反式脂肪酸测定方法的研究

简要介绍了反式脂肪酸(TFA)的生成途径及主要的食物来源,反式脂肪酸对人体健康的主要危害和影响,综述了反式脂肪酸的分析检测方法如气相色谱法、红外光谱法、Ag离子色谱技术、毛细管电泳法等,并比较了各种方法的优缺点。     

傅立叶变换红外光谱法测定食品中反式脂肪酸

建立了一种食品中反式脂肪酸含量的测定方法,以酸水解法提取食品中脂肪酸,用傅立叶变换红外光谱仪对反式脂肪酸含量进行了快速测定,回收率达到89.26%~106.51%,相对标准偏差2.29%,结果重复性好,准确可靠。     

化学法测定脂肪酸酰胺含量的研究

脂肪酸酰胺 (油酸酰胺、芥酸酰胺、硬脂酸酰胺等 )是一类重要的精细化工产品 ,具有多种用途、以及广阔的市场 ,已在我国的纺织、塑料、油墨及涂料等行业推广使用 ,并且形成了一定的生产规模 ,产品质量也与国外产品相当。但现在还缺少产品的纯度 (含量 )的测定方法 ,为此 ,我们在有关单位的指导和帮助下 ,研究摸索出一种化学测定方法 ,现将归纳总结如下 :1　实验部分1 .1　不含氨的蒸馏水的制备1 .1 .1　蒸馏法　每升水中 0 .1ｍｌ硫酸 ,进行重蒸馏。接收馏出液于玻璃容器中。1 .1 .2　离子交换法　让蒸馏水通过强酸性阳离子交换树脂柱来制备…     

银杏叶中脂肪酸的含量及化学组成

银杏叶经石油醚（６０￣９０℃）提取,其软膏的收率为５．１％,其中游离脂肪酸的含量为２３．２％,该软膏经皂化,中和及萃取等处理,分离得到脂肪酸粗制品,其甲基化衍生物通过ＧＣ－ＭＳ鉴定其化学组成。     

反式脂肪酸的危害及其测定方法

在不饱和脂肪酸中,会因为双键位置不同而产生几何异构体。反式脂肪酸主要来源于氢化油脂。摄入反式脂肪酸能升高血清总胆固醇和LDL-C水平,降低HDL-C水平,可能导致心血管疾病。另外,摄入反式脂肪酸也能引起必需脂肪酸缺乏,糖尿病,影响新生儿生长发育。因此,需要通过改善人们的饮食结构、减少油脂氢化、精炼过程中反式脂肪酸的产生等措施来降低反式脂肪酸对人体健康的不利影响。本文以反式油酸为例,介绍了反式脂肪酸的性质、危害、测定方法。     

气相色谱法测定食品油脂中的十八碳反式脂肪酸

反式脂肪酸是在油脂的加氢反应或高温精炼过程中伴随产生的一类不饱和脂肪酸,过多的食用这些成分可能会对人体健康产生危害。食品油脂中以十八碳反式脂肪酸最为常见。采用气相色谱法对食品中十八碳反式脂肪酸的检测进行了实验摸索,获得了一套准确度高、精确度好的方法,可应用于日常监督检测。     

沙棘油中脂肪酸的气相色谱-质谱检测方法

对国标中脂肪酸的前处理方法做了优化,并利用气相色谱-质谱联用仪检测不同沙棘油样品中脂肪酸的组成与含量,作为鉴别沙棘油原料品质的依据.通过对10种沙棘油样品进行测试,结果表明,该方法变异系数在0.32％～4.1％,重复性好,可用于原料的鉴别检验分析.     

脂肪类复合相变储能材料中脂肪酸最佳质量含量的确定方法

为确定脂肪类复合相变储能材料中脂肪酸最佳质量含量,比较了目测逼近法、称重测量法和渗透直径百分比判定法3种方法,并以确定癸酸-肉豆蔻酸/膨胀石墨（CA-MA/EG）复合相变材料中癸酸-肉豆蔻酸的最佳质量含量为例,阐述了3种方法的使用及其特点。结果表明：目测逼近法操作简单,主要依靠经验与主观判断;渗透质量百分比判定法操作略显复杂,但科学严谨、结果精确;渗透直径百分比判定法可根据实际情况灵活设置判定标准,判定结果能准确反映复合相变材料的稳定性。     

高效液相色谱法测定妥尔油脂肪酸中松香酸含量

建立了高效液相色谱-紫外可见检测器法(HPLC-VWD)测定妥尔油脂肪酸中松香酸含量。通过实验确定较优分析方法,结果表明,此方法在5~500 mg/L范围内具有良好的线性(r=0.9999),平均加标回收率为99.3%,准度度高,重复性实验相对标准偏差(RSD)均小于1.0%,精密度良好。此方法可用于精确测定妥尔油脂肪酸中松香酸含量。     

气相色谱法测定五种食用植物油中的饱和脂肪酸

通过气相色谱法对市售五种食用植物油的饱和脂肪酸含量进行了测定,采用面积归一化法计算油中每种脂肪酸相对百分含量。结果表明,五种食用植物油饱和脂肪酸的平均含量方别为:花生油(17.7%),玉米油(14.6%),大豆油(15.6%),山茶油(9.6%),菜籽油(6.2%),棕榈酸和硬脂酸是五种食用植物油中最主要的饱和脂肪酸。饱和脂肪酸的过量摄入是导致肥胖等疾病的主要原因之一,因此对其在常用食用油中含量的研究具有较为深远的意义。     

Structural Determination and Occurrence in Ahiflower Oil of Stearidonic Acid Trans Fatty Acids

Several marine oils and seed oils on the market contain relevant quantities of stearidonic acid (18:4n‐3, SDA). The formation of 18:4n‐3 trans fatty acids (tFA) during the refining of these oils necessitates the development of a method for their quantification. In this study, 18:4n‐3 was isolated from Ahiflower and isomerized to obtain its 16 geometric isomers. The geometric isomers of 18:4n‐3 were isolated by silver ion HPLC (Ag⁺‐HPLC) and characterized by partial reduction with hydrazine followed by gas chromatography analysis. The elution order of all 16 isomers was established using a 100 m × 0.25 mm 100% poly(biscyanopropyl siloxane) capillary column and at the elution temperature of 180 °C. The 4 mono‐trans‐18:4n‐3 isomers produced during the refining of oils rich in 18:4n‐3 were chromatographically resolved from each other, but c6,t9,c12,c15‐18:4 coeluted with the tetra‐cis isomer. These 2 fatty acids (FA) were resolved by reducing the separation temperature to 150 °C, but this change caused tetra‐cis‐18:4n‐3 to coelute with t6,c9,c12,c15–18:4. Combining the results from 2 isothermal separations (180 and 150 °C) was necessary to quantify the 4 mono‐trans 18:4n‐3 FA in Ahiflower oil.     

几种食用油中不饱和脂肪酸和皂化值的测定研究

以茶籽油、玉米油、橄榄油、芝麻油、花生油为原料,利用容量分析方法测定其不饱和脂肪酸含量及皂化值.经碘酊法测定,这5种食油用的不饱和脂肪酸含量(以碘值衡量)最高的为茶籽油,达95.46g·(100g)-1,碘值最低的为花生油54.67g·( 100g)-1.这5种植物油碘值由大至小依次为:茶籽油＞玉米油＞橄榄油＞芝麻油＞...     

Evaluation of Trans and Essential Fatty Acid Content in Some Egyptian Consumer-Available Hydrogenated Fats

The fatty acid composition of cottonseed and com oils was determined before and after the technological hydrogenation process. In hydrogenated cottonseed and corn oils the essential fatty acid content (linoleic, 18:2 ω⁶) was decreased while the trans-18:1 acid was increased as compared to the native oils. The trans as well as the essential fatty acid contents in some consumeravailable hydrogenated fats were evaluated. The composition of cis and trans monoene isomers were also determined. This study revealed that some of the Egyptian consumer-available hydrogenated fats contain considerable amounts of trans acids.     

高效液相色谱法测定化妆品中5种α-羟基酸

样品用水超声提取20 min,离心、过滤,以Agilent ZORBAX-C8分析柱分离分析,二级管阵列检测器检测,结合保留时间和光谱定性分析,外标法定量.5种α-羟基酸在100～1000 mg/L浓度范围内线性关系良好,相关系数R＞0.9998.这5种α-羟基酸在200和500 mg/L添加水平下的回收率在95.7％～110.0％之间,相对标准偏差(RSD)小于1.5％(n=6).方法中酒石酸、乙醇酸、R-苹果酸、乳酸、柠檬酸、L-苹果酸的检出限分别为4.6、16.1、13.3、23.8、19.7和38.7 mg/kg.结果表明,该方法适用于化妆品中5种α-羟基酸含量的检测.     

Determination of Oil Content and Fatty Acid Composition of Sesame Mutants Suited for Intensive Management Conditions

Sesame mutants with closed capsules, determinate growth habit and wilt resistance, have been proposed to be suitable for intensive management conditions facilitating mechanized harvesting. The objective of our experiment was to determine the oil content and fatty acid composition of these mutants before they are placed on the market. Oil content and fatty acids were studied in 19 mutants, 6 breeding lines and 4 control source genotypes. The oil contents of the seeds ranged from 46.4 to 62.7%. The mutants had generally a lower oil content than the control genotypes except the wilting tolerant group. For unsaturated fatty acids, oleic acid was higher in the mutants and breeding lines while linoleic acid was lower in the seed oil. However, no mutants or breeding lines were found with radically different composition or with any undesirable lipid component. The closed capsule and determinate growth habit mutants need to be improved for oil content while their fatty acid composition is fine.     

Oil Content and Fatty Acid Composition in Seeds of Three Safflower Species

Seeds of six safflower (C. tinctorius L.) genotypes and 19 accessions of two wild species were analyzed for oil and fatty acid composition. Oil content ranged from 29.20 to 34.00, 20.04 to 30.80 and 15.30 to 20.80% in C. tinctorius, C. oxyacantha Bieb. and C. lanatus L., respectively. The main fatty acids of oleic, linoleic, palmitic and stearic acids composed 96–99% of the total fatty acids in all species. The sum of myristic, palmitoleic, arachidic, and behenic fatty acids in oil of the species ranged from 0.43 to 0.57%. The oleic acid in seed oil of C. tinctorius, C. oxyacantha and C. lanatus ranged from 12.24 to 15.43, 14.11 to 19.28 and 16.70 to 19.77%, respectively. The corresponding ranges for linoleic acid were 71.05 to 76.12, 63.90 to 75.43 and 62.47 to 71.08%. Palmitic acid in seed oil varied from 5.48 to 7.59% in C. tinctorius, 6.09 to 8.33% in C. oxyacantha and 7.44 to 8.78% in C. lanatus. The stearic acid of the seed oil showed a variation of 1.72 to 2.86, 2.50 to 4.87 and 3.14 to 4.79% in genotypes of these species, respectively. The fatty acids composition of oil among the cultivated and wild species were not considerably different, indicating that seed oil of the wild safflower is possibly suitable for human consumption and industrial purposes.     

Oil Content,Oil Yield and Fatty Acid Profile of Groundnut Germplasm in Mediterranean Climates

A high amount of good-quality vegetable oil in seeds has an overwhelming contribution to the groundnut (Arachis hypogaea L.) cultivation throughout the world. In order to take into account great variation in oil characteristics in Arachis subspecies and botanical varieties, 256 groundnut genotypes including ICRISAT’s mini core collection were investigated. Significant variability in oil content (31.7–57.0%) was detected among groundnut genotypes. Oil yield varied from 9.5 to 179.3 kg da^?1 with the average being 67.7 kg da^?1. Significant genotypic differences were also observed for all the fatty acids studied. Oleic and linoleic acids accounted for the major fraction with mean values of 45.3 and 32.1% in the ranges of 35.3–60.9% and 16.1–43.6%, respectively. Significant negative correlation was observed between oleic and linoleic acid. In the present investigation, desirable values were obtained for oil traits which would be useful to develop nutritional and health-beneficial cultivars.