Fatty acids and triacylglycerols of cherry seed oil

Cherry seed oil, from the Rosaceae family, prunoid subfamily, is characterized by the existence of about 10% α-eleostearic acid. The structure of the acid was proven by H and¹³C nuclear magnetic resonance. The triacylglycerols of this oil were identified and quantitated by highperformance liquid chromatography by means of several types of detectors. α-Eleostearic acid was not found in the seeds of previously studied prunoids (almond, peach, apricot and plum). The main fatty acids found in the seeds of cherry and other prunoids were linoleic (L), oleic (O) and palmitic acids, and the major triacylglycerols were LLO, LOO and OOO. These chemical data support the botanical relationship within the prunoid subfamily and show the proximity of cherry to the Chrysobalanaceae family.     

Influence of lipase-catalyzed interesterification on the oxidative stability of melon seed oil triacylglycerols

Melon seeds are rich in oil. However, the stability of melon seed oil (MSO) is low because of its high content of the essential fatty acid, linoleic acid (18:2n-6). MSO was physically blended or enzymatically interesterified with higholeic sunflower oil (HOSO). The fatty acid composition of MSO was remarkably changed after interesterification. Palmitic (16:0), stearic (18:0), and oleic (18:1n-9) acid contents increased at the sn-2 position of triacylglycerols, whereas 18:2n-6 decreased due to interesterification. The oxidative stability of the physical and Pseudomonas sp. (PS30) lipase-interesterified blends was assessed with the Oxidative Stability Instrument, peroxide value, and conjugated diene methods. The stability of MSO increased with increased proportions of HOSO, which was the source of 18:1n-9 in the blends. The ratio of 18:1n-9/18:2n-6 improved from 0.18 in MSO to 1.47 in the enzymatically interesterified blend. Calculated oxidizability and the results of oxidation tests of the blends confirmed the improvement in MSO stability by both physical blending and enzymatic interesterification.     

Influence of lipase-catalyzed interesterification on the oxidative stability of melon seed oil triacylglycerols

Melon seeds are rich in oil. However, the stability of melon seed oil (MSO) is low because of its high content of the essential fatty acid, linoleic acid (18:2n-6). MSO was physically blended or enzymatically interesterified with higholeic sunflower oil (HOSO). The fatty acid composition of MSO was remarkably changed after interesterification. Palmitic (16:0), stearic (18:0), and oleic (18:1n-9) acid contents increased at the sn-2 position of triacylglycerols, whereas 18:2n-6 decreased due to interesterification. The oxidative stability of the physical and Pseudomonas sp. (PS30) lipase-interesterified blends was assessed with the Oxidative Stability Instrument, peroxide value, and conjugated diene methods. The stability of MSO increased with increased proportions of HOSO, which was the source of 18:1n-9 in the blends. The ratio of 18:1n-9/18:2n-6 improved from 0.18 in MSO to 1.47 in the enzymatically interesterified blend. Calculated oxidizability and the results of oxidation tests of the blends confirmed the improvement in MSO stability by both physical blending and enzymatic interesterification.     

高效液相色谱-串联质谱法测定油辣椒中罗丹明B

建立了油辣椒中罗丹明B的高效液相色谱-串联四极杆质谱联用测定方法,该方法经乙腈提取样品,以waters-C18柱（2.1×50mm,1.7μm）分离,流动相为甲醇-0.1%甲酸水,电喷雾正离子MRM模式检测。方法检出限0.1ng/mL,线性范围0.1μg/L～10μg/L,加标回收率99.5%～106.4%,相对标准偏差为1.08～3.07%。     

Preparation of stearidonic acid‐enriched triacylglycerols from Echium plantagineum seed oil

HPLC analysis of Echium plantagineum seed oil shows a complex triacylglycerol (TAG) profile. TAG species were separated on an analytical scale by HPLC and their fatty acid (FA) composition is reported. GLC analyses showed that some TAG fractions reached a stearidonic acid (SDA, 18:4n‐3) percentage significantly higher than that in the original oil. TAG separation on a bigger scale was also essayed, by means of a gravimetric normal‐phase chromatographic column, using silver ion‐silica gel as stationary phase. Gradient elution with solvents of increasing polarity was applied, allowing the separation of valuable TAG species containing γ‐linolenic acid (GLA, 18:3n‐6), α‐linolenic acid (ALA, 18:3n‐3) and SDA as the main constituents (more than 85% of the total FA). An enzymatic hydrolysis reaction showed the distribution of FA in the isolated species of TAG. SDA was the major FA in the sn‐2 position (more than 50% of total FA), followed by ALA (19%) and GLA (18.5%).     

Study on the aluminium chloride-modification for heavy fraction of light diesel oil using tandem mass spectrometry

Tandem mass spectrometry was used to follow the low temperature catalytic modification of the diesel oil heavy fraction in the presence of aluminium chloride. The molecular distribution from chemical ionization mass spectroscopy (c.i.m.s.) of raw feedstock ranges from 150 to 250, with an average molecular weight of 219 (v.p.o.). That of the finally modified pitch ranges from 200 to 800, mainly concentrated between 200 and 500 with v.p.o. molecular weight of 452. The m.s.-m.s. fragmentation analysis of three dominant, characteristic protonated parent ions m/z 207, 373, 385, showed ethyl phenanthrenes (-anthracenes), dimers from phenanthrene (anthracene) and C₁-phenanthrene with substantial naphthenic groups, dimers from C₁-phenanthrenes and copolymers from hexahydropyrene with phenanthrene, chrysene with C₂-naphthalene, etc., respectively, to be the main structural types of these parent mass numbers. This modified pitch material, with a characteristic low degree of condensation and extensive naphthenic structures proved to be suitable for transformation into mesophase pitch with high fluidity and a large domain-type anisotropic texture.     

Viscosity estimation of triacylglycerols and of some vegetable oils, based on their triacylglycerol composition

The experimentally determined kinematic viscosities of simple triacylglycerols [trilaurin, trimyristin (MMM), tripalmitin (PPP), tristearin (SSS), triolein (OOO), and trilinolein (LiLiLi) were correlated to a modified Andrade-type equation. The constants for the modified equation were derived for each simple triacylglycerol. The method was also used to estimate the viscosity of mixed triacylglycerols [1,2-dimyristoyl-3-palmitoyl (MMP), 1,2-dioleoyl-3-palmitoyl (OOP), 1,2-dimyristoyl-3-oleoyl (MMO), and 1,2-dipalmitoyl-3-oleoyl (PPO)], binary triacylglycerol mixtures (PPO/OOP, PPP/SSS, and OOO/SSS of different portions), and three types of vegetable oils [refined, bleached, and deodorized palm oil; cocoa butter; and canola oil] by applying modified Kay’s rule utilizing the simple triacylglycerol constants derived earlier. In all cases, the estimated values for liquid viscosity were compared with experimental values determined in this work and with previous work from the literature. When applied to vegetable oils, the method requires knowledge of their triacylglycerol composition. Despite its simplicity, the method gives a reasonable estimate. The method may be used to predict the viscosity of different blends of vegetable oils, and the accuracy is expected to increase when more experimental data on simple triacylglycerols become available.     

荞麦籽油的脂肪酸组成与含量分析

通过气相色谱-质谱联用(GC-MS)测定荞麦籽油中的脂肪酸含量,用外标法与峰面积归一法进行定量分析。荞麦籽油脂肪酸种类丰富,以不饱和脂肪酸为主,其中单不饱和脂肪酸为45.10%,多不饱和脂肪酸为32.76%。荞麦籽油中4种脂肪酸含量:油酸亚油酸棕榈酸硬脂酸。     

Biodiesel production from high FFA rubber seed oil

Currently, most of the biodiesel is produced from the refined/edible type oils using methanol and an alkaline catalyst. However, large amount of non-edible type oils and fats are available. The difficulty with alkaline-esterification of these oils is that they often contain large amounts of free fatty acids (FFA). These free fatty acids quickly react with the alkaline catalyst to produce soaps that inhibit the separation of the ester and glycerin. A two-step transesterification process is developed to convert the high FFA oils to its mono-esters. The first step, acid catalyzed esterification reduces the FFA content of the oil to less than 2%. The second step, alkaline catalyzed transesterification process converts the products of the first step to its mono-esters and glycerol. The major factors affect the conversion efficiency of the process such as molar ratio, amount of catalyst, reaction temperature and reaction duration is analyzed. The two-step esterification procedure converts rubber seed oil to its methyl esters. The viscosity of biodiesel oil is nearer to that of diesel and the calorific value is about 14% less than that of diesel. The important properties of biodiesel such as specific gravity, flash point, cloud point and pour point are found out and compared with that of diesel. This study supports the production of biodiesel from unrefined rubber seed oil as a viable alternative to the diesel fuel.     

Processability characteristics and physico‐mechanical properties of natural rubber modified with rubber seed oil and epoxidized rubber seed oil

The processability characteristics and physico‐mechanical properties of natural rubber (NR) modified with raw rubber seed oil and epoxidized rubber seed oil have been studied. The modified mixes showed higher scorch time and lower cure rate, crosslink density, and ultimate state of cure compared to an unmodified mix. The thermal stability of the vulcanizates was practically unaffected by the modification. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1413–1418, 2000     

Regioisomers of octanoic acid-containing structured triacylglycerols analyzed by tandem mass spectrometry using ammonia negative ion chemical ionization

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.     

葵花籽油酯交换研究

以葵花籽油为原料,KOH作催化剂,对葵花籽油与甲醇进行酯交换反应研究,寻求酯交换反应的最佳条件。     

Triacylglycerols of Apiaceae seed oils: Composition and regiodistribution of fatty acids

Oils from the seeds of caraway (Carum carvi), carrot (Daucus carota), celery (Apium graveolens) and parsley (Petroselinum crispum), all from the Apiaceae family, were analyzed by gas chromatography for their triacylglycerol (TAG) composition and fatty acid (FA) distribution between the sn‐1(3) and sn‐2 positions of TAG. Twenty‐two TAG species were quantified. Glyceryl tripetroselinate was the major TAG species in seed oils of carrot, celery and parsley, with levels ranging from 38.7 to 55.3%. In caraway seed oil, dipetroselinoyllinoleoylglycerol was the major TAG species at 21.2%, while the glyceryl tripetroselinate content was 11.4%. Other TAG species were linoleoyloleoylpetroselinoylglycerol and dipetroselinoyloleoylglycerol. Predominantly, TAG were triunsaturated (72.2–84.0%) with diunsaturates at 14.4–25.9%, and small amounts of monounsaturated TAG. Results for regiospecific analysis showed a non‐random FA distribution in Apiaceae for palmitic, petroselinic, linoleic and oleic acids. Petroselinic acid was predominantly located at the sn‐1(3) position in carrot, celery and parsley seed oils, while it was mainly at the sn‐2 position in caraway seed oil. The distribution of linoleic acid was opposite to that of petroselinic acid. Oleic acid was mostly located at the sn‐2 position, except for caraway, where it was evenly distributed between the sn‐1(3) and sn‐2 positions. Both the saturated FA, palmitic and stearic acid, were located mainly at the sn‐1(3) position. The presence of a high level of tripetroselinin in parsley seed oil (55.3%) makes it a potential source for the production of petroselinic acid.     

Detection of adulteration in camellia seed oil and sesame oil using an electronic nose

An electronic nose was used for the detection of maize oil adulteration in camellia seed oil and sesame oil. The results of multivariate analysis of variance showed that the sensor signals of different kinds of oil are significantly different from each other. Principal component analysis (PCA) cannot be used to discriminate the adulteration of camellia seed oil, but can be used in the discrimination of adulteration in sesame oil. Linear discriminant analysis (LDA) is more effective than PCA and can be used in adulteration discrimination for both camellia seed oil and sesame oil. In order to check the discriminative power of LDA, canonical discriminant analysis was performed as well. Acceptable results were also obtained: The accuracy of prediction was 83.6% for camellia seed oil and 94.5% for sesame oil. The artificial neural network (ANN) model was used to detect the percentage of adulteration in camellia seed oil and sesame oil. The results showed that, based on ANN as its pattern recognition technique, the electronic nose cannot predict the percentage of adulteration in camellia seed oil, but can be used in the quantitative determination of adulteration in sesame oil.     

Tocopherol oil concentration in field-grown sunflower is accounted for by oil weight per seed

Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil⁻¹) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed⁻¹. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil⁻¹) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols.     

橡籽油的酸催化水解工艺研究

以橡籽油为原料进行常压一次酸催化水解反应。研究了反应温度、反应时间、催化剂用量、油水比和乳化剂用量对水解反应的影响,得出橡籽油水解的最优条件:反应温度为95℃,反应时间为9 h,催化剂浓硫酸用量为10%,油水比为1∶2,乳化剂十二烷基磺酸钠用量为1%,此时橡籽油的水解产物酸值为189.41mg KOH/g,水解率为94.71%。     

Analysis of triacylglycerols by silver-ion high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

Triacylglycerols of the seed oils rich in α- and/or γ-linolenic acid moieties were separated by silver-ion high-performance liquid chromatography (HPLC) followed by on-line atmospheric pressure chemical ionization-mass spectrometric (APCI-MS) detection. Mass spectra of most triacylglycerols exhibited abundant [M + H]⁺ and [M − RCO₂]⁺ ions, which defined the molecular weight and the molecular association of fatty acyl residues of a triacylglycerol, respectively. Silver ions formed weaker complexes with triacylglycerols containing γ-linolenic acid than with those containing α-linolenic acid, i.e., the elution order of molecules wasXYT _γ>XYT _α’,XT _γ T _α>XT _α T _α>, andT _γ T _γ T _γ>T _γ T _γ T _α>T _γ T _α T _α>T _α T _α T _α, whereT _α=α-linolenic acid,T _γ=γ-linolenic acid, andX, Y=fatty acids different from linolenic acid. Furthermore, silver-ion HPLC resulted in partial separation within equally unsaturated triacylglycerols according to differences in the combined number of acyl carbons. Regioisomeric forms of triacylglycerols were not determined from the seed oil samples, although differences were measured with reference compounds in the relative abundances of [M − RCO₂]⁺ ions formed by a loss of a fatty acyl residue from thesn-2 position and thesn-1/3 positions. Silverion HPLC/APCI-MS provided valuable information for structure elucidation of seed oil triacylglycerols: 43 molecular species were identified from cloudberry seed oil, 39 from evening primrose oil, 79 from borage oil, 44 from alpine currant, and 56 from black currant seed oils. The quantitation requires to be studied further, especially in those cases where several molecular weight species of triacylglycerols eluted in a single chromatographic peak.     

Composition of organic and conventionally produced sunflower seed oil

The aim of the present study was to highlight the main differences between seed oils produced from conventionally cultivated crops and organically cultivated ones and processed using mild extraction procedures. The composition and the nutritional and health aspects of both types of sunflower seed oils were compared and were analytically tested to determine the macroscopic differences in proximate composition, the main differences in the minor components, the main quality parameters, the in vitro antioxidant activity, and the presence of trans-ethylene steroisomers in FA. No significant trends were found in the oil samples for TAG and FA composition, but remarkable differences were found in the composition of minor components and in the main chemical and analytical quality properties. The organically grown samples had a higher total antioxidant activity compared with the conventional samples. Trans FA were found only in the conventional oils.     

均匀设计优化环氧橡胶籽油的制备工艺

以橡胶籽油、甲酸和双氧水为原料,磷酸作催化剂,采用无溶剂法合成环氧橡胶籽油,采用均匀设计法研究了甲酸用量、反应时间及双氧水用量等对环氧值的影响。结果表明,最佳制备工艺条件为:橡胶籽油100 g,甲酸12.80 g,质量分数为30%的双氧水50.53 g,反应时间6 h,反应温度50～55℃,产品环氧值达11.68%。     

HPLC-UV法测定薏苡仁指标性成分甘油三油酸酯含量

目的:建立高效液相色谱-紫外法测定薏苡仁指标性成分甘油三油酸酯含量的方法。方法:采用Microsorb C18色谱柱(4.6mm×250mm,5μm),以乙腈-异丙醇(60∶40)为流动相,流速为1m L·min-1,检测波长为205nm,柱温为20℃。结果:薏苡仁指标性成分甘油三油酸酯的线性范围为5.998~59.98μg(r=0.9993),平均回收率(n=6)为100.50%(RSD=1.307%)。结论:本法采用高效液相色谱,结合常规紫外检测器,建立了一种准确可靠,通用性较强的薏苡仁中甘油三酯的含量测定方法。