人初乳脂肪酸组成及sn-2位脂肪酸分布的研究

选择广州市健康产妇20例,用超声法快速萃取乳中脂肪,采用DM-FFAP毛细管柱气相色谱对人初乳脂中总脂肪酸组成及sn-2位脂肪酸进行了测定,并采用SPSS13.0软件对测定数据进行统计分析。结果表明:总脂肪酸组成中饱和脂肪酸（主要为棕榈酸）含量低,为36.47%,不饱和脂肪酸含量高（主要为油酸和亚油酸）,为63.9%;sn-2位脂肪酸组成中饱和脂肪酸含量为61.48%,不饱和脂肪酸含量为37.95%;棕榈酸多分布在sn-2位（72.08%）,油酸和亚油酸多分布在sn-1,3位。初乳中脂肪酸的组成和分布具有独特的特点,对婴儿生长发育具有非常重要意义,本文对开发人乳脂替代品具有理论指导意义。      

奶山羊初乳短、中链脂肪酸组成研究

以西北农林科技大学西农萨能羊原种场的产奶母羊为研究对象，采集35只2．5～5岁母羊分娩后1～5d的初乳和第5周常乳乳样，用气相色谱仪对乳中的短、中链脂肪酸组成含量进行测定。结果表明，初乳1～5d中，丁酸（C4：0）、己酸（C6：0）、辛酸（C8：0）、癸酸（C10：0）、月桂酸（C12：0）、肉豆蔻酸（C14：0）的含量存在极显著差异（P〈0．01），棕榈酸（C16：0）、硬脂酸（C18：0）、油酸（C18：1）和亚油酸（C18：2）的含量差异显著（P〈O．05）；而初乳与常乳中，辛酸（C8：0）、癸酸（C10：0）、月桂酸（C12：0）的含量差异极显著（P〈0．01），丁酸（C4：0）、棕榈酸（C16：0）含量差异显著（p〈0．05），其余脂肪酸含量差异均不显著（P〉0．05）。羊初乳中丁酸（C4：0）含量受产奶量影响不显著，处于相对稳定状态：其他短链脂肪酸和中链脂肪酸中棕榈酸（C16：0）的含量随产奶量增加而减少，长链脂肪酸随产奶量增加而增加。     

火麻油总脂肪酸及sn-2位脂肪酸组成分析

采用气相色谱法测定火麻油中总脂肪酸和sn-2位脂肪酸的组成和含量,并与其他9种常见植物油进行对比,旨在为火麻油的营养价值研究提供基础数据。结果表明,3种不同品牌火麻油主要由软脂酸（C16∶ 0）、硬脂酸（C18∶ 0）、油酸（C18∶ 1n9c）、亚油酸（C18∶ 2n6c）、α-亚麻酸（C18∶ 3n3）组成,其中多不饱和脂肪酸含量为70.57%~78.73%,sn-2位多不饱和脂肪酸含量为77.61%~83.74%,说明以亚油酸和α-亚麻酸为主的多不饱和脂肪酸更易连接在甘三酯结构的sn-2位上。另外,对比其他9种常见植物油,火麻油总脂肪酸和sn-2位脂肪酸中油酸含量均最低,亚油酸和亚麻酸含量较高;多不饱和脂肪酸含量均最高,分别为77.90%和83.74%;n-6系脂肪酸与n-3系脂肪酸比例分别为3.7∶ 1和4.2∶ 1。研究结果表明,火麻油是一种不饱和脂肪酸含量较高且易于被人体吸收代谢的植物油。     

不同部位猪脂的总脂肪酸组成及Sn-2位脂肪酸成分分析

选择11例猪的4个部位(猪尾巴、猪脖、奶腩和猪板),用乙酸甲酯萃取脂肪,采用DIKMA CP-SIL88FS(60 m×0.25 mm id×0.20μm)毛细管柱气相色谱对各部位猪脂总脂肪酸及Sn-2位脂肪酸组成进行了测定,并采用SPSS 13.0软件对数据进行统计分析。结果表明:猪尾巴油、猪脖油和奶腩油的总脂肪酸及Sn-2位脂肪酸组成和分布与猪板油相比均存在显著性差异,且不饱和脂肪酸和单不饱和脂肪酸含量均高于猪板油。     

松籽油脂肪酸组成及分布特征分析

通过气相色谱法分析了松仁油的总脂肪酸组成及其上位置分布特点。结果表明,松仁油主要含有亚油酸（46.29%）、油酸（26.68%）和松籽油酸（13.84%）。sn2位置上的亚油酸（66.84%）和油酸（28.33%）含量高于sn1,3上的含量,但是Δ5系列多不饱和脂肪酸（Δ5-PUFA）主要分布在sn1,3位置上。Δ5-PUFA的存在和它们选择性地分布在sn1,3位等特点是包括红松籽油在内主要松属植物果实油脂的特点。松籽油主要由12种甘油三酯组成,其中含量比较多的是LLPi（24.13%）,OLL/LOL（17.87%）和LOPi（14.32%）。我们还对植物甾醇和维生素进行分析,结果显示松籽油含有141.64mg/100g的总植物甾醇和23.63mg/100g的总生育酚。      

无锡地区人乳脂肪脂肪酸组成及sn-2位脂肪酸分布

采集无锡地区150例人乳样品,提取乳中脂肪后,采用气相色谱法对人乳脂肪中总脂肪酸及sn-2位脂肪酸进行测定。结果表明:人乳脂肪总脂肪酸中饱和脂肪酸含量较低,主要为棕榈酸,不饱和脂肪酸含量较高,主要为油酸和亚油酸。随着泌乳期的延长,中碳链饱和脂肪酸(C8∶0、C10∶0、C12∶0)及单不饱和脂肪酸(C16∶1)含量逐渐增加,而部分长碳链饱和脂肪酸及长碳链多不饱和脂肪酸如二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)含量明显下降。人乳脂肪中sn-2位脂肪酸组成中饱和脂肪酸含量约为70%,主要为棕榈酸。     

驴油总脂肪酸及sn-2位脂肪酸组成分析

采用高效气相色谱分析驴油中总脂肪酸及sn-2位脂肪酸组成和含量。结果表明:驴油总脂肪酸中不饱和脂肪酸含量为59.301%,sn-2位脂肪酸中不饱和脂肪酸含量为67.833%;人体必需脂肪酸在sn-2位上的含量比在总脂肪酸中的含量增加了7.702个百分点。驴油是一种脂肪酸组成像植物油的动物油。     

沪浙地区不同泌乳期母乳脂肪酸组成及分布研究

研究了我国沪浙地区不同泌乳期(0～1,1～3,3～6和6～12月)母乳总脂肪酸、甘油三酯sn-2位脂肪酸和磷脂脂肪酸组成及分布。结果显示,随着泌乳期的延长,母乳脂肪中的中链饱和脂肪酸(MCSFA)、C_(12:0)和C_(14:0)含量逐渐升高,多不饱和脂肪酸(PUFA)、C_(18:2n-6)(LA)和C_(18:3n-3)(ALA)含量先升高后下降,C_(20:4n-6)(ARA)和C_(22:6n-3)(DHA)含量先显著下降而后趋于稳定,而饱和脂肪酸(SFA)、C_(16:0)和C_(18:0)含量几乎没有变化。母乳脂肪酸在甘油三酯结构中的位置分布具有独特性:MCSFA、SFA、C_(12:0)、C_(16:0)、ARA和DHA主要结合在sn-2位上,而MUFA、C_(18:1n-9)、PUFA、LA和ALA主要分布在sn-1,3位上,且这种独特的位置分布几乎不随泌乳期的变化而变化。母乳磷脂脂肪酸中的ARA和DHA含量尽管在不同泌乳期之间有所差异,但均显著高于其在母乳总脂肪酸中的含量。研究结果为我国婴儿配方乳粉的脂质母乳化特别是结构母乳化提供了重要的数据支撑。     

青海牦牛乳脂肪Sn-2位脂肪酸组成分析

以采自青海地区不同海拔高度的的牦牛乳脂肪为研究对象,利用气相色谱仪及薄层层析法测定牦牛乳脂肪的Sn-2位脂肪酸的组成,并研究不同海拔高度的牦牛乳脂肪的Sn-2位脂肪酸组成是否存在显著性差异,并分析其原因。结果表明青海牦牛乳脂肪的甘油三酯的总脂肪酸共有12种,含量较高的为棕榈酸(31.35%～36.48%),油酸(24.91%～30.99%)和硬脂酸(9.82%～13.87%)。青海牦牛乳脂肪的Sn-2位脂肪酸组成为:己酸(0.66%～1.02%),癸酸(2.46%～3.98%),月桂酸(2.43%～4.88%),十四烷酸(14.66%～20.68%),十五烷酸(1.19%～1.76%),棕榈酸(39.91%～46.23%),棕榈油酸(2.81%～5.35%),硬脂酸(4.75%～8.31%),油酸(17.42%～20.81%),亚油酸(0.00%～～1.72%),亚麻酸(0.00%～1.71%)。显著性分析显示:随着海拔的升高,结合在牦牛乳甘油三酯Sn-2位上的饱和脂肪酸(SFA)占比先逐渐升高,后显著降低(P0.05)。不饱和脂肪酸(UFA)的占比先逐渐降低,趋于平缓后显著升高(P0.05)。     

薄层色谱联用气相色谱法研究食用植物油中sn-2 位脂肪酸的分布

选取大豆油、花生油、玉米油、菜籽油、芝麻油、棕榈油、橄榄油、茶籽油、葵花籽油、稻米油、椰子油、亚麻籽油、山柚油13类30个样品作为分析对象,采用专一性猪胰脂肪酶水解脂肪酸甘油三酯,通过薄层色谱分离得到sn-2位单甘酯,甲酯化后进气相色谱仪,对sn-2位脂肪酸组成进行分析并与全脂肪酸组成相比较。结果表明:植物油中脂肪酸主要为棕榈酸(C16∶0)、硬脂酸(C18∶0)、油酸(C18∶1)、亚油酸(C18∶2)、亚麻酸(C18∶3)。以C16∶0/C18∶0比值-C18∶2/C18∶1比值作图可用于区别不同种类植物油;然而,除椰子油和亚麻籽油等特征脂肪酸含量高的油脂外,多数植物油中sn-2位脂肪酸主要为油酸和亚油酸,两者加和多大于90%。因此,采用特征sn-2位脂肪酸区别不同植物油的效果不及全脂肪酸比值分析。但是,sn-2位脂肪酸更亲和人体,有利于人体吸收,在营养学上更有实用意义,研究结果可为植物油的营养价值研究提供数据基础。     

不同胎次中国荷斯坦牛鲜乳脂肪酸组成研究

对5个胎次共98头中国荷斯坦牛鲜奶乳成分及脂肪酸含量进行了测定分析。结果表明，乳脂率、乳蛋白率及体细胞数在胎次间存在显著（P＜0．05）或极显著（P＜0．01）差异；短、中链脂肪酸（C4∶0～C16∶0）中，除C6∶0在第一胎与其他4胎间含量差异显著（P＜0．05）、C12∶0在第2、5胎间含量差异显著（P＜0．05）外，其他脂肪酸含量在胎次间差异不显著（P＞0．05）；长链脂肪酸中，硬脂酸（C18：0）在第1胎含量最高。第3胎含量最低，1、3胎间差异极显著（P＜0．01）；油酸（C18∶1）和亚油酸（C18∶2）含量在胎次间变化规律相似，均表现为第1胎最低，第3胎最高，且两胎间存在极显著（P＜0．01）和显著差异（P＜0．05）。     

Fractionized milk composition during removal of colostrum and mature milk

Experiments were designed to study compositional differences in colostrum and mature milk and during the course of milk removal. Fractionized milk samples during the course of machine milking were analyzed in single (right rear) quarters in the cisternal fraction, after 25, 50, 75, and 100% of spontaneously removed milk, in residual milk, and in composite samples from all quarters on d 2 (colostrum) and in wk 4 (mature milk) of lactation. Somatic cell counts; concentrations of dry matter, total protein, insulin-like growth factor-I, insulin, prolactin, tumor necrosis factor-alpha, Na, and Cl; gamma-glutamyltransferase activity; and electrical conductivity were higher, whereas lactose concentration was lower on d 2 than in wk 4. Concentrations of fat, potassium chloride, and osmolarity did not differ between lactational periods. During the course of milking, concentrations of dry matter, fat, lactose, and potassium, and osmolarity increased, whereas somatic cell counts, protein, insulin like-growth factor-I, insulin, prolactin, and sodium concentrations, electrical conductivity and gamma-glutamyltransferase activity decreased on d 2, and protein, sodium, and electrical conductivity decreased in wk 4. In conclusion, various milk constituents differed considerably between lactational periods (colostrum and mature milk). Milk isotonicity was only in part associated with lactose concentration. Electrical conductivity was associated with Na, K, and fat concentrations and was highest in the cisternal fraction. Changes in milk constituents during milking need to be considered if milk samples are taken for analytical purposes and to evaluate the health status of the udder.     

马奶和成熟母乳甘油三酯中脂肪酸组成及分布

脂肪酸的组成和位置分布影响乳脂肪的物理和营养特性。本文测定了马奶和母乳总脂肪酸组分并且通过脂肪酶水解马奶和母乳脂肪,薄层色谱分离出2-甘油一酯,甲酯化后气相色谱测定了母乳和马奶中sn-2脂肪酸。结果表明,母乳中棕榈酸、油酸、亚油酸含量分别为19.07%、36.43%、23.73%,马奶中含量分别为24.47%、17.40%、4.78%。母乳sn-2位脂肪酸中饱和脂肪酸占59.41%,其中含棕榈酸48.36%,肉豆蔻酸6.00%,马奶sn-2位脂肪酸中饱和脂肪酸占71.46%,含棕榈酸47.00%,肉豆蔻酸12.48%。母乳脂肪酸的分布并非随机的,马奶脂肪酸分布类似于母乳,为母乳脂肪替代物的研究提供一定的数据支持及底物参考。     

Bovine colostrum: Postpartum changes in fat globule size distribution and fatty acid profile

Although “zero waste” valorization concepts are gaining increasing attention, colostrum, a byproduct of milk production, remains underused due to technological challenges. Information about the fat fraction and the size of fat globules is needed to address these challenges, but such information is currently lacking. This study aimed to fill this gap in the knowledge by measuring the size distribution of bovine colostrum fat globules (CFG) and analyzing its relationships with postpartum milkings, parity, and fatty acids (FA) profile. Four sequential postpartum colostrum samples were collected from 44 cows and analyzed for the abovementioned parameters. The results indicated that CFG size increases almost twice during postpartum milkings (from ～5 to ～10 µm), whereas lactation has little, if any, effect on CFG size. The FA profile analyses showed that the content of most FA in the fourth postpartum milking was different from the previous milkings. The correlation analyses between CFG size and FA profile also demonstrated that the fourth milking was clearly distinguishable from the first 3 postpartum milkings. For example, the saturated FA content from the first 3 milkings had a positive correlation with smaller CFG (and a negative correlation with larger CFG), whereas the fourth milking demonstrated no correlations. Based on these CFG size and FA profile analyses, the results of this study suggest that the first 3 postpartum milkings can be considered as colostrum, whereas the fourth milking represents transition milk. Information about CFG size distribution enables modification of the FA profile of colostrum products and the ability to create better valorization technologies for colostrum-based food and feed supplements.     

Long-term effects of feeding monensin on milk fatty acid composition in lactating dairy cows

The objective of this study was to determine the long-term effects of feeding monensin on milk fatty acid (FA) profile in lactating dairy cows. Twenty-four lactating Holstein dairy cows (1.46 ± 0.17 parity; 620 ± 5.9 kg of live weight; 92.5 ± 2.62 d in milk) housed in a tie-stall facility were used in the study. The study was conducted as paired comparisons in a completely randomized block design with repeated measurements in a color-coded, double blind experiment. The cows were paired by parity and days in milk and allocated to 1 of 2 treatments: 1) the regular milking cow total mixed ration (TMR) with a forage-to-concentrate ratio of 60:40 (control TMR; placebo premix) vs. a medicated TMR [monensin TMR; regular TMR + 24 mg of Rumensin Premix per kg of dry matter (DM)] fed ad libitum. The animals were fed and milked twice daily (feeding at 0830 and 1300 h; milking at 0500 and 1500 h). Milk samples were collected before the introduction of treatments and monthly thereafter for 6 mo and analyzed for FA composition. Monensin reduced the percentage of the short-and medium-chain saturated FA 7:0, 9:0, 15:0, and 16:0 in milk fat by 26, 35, 19, and 6%, respectively, compared with the control group. Monensin increased the percentage of the long-chain saturated FA in milk fat by 9%, total monounsaturated FA by 5%, total n-6 polyunsaturated FA (PUFA) by 19%, total n-3 PUFA by 16%, total cis-18:1 by 7%, and total conjugated linoleic acid (CLA) by 43% compared with the control group. Monensin increased the percentage of docosahexaenoic acid (22:6n-3), docosapentaenoic acid (22:5n-3), and cis-9, trans-11 CLA in milk fat by 19, 13, and 43%, respectively, compared with the control. These results suggest that monensin was at least partly effective in inhibiting the biohydrogenation of unsaturated FA in the rumen and consequently increased the percentage of n-6 and n-3 PUFA and CLA in milk, thus enhancing the nutritional properties of milk with regard to human health.     

人乳短链脂肪酸的组成、检测方法与消化代谢研究进展

短链脂肪酸(SCFAs)是指碳链长度在4~8的有机脂肪酸,也称为挥发性脂肪酸,在哺乳动物乳和胃肠道系统中含量较高。人类日常饮食的短链脂肪酸主要来自于牛羊乳。人乳中含有的短链脂肪酸可调节婴儿脂质代谢、降低肥胖风险,对于婴儿的生长发育具有重要作用。对人乳短链脂肪酸的组成、检测方法及其消化代谢进行综述,为人乳营养价值的研究和婴儿配方奶粉的开发研制提供参考。     

基于人乳脂肪组成的酶法人乳脂肪替代物的构建

为了开发新型高相似性人乳脂肪替代物,依据中国人乳脂肪的脂肪酸组成和甘油三酯结构,以巴沙鱼油、樟树籽仁油、亚麻籽油、微生物油(富含ARA)及DHA藻油(质量比为153.81∶15.16∶62.33∶7.89∶10.81)为原料油脂,以固定化脂肪酶Lipozyme RM为催化剂,在60℃下酯交换反应8 h制备人乳脂肪替代物,测定其脂肪酸、sn-2位脂肪酸及甘油三酯组成及含量,分析其红外光谱图、熔融性质、结晶性质及流变学性能。结果表明,构建的人乳脂肪替代物中链脂肪酸含量为12%、亚油酸和亚麻酸总含量为19.53%且比例约为1∶1.5,ARA含量为1.17%,DHA含量为1.11%,其sn-2位富含棕榈酸(43.10%),结构甘油三酯含量高(58.75%),无反式脂肪酸生成,熔融温度低于人体温度且在20℃下仍能保持18.7%的固体脂肪含量,结晶形态细腻且流变性能优异。制备的人乳脂肪替代物具有应用于婴幼儿配方奶粉、婴幼儿米糊和婴幼儿饼干等各种婴幼儿食品的潜力。     

Genetic determination of fatty acid composition in Spanish Churra sheep milk

The objective of this study was to estimate the genetic variation of ovine milk fatty acid (FA) composition. We collected 4,100 milk samples in 14 herds from 976 Churra ewes sired mostly by 15 AI rams and analyzed them by gas-liquid chromatography for milk fatty acid composition. The studied traits were 12 individual FA contents (proportion in relation to the total amount of FA), 3 groups of fatty acids [saturated fatty acids (SFA), monounsaturated FA (MUFA), and polyunsaturated FA (PUFA)], and 2 FA ratios (n-6:n-3 and C18:2 cis-9,trans-11:C18:1 trans-11). In addition, percentages of fat and protein and daily milk yield were studied. For the analysis, repeatability animal models were implemented using Bayesian methods. In an initial step, univariate methods were conducted to test the hypothesis of the traits showing additive genetic determination. Deviance information criterion and Bayes factor were employed as model choice criteria. All the studied SFA showed additive genetic variance, but the estimated heritabilities were low. Among unsaturated FA (UFA), only C18:1 trans-11 and C18:2 cis-9,cis-12 showed additive genetic variation, their estimated heritabilities being [marginal posterior mean (marginal posterior SD)] 0.02(0.01) and 0.11(0.04), respectively. For the FA groups, only PUFA showed significant additive genetic variation. None of the studied ratios of FA showed additive genetic variation. In second multitrait analyses, genetic correlations between individual FA and production traits, and between groups of FA and ratios of FA and production traits, were investigated. Positive genetic correlations were estimated among medium-chain SFA, ranging from 0 to 0.85, but this parameter was close to zero between long-chain SFA (C16:0 and C18:0). Between long- and medium-chain SFA, estimated genetic correlations were negative, around −0.6. Among those UFA showing significant additive genetic variance, genetic correlations were close to zero. The estimated genetic correlations among all the investigated FA, milk yield, and fat and protein percentages were not different from zero. Our results suggest that low additive genetic variation is involved in the determination of the FA composition of milk fat in Churra sheep under current production conditions, which results in low values of heritabilities.     

GC-MS测定人乳及动物乳中支链脂肪酸组成

支链脂肪酸（BCFA）是乳中微量但对婴幼儿的生长发育具有重要意义的生物活性成分。利用GC-MS对人乳和4种动物乳（牛乳、羊乳、牦牛乳、骆驼乳）中BCFA种类及含量进行测定。结果表明：5种乳中共有64种脂肪酸,其中含15种BCFA,17种饱和脂肪酸（SFA）,18种单不饱和脂肪酸（MUFA）和14种多不饱和脂肪酸（PUFA）;BCFA含量呈现出很大的物种间差异,动物乳中的支链脂肪酸含量显著高于人乳（p<0.001）,牛乳、牦牛乳、羊乳、骆驼乳和人乳中BCFA多为异构（iso）和反异构（anteiso）BCFA,含量分别为2.82%、4.90%、3.35%、8.00%和0.28%;人乳中BCFA受孕龄影响显著（p<0.01）,足月儿乳母的母乳中含有丰富的BCFA。     

Effects of selenium form on blood and milk selenium concentrations,milk component and milk fatty acid composition in dairy cows

BACKGROUND: Human health may be improved if milk with a favorable fatty acid composition and Se concentration is ingested. The present study is to determine how a basal diet supplemented with daily 5 mg Se as Se‐enriched yeast (SY) or sodium selenite (SS) affects the fatty acid composition and Se concentration of bovine milk. The effects of Se form on blood Se concentration, erythrocyte glutathione peroxidase 1 (GPx1) activity, serum GPx3 activity and milk yield and component were also studied. RESULTS: Both Se forms, when compared to control group, increased Se concentrations of blood (P < 0.01) and milk (P < 0.01), erythrocyte GPx1 activity (P < 0.05) and milk percentages of polyunsaturated fatty acids (PUFA) (P < 0.05) and cis‐9,cis‐12 linoleic acid (P < 0.05). Cows supplemented with SY had higher Se levels in blood (P < 0.01) and milk (P < 0.01) and percentage of PUFA in milk (P < 0.05) when compared with those supplemented with SS. Milk yield, milk component and serum GPx3 activity were not significantly affected by Se form. CONCLUSION: Supplementation of diet with SY appears to be of more benefit than SS in producing favorable milk with high PUFA and Se concentrations. Copyright © 2010 Society of Chemical Industry