正相高效液相色谱法同时测定肉制品中4 种羟基十八碳二烯酸异构体的含量

为建立同时测定肉制品中13-羟基-9Z,11E-十八碳二烯酸（13-hydroxy-9Z,11E-octadecadienoic acid，13-Z,E-HODE）、13-羟基-9E,11E-十八碳二烯酸（13-hydroxy-9E,11E-octadecadienoic acid，13-E,E-HODE）、9-羟基-10Z,12E-十八碳二烯酸（9-hydroxy-10Z,12E-octadecadienoic acid，9-Z,E-HODE）、9-羟基-10E,12E-十八碳二烯酸（9-hydroxy-10E,12E-octadecadienoic acid，9-E,E-HODE）的高效液相色谱检测方法，肉制品中的13-Z,E-HODE、13-E,E-HODE、9-Z,E-HODE和9-E,E-HODE经甲醇提取、采用Sep-Pak C18柱净化浓缩后，在硅胶柱Absolute SiO2（250 mm×4.6 mm，5 μm）上以正己烷-异丙醇-乙酸（98.3∶1.6∶0.1，V/V）为流动相进行分离，选用二极管阵列检测器在234 nm进行测定。结果表明，13-Z,E-HODE、13-E,E-HODE、9-Z,E-HODE和9-E,E-HODE分别在质量浓度为0.5～20.0、0.25～10.0、0.75～12.5 μg/mL和0.5～7.5 μg/mL的范围内线性关系良好（R2分别为0.999 4、0.999 2、0.999 2、0.999 6），检出限分别为0.075、0.035、0.090、0.060 μg/g，定量限分别为0.25、0.12、0.32、0.20 μg/g，不同添加水平的平均回收率分别为89.03%、89.03%、89.33%、87.93%。对18 种肉制品含量分析表明，所有样本都含有13-Z,E-HODE、13-E,E-HODE、9-Z,E-HODE和9-E,E-HODE，含量分别为1.73～9.10、0.56～5.79、2.37～11.02、0.78～5.82 μg/g。综上，建立的检测方法快捷、准确、重复性好，可用于同时测定肉制品中13-Z,E-HODE、13-E,E-HODE、9-Z,E-HODE和9-E,E-HODE的含量。     

琼崖海棠籽油的理化性质及脂肪酸组成分析

以琼崖海棠籽为原料,机械压榨法制取琼崖海棠籽油,分析了琼崖海棠籽油的理化指标,并通过气相色谱-质谱( GC - MS)联用分析其脂肪酸组成.结果表明:琼崖海棠籽油的酸值(KOH) 27mg/g,过氧化值1.184 meq/kg,折光指数(n20d)1.489 2,碘值(Ⅰ)83.96 g/100 g,水分及挥发物0.070％,灰分0.029％,皂化值(KOH) 192.3 mg/g,相对密度(d25 4疗)0.934 8;其主要脂肪酸组成是9-十八碳烯酸(27.67％),9,12-十八碳二烯酸(16.78％),9-十八碳烯酸(E)(13.54％),十八碳酸(12.92％),十六碳酸(10.77％),11,14-二十碳二烯酸(7.17％),正十六碳酸(5.24％),十七碳酸(5.13％).     

水果黄瓜和旱黄瓜脂肪酸的分析

采用索氏提取法对水果黄瓜和旱黄瓜中脂肪酸进行了提取,以气相色谱-质谱联用仪分别进行了分析.分离鉴定出11种脂肪酸,并对其主要成分进行了鉴定,水果黄瓜中主要化学成分为:9,12-十八碳二烯酸(15.88%)和9,12,15-十八碳三烯酸(35.77%).旱黄瓜中主要化学成分为:9,12-十八碳二烯酸(15.41%)和9,12,15-十八碳三烯酸(24.24%).     

SP-2560毛细管柱拆分9-十八碳烯酸甲酯顺反异构体的研究

采用SP-2560毛细管柱气相色谱法成功分离了9-十八碳烯酸甲酯顺反异构体。在优化的气相色谱条件下,9-十八碳烯酸甲酯顺反异构体的色谱峰实现基线完全分离,保留时间差在0.5 min以上,分离度Rs>3。9-十八碳烯酸甲酯顺反异构体混标浓度与检测器的响应信号之间呈现线性关系,采用内标法能够获得较好的相关性(R>0.99),线性范围为25~10 000μg/mL,同时具有较低的检出限(约0.2μg)和较高的精密度(RSD<5%)。9-十八碳烯酸甲酯顺反异构体的成功分离为气相色谱法测定食品中的反式脂肪酸奠定了重要基础。     

油菜蜂花粉中抗前列腺增生的活性成分

以油菜蜂花粉为原料,研究其抗良性前列腺增生的活性成分。采用乙醇提取油菜蜂花粉,经不同溶剂萃取,通过诱导BPH模型小鼠研究不同萃取物抗BPH活性。利用各种色谱柱分离,并利用~1H-NMR、~(13)C-NMR、~(135)DEPT-NMR鉴定化学结构。乙酸乙酯萃取物具有显著抗BPH活性(P0.05)。分离纯化得到了6个单体化合物鉴定为:山奈酚-3-O-β-D吡喃葡萄糖苷、十八碳-9Z,12Z,15Z-三烯酸甘油酯、3'-甲氧基-1'-十八碳-9 Z,12 Z,15 Z三烯酸甘油酯、十八碳-9 Z,12 Z,15 Z-三烯酰基-N-乙基甘油醚、2'-甲氧基-1',3'-十八碳-9 Z,12 Z,15 Z-三烯酸甘油二酯、α-亚麻酸。     

热处理对亚麻籽油理化指标及流变影响

使用优化的检测方法探究简单加热体系下亚麻籽油中脂肪酸含量、酸价、碘价、过氧化值、皂化价的变化,以及温度、油脂劣变对亚麻籽油品质的影响。通过脂肪酸测定,保留时间为17.641 min时,经过加热处理的亚麻籽油相比未经过加热处理的亚麻籽油,新生成(Z, Z, Z)-8, 11, 14-二十碳三烯酸、(E, E)-9, 11-十八碳二烯酸甲酯和9, 12-十八碳二烯酸甲酯,而且含量较大。保留时间为17.782 min时,经过加热处理的亚麻籽油相比未经过加热处理的,新生成13, 16-十八碳二炔酸甲酯。对亚麻籽油进行流变试验, 3种样品在较大的剪切频率下都呈牛顿流体。原油的流动效果在流动扫描、振荡应变、振幅扫描、温度扫描4个因素影响下都呈现出比加热后的样品流动性更强的现象,且对样品处理的温度越高,其流动性就越差。     

腌腊肉制品中13-HODE、9,10-DHODE、9,10-EPODE、9,10,13-THODE的HPLC-MS/MS检测

采用高效液相色谱-串联质谱法对腌腊肉制品中13-羟基-9,11-十八碳二烯酸（13-hydroxy-9,11-octadecadienoic acid,13-HODE）、9,10-二羟基-12-十八碳烯酸（9,10-dihydroxy-12-octadecenoic acid,9,10-DHODE）、9,10-环氧-12-十八碳烯酸（9,10-epoxyoctadec-12-enoic acid,9,10-EPODE）及9,10,13-三羟基-11-十八碳烯酸（9,10,13-trihydroxy-11-octadecenoic acid,9,10,13-THODE）进行检测。腌腊肉制品中13-HODE、9,10-DHODE、9,10-EPODE、9,10,13-THODE用甲醇提取,经固相萃取柱去净化浓缩,然后以0.1%甲酸与乙腈为流动相,在XBridge色谱柱上进行梯度分离,采用电喷雾源负离子多反应监测模式进行分析。结果表明,13-HODE、9,10-DHODE、9,10-EPODE、9,10,13-THODE分别在质量浓度为0.05～2.0、0.01～0.5、0.05～1.0、0.01～0.5 μg/mL的范围内具有较好的线性关系（R2＞0.999）;检出限分别为0.120、0.008、0.200、0.016 μg/g;不同添加水平的平均回收率分别为95.1%、85.2%、86.8%、86.2%。对26 种腌腊肉制品含量分析表明,所有样本都含有13-HODE、9,10-DHODE、9,10,13-THODE,含量分别在1.4～100.7、0.1～3.9、0.4～10.2 μg/g范围内,21 种样本中含有9,10-EPODE,含量范围为0.8～6.9 μg/g。结果表明,腌腊肉制品中存在目标分析物的异构体,羟基脂肪酸实际含量可能大大高于检测的量。     

亚油酸水合酶生物合成微生物源羟基不饱和脂肪酸的研究进展

羟基不饱和脂肪酸（Hydroxy unsaturated fatty acids, HUFA）是一类功能性脂肪酸,其生物合成法特异性强、对环境友好,是HUFA制备的主要方法之一。本文就两种较受关注的微生物源HUFA,即10-羟基-12-十八碳烯酸（10-hydroxy-12-octadecenoic acid,10-HOE）、13-羟基-9-十八碳烯酸（13-hydroxy-9-octadecenoic acid,13-HOE）进行了来源、功能特性及应用的介绍,归纳总结了用于合成10-HOE和13-HOE的亚油酸水合酶的研究进展;最后展望了HUFA功能特性和生物合成的研究方向,建议基于胶体界面化学理论来提高亚油酸水合酶合成HUFA的转化效率。     

薏米中营养成分的分析

采用索氏提取法对薏米中脂肪酸进行了提取并进行了甲酯化处理，以气相色谱-质谱联用仪进行了分析，共分离鉴定出12种脂肪酸，共占薏米中脂肪酸总量的95．66％。其中主要成分为：十六酸（棕榈酸）13．05％，9，12-十八碳二烯酸（亚油酸）35．75％，9-十八碳烯酸（油酸）39．85％。     

气相色谱-质谱法测定东盟进口小食品中的 反式脂肪酸

目的建立气相色谱-质谱法检测东盟进口小食品中反式脂肪酸的分析方法。方法样品经油脂的提取、甲酯衍生化,在气相色谱中采用安捷伦CP-Sil 88 for FAME毛细管色谱柱进行分析,质谱分析采用全扫描模式。对柱长、载气流速和和柱温进行了优化,采用优化后的条件对样品进行测定。结果反-9-十八碳烯酸甲酯和反-9,12-十八碳二烯酸甲酯标准品在10~80 mg/L范围内线性关系良好,r~2分别为0.9989和0.9985,方法的检出限(limit of detection,LOD)和定量限(limit of quantification,LOQ)分别为0.4 mg/L和1.0 mg/L。2种物质在3个添加水平的平均回收率为90.5%~105.6%,相对标准偏差为3.5%~8.2%。样品中反-9-十八碳烯酸甲酯和反-9,12-十八碳二烯酸甲酯的分离度好。结论该方法准确度和精密度良好,分离效果好,可以用于对东盟小食品中反式脂肪酸的检测。     

氧脂素对赭曲霉孢子产生、赭曲霉毒素A合成及粮食受侵染程度的影响

为明确氧脂素羟基十八碳二烯酸（hydroxyoctadecaenoic acid,HODE）对不同密度赭曲霉的孢子产生和赭曲霉毒素A（ochratoxin A,OTA）合成的作用,测定不同密度赭曲霉培养过程中9S-HODE、13S-HODE和OTA的产量,添加9S-HODE和13S-HODE后孢子和OTA产量,最后测定不同密度赭曲霉对粮食的侵染程度。结果显示,低接种密度的赭曲霉9S-HODE/13S-HODE比值及OTA产量更高;添加9S-HODE抑制赭曲霉孢子形成、促进OTA合成,13S-HODE作用相反;孢子接种密度为103?个/mL和106?个/mL的赭曲霉侵染花生、大豆、玉米及小麦后,发芽率分别降低29%、21%、17%、14%和35%、29%、20%、22%。这表明群体密度影响赭曲霉9S-HODE、13S-HODE和OTA产量,9S-HODE和13S-HODE可能是赭曲霉群体感应信号分子,二者在调节赭曲霉孢子产生和OTA合成上作用相反,高群体密度赭曲霉对粮食的侵染能力更强,脂肪及蛋白含量高的粮食可能更易被赭曲霉侵染。     

New insights on the metabolism of ricinoleic acid in ruminants

Dairy goats were fed a total mixed ration with or without the inclusion of castor oil [40 g/kg of dry matter (DM)] to study the metabolism of ricinoleic acid (12-OH,cis-9–18:1). Ten goats, at 39.7 ± 4.0 d in milk, were individually penned and allocated at random to the 2 experimental diets. Goats were manually milked twice a day. Milk fatty acids (FA) were analyzed as methyl esters and hydroxyl groups were derivatized in trimethylsilyl ethers. Apart from ricinoleic acid, 6 FA were only detected in the milk of the castor oil group. Ricinoleic acid composed 0.3% of total FA in milk of the castor oil group, whereas the hydroxy-FA (8-OH-14:0, 10-OH-16:0, and 12-OH-18:0) and oxo-FA (8-oxo-14:0, 10-oxo-16:0, and 12-oxo-18:0) reached 7.5% of total FA in milk. We anticipate that these FA were derived from the metabolism of ricinoleic acid, although it was not clear if they were produced in the rumen or in the tissues. To confirm that, we conducted in vitro batch incubations repeated for 3 consecutive weeks with castor oil (40 g/kg of DM) and strained rumen fluid from 2 fistulated sheep. To examine the products formed over time, incubation tubes were stopped at 0, 6, 12, 24, 48, and 72 h. The results of the in vitro experiment showed that ricinoleic acid was metabolized in the rumen at a slow rate and the main products formed were 12-OH-18:0 and 12-oxo-18:0, by hydrogenation of the cis-9 double bond, followed by oxidation of the hydroxyl group, respectively. Our results suggest that the 12-OH-18:0 and 12-oxo-18:0 escape rumen and are further metabolized through partial β-oxidation in ruminant tissues. We propose that the 10-OH-16:0 and 8-OH-14:0 found in goat milk of the castor oil group are successive products of the β-oxidation of 12-OH-18:0, and the 10-oxo-16:0 and 8-oxo-14:0 are successive products of the 12-oxo-18:0 in tissues. Overall, our results indicate that ricinoleic acid is extensively metabolized in the rumen and tissues, producing mainly oxo- and hydroxy-FA that are further excreted in milk.     

Effects of vitamin E and flaxseed on rumen-derived fatty acid intermediates in beef intramuscular fat

To elucidate the effects of dietary vitamin E with or without flaxseed on beef fatty acid composition, 80 feedlot steers were fed 4 diets: Control-E (451 IU dl-α-tocopheryl acetate/head/day), Control+E (1051 IU dl-α-tocopheryl acetate/head/day), Flax-E (10% ground) and Flax+E. Vitamin E had no effect on animal growth or carcass weight (p>0.05), while flaxseed-fed steers had greater average daily gain (p=0.007), final live weight (p=0.005) and heavier carcasses (p=0.012). Feeding flaxseed increased the total n-3 fatty acid content of beef and this response was further accentuated by the inclusion of high levels of vitamin E in the diet. Feeding flax increased levels of some 18:3n-3 partial hydrogenation products including c15- and t13/14-18:1 and several 18:2 isomers (p<0.001) but decreased t10-18:1 (p<0.001). Vitamin E enhanced intramuscular levels of 18:3n-3 and its biohydrogenation products leading to greater accumulations of total n-3 fatty acids in lean ground beef. The consequences of increasing the concentrations of partially hydrogenated products on human health have yet to be investigated.     

A method for the quantitative determination of ω-3-polyunsaturated fatty acids by reductive ozonolysis

There is great interest in the isolation and concentration of ω-3-polyunsaturated fatty acids because of their role in coronary heart diseases [1–3]. For that reason suitable methods for determination of such fatty acids are necessary. The analytical determination of ω-3-docosahexaenoic and ω-3-eicosapentaenoic acid in complex mixtures of unsaturated fatty acids like marine lipids by packed column gaschromatography [4] will not be succesfull, if you want to avoid preseparations [5, 6]. Good results can be achieved by means of capillary gaschromatography [7, 8] and high performance liquid chromatography [9]. In the cases of enrichment it is sufficient to know only the total content of ω-3-fatty acids. By means of reductive ozonolytical cleavage used for exploring fatty acids structures [10, 11] every fatty acid family gives characteristic cleavage products at their alkyl ends: ω-3 = propanal; ω-6 = hexanal; ω-9 = nonanal [12, 13]. Taking that fact in consideration we developed a simple method for the quantitative determination of total ω-3-fatty acid content in lipids.     

绿豆胚芽中脂肪酸组成和维生素E的分析

利用气相色谱对绿豆胚芽中脂肪酸组成进行了测定,结果表明绿豆胚芽油中脂肪酸主要由棕榈酸和不饱和酸组成,其中棕榈酸占２５．１４％、油酸占９．７４％、亚油酸占４２．２２％、亚麻酸占１６．９７％,与一般食用油脂相比较,绿豆胚芽油中亚麻酸含量明显高于常用油脂的亚麻酸含量。同时利用高效液相色谱法测定了ＶＥ的含量,流动相选用甲醇∶水（９８∶２,Ｖ／Ｖ）,流速０．６ｍｌ／ｍｉｎ,检测波长２９２ｎｍ,在ＺｏｒｂａｘＣ１８柱上测定了ＶＥ的含量,ＶＥ的平均含量为２３１ｍｇ／１００ｇ胚芽油,ＶＥ的回收率为９２．００％～１０２．００％,相对标准偏差为４．３３％。     

Features of fatty acid composition of queen bee jelly]

Gas liquid chromatography and chromato-mass-spectrometry were used to study Queen bee jelly fatty acid composition. Trans-10-hydroxy-2-decenoic acid was determined as the mane component of Queen bee jelly fatty acid fraction. Mass-fragmentography GC-MS method was developed for determination of the trace trans-10-hydroxy-2-decenoic acid to authenticate Queen bee jelly in products and BAS.     

高效液相色谱示差折光法检测紫胶桐酸

采用高效液相色谱(high performance liquid chromatography,HPLC)法,利用示差折光检测器(refractive index detector ,RID)测定紫胶桐酸含量。色谱柱为Agilent ZORBAX SB-C18(4.6mm×250mm,5μm),以V(甲醇):V(水)＝60:40(0.1%三氟乙酸)作为流动相,流速1mL/min,进样体积10μL,柱温30℃。结果表明：紫胶桐酸在0.01～1.0mg/mL呈良好的线性关系,R2＝0.9994;最低检测限为0.008mg/mL;精密度RSD值为0.86%;平均加标回收率为100.23%,RSD值为0.65%。采用HPLC-RID测定紫胶桐酸的含量,操作简单,结果准确,稳定性和可信度好。     

反相高效液相色谱法快速测定乳铁蛋白含量

目的建立一种反相高效液相色谱法(RP-HPLC)快速测定乳铁蛋白在乳原料及乳制品中含量的方法。方法根据酪蛋白在等电点(p H 4.6)凝聚沉淀特点,采用RP-HPLC法,用p H4.6醋酸盐缓冲液溶解分离乳铁蛋白,用C18色谱柱快速分离,用流动相A为0.1%三氟乙酸水溶液,流动相B为含有0.09%(V:V)三氟乙酸的90%(V:V)乙腈水溶液,进行梯度洗脱,检测波长214 nm,流速0.7 m L/min。结果乳铁蛋白在10~500 mg/L之间呈现良好的线性,相关系数为0.9999,平均回收率为98.0%,RSD=0.8%(n=9)。结论该方法推广性高、快速,简便、准确,可用于乳铁蛋白原料、奶粉、牛奶及保健品等中乳铁蛋白的含量检测。     

猕猴桃皮中6种多酚类化合物的HPLC检测法建立

建立使用高效液相色谱法同时测定猕猴桃皮中6种多酚类化合物含量的方法。检测方法为:色谱柱为InertSustain C18(4.6 mm×250 mm,5 μm),以甲醇-10 mmoL/L KH₂PO₄水溶液(pH2.0)为流动相进行梯度洗脱,柱温40 ℃,流速1 mL/min,进样量10 μL,检测波长为280 nm。结果表明:此方法可使6种目标组分在50 min内得到良好的分离,且方法重复性好(RSD≤1.40%)、稳定性较强(RSD≤2.86%)、精密度较高(RSD≤1.85%)、回收率在84.90~108.78%之间。该方法操作简单、快速,能为猕猴桃皮多酚的相关研究提供有效数据。