大叶女贞籽脂肪酸组成分析

利用气相色谱测定大叶女贞籽油中的脂肪酸组成进行分析,研究结果表明大叶女贞籽中脂肪酸主要有C16:0,C18:0,C18:1,C18:2,C18:3五种脂肪酸,其含量分别为11.22%,4.40%,28.02%,50.06%,3.04%.这五种脂肪酸分别为棕榈酸、硬脂酸、油酸、亚油酸以及亚麻酸.大叶女贞籽油中不饱和酸占总脂肪散的80%以上,属于不饱和型油脂,具有一定开发利用潜力的油料资源.     

我国不同产区核桃油组成成分与氧化稳定性研究

选取我国西南、西北和东部三大产区的 16 种薄皮核桃分别压榨制油,测定核桃油的脂肪酸组成、甘油三酯组成、总酚、生育酚、植物甾醇和氧化稳定性指数。结果表明,不同产区核桃油的脂肪酸组成主要为亚油酸 C18∶2(51.21%~68.97%),油酸 C18∶1(12.56%~26.04%),亚麻酸 C18∶3(6.82%~15.01%)和棕榈酸 C16∶0(3.05%~8.27%),甘油三酯包含三亚酸甘油酯 LLL(27.87%~39.47%)和油酸亚油酸亚麻酸甘油酯 OLLn(17.07%~24.18%)。微量伴随物植物甾醇,生育酚和总酚含量分别为 540~1 594 mg/kg,10~1 303 mg/kg,345~2 579 mg/kg。根据与其他国家和地区的核桃油比较,可以推断出不同的种植区域地理位置和气候的差异,导致了核桃油成分的差异。在此基础上将氧化稳定性指数与脂肪酸组成、微量伴随物含量进行多元线性回归分析后,得出亚油酸,α-生育酚和总酚是影响核桃油氧化稳定性的主要因素。     

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。     

新疆野蔷薇种子油的脂肪酸组成分析

采用超声辅助提取法提取野蔷薇种子油,以气相色谱-质谱联用技术对油脂进行脂肪酸组成分析.结果表明:野蔷薇种子油中的主要脂肪酸为棕榈酸、油酸、亚油酸、亚麻酸,其中不饱和脂肪酸占总量的92.41%;主要成分棕榈酸占5.88%,油酸占12.39%,亚油酸占56.52%,亚麻酸占23.50% .     

腊肉加工过程中游离脂肪酸的变化研究

分别对腊肉加工过程中肥肉和瘦肉的游离脂肪酸(FFA)的变化进行了测定,结果表明:肥肉中主要的FFA为油酸(C18∶1)、硬脂酸(C18∶0)、棕榈酸(C16∶0)和亚麻酸(C18∶3),且总FFA不断积累,81h达到最大值;脂肪酸在肥肉中的释放速率为亚油酸>亚麻酸>硬脂酸>油酸>棕榈酸。瘦肉中主要的FFA为硬脂酸、棕榈酸、亚油酸(C18∶2)和油酸,总FFA也不断积累,43h达到最大值;脂肪酸在瘦肉中的释放速率为硬脂酸>亚油酸>棕榈酸>油酸。腊肉加工过程中,脂质发生的降解和氧化对形成腊肉特有的风味发挥了重要作用。     

同种溶剂两步浸提法分离提取花椒籽皮油和仁油

以大红袍花椒籽为原料,以油脂提取率为指标,采用同种溶剂两步浸提法分离提取花椒籽皮油和仁油,优化其提取工艺。结果表明：采用溶剂油在优化工艺条件下分步提取花椒籽皮油和仁油,提取率分别达到96.00%和97.51%,提取后的皮油产品主要含棕榈酸、棕榈油酸、油酸和亚油酸等饱和与不饱和高级脂肪酸甘油酯,而仁油产品主要含油酸、亚油酸、亚麻酸等不饱和高级脂肪酸甘油酯,有望开发为一种高营养保健食用油脂。     

山核桃油中的脂肪酸GC法分析

利用GC(气相色谱)分析了索氏法、超声波法、水剂法三种方法提取的安徽宁国产山核桃油中的脂肪酸的成分及含量.脂肪酸组成中分另q以不饱和脂肪酸为主,其含量占比例分别为92.11%,92.64%,92%,主要为油酸(C18 : 1)、亚油酸(C18 : 2)及亚麻酸(C18 : 3),饱和脂肪酸含量分别为7.8%,7.2%,7.56%,主要为棕榈酸.     

紫苏子油中游离脂肪酸的动态分析

采用毛细管气相色谱的方法,以十五碳烷酸为内标,对紫苏子油中的五种游离脂肪酸:棕榈酸(C16:0)、硬脂酸(C18:0)、油酸(C18:1)、亚油酸(C18:2)、亚麻酸(C18:3)进行分析,研究紫苏子油中五种游离脂肪酸在储藏期间的变化.此分析方法无需进行甲基化,直接分析游离脂肪酸的变化.研究中对每种脂肪酸都作了方法学研究,脂肪酸的线性范围在147～922 ppm之内,12值≤0.9997.精密度≤2.43%(n=5).最后用此法测定了不同储藏期间的样品,结果显示随储藏时间的延长,游离脂肪酸的总量增加,但各脂肪酸的变化情况不同.     

苹果籽油脂肪酸及甘油三酯组成分析

采用GC分析溶剂浸提法所得苹果籽油脂肪酸组成,结果表明苹果籽油中主要含有6种脂肪酸,分别为棕榈酸、硬脂酸、油酸、亚油酸、花生一烯酸和亚麻酸,不饱和脂肪酸含量近80%;胰脂酶水解甘油三酯表明苹果籽油sn–2位脂肪酸以油酸、亚油酸为主,含量占90%以上;RP–HPLC–ELSD分析了苹果籽油的甘油三酯组成,主要包括11种甘油三酯,其中LLL、OLL、OOL占70%以上,进一步验证了苹果籽油属于油酸―亚油酸型油脂。     

不同品种燕麦的油脂组成及与其它营养物质相关性研究

对我国12种燕麦的主要营养成分,尤其是油脂及其脂肪酸的组成进行了系统研究,并探讨它们之间的相关性。研究结果表明,我国12种燕麦的油脂含量存在较大的差异,并且油脂含量与颗粒重、淀粉呈负相关,而与蛋白质、维生素E呈正相关。燕麦油脂中的脂肪酸主要是由棕榈酸、油酸、亚油酸、硬脂酸和亚麻酸组成。燕麦油脂的含量与脂肪酸组成有一定的相关性,与硬脂酸和油酸呈正相关,而与棕榈酸、亚油酸和亚麻酸呈负相关。燕麦中性油脂(NL)中含有较多的油酸,而糖脂(GL)和磷脂(PL)中含有更多的棕榈酸和亚油酸。     

Short communication: influence of dietary tallow and fish oil on milk fat composition

Four midlactation Holstein cows in a 4 x 4 Latin square design were fed one of four diets that contained 3% added fat (dry matter basis) as 100:0, 67:33, 50:50, or 33:67 tallow:fish oil. Feed intake and yield and composition of milk were not affected by treatment. The proportion of fatty acids 18:0 and cis-18:1 decreased and trans-18:1, conjugated linoleic acid, 18:3, 20:4, and 20:5 increased in milk fat with increasing fish oil. The efficiency of transferring dietary 20:5 and 22:6 to milk fat was < 7%.     

Lipid content and fatty acid composition of green algae Scenedesmus obliquus grown in a constant cell density apparatus

The lipids of alga Scenedesmus obliquus grown under controlled conditions were separated and fractionated by column and thin-layer chromatography, and fatty acid composition of each lipid component was studied by gas-liquid chromatography (GLC). Total lipids were 11.17%, and neutral lipid, glycolipid and phospholipid fractions were 7.24%, 2.45% and 1.48% on a dry weight basis, respectively. The major neutral lipids were diglycerides, triglycerides, free sterols, hydrocarbons and sterol esters. The glycolipids were: monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. The phospholipids included: phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine. Fourteen fatty acids were identified in the four lipid fractions by GLC. The main fatty acids were C18:2, C16:0, C18:3(alpha), C18:1, C16:3, C16:1, and C16:4. Total unsaturated fatty acid and essential fatty acid compositions of the total algal lipids were 80% and 38%, respectively.     

Effect of feed on the composition of milk fat.

Researchers attending the Wisconsin Milk Board 1988 Milk Fat Roundtable indicated that the ideal nutritional milk fat would contain 10% polyunsaturated fatty acids, 8% saturated fatty acids, and 82% monounsaturated fatty acids. This cannot be accomplished by modifying diets of lactating cows. Monounsaturated fatty acid (C18:1) content can be increased by 50 to 80% and may approach 50% of milk fatty acids by feeding lipids rich in 18-carbon fatty acids. Because of ruminal hydrogenation and intestinal and mammary desaturase activity, degree of unsaturation of dietary 18-carbon fatty acids is not critical in influencing milk fat C18:1. Feeding low roughage diets increases the proportion of C18:1 in milk fat, and effects of feeding low roughage diets and lipid may be additive. Palmitic acid (C16:0) content of milk fat can be reduced by 20 to 40% unless the supplemented lipid is rich in C16:0. Milk fat alteration is dependent on the level of lipid supplementation. Limited evidence indicates frequency of lipid feeding and physical form of oil (free oil vs. oilseed), and heat treatment of oilseeds has relatively little influence on modification of milk fat. Significant changes in milk fat composition can be achieved on farm via nutritional modifications.     

Genotype,environment and genotype × environment effects on trypsin inhibitor in peas

Four multiparous ruminally canulated cows and four primiparous cows without a ruminal cannula were used in a 4 × 4 Latin square experiment to study the effect of dietary fat source on milk fatty acid composition. Cows were fed a diet containing 550 g lucerne silage and 450 g concentrate kg^?1 dietary DM. The four diets were control and fat supplementation (32 g fat kg^?1 diet DM) as roasted soya beans, calcium salts of palm oil fatty acids (Megalac®). or hydrogenated tallow (Alifet®). Cows fed supplemental fat as roasted soya beans. Megalac®. or Alifet® produced 33.8, 32.6, and 32.5 kg day^?1 of 3.5% FCM. respectively, compared with 31.6 kg day^?1 with no fat supplementation. Addition of fat decreased milk protein percentage. Milk fat percentage was increased with Megalac® and decreased with Alifet® feeding. Dietary fat decreased the proportion of short- and medium-chain fatty acids (C6-C14:0) in milk and increased the proportion of long-chain fatty acids (C16 : 0 and longer). Roasted soya beans were most effective in reducing C16 : 0 and increasing C18 : 1, C18 : 2 and C18 : 3 acids in milk fat. Megalac® did not decrease milk C16 : 0 content, and neither Megalac® nor Alifet® affected C18 : 2 content.     

Influence of triglycerides and free fatty acids in milk replacers on calf performance, blood plasma, and adipose lipids

In a 4-wk study of 48 3-day-old calves we compared effects of feeding various fats or their free fatty acids in skim milk-powder based milk replacer, on calf performance, feed utilization, and blood plasma and adipose lipids. When fat was fed, calf performance and feed utilization were equivalent for tallow and coconut oil diets but markedly poorer for corn oil. Complete replacement (tallow) or one-half replacement (coconut and corn oils) of the fats with their free fatty acids reduced calf gains and feed efficiency. Tallow free fatty acids gave lower digestibilities of palmitic and stearic acid and reduced calcium absorption. Free fatty acids from both coconut and corn oils reduced diet palatability and intake; those from tallow and coconut oil markedly interfered (in vitro) with rennet clotting of milk replacers. The main lipid classes in blood plasma for all treatments were cholesteryl esters and phosphatidylcholine. High concentrations (56 to 87%) of linoleic acid occurred in cholesteryl esters for all diets despite low concentrations of linoleic acid in the tallow and coconut oil diets.     

木薯蚕蛹油中脂肪酸成分分析

采用气相色谱-质谱法(GC-MS)和气相色谱法(GC)分析木薯蚕蛹油中脂肪酸的组分及含量。通过GC-MS定性测定,木薯蚕蛹油中含有11种脂肪酸,通过面积归一法分析。各脂肪酸含量为α-亚麻酸43.41%,棕榈酸21.15%,油酸11.59%,亚油酸10.28%,硬脂酸8.08%,棕榈油酸1.88%,豆蔻酸0.93%,十五碳酸0.31%,反式6-油酸0.24%,月桂酸0.16%和9,10-甲基十九烷酸0.16%;通过GC定量测定,木薯蚕蛹油含α-亚麻酸57.63%,棕榈酸20.62%,油酸7.68%,亚油酸6.28%和硬脂酸3.38%。木薯蚕蛹中含有丰富的不饱和脂肪酸,特别是较多的α-亚麻酸。     

Fatty acid composition of caprine milk: major, branched-chain, and trans fatty acids.

The fatty acid composition of caprine milk fat was studied using capillary gas chromatography. Milk was obtained from five goat herds belonging to different breeders in the Murcia region (Spain) and collected monthly (from November to May). The results showed significant differences among herds mainly in long-chain fatty acids (C16:0, C18:0, and C18:2). There were five branched-chain fatty acids (iso- and anteiso-C15:0, iso- and anteiso-C17:0, and iso-C16:0) with > 0.1% of the total fatty acid methyl esters and another 31 (the most monomethylated) with < 0.1%, including 4-ethyloctanoate, which is implicated in goat-like flavors. To study the content of trans unsaturated fatty acids, the fatty acid methyl esters were previously fractionated by AgNO3-thin layer chromatography. The mean contents of trans-C16:1 and trans-C18:1 were 0.16 and 2.12%, respectively. The distribution profile of trans-C18:1 was also studied.     

光山县长林系列油茶良种茶籽脂肪含量和脂肪酸组成分析

从河南省林木品种审定委员会认定的适宜在本地区推广的长林系列品种中选出具有代表性的主栽油茶品种长林18号、40号、53号和配栽油茶品种长林166号,采用气相色谱-质谱法(GC-MS)对4个油茶品种茶籽仁中脂肪酸组成和含量进行分析,检验了其干籽出仁率和脂肪含量,并对脂肪含量及脂肪酸组分进行了相关性分析。结果表明:3个主栽品种与1个配栽品种干籽出仁率的差异达到了显著水平(p0.05),但不同品种茶籽脂肪含量差异不大;共检测到了17种脂肪酸组分,其中,茶籽仁中常量组分顺-油酸的含量26.25%～30.82%、棕榈酸的含量2.86%～3.22%、亚油酸的含量3.25%～3.86%。长林40号茶籽中饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸比值为1:6.08:1.05,最接近国际营养学家提出油脂中三类脂肪酸的最佳供能比1:6:1。相关性分析显示,脂肪含量与棕榈酸有一定的相关性,相关系数达到了0.64。结合河南省林木品种审定委员会的研究结论可得,长林40号油茶良种不仅产量高、抗性强,而且干籽出仁率高、含油量高,茶籽脂肪酸组成合理,综合性状优于其他三个品种。     

Effects of fat source and copper on unsaturation of blood and milk triacylglycerol fatty acids in Holstein and Jersey cows

Fatty acid composition of plasma triacylglycerides and milk fat was analyzed from Holstein and Jersey cows with control or depleted copper status and fed roasted whole soybeans or tallow. Conjugated linoleic acid in plasma was higher in Jersey cows. Dietary fat source influenced the proportions of all fatty acids in plasma and in milk, except for conjugated linoleic acid in milk. Feeding soybeans increased plasma C14:1, C18:0, C18:2, and conjugated linoleic acid, and decreased C14:0, C16:0, C16:1, and cis- and trans-C18:1 compared with feeding tallow. Low copper diets decreased C18:0 and increased cis- and trans-C18:1, and conjugated linoleic acid in plasma. A fat source x copper status interaction occurred for cis-C18:1 in plasma. Proportions of C4:0 to C14:0 were higher, and cis16:1, cis- and trans-C18:1, and conjugated linoleic acid were lower in milk fat of Jersey compared with Holstein cows. Generally, the effects of copper depletion were less apparent in milk than in plasma. Copper depletion increased C4:0, trans-C18:1, and conjugated linoleic acid, and decreased C16:1 in milk. Feeding whole soybeans increased C4:0 to C14:0, C18:0, C18:2, and C18:3, and decreased C14:1, C16:0, C16:1, and cis- and trans-C18:1 in milk. Breed x fat interactions occurred for C4:0, C14:1, C16:1, and conjugated linoleic acid in milk. Copper status x fat source interaction occurred for trans-C18:1. The breed x copper status interaction was apparent in milk fat for C16:1 and C18:0 and conjugated linoleic acid in milk. Both C18:0 and trans-C18:1 were desaturated by mammary tissue; however, whereas desaturation of C18:0 was linear, desaturation of trans-C18:1 reached a plateau that could have been caused by presence of the trans-10 isomer, which is not desaturated and was not separated from trans-11 C18:1 in our analysis. Comparison of the plasma triacylglycerol fatty acid profile with the milk fat profile was useful to interpret separate events of biohydrogenation in the rumen and desaturation by the mammary gland.     

南极大磷虾油脂的提取及其脂肪酸组成分析

通过单因素实验和正交实验对有机溶剂萃取南极大磷虾油脂的工艺参数进行了优化,并利用气相色谱分析了所提油脂的脂肪酸组成。研究结果表明无水乙醇为南极大磷虾油脂的最佳提取试剂,当提取温度为65℃,时间为3h,料液比为1:9(w:v)时,可获得最高提取率为19.60g/100g(干基)。气相分析发现南极大磷虾油脂中含有14种脂肪酸,其中不饱和脂肪酸占34.73%,饱和脂肪酸占65.26%;主要脂肪酸种类包括棕榈酸(29.3%)、二十二酸(20.1%)、油酸(13.7%)、十四酸(11.7%)、二十二碳六烯酸(10.2%)、十六烯酸(7.39%)、亚油酸(2.04%)。