德阳市市售植物油中反式脂肪酸含量调查

目的 了解德阳市市售植物油中反式脂肪酸的含量范围。方法 利用分层随机抽样抽取12类德阳市市售植物油共计121份样品,应用气相色谱法对样品中反式脂肪酸进行分离检测,采用归一化法进行结果计算。结果 德阳市市售植物油中12种反式脂肪酸的含量范围为未检出至3.19%,以反式亚麻酸（C18:3T）为主,其中橄榄油未检测出反式脂肪酸,最常见的菜籽油、玉米油、调和油、大豆油的反式脂肪酸平均含量分别为1.64%、2.20%、1.75%、2.58%。结论 德阳市市售植物油中普遍存在反式脂肪酸且含量各不相同。     

“坏”植物油——反式脂肪酸

吃植物油比吃动物油好,这已被大家认识,但是,并不是所有的植物油都对身体有益。在节日里,你也许刚品尝过美味的蛋糕、饼干、速溶咖啡,甚至快餐等,如果是这样的话,你可要注意了,自己是否摄取了太多的反式脂肪酸?反式脂肪酸是植物油经过人工氢化后产生的固体油脂,是脂肪家族中最坏的成员。     

中国市场食品中反式脂肪酸分析调查初探

目的:分析反式脂肪酸在常见食品中的含量,为消费者健康和相关管理法规的出台提供基础数据。材料:从各大超市选择可能含有反式脂肪酸的食品,共五大类约70种样品,详细登记食品标签上的信息后进行分析。方法:采用国家标准方法进行检测,并采用国际标准方法进行验证。结果:所选择的大部分样品中能检测到反式脂肪酸,氢化豆油中含量最高;休闲食品中各种"派"的反式脂肪酸含量较高,部分糖果、巧克力中也含有一定量的反式脂肪酸。结论:建议居民科学选择食物,并呼吁有关部门尽快出台限制食品反式脂肪酸的管理措施。     

远离反式脂肪酸,保护自己的健康

<正>反式脂肪酸的来龙去脉反式脂肪酸又称反式脂肪,它大量存在于氢化植物油中,氢化植物油作为许多食品专用油的基料,广泛用于做人造植物奶油、人造黄油、起酥油等。     

食品中反式脂肪酸的健康损害及研究进展

反式脂肪酸一般是植物油通过人工氢化之后,形成氢化植物油而得到的化学物.近年来对反式脂肪酸对健康的危害研究越来越多,同时存在一定的争议.本研究通过查阅相关资料和文献,对食品中反式脂肪酸的来源、检测方法及健康危害进行综述,为提高公众对TFA的了解程度合理膳食提供有益的参考.     

中国市售桶装植物油脂肪酸的研究

目的对市售桶装植物油中脂肪酸进行分析,探讨其组分及含量特点。通过植物油中各类脂肪酸比例的特点,分析脂肪酸特征。方法从北京、云南、浙江、湖南、河南、哈尔滨、江苏、甘肃8个地区,选取市场普遍销售的或各地自产的品牌桶装植物油,共计8个品种,每个样品采集2个不同批号。对植物油脂进行皂化和甲酯化后,利用岛津GC2014气相色谱仪对样品进行气相色谱分析。结果市售桶装植物油主要以棕榈酸、油酸、亚油酸和α-亚麻酸为主,反式脂肪酸的平均含量为1.05g/100g。植物油的饱和脂肪酸∶单不饱和脂肪酸∶多不饱和脂肪酸的比值范围为1∶1.6～9.4∶0.9～7.4;多不饱和脂肪酸中n-6/n-3的比值范围为0.37～289.5∶1。结论市售桶装植物油反式脂肪酸含量低,但脂肪酸组成比例大多不符合中国营养学会提出的标准,并且多数缺乏n-3多不饱和脂肪酸。     

过量食用反式脂肪酸危害宝宝健康

最近,一种叫反式脂肪酸的物质引起人们的高度关注。它存在于氢化植物油中,食用过多的反式脂肪酸会大大增加心血管、糖尿病、老年痴呆、肥胖和儿童生长发育疾病的风险。几乎所有的面包、蛋糕、饼干等烘焙类食品包装的配料表上,我们都能看到精炼植物油、人造奶油、食用氢化油、氢化植物油这些名称。     

傅立叶变换红外光谱法分析食品及油脂中反式脂肪酸

目的：采用傅立叶变换红外光谱法定性定量分析食品及油脂中反式脂肪酸含量。方法：食品中提取的脂肪或油脂样品直接置于红外光谱仪的水平衰减全反射（HATR）部件的槽式ZnSe晶体上,氘化三甘氨酸硫酸酯（DTGS）检测器检测。通过966 cm-1处反式双键的特征峰进行定性,由峰面积与反式脂肪酸含量的线性校准曲线定量计算反式脂肪酸在油脂中的百分含量。结果：该方法可通过反式双键的特征峰对样品油脂中的反式脂肪酸进行准确定量。结论：此方法具有简单、快速、准确的特点,适用于食品营养标签的测定。     

吃人造奶油悠着点

西餐来得快而简单,很受现代人,尤其是上班族的青睐,对儿童也有较大的吸引力。偶尔进食并无大碍,但是长期食用则会对健康构成一定的危害。因为在蛋糕、面包上常常涂有一层人造奶油或黄油。科学家们发现在人造奶油和经过氢化的色拉油中,含有一种对人体健康有害的物质,叫反式脂肪酸。 我们知道,通过氢化作用使植物油硬化即人造奶油,也就是说。将液态的不饱和脂肪通过加氢变成固态或半固态的油脂。但在这一氢化过程中可将自然产生的顺式脂肪酸转化成没有必需脂肪酸功能的反式脂肪酸。也就是说“氢化”     

反式脂肪酸

反式脂肪酸属植物脂肪,是经过加工、被氢化了的植物油。反式脂肪酸中最典型的代表就是人造奶油和人造黄油。因为反式脂肪酸较稳定、易保存,食品中添加了反式脂肪酸后,会增加食品口感,让食物变得更松脆美味,所以反式脂肪酸目前被广泛添加于食品中。长期以来,人们一直认为人造奶油和人造黄     

Trans fatty acids — Determination in food fats

Trans fatty acids are formed during the catalytic hydrogenation of animal and vegetable oils and occur naturally in dairy and ruminant tissue fats. Numerous studies have been made of the physiological effects of these acids.¹ Recently, the COMA report on “Diet and Cardiovascular Disease”² recommended the inclusion of a combined trans and saturated fatty acid contents in labelling of fatty foods. The analysis of trans fatty acids in widely differing food fats is by no means straightforward and the choice of analytical method needs careful consideration. Techniques including infrared spectroscopy, gas chromatography and argentation chromatography are described in this review. The infrared technique is the most suitable for labelling purposes, being rapid, simple, reproducible and applicable to all food fats including those containing hydrogenated fish oils. It is suggested that the IUPA C Official Method³ should be specified in any labelling regulations to ensure the reliability of the data and to facilitate comparison of figures produced by different laboratories.     

Trans fatty acids: are the effects only marginal?

In the process of converting vegetable oils into solid fats, a process known as partial hydrogenation, some unsaturated bonds are converted to an unnatural trans position. In humans, trans fatty acids increase low-density lipoprotein cholesterol and decrease high-density lipoprotein cholesterol. In addition, positive associations between intake of trans fatty acids and coronary heart disease have been observed in epidemiological studies. The combined results of metabolic and epidemiological studies provide strong evidence that trans fatty acid intake is causally related to risk of coronary disease. Because the consumption of partially hydrogenated fats is almost universal in the United States, the number of deaths attributable to such fats is likely to be substantial. Federal regulations should require manufacturers to include trans fatty acid content in food labels and should aim to greatly reduce or eliminate the use of partially hydrogenated vegetable fats.     

Acute postprandial effect of hydrogenated fish oil, palm oil and lard on plasma cholesterol, triacylglycerol and non-esterified fatty acid metabolism in normocholesterolaemic males

The majority of research has focused on the association between trans unsaturated fatty acids (TUFA) from hydrogenated vegetable oils and heart disease even though TUFA are also produced from hydrogenated fish oil. We compared the acute effect of three solid fats on postprandial cholesterol, triacylglycerol (TAG) and NEFA concentrations in normocholesterolaemic males. Eight healthy male volunteers consumed each of the three 40 g fat meals (partially hydrogenated fish oil (PHFO), palm oil and lard) in random order and blood samples were drawn at 2, 4, 6 and 8 h thereafter for lipid analysis. The postprandial response in plasma TAG, TAG-rich lipoprotein-TAG (TRL-TAG), total cholesterol and plasma NEFA, measured as the area under the postprandial curve, was not significantly different between the three meals (P>0.05), which varied in MUFA, PUFA and TUFA content. There was no marked elevation of longer-chain fatty acids (C20-22, cis or trans isomers) into the TRL-TAG fraction following the PHFO meal even though they provided 40 % of the total fatty acids in the PHFO meal. The postprandial TRL-TAG response to PHFO was expected to be higher, as it is higher in TUFA, lower in PUFA and similar in saturated fatty acid composition compared with the lard and palm oil test meals. The absence of a higher postprandial response following ingestion of PHFO could be as a result of reduced absorption and increased oxidation of long-chain fatty acids (both cis and trans isomers).     

Reassessment of trans fatty acid availability in the US diet

This report updates our 1984 estimate of the amount of trans fatty acids available for consumption in the US diet, namely 7.6 g.person-1.d-1, for 1989. Compared with 1984 data, we found essentially no change in 1989 for the per capita availability of trans fatty acids from total food service fats and oils. The 1989 value we obtained for industrial fats and oils is somewhat higher than the value we reported for 1984, in part because more complete data were available for 1989. In contrast, however, since 1984 the per capita availability of trans fatty acids from household salad and cooking oils, household shortenings, and all margarines and spreads (retail, food service, and industrial) has decreased. Overall, our reassessed (1989) value for total trans fatty acid availability is 8.1 g.person-1.d-1, which is similar to our original estimate. This total may increase slightly (approximately 0.3 g.person-1.d-1) as a result of the recent switch by many establishments from the use of tallow to partially hydrogenated vegetable oils for frying.     

Home use of margarine is an important determinant of plasma trans fatty acid status: a biomarker study

The contribution of the home use of margarines, made with partially hydrogenated vegetables oils, to total trans fatty acid intake is difficult to determine using dietary assessment because food composition databases are incomplete for trans fatty acids; moreover, hidden fats in manufactured foods may be the predominant sources of trans fatty acids. The objective of our study was to determine, using plasma phospholipid trans fatty acid composition as a surrogate measure of exposure, whether the home use of margarine or butter is an important determinant of trans fatty acid status. We conducted a community-based (Dunedin, New Zealand), cross-sectional survey of people who consumed either margarine (n 65) or butter (n 64) but not both for home use. The levels of the 18:1 trans isomers commonly found in partially hydrogenated vegetable oils were all significantly higher in the plasma phospholipids of margarine compared with butter consumers, with the exception of 18:1n-7t, which did not differ. Among margarine consumers, the percentage of total fat from margarine was significantly correlated with levels of phospholipid 18:1n-6t, 18:1n-8t and 18:1n-12/9t isomers (r 0.57-0.63, P<0.001) but only weakly with 18:1n-7t (r 0.30, P=0.016). The intake of fat from fast foods, bakery products or meat and meat products was not associated with plasma phospholipid trans isomeric composition. The home use of margarine, made with partially hydrogenated vegetable oils, is an important determinant of trans fatty acid exposure in New Zealand.     

Exchanging partially hydrogenated fat for palmitic acid in the diet increases LDL-cholesterol and endogenous cholesterol synthesis in normocholesterolemic women

Partial hydrogenation of oil results in fats containing unusual isomeric fatty acids characterized by cis and trans configurations. Hydrogenated fats containing trans fatty acids increase plasma total cholesterol (TC) and LDL-cholesterol while depressing HDL-cholesterol levels. Identifying the content of trans fatty acids by food labeling is overshadowed by a reluctance of health authorities to label saturates and trans fatty acids separately. Thus, it is pertinent to compare the effects of trans to saturated fatty acids using stable isotope methodology to establish if the mechanism of increase in TC and LDL-cholesterol is due to the increase in the rate of endogenous synthesis of cholesterol. Ten healthy normocholesterolemic female subjects consumed each of two diets containing approximately 30% of energy as fat for a fourweek period. One diet was high in palmitic acid (10.6% of energy) from palm olein and the other diet exchanged 5.6% of energy as partially hydrogenated fat for palmitic acid. This fat blend resulted in monounsaturated fatty acids decreasing by 4.9 % and polyunsaturated fats increasing by 2.7%. The hydrogenated fat diet treatment provided 3.1% of energy as elaidic acid. For each dietary treatment, the fractional synthesis rates for cholesterol were measured using deuterium-labeling procedures and blood samples were obtained for blood lipid and lipoprotein measurements. Subjects exhibited a higher total cholesterol and LDL-cholesterol level when consuming the diet containing trans fatty acids while also depressing the HDL-cholesterol level. Consuming the partially hydrogenated fat diet treatment increased the fractional synthesis rate of free cholesterol. Consumption of hydrogenated fats containing trans fatty acids in comparison to a mixtur e of palmitic and oleic acids increase plasma cholesterol levels apparently by increasing endogenous synthesis of cholesterol.     

Consumption pattern of dietary fats in Chile: n-6 and n-3 fatty acids

Chile consumes both vegetable and animal fats. Vegetable oils are almost totally imported but animal fats, mainly from marine origin, are locally produced. The country is the second world producer of fish meal and fish oil, and fish oil has been incorporated into the human nutrition through the manufacture of blends of vegetable oil with fractions of deodorized fish oil. Consumption of such oils contributes as a significant source of n-6 and n-3 fatty acids, mainly for the low-income consumers. The use of fish meal and fish oil for animal nutrition is also an additional source of n-3 fatty acids for the Chilean population. Pork, poultry and eggs are important sources of essential fatty acids, especially long-chain n-3 fatty acids. As result of the consumption of these products, milk from low-income Chilean mothers shows significantly higher total n-3 fatty acids relative to mothers from the USA and Germany. Safety concerns about fats consumption in Chile are regulated by a Food Safety Codex recently promulgated which follows FAO/WHO Codex Alimentarius directives.     

Role of trans fatty acids in health and challenges to their reduction in Indian foods

Evidence indicates that dietary trans fatty acids (TFA) obtained from partially hydrogenated vegetable oils (PHVO) increase the risk of coronary heart disease (CHD). Studies have implicated TFA in increasing the risk and incidence of diabetes. Furthermore, TFA may compromise fetal and early infant growth and development. In rats, partial substitution of either linoleic acid (18:2 n-6) with saturated fatty acids (SFA, 6 en %) or SFA with TFA (3 en % from vanaspati) decreased peripheral insulin sensitivity, but these effects were greater in TFA group. Since a large proportion of Indian population is insulin resistant, the TFA content in Indian edible fats/oils and foods should be reduced. Vanaspati (PHVO) provides up to 40% TFA, is used in Indian cooking and in the preparation of commercially fried, processed, bakery, ready-to-eat and street foods. TFA in biscuits and sweets range 30-40 and 6-26% of total fatty acids respectively. There is no regulation on TFA content in vanaspati, bakery fats and shortenings. Reduction in Indian edible fats/ oils and foods can be achieved by: a) specifying limits of TFA in vanaspati, bakery fats and shortenings by upgrading technology; b) advocating the substitution of natural plant oils containing lower percent of polyunsaturated fatty acids for PHVO. Indian edible oil industry needs to develop and adopt alternative technologies to produce zero TFA. Consumer education about negative health effects of TFA and providing food based guidelines to reduce TFA consumption in the entire population need to be actively pursued.     

Isomeric trans fatty acids in the U.S. diet.

Since actual consumption data for trans fatty acid (FA) intakes for the U.S. population do not exist, estimates of trans fatty acids (FAs) available in the U.S. food supply have been calculated from U.S. Department of Agriculture-Economic Research Service (USDA-ERS) fats and oils production figures and food disappearance data for fats and oils. Based on weighted averages for the trans levels in each fats and oils category, these estimates of trans FAs available in the U.S. food supply range from 12.5 to 15.2 g/person/day (average 13.3 +/- 1.1 g/person/day). Estimates of trans FA consumption have been calculated; these estimates predict a wide range from 1.6 to 38.7 g/person/day. These calculations are based on published estimates of trans FAs available in the total fat of 5-15%, and the total fat intake (range 31-258 g/person/day) of a representative sample of adults (ages 20-59) as determined by the Lipid Research Clinics (LRC). Using an equation based on a relationship between trans FAs in adipose tissue and dietary fat, an intake range of 0.7-28.7 g/person/day trans FAs for the same LRC fat consumption data can be predicted. Adipose tissue isomer profiles that indicate 90-95% of the trans FAs in the tissues comes from partially hydrogenated vegetable fats and oils allow us to predict a dietary intake range from 11.1 to 27.6 g/person/day trans FAs. The significance of these estimates to nutrition policy is discussed.