中国居民膳食中原料食物的各种反式脂肪酸的调研

通过本实验室建立的Ag+-TLC/GC连用技术测定我国日常膳食组成的原料食物中反式脂肪酸(TFAs)含量。测定结果表明我国食物中普遍存在反式脂肪酸,9t C18:1、10t-C18:1、11t C18:1和9t12t C18:2是其存在的主要形式。反刍动物产品中存在较高的9t C16:1、t C18:1和9t12t C18:2等各种反式脂肪酸(仅羊肉中未检出9t12t C18:2),且均以t C18:1为主,其中奶粉、奶油、鲜牛奶和酸奶等奶制品中含量最高的反式脂肪酸异构体均为11t C18:1。羊肉中9t C18:1、10t C18:1和11t C18:1的含量比较均衡,其它反刍动物产品中12t C18:1、13/14t C18:1、15t C18:1、16t C18:1的总量达到总反式脂肪酸含量的(25.9±1.8)%。坚果类食品中,TFA主要为t C18:1和9t12t C18:2,且9t12t C18:2含量约为总TFAs的10%。其它原料食物,如水果、蔬菜、畜禽肉、鱼虾及腌菜中TFAs含量极低。     

7类食品中反式脂肪酸含量的调查

对采集的7类76种食品中的反式脂肪酸(TFAS)异构体构成及其含量进行调查。采用气相色谱内标法测定反式脂肪酸(TFAS)含量。结果表明:68%样品中的TFAS含量≤0.3 g/100 g,29%样品的TFAS含量在0.3～2.0 g/100 g,只有3%样品的TFAS含量>2 g/100 g。除锅巴和膨化食品外,被检食品中的TFAS异构体的组成主要是以C18∶1t为主,其C18∶1 t总量占总TFAS含量的60%～96%,说明反式脂肪酸(TFAS)广泛存在于被检的各类食品中,除含人造奶油、代可可脂高的少数食品外,绝大多数食品中的TFAS含量水平不高。     

食品中17种反式脂肪酸的气相色谱测定方法

本文建立了适合食品中反式脂肪酸(Trans Fatty Acids,TFAs)的检测方法,并采集典型样品对其中的反式脂肪酸的含量进行测定,以了解其中的TFAs水平。加入内标物的试样(油脂试样除外)经水解-乙醚溶液提取其中的脂肪后,在碱性条件下皂化和甲酯化,生成脂肪酸甲酯,经毛细管气相色谱分析,内标法定量计算。结果表明,本研究条件下的反式脂肪酸甲酯能够有较好的分离,线性良好,线性相关系数R2均大于0.99。所采集的样品中有不同含量水平的反式脂肪酸,主要包括以下几类t C14∶1、t C15∶1、t C16∶1、t C18∶1、t C18∶2,根据样品类别的不同所含有的反式脂肪酸的类别也有所差异。     

上海市15岁及以上居民膳食反式脂肪酸摄入量及其风险评估

目的 了解上海市常见市售食品中反式脂肪酸（TFAs）含量，评估上海15岁及以上居民膳食TFAs的摄入水平及其潜在健康风险。方法 在本市超市、农贸市场、餐饮店等采样点采集11大类664份食品样品，采用《食品安全国家标准 食品中反式脂肪酸的测定》（GB 5009.257—2016）检测TFAs含量。结合“2013年上海市居民膳食与健康状况监测”消费量数据，采用简单分布模型（确定性评估）方法，计算每个个体每日TFAs摄入量及其供能比。结果 在各类食品中，植物油中TFAs平均含量最高，达0.7 g/100 g，乳及乳制品中TFAs平均含量次之，为0.67 g/100 g，牛羊肉及其制品中的TFAs平均含量也较高，为0.51 g/100 g。上海市15岁及以上人群TFAs平均摄入量为0.34 g/d，平均供能比为0.18%，远低于WHO的建议水平（1%）。从个体TFAs供能比在人群中的分布来看，大部分居民供能比在0.1%~0.3%范围内，最大值为0.68%。从不同类食品对TFAs摄入的贡献率来看，加工食品占总摄入水平的75.16%，其中植物油贡献率最高，约占51.58%。结论 植物油是上海市15岁及以上居民膳食TFAs的最主要来源；上海市15岁及以上人群膳食摄入TFAs的健康风险很低。     

气相色谱法测定焙烤食品中反式脂肪酸含量

反式脂肪酸是一种具有反式构型的不饱和脂肪酸,摄入量过多会对人体健康造成一系列不良影响。采用气相色谱法测定、内标法定量,对面包、饼干、蛋糕等11种市售常见焙烤食品中的反式脂肪酸含量进行测定分析。试验结果表明,13种反式脂肪酸甲酯异构体的分离良好,11种样品中反式脂肪酸含量为0.10%～2.81%,其中丹麦小牛角面包最高,为2.81%;若以占脂肪的比例计,则反式脂肪酸含量为1.18%～10.75%,其中以trans C18∶1为主要的反式脂肪酸,占所测总反式脂肪酸含量的46.59%～80.65%。     

婴幼儿配方谷粉中多组分反式脂肪酸的同步测定

建立多组分反式脂肪酸同步测定方法,并对38批市售婴幼儿配方谷粉中各组分反式脂肪酸(TFAs)的含量进行测定。结果显示:婴幼儿配方谷粉样品中TFAs平均含量为0.749 3mg/g,总体含量较低,约76.3%的样品中TFAs总含量在0.04~1.0 mg/g,主要组分为C_(18:1-11T),C_(19:1-7T),C_(18:3-9T,12T,15T),C_(18:1-9T)和C_(18:2-9,12TT),经分析配料配方与加工工艺是影响婴幼儿配方谷粉中TFAs含量的2个主要因素。     

Ag+-SPE／GC测定食物中trans C16：1，trans C18：1，trans C18：2和共轭亚油酸的含量

为研究不同来源的反式脂肪酸(TFAs)对人体健康的影响,本文拟调查食物中trans C_(16:1),trans C_(18:1),trans C_(18:2)和共轭亚油酸(CLA)异构体的组成和含量,为明确不同食物中TFAs和CLA与健康的关系提供科学理论依据。结合银离子固相萃取柱(Ag~+-SPE)和GC色谱2种升温程序测定反刍动物油脂、食用油和煎炸油中trans C_(16:1),trans C_(18:1),trans C_(18:2)和CLA异构体的含量。结果显示,从样品中共检测出23种TFAs,其中7种trans C_(16:1),10种trans C_(18:1),6种trans C_(18:2)和6种CLA异构体。反刍动物油脂中trans C_(16:1), trans C_(18:1)和CLA显著高于食用油和煎炸油,而煎炸油中trans C_(18:2)含量较高。反刍动物油脂中9t C_(16:1),11t C_(18:1),9t12t C_(18:2)是主要TFAs异构体,10t12c C_(18:2)是主要的CLA异构体;而食用油和煎炸油中12t C_(16:1),9t C_(18:1),9c12t C_(18:2),9t12c C_(18:2)为主要的TFAs异构体,10t12c C_(18:2)和11c13t C_(18:2)是CLA的主要异构体。通过食用油煎炸前、后脂肪酸的对比发现,茶籽油脂肪酸组成变化最小,而大部分煎炸油比未煎炸油中trans C_(18:2),trans C_(18:1)的含量显著增加。可见,反刍动物油脂和食用油、煎炸油中主要TFAs异构体不同,而不同异构体脂肪酸对人体健康影响不同。茶籽油煎炸前后脂肪酸组成变化较小,食用中适合煎炸;而富含多不饱和脂肪酸的食用油经煎炸后会产生较多的对人体健康存在更大隐患的trans C_(18:2),因此对煎炸油品质的控制应引起有关生产和使用企业的高度重视。     

中国市售食品中反式脂肪酸含量的现状研究

采用气相色谱和红外光谱相结合的方法,对2005年至2009年在中国市场上出售的52个著名品牌的167种食品中所含脂肪组成与反式脂肪酸(TFAs)含量进行了测定。检测结果表明,87%的被检食品中含有反式脂肪酸,其中,涂抹奶油、威化饼干、蛋糕、派类食品是反式脂肪酸(TFAs)含量较高的食品类别。"洋快餐"的套餐中,反式脂肪酸(TFAs)含量每份1.00～2.00g。包括"洋快餐"食品在内的许多食品标签中,有关脂肪含量的标注存在严重缺陷。加工食品的配方标识中,有关"部分氢化油"和反式脂肪酸(TFAs)的标注名称没有统一的标准。     

乳中C18:1反式脂肪酸的色谱保留时间规律与质谱特征研究

用高速离心提取乳中脂肪,经两步甲酯化后,采用100m长CP-Sil 88 FAME毛细管柱、程序升温,GC/MS法测定.研究了反式C18∶ 1长链脂肪酸的反式异构体气相色谱出峰顺序,得到其保留时间规律;研究了C18∶ 1反式脂肪酸的质谱断裂规律,选择3个特征离子来鉴定脂肪酸成分.本方法分离效果好,操作简便、快速,结果可靠,适用于测定乳中反式C18∶ 1脂肪酸异构体含量.     

银离子固相萃取法测定反刍动物反式脂肪酸异构体含量

利用氨丙基硅胶柱从反刍动物脂质中分离甘油三酯和磷脂,以氢化大豆油作为对照。采用银离子固相萃取柱分离甘油三酯和磷脂中反式脂肪酸异构体,气相色谱仪测定反式脂肪酸含量。结果显示:在3种反刍动物脂质中检测出trans-16:1,trans-18:1和trans18:2 3类反式脂肪酸,其中总脂质和甘油三酯总反式脂肪酸含量最高的是羊肉脂质,分别占总脂肪酸的7.64%和7.38%;磷脂中总反式脂肪酸最高的是牛肉脂质,占总脂肪酸的5.89%。银离子固相萃取柱能够从反刍动物脂质中分离出9种trans18:1异构体,其中含量最高的是11t18:1,分别为总脂质、甘油三酯和磷脂trans18:1的30.33%~39.03%,38.08%~45.09%和27.10%~44.47%。通过PLS-DA分析3种反刍动物反式脂肪酸异构体之间的差异,羊肉脂质中甘油三酯中的9t18:1和磷脂中的11t18:1含量均显著高于牛奶脂质和牛肉脂质(P<0.05);牛肉脂质中磷脂中的9t18:1和15t18:1含量均显著高于牛奶脂质和羊肉脂质(P<0.05);牛奶脂质磷脂中的12t18:1和16t18:1的含量均显著高于牛肉脂质和羊肉脂质(P<0.05)。反刍动物磷脂中的反式脂肪酸异构体有较大差异。     

Assessment of Trans Fatty Acids Content in Popular Western‐Style Products in China

ABSTRACT: To date, the published information on trans fatty acids (TFAs) in food products in China remains scarce and of questionable accuracy. Systematic approaches to educate the consumers and to ensure proper labeling of TFAs are among the many urgent challenges the regulatory agencies in this rapidly growing country have to face. In the present study, 97 most popular, national brand food products on the Chinese market, including 6 cheeses, 10 chocolates, 10 crisps, chips, and fries, 10 ice creams, 15 margarines, 10 pies and cakes, 8 sauces and dressings, 19 wafers and biscuits, and 9 Chinese‐style snacks, were assayed to profile their fat content and fatty acid composition, particularly the TFAs. The highest level of TFAs, up to 30.9% of total fatty acids, were found in pies. The average TFAs contents in different product categories, ranging from high to low, were: pie and cake (12.07%), cheese (6.95%), margarine (5.09%), wafer and biscuit (4.35%), ice cream (2.67%), sauce and dressing (2.65%), crisps, chips, and fries (2.15%), chocolate (1.44%), and Chinese‐style snacks (0.83%). One hundred percent of cheese contained TFAs, so did pie and cake, followed by crisps, chips, and fries (90%), sauce and dressing (88%), ice cream and margarine (80%), chocolate (60%), wafer and biscuit (53%), then Chinese‐style snacks (33%). Profiling of key TFAs constituents could yield information characteristic to the types of partially hydrogenated oils employed, which is a critical step towards product reformulation in order to reduce or eliminate TFAs in the products.     

番茄红素油树脂中脂肪酸组成的分析

番茄红素油树脂是以番茄皮渣为原料、以非极性溶剂为介质来进行抽提而得到的油溶性成分的混合物,其中除含有番茄红素外,还含有一定数量油脂及脂肪酸,维生素E、甾醇及磷脂等类脂性成分.本研究通过对皂化后所得脂肪酸经AMP衍生化所产生衍生产物的GC／MS法,对其中的脂肪酸组成及其含量进行了分析.结果表明,番茄红素油树脂中脂肪酸组成包括14∶0,16∶0,18∶0,18∶1,18∶2,18∶3等几种,以饱和脂肪酸为主,约占脂肪酸总量的75%,而不饱和脂肪酸仅占25%,并且所有脂肪酸的碳链均较短.     

C18 : 1, C18 : 2 and C18 : 3 trans and cis fatty acid isomers including conjugated cis δ9,trans δ11 linoleic acid (CLA) as well as total fat composition of German human milk lipids

In particular with respect to infant nutrition knowledge of the current contents of trans fatty acids (TFA) and of conjugated linoleic acid (CLA) in human milk lipids is of interest. After pre-separation by Ag-TLC 11 trans-C18 : 1 isomers could be quantified by GC with a mean total content of 2.40 ± 0.60 wt% in samples from 40 German women. For the positional isomers t4, t5, t6–8, t9, t10, t11, t12, t13, t14, t15 and t16 contents of 0.02, 0.02, 0.21, 0.37, 0.32, 0.68, 0.23, 0.15, 0.18, 0.09 and 0.14 wt% were established, with vaccenic acid being the predominant isomer. Further, small trans-C14 : 1 and trans-C16 : 1 contents of 0.08% and 0.15% on average were found. As the trans-C18 : 1 isomers also the trans-C16 : 1 isomers of human milk lipids could for the first time be baseline-resolved by GC to a great extent. Moreover, besides a mean CLA (c9,t11) content of 0.40 ± 0.09% further 6 cis/trans isomers of linoleic acid with a total content of 1.07 ± 0.56% on average (w/o CLA) were determined. Further, 4 trans isomers of α-linolenic acid could be baseline-resolved exhibiting a total content of 0.11%. Altogether German human milk lipids on average were found to contain 3.81 ± 0.97% TFA with a range of 2.38–6.03%. Direct connections between the dietary intake of trans-C18 : 1 isomers and the composition of human milk lipids could be established. The major fatty acids exhibited the following contents (wt%): C4: 0.16, C6: 0.18, C8: 0.06, C10: 0.58, C12: 3.12, C14: 6.43, C16: 25.28, C18: 7.41, C18 : 1 (total): 33.67, C18 : 2 (total): 10.63 and α-C18 : 3: 0.87.     

反式脂肪酸红外光谱和气相色谱分析

用傅立叶转换红外光谱测定好丽友·派、乐思人造奶油和法国百吉福天天奶酪样品反式脂肪酸含量,分别为30．9%、13．2%和7．9%；费列罗榛果威化果仁巧克力样品未检测出反式脂肪酸含量。用Agilent 112-88A7HP-88毛细管柱分析样品中脂肪酸组成和含量,顺、反式脂肪酸分离良好,检出限为9．8μm/mL,线性γ值为0．9992,加标回收率为89．54%～102．85%,相对标准偏差(RSD)为0．92%～1．46%；测得好丽友·派、乐思人造奶油和法国百吉福天天奶酪样品中十八碳反式单烯酸含量分别为20．70%、8．72%和3．98%,约占总反式脂肪酸量50%～60%。     

Trans fatty acids content and fatty acid profiles in the selected food products from Korea between 2005 and 2008

Since a high intake of trans fatty acids (TFA) has been associated with the increased risk of developing cardiovascular disease, food regulation worldwide has been amended with respect to nutrition labeling and health claims on TFA. In the present study, the TFA levels of Korean food products were investigated to assess the regulation effect of TFA labeling. Same Korean food products within 7 different categories were purchased in years 2005 and 2008, and the contents of TFA and lipid and fatty acid composition were investigated. Lipid and TFA contents decreased in all food products manufactured in 2008. TFA levels were 0.01 to 6.88 g/100 g food in 2005, but the levels remarkably decreased to nondetectable level or up to 0.5 g TFA/100 g food in 2008. The foods from 2005 contained a various level of TFA ranging 0.6% to 44.6% of total fatty acids; however, the TFA level significantly decreased in most foods up to 3.8% from year 2008. For TFAs, trans C18:1 levels were greater than trans isomers of C18:2, and the levels in 2005 were significantly reduced in 2008 (P < 0.05). TFA levels at the sn-2 position were up to 48.3% of total fatty acids in 2005, but the level considerably decreased up to 5.4% in 2008. The considerably decreased content of TFA in 2008 suggested that food manufacturers recognized the adverse effect of TFA on human health and followed the compulsory trans fat labeling rule by Korean Food and Drug Administration (KFDA), which started December 2007.     

Formulation of Corn-Based Snacks with High Nutritive Value: Biological and Sensory Evaluation

Three composite flours were formulated by linear-programming using corn, chickpea, soybean-meal and methionine to meet the FAO/WHO pattern for lysine and sulfur amino acids. Fried snack foods were manufactured with these flours. The experimental products showed higher protein contents (18.11, 15.69, 13.16%) than a commercial corn snack used as control (7.14%). PER values of experimental snacks (2.69, 2.65, 2.54) were not statistically different from that of casein (2.77) (p>0.05). Two of the formulated products (15.69% and 13.16% protein) showed no significant differences from the control with respect to typical odor and flavor, texture and acceptability (p>0.05). These nutritionally-improved products represent a good alternative to commercially available corn-based snacks.     

Formation of trans fatty acids in edible oils during the frying and heating process

To assess an impact of heated edible oils on intake of trans fat, the formations of trans fatty acids (TFAs) in cooking conditions was estimated by a frying and heating model system. For the frying model, sliced raw potatoes (10% of the frying oil (w/w)) were fried in commercially available canola oil at 160, 180 and 200 °C, and the 10 frying cycles were performed. The TFAs contained both in fried potatoes and in frying oils were measured by gas chromatography (GC). Lipids content of raw potatoes was about 0.1% (w/w) and TFAs in the raw potatoes were negligible. On the other hand, fried potatoes contained lipids at the level of 8.8%–9.2% and their fatty acid composition was mostly in correspondence with that of the frying oil. The TFAs amount of potatoes fried by the tenth frying operation was at the level of 0.99–1.05 g/100 g lipids. When 100 g potatoes fried in this process were consumed, the TFAs intake was estimated at less than 0.1 g. After 10 frying operations, TFAs content, acid values and peroxide values of the frying oils were measured and compared with those of corresponding heated canola oils without food. The amounts of trans 18:1 FAs contained both in the frying oil and in heated oil were less than the quantitative limit (0.047 g/100 g oil). The increases of trans 18:2 FAs and trans 18:3 FAs of the used frying oil were 0.02 g/100 and 0.05 g/100 g, respectively, compared with those of the fresh oil. trans 18:2 FAs accumulation in the heated oil was slightly less than that in the frying oil. To elucidate TFAs accumulation in various edible oils during cooking, six kinds of commercially available edible vegetable oils were heated to 180 °C in glass test tubes. Small changes in TFAs amounts were observed after four hours heating. These results suggested that an ordinary frying process using unhydrogenated edible oils has little impact on TFAs intake from edible oils.     

沙棘果油脂肪酸与微量元素测定

该文测定了沙棘果油中脂肪酸与8种微量元素。沙棘果油由亚临界流体萃取而得,经脂肪皂化和脂肪酸甲酯化,气相色谱-质谱联用法测定脂肪酸,内标法定量;在浓HNO 3中经微波消解,电感耦合等离子体原子发射光谱法测定微量元素,外标法定量。共检测到19种脂肪酸,其中饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸百分比含量分别为24.42%、47.26%和28.31%,C16∶0、C16∶1、C18∶1、C18∶2、C18∶3含量较高,分别为39.71、44.29、48.15、35.25和35.25 mg/g。试样中K、Na、Ca、Mg、Cu、Zn、Fe和Mn的检测限分别为0.5、0.25、0.125、0.1、0.1、0.1、0.2和0.4μg/g,各元素的平均回收率为85.0%~94.4%,相对标准偏差(relative standard deviation,RSD)为3.28%~9.23%(RSD<10%)。沙棘果油中Na、Ca、K、Mg、Fe、Zn含量较高,分别为149.28、65.29、41.08、21.27、14.43和4.71μg/g。沙棘果油中不饱和脂肪酸与人体所需微量元素含量较高,具有很高的营养价值,该研究结果为沙棘的进一步开发利用提供了基础数据。