipids contained 25.6% of plastochromanol‐8, derivative of γ‐tocotrienol with longer side chain; perilla and chia oils contained only 1.4% of it. Phytosterols were present at 4072, 4606, and 4132 mg/kg in those seeds, respectively. Among sterols, β‐sitosterol dominated and was found at 35.6, 73.3, and 49.8% of the total amounts of sterols in flax, perilla, and chia seed lipids. All of the investigated oilseeds have an excellent nutritional quality and can be a potential source of nutraceutical fats which can enrich diet in linolenic acid and other functional components. 相似文献
12.
Hiromi Yoshida Yuka Tomiyama Yuki Hirakawa Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2004,106(2):101-109
Whole pumpkin seeds (Cucurbita spp.) of two cultivars were exposed to microwaves for 6, 12, 20 or 30 min at a frequency of 2450 MHz. The kernels were separated from the whole seeds, and were investigated not only for the different acyl lipids and their fatty acid compositions, but also for the molecular species of triacylglycerols (TAGs). A modified argentation TLC procedure, developed to optimize the separation of the complex mixture of total TAGs, provided 11 different groups of TAGs, based on both the degree of unsaturation and the chain‐length of fatty acid groups. With a few exceptions, dioleopalmitin (5.8–18.8 wt‐%), dipalmitolinolein (8.1–8.8 wt‐%), triolein (6.3–20.5 wt‐%), palmitoleolinolein (15.0–16.1 wt‐%), dioleolinolein (16.7–23.0 wt‐%), dilinoleopalmitin (4.6–15.4 wt‐%) and dilinoleolein (6.7–19.4 wt‐%) were the main TAG components. When pumpkin seeds were microwaved for 20 min or more, significant differences (p <0.05) occurred in the acyl lipids as well as their fatty acid distributions with a few exceptions. Therefore, microwave roasting caused a significant decrease (p <0.05), not only in TAGs molecular species containing more than 4 double bonds, but also in the amounts of diene species present in triacylglycerols. These results contribute to the study of the functional properties of pumpkin seed products. 相似文献
13.
This study uses normal-phase HPLC with on-line positive ion electrospray mass spectrometry (ESI-MS) to obtain quantitative
compositional data on both synthetic and butterfat short-chain TAG. The product ion tandem MS of standards averaged 11.1 times
lower in abundance of the ion formed by cleavage of FA from the sn-2-position for the pairs of regioisomers in the TAG classes: L/L/S-L/S/L and L/S/S-S/L/S, where L denotes long and S short
acyl chain (C2−C6). The molar correction factors, determined for 42 regioisomeric pairs of short-chain TAG of 20 randomized mixture of standards,
differed by 1.4–80% as the ratios varied between 0.217 and 5.847. Butterfat TAG were resolved into four fractions on short
flash chromatography grade silica gel columns. Pairs of regioisomers in the TAG classes L/S/S-S/L/S with predominance of L/S/S
isomers and the sole regioisomers in the TAG classes L/L(M)/S were identified by tandem MS, where M denotes either 8∶0 or
10∶0 acyl chain. The total proportion of L/L(M)/S isomers was estimated at 34.7 and that of L/S/S-S/L/S at 1.0 mol%, including
a small proportion of S/S/S. In contrast to previous work, the present data indicate the presence of a small proportion of
butyric and caproic acids in the sn-1-position. The overall distribution of the FA in the short-chain TAG of butterfat, calculated from direct MS measurements,
was consistent with the results of indirect determinations based on stereospecific analyses of total butterfat. 相似文献
14.
Weifei Wang Long Xu Yuxiao Zou Daorui Pang Wei Shi Lixia Mu Erna Li Dongming Lan Yonghua Wang Sentai Liao 《European Journal of Lipid Science and Technology》2020,122(2)
A comprehensive identification of lipid compositions and tocochromanols in Antheraea pernyi (A. pernyi) and Bombyx mori (B. mori) pupae oil is reported in the present study. Fatty acid profiling shows that both oils contain high levels (79.67% vs 71.11%) of unsaturated fatty acids, especially linoleic acid and linolenic acid. Moreover, linolenic acid is preferentially enriched at the sn‐2 positions of triacylglycerols (TAGs). Liquid chromatograph‐mass spectrometry (LC‐MS) analysis demonstrates that POO (TAG with one palmitoyl and two oleoyls) is the primary TAG form with percentages of 20.18% in A. pernyi and 15.00% in B. mori. The dominating phospholipid species are phosphatidylcholine (PC, 30.40% vs 54.61%) and phosphatidylethanolamine (PE, 34.82% vs 20.39%). Four sterol constituents with total contents of 382.56 ± 3.12 and 371.65 ± 2.98 µg g?1 are identified and analyzed quantitatively. Additionally, the levels of tocochromanols (20.15 ± 0.89 vs 17.15 ± 0.71 mg g?1) are quantified in both silkworm pupae oils. Overall, silkworm oil acts as an enriched source of functional lipids and tocochromanols. Practical Applications: A systematic investigation on the principal lipid classes and tocochromanols of Antheraea pernyi pupae and Bombyx mori pupae oil is reported in this study. The informative data provide supporting evidence for comprehensive utilization of silkworm oil for production of nutritional and healthy products. 相似文献
15.
S. Kermasha S. Kubow M. Safari A. Reid 《Journal of the American Oil Chemists' Society》1993,70(2):169-173
Triacylglycerol (TAG) standards were separated by analytical high-performance liquid chromatography (HPLC) with laser light-scattering
detection (LLSD). A high sensitivity for TAGs was observed with LLSD whereas poor sensitivity was observed with ultraviolet
detection. The HPLC-LLSD analytical separation of butterfat TAGs showed that the TAGs were eluted according to increasing
carbon number. Preparative HPLC-LLSD was used to characterize butterfat TAGs that contained hypercholesterolemic fatty acids
(laurate, myristate, palmitate) with carbon chainlengths of 12 or greater. These TAG fractions accounted for 29.2% of the
total butterfat TAGs. Analysis of the positional distribution of fatty acids of selected butterfat TAGs containing hypercholesterolemic
fatty acids showed the presence of positional isomers in each of these fractions. These butterfat TAGs also showed the predominant
presence of hypercholesterolemic fatty acids at thesn-2 position. The characterization of the positional distribution of hypercholesterolemic fatty acids in butterfat TAGs is
the first step for the determination of the metabolic role of the positional distribution in the hypercholesterolemic effects
of butter. 相似文献
16.
Physicochemical Properties of <Emphasis Type="Italic">Acer truncatum</Emphasis> Seed Oil Extracted Using Supercritical Carbon Dioxide
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Acer truncatum seed oil rich in nervonic acid was extracted using supercritical carbon dioxide. GC (Gas Chromatography) analysis revealed that the oil contained approximately 6.22% nervonic acid. The sn‐2 compositions were also determined using lipase hydrolysis. A total of 52 triacylglycerides (TAG) were tentatively identified in the oil using an ultra‐performance convergence chromatography (UPC2) coupled with quadrupole time‐of‐flight mass spectrometry (Q‐TOF‐MS) for the first time. In addition, the contents of phytosterols (1961.9–2402.8 μmol/kg) and β‐carotene (2.09–2.35 μmol/kg) were also quantified for the first time, along with tocopherols (2352.0–2654.3 μmol/kg). The γ‐tocopherol (1296.9‐1442.3 μmol/kg) was the primary tocopherol, while β‐sitosterol (1355.2–1631.3 μmol/kg) was the dominant phytosterol. The physicochemical properties of the oil were also investigated. This study indicated that A. truncatum seed oil is rich in nervonic acid and other nutraceutical constituents. It has a high potential in functional foods for improving human health. 相似文献
17.
The bottom-up solution to the triacylglycerol lipidome using atmospheric pressure chemical ionization mass spectrometry 总被引:1,自引:0,他引:1
Byrdwell WC 《Lipids》2005,40(4):383-417
Presented here is an approach to representing the data from atmospheric pressure chemical ionization (APCI) mass spectrometry
(MS) of triacylglycerols (TAG) using a set of one, two, or three Critical Ratios. These Critical Rations may be used directly
to provide structural information concerning the regioisomeric composition of the triacylglycerols (TAG), and about the degree
of unsaturation in the TAG. An AAA-type, or Typel, TAG has only one Critical Ratio, the ratio of the protonated molecule,
[M+H]+, to the DAG fragment ion, [AA]+. The Critical Ratio for a Type I TAG is [MH]+/Σ[DAG]+, and the mass spectrum of a Type I TAG can be reproduced from only this one ratio. An ABA/AAB/BAA, or Type II, TAG has two
Critical Ratios, the [MH]+/Σ[DAG]+ ratio and the [AA]+/[AB]+ ratio. The [AA]+/[AB]+ ratio for a single TAG or TAG mixture can be compared with the [AA]+/[AB]+ ratios of pure regioisomeric standards, and the percentage of each regioisomer can be estimated. The abundance of the protonated
molecule and the abundances of the two [DAG]+ fragment ions can be calculated from the two Critical Ratios for a Type II TAG. To calculate the abundances, the Critical
Ratios are processed through the Bottom-Up Solution to the TAG lipidome. First, Critical Limits are calculated from the Critical
Ratios, and then the Critical Ratios are classified into Cases by comparison with the Critical Limits. Once the Case classification
is known, the equation for the abundance of each ion in the mass spectrum is given by the Bottom-Up Solution. A Type III TAG
has three different FA and three Critical Ratios. The [MH]+/Σ/[DAG]+ ratio is the first Critical Ratio, the [AC]+/([AB]++[BC]+) ratio is the second Critical Ratio, and the [BC]+/[AB]+ ratio is the third Critical Ratio. The second critical ratio for a Type III TAG can be compared with regioisomeric standards
to provide an estimate of the percentage composition of the regioisomers. The three Critical Ratios for a Type III TAG can
be processed through the Bottom-Up Solution to calculate the four ion abundances that make up the APCI-MS mass spectrum. The
Critical Ratios constitute a reduced data set that provides more information in fewer values than the raw abundances. 相似文献
18.
Hiromi Yoshida Masayuki Saiki Yuka Tomiyama Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2008,110(2):158-163
The fatty acid distributions of triacylglycerols (TAG) and major phospholipids (PL) obtained from adzuki beans (Vigna angularis) were investigated. The total lipids extracted from the beans were separated by thin‐layer chromatography (TLC) into eight fractions. The major lipid components were PL (63.5 wt‐%), TAG (21.2 wt‐%), steryl esters (7.5 wt‐%) and hydrocarbons (5.1 wt‐%), while free fatty acids, diacylglycerols (1,3‐DAG and 1,2‐DAG) and monoacylglycerols were also present in minor proportions (0.2–1.1 wt‐%). The major PL components isolated from the beans were phosphatidylcholine (45.3 wt‐%), phosphatidylethanolamine (25.8 wt‐%) and phosphatidylinositol (21.5 wt‐%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. With a few exceptions, however, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident in the beans: Unsaturated fatty acids were predominantly concentrated in the sn‐2 position while saturated fatty acids primary occupied the sn‐1 or sn‐3 position in the oils of the adzuki beans. In general, these results could be useful to both consumers and producers for the manufacture of traditional adzuki foods in Japan. 相似文献
19.
Jiann-Tsyh Lin 《Journal of the American Oil Chemists' Society》2009,86(11):1031-1035
The triacylglycerols (TAG) containing dihydroxy fatty acids have been recently identified by mass spectrometry in castor oil.
These new dihydroxy fatty acids were proposed as 11,12-dihydroxy-9-octadecenoic acid (diOH18:1), 11,12-dihydroxy-9,13-octadecadienoic
acid (diOH18:2) and 11,12-dihydroxyoctadecanoic acid (diOH18:0). The ratios of regioisomers of the TAG were estimated by fragment
ions from the loss of fatty acids at the sn-2 position as α,β-unsaturated fatty acids by electro spray ionization-mass spectrometry of the lithium adducts (MS3). The content of regioisomeric diOH18:1-OH18:1-diOH18:1 (ABA, with two different fatty acids) was about 92% in the total
of stereoisomeric diOH18:1-OH18:1-diOH18:1, OH18:1-diOH18:1-diOH18:1 and diOH18:1-diOH18:1-OH18:1 combined. The approximate
contents of other regioisomers were as follows: diOH18:1-OH18:1-OH18:1 (92%), diOH18:1-diOH18:0-diOH18:1 (91%), diOH18:2-OH18:1-OH18:1
(80%) and diOH18:0-OH18:1-OH18:1 (96%). The ratios of regioisomers of TAG (ABC) containing three different fatty acids were
estimated as about 7:1:2 (OH18:1:diOH18:1:diOH18:2) and about 7:2:1 (OH18:1:diOH18:0:diOH18:1). Ricinoleate (OH18:1) was predominately
at the sn-2 position of TAG (both AAB and ABC) containing dihydroxy fatty acids and ricinoleate. Dihydroxy fatty acids were mainly
at the sn-1,3 positions of TAG containing dihydroxy fatty acids and ricinoleate in castor oil. The ratios of the three regioisomers
of TAG (ABC) containing three different fatty acids by mass spectrometry are first reported here. 相似文献
20.
Application of Taguchi Method in the Enzymatic Modification of Menhaden Oil to Incorporate Capric Acid
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Structured lipids (SL) were produced using menhaden oil and capric acid or ethyl caprate as the substrate. Enzymatic reaction conditions were optimized using the Taguchi method L9 orthogonal array with three substrate molar ratio levels of capric acid or ethyl caprate to menhaden oil (1:1, 2:1, and 3:1), three enzyme load levels (5, 10, and 15% [w/w]), three temperature levels (40, 50, and 60 °C), and three reaction times (12, 24, 36 hours). Recombinant lipase from Candida antarctica, Lipozyme® 435, and sn‐1,3 specific Rhizomucor miehei lipase, Lipozyme® RM IM (Novozymes North America, Inc., Franklinton, NC, USA), were used as biocatalysts in both acidolysis and interesterification reactions. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, and oxidative stability were compared. Optimal conditions for all reactions were 3:1 substrate molar ratio, 10% [w/w] enzyme load, 60 °C, and 16 hours reaction time. Reactions with ethyl caprate incorporated significantly more C10:0, at 30.76 ± 1.15 and 28.63 ± 2.37 mol% versus 19.50 ± 1.06 and 9.81 ± 1.51 mol%, respectively, for both Lipozyme® 435 and Lipozyme® RM IM, respectively. Reactions with ethyl caprate as substrate and Lipozyme® 435 as biocatalyst produced more of the desired medium‐long‐medium (MLM)‐type TAGs with polyunsaturated fatty acids (PUFA) at sn‐2 and C10:0 at sn‐1,3 positions. 相似文献