不同煎炸食材对米糠油煎炸品质影响的研究

利用米糠油对不同煎炸食材进行间歇性煎炸,通过对煎炸油色泽、酸值、羰基值、脂肪酸组成、反式脂肪酸含量、维生素E含量的检测分析,对比研究植物淀粉基食材(薯条)、高含水量食材(豆腐)、肉类食材(鸡翅)、面粉基食材(油条)4种代表性煎炸食材对煎炸油品质的影响。结果表明:不同煎炸食材因所含主要组分的不同,对煎炸油品质劣变呈现出不同程度的影响;煎炸油酸值增大程度依次为豆腐鸡翅油条薯条;羰基值增大程度依次为油条薯条豆腐鸡翅;总反式脂肪酸增大程度依次为油条鸡翅薯条=豆腐;维生素E含量降低程度依次为薯条油条鸡翅豆腐。     

煎炸油在煎炸过程中脂肪酸组成的变化

以大豆油、棉籽油、棕榈液油和氢化油作为煎炸油,分别进行薯条和鸡翅的煎炸实验。结果表明：在煎炸过程中,各种煎炸油的脂肪酸含量均会发生一定的变化。采用C18:2/C16:0比值变化作为研究煎炸油脂肪劣变的指标,氢化油煎炸过程中C18:2/C16:0比值减少的程度最小(P＜0.05),证明其煎炸过程中脂肪酸的稳定性最好。但对于反式脂肪酸含量变化来说,均没有显著增加(P＞0.05),其中氢化油的反式脂肪酸含量从煎炸前的10.39%降低到煎炸后的6.66%,变化显著(P＜0.05),不过高反式脂肪酸含量的煎炸油在煎炸后其反式脂肪酸含量还保持在较高水平。     

煎炸不同食材的花生油中极性组分与氧化甘三酯聚合物含量的相关性研究

利用花生油分别对油条、薯条、鸡翅、豆腐4种食材进行32 h连续煎炸,对每隔2 h所取煎炸油样进行极性组分、氧化甘三酯聚合物含量的检测,并与不加任何食材的空白煎炸油脂进行对比,分析研究花生油连续煎炸不同食材过程中极性组分、氧化甘三酯聚合物及其他指标的综合变化。结果表明:随煎炸时间的延长,煎炸油中极性组分、氧化甘三酯聚合物含量升高,煎炸油酸值升高、色泽加深,反式脂肪酸含量升高,经32 h连续深度煎炸,油条、薯条、鸡翅、豆腐、空白5种煎炸油中极性组分从初始的3.34%分别增至32.98%、30.61%、15.50%、29%、47.02%,其中油条、薯条、鸡翅、空白煎炸油中极性组分含量分别在32、24、30、16 h时超出27%的国标限量。氧化甘油三酯聚合物含量从初始的0.43%分别增至18.97%、23.68%、6.52%、16.92%、38.83%。煎炸油中极性组分与氧化甘油三酯聚合物含量间存在极显著的线性相关(P0.01),R2分别为0.996 4、0.993 7、0.9972、0.974 0、0.991 2。经32 h连续煎炸,5种煎炸油的酸值从初始的0.17 (mgKOH/g)的分别增至7.15、2.24、2.39、2.75、2.18(mg KOH/g);反式酸含量从初始的0.17%增加至0.34%、0.28%、0.39%、0.38%、3.54%。     

油脂对油炸食品中反式脂肪酸含量的影响

目的:研究花生油、大豆油、菜籽油、24°棕榈油以及42°棕榈油5种油脂连续油炸薯条、油条和鸡块后,对油炸食品中反式脂肪酸含量的影响,从而为油炸食品工艺的选择提供实验依据。方法:采用5种油脂连续油炸薯条(176℃、2 min、45 s)、油条(176℃、2 min、30 s)和鸡块(176℃,3 min)5 d,并采用气相色谱法分析不同油脂对油炸食品中反式脂肪酸含量的影响。结果:使用不同种类油脂油炸的薯条、油条和鸡块均产生反式脂肪酸,其中,菜籽油煎炸的薯条和油条中反式脂肪酸最多,为38.74 mg/100 g和37.51 mg/100 g,棕榈油煎炸的油炸食品中反式脂肪酸含量最少,薯条为4.98 mg/100 g、油条为6.01 mg/100 g、鸡块为4.36 mg/100 g。结论:为使食品加工所产生的反式脂肪酸最少,应选用稳定性较好的42°棕榈油。     

不同油脂对油炸食品中苯并(a)芘含量的影响

以薯条、油条和鸡块为研究对象,探究花生油、大豆油、菜籽油、24°棕榈油、42°棕榈油5种煎炸油对油炸食品中苯并(a)芘含量的影响,以期在今后的油炸烹饪过程中控制油炸食品中苯并(a)芘的含量。采用5种煎炸油176℃油炸薯条(165 s)、油条(150 s)和鸡块(210 s),并用液相色谱法分析不同油脂对油炸食品中苯并(a)芘含量的影响。结果表明:随煎炸批次的增加,不同油脂煎炸食品中苯并(a)芘含量也逐渐增加。花生油煎炸的食品中苯并(a)芘含量最高,薯条为1.64μg/kg,油条为1.73μg/kg,鸡块为1.15μg/kg;42°棕榈油煎炸的食品中苯并(a)芘含量最低,薯条为0.04μg/kg,油条为0.10μg/kg,鸡块为0.05μg/kg。综上所述,42°棕榈油煎炸的食品中苯并(a)芘含量较低,煎炸稳定性较好。     

快餐煎炸对油脂中3-氯丙醇酯(3-MCPD)以及缩水甘油(GEs)的影响

以起酥油作为煎炸用油,模拟西式快餐模式最典型的食品(薯条与鸡翅)进行煎炸,探究在煎炸过程中3-氯丙醇(3-MCPD)酯及缩水甘油酯(GEs)的变化规律,并对市售产品进行分析。结果表明：在薯条煎炸体系中：油脂3-MCPD前期急速下降,降解至一定量后趋于稳定,GEs含量呈现持续下降的变化规律;在鸡翅煎炸体系中：油脂3-MCPD与GEs含量都呈现出前期急速下降后期缓慢下降的特点。通过相关性分析得到油脂品质极性物质(Total polar compounds, TPC)、AV(Acid value, AV)与3-MCPD、GEs之间呈现出显著负相关的关系。后期收集市售起酥油产品及煎炸食品分析脂肪酸组成发现市面上的西式快餐门店以起酥油煎炸为主。同时对60个不同批次的鸡翅薯条样品中提取的油脂进行分析,3-MCPD在0.5～1.5 mg/kg的范围内呈正态分布,分布的顶峰位于0.75～1.0 mg/kg范围内;而GEs在0.1～2.5 mg/kg的范围内呈偏正态分布,分布的顶峰位于0.25～0.75 mg/kg范围内。     

煎炸方式和煎炸食材对花生煎炸油中3-氯丙醇酯和缩水甘油酯含量的影响

以花生油为煎炸油,采用不同煎炸方式（连续煎炸32 h、间歇煎炸15 h）对不同食材（油条、薯条、鸡翅、豆腐）进行煎炸实验,并对煎炸过程所取油样中3-氯丙醇酯（3-monochloropropane-1,2-diol esters,3-MCPDE）、缩水甘油酯（glycidyl esters,GEs）含量和极性组分（polar components,PC）质量分数进行检测,分析煎炸方式和煎炸食材对花生煎炸油中3-MCPDE和GEs含量的影响。结果表明：在32 h连续煎炸过程中,油条、薯条、豆腐、鸡翅及空白煎炸油中3-MCPDE含量由初始的0.84 mg/kg分别于煎炸12、4、12、16、8 h时达到最大值（分别为2.08、2.96、17.45、7.12、8.02 mg/kg）,之后呈现下降趋势;GEs含量从初始的2.43 mg/kg至连续煎炸32 h时分别升高至20.80、7.20、5.00、2.10、66.34 mg/kg;PC质量分数达到27%的限量时,不同食材煎炸油中3-MCPDE和GEs总量排序为：空白煎炸油（66.51 mg/kg）＞油条煎炸油（21.48 mg/kg）＞豆腐煎炸油（12.93 mg/kg）＞薯条煎炸油（8.51 mg/kg）＞鸡翅煎炸油（6.60 mg/kg）。在15 h间歇煎炸过程中,煎炸开始3 h后,油条、薯条、豆腐、鸡翅及空白煎炸油中3-MCPDE含量由最初的0.84 mg/kg分别升高至9.96、2.17、4.60、11.02、5.41 mg/kg,至15 h煎炸结束时,其含量又分别变化为3.51、1.58、12.88、11.81、3.72 mg/kg;GEs含量由最初的2.43 mg/kg分别增加至46.47、9.06、9.00、40.36、47.05 mg/kg;经15 h间歇煎炸,5 种煎炸油PC质量分数均未超标,此时3-MCPDE和GEs总量排序为：鸡翅煎炸油（52.17 mg/kg）＞空白煎炸油（50.87 mg/kg）＞油条煎炸油（49.98 mg/kg）＞豆腐煎炸油（21.88 mg/kg）＞薯条煎炸油（10.64 mg/kg）。同样的煎炸方式、不同食材煎炸油中3-MCPDE、GEs及PC 3 种组分的总相对含量增幅排序为：32 h连续煎炸时,空白煎炸油＞油条煎炸油＞薯条煎炸油＞鸡翅煎炸油＞豆腐煎炸油;15 h间歇煎炸时,鸡翅煎炸油＞油条煎炸油＞空白煎炸油＞豆腐煎炸油＞薯条煎炸油。同样的煎炸食材,煎炸时长相近（间歇煎炸15 h、连续煎炸16 h）时,连续煎炸油中3-MCPDE、GEs及PC 3 种组分总相对含量的增幅普遍低于间歇煎炸。综上,油脂煎炸过程中形成3-MCPDE和GEs的含量及其安全风险应引起高度关注。     

花生油煎炸不同食材过程中3-氯丙醇酯与缩水甘油酯含量变化的研究

对花生油进行油条、薯条、鸡翅、豆腐以及空白煎炸试验,对不同煎炸时间所取油样中3-氯丙醇酯与缩水甘油酯含量进行检测分析,研究花生油煎炸不同食材过程中3-氯丙醇酯与缩水甘油酯含量的变化。结果表明:在间歇煎炸开始后的3 h,油条、薯条、鸡翅、豆腐煎炸油及空白煎炸油中3-氯丙醇酯含量明显升高,由最初的0.84 mg/kg分别增加至9.96、2.17、6.86、4.60、5.41mg/kg;至间歇煎炸15 h,上述对应煎炸油中3-氯丙醇酯含量分别为3.51、1.58、9.88、12.88、3.72mg/kg,缩水甘油酯含量由最初的2.43 mg/kg分别增加至46.47、9.06、40.36、9.00、47.15 mg/kg。随煎炸时间的延长,3-氯丙醇酯增幅最大的是豆腐煎炸油和鸡翅煎炸油,缩水甘油酯增幅最大的是鸡翅煎炸油、油条煎炸油和空白煎炸油。至煎炸15 h,5种煎炸油样的极性组分和酸值均未超出国标限量,但3-氯丙醇酯与缩水甘油酯含量的升高对煎炸食品安全的影响应引起高度关注。     

菜籽油和棉籽油餐饮煎炸过程中脂肪酸组成和极性组分变化规律研究

以菜籽油和棉籽油为煎炸油,薯条和鸡块为煎炸食物,餐饮条件下连续煎炸4 d,研究菜籽油和棉籽油餐饮煎炸过程中脂肪酸组成和极性组分的变化规律。结果表明:煎炸过程中菜籽油和棉籽油饱和脂肪酸(SFA)含量、极性组分(TPC)含量随煎炸时间延长升高而不饱和脂肪酸(UFA)含量降低,指标无论增加或降低,变化速率都呈现先快后慢趋势;餐饮煎炸4 d后,菜籽油SFA含量达21. 04%～23. 37%,TPC含量达21. 6%～22. 9%,UFA含量低至72. 47%～74. 82%,棉籽油SFA含量达29. 69%～35. 37%,TPC含量达23. 3%～25. 5%,UFA含量低至60. 29%～65. 88%;公式y=alnx+b描述煎炸油品质随煎炸时间变化效果良好,推导得脂肪酸组成与极性组分含量的良好线性关系;双因素方差分析显示,油品和食物会显著影响煎炸油的脂肪酸组成(P 0. 001)和极性组分含量(P 0. 05),而交互作用不显著(P 0. 05)。     

不同煎炸条件对茶叶籽油苯并（a）芘含量的影响

以茶叶籽油为煎炸用油,研究了不同煎炸原料、煎炸温度和煎炸时间对茶叶籽油苯并(a)芘(BaP)含量的影响,并对其氧化指标进行了初步测定。结果表明:煎炸鸡翅的茶叶籽油180℃煎炸10 h后BaP含量最多,为8.82μg/kg,其次为煎炸豆腐和土豆的茶叶籽油,煎炸油条的茶叶籽油BaP含量最少;煎炸原料中BaP的增加量为鸡翅土豆豆腐油条;以鸡翅为原料煎炸温度越高,茶叶籽油中BaP生成量越多,200℃煎炸10 h后BaP含量达11.86μg/kg;随煎炸时间的延长,BaP含量上升速率加快,180℃煎炸50 h后茶叶籽油BaP含量由1.92μg/kg上升至16.13μg/kg,此时过氧化值、酸值(KOH)和茴香胺值分别为18.75 mmol/kg、3.32 mg/g和77.25。     

不同高温烹饪方式加工过程中滩羊肉风味化合物的差异比较

探讨滩羊肉高温烹饪（炒制、煎制、炸制）加工过程中挥发性风味化合物形成、变化及差异。在整体气味感知上,利用电子鼻可以区分生肉与炒制、煎制、炸制样品之间的不同气味。采用顶空固相微萃取-气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）对挥发性化合物进行定性分析,通过偏最小二乘判别分析（partial least squares-discrimination analysis,PLS-DA）法,辨别3?种加工方式不同加工阶段可挥发性成分组成。结果表明：在整体气味感知上,采用电子鼻可以区分3?种加工方式各个加工阶段,在炒制煸炒脂肪出油阶段、煎制1?min阶段、炸制3?min阶段响应值最强。GC-MS鉴定滩羊高温烹饪肉制品挥发性化合物273?种,其中炒制174?种,炸制158?种,煎制134?种。煎制、炸制前期就产生了大量的挥发性风味物质,而炒制是在加工后期才产生大量的挥发性风味物质。PLS-DA评分散点图将原料肉、3?种加工方式的滩羊肉制品挥发性化合物区分开,且有各自清晰的气味特征。醛类是3?种滩羊肉制品主要的挥发性化合物,己醛的浓度含量最高。炒制煸炒脂肪出油阶段增加了滩羊肉的可挥发性风味化合物种类及相对含量,对风味的整体贡献最高,尤其是酸类、酯类、杂环类化合物的贡献。     

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。     

油炸过程中淡水小龙虾理化性质与品质变化

研究分析油炸工艺（油炸温度（140、160、180、200 ℃）和油炸时间（15、30、45、60 s））对淡水小龙虾（虾壳、虾肉、虾黄）理化性质及品质的影响。测定淡水小龙虾中心温度、油炸损失率、色泽、质构特性、挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARs）值以及菌落总数（total plate count,TPC）的变化。结果表明：油炸温度对虾肉中心温度影响不显著,而油炸时间对虾肉中心温度影响显著（P＜0.05）;油炸温度180 ℃、油炸45 s时,虾肉中心温度可达到肌肉熟制标准温度;随着油炸温度升高及油炸时间延长,小龙虾油炸损失率显著上升（P＜0.05）;虾壳、虾肉、虾黄亮度值、红度值均呈上升趋势,而黄度值呈下降趋势;虾肉硬度、回复性、弹性、黏性、咀嚼性均显著增加（P＜0.05）;油炸过程中,虾肉TVB-N含量显著增加（P＜0.05）,但均低于10 mg/100 g,表明虾肉油炸后保持较好的新鲜度;虾肉TBARs值随油炸温度升高、油炸时间延长而增加,其中油炸时间对TBARs值影响较明显;新鲜虾肉初始带菌量非常高,油炸处理后虾肉TPC显著降低（P＜0.05）,油炸时间对虾肉TPC影响不明显。     

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.     

Effects of the addition of green tea powder on the quality and antioxidant properties of vacuum-puffed and deep-fried Yukwa (rice snacks)

Vacuum-puffing has been found to be a very useful process for production of non-deep-fried Yukwa as it ideally produced highly porous and soft texture. In this study, we compared the effects of different green tea powder (GTP) concentrations of 0, 2, 5 and 10 g/100 g on the qualities of vacuum-puffed Yukwa and deep-fried Yukwa. The fat contents of deep-fried Yukwa were significantly higher than vacuum-puffed Yukwa at the same GTP concentrations. Yukwa bases of 10 g/100 g GTP level contained higher total catechins and caffeine contents for vacuum-puffed Yukwa than deep-fried Yukwa. Vacuum-puffed Yukwa had more total phenolics and flavonoids, and a better scavenging effect on DPPH and reducing power than deep-fried Yukwa at the same green tea concentrations. Vacuum-puffing produced more breakable expanded pellets than deep-frying. The sensory evaluation of Yukwa base showed deep-fried Yukwa added with 2 g/100 g GTP was preferred for all the examined properties.     

加工方式对海带和紫菜中砷及其形态的影响

研究浸泡、油炸、水煮和烘烤四种加工方式对海带和紫菜中总砷及其形态含量的影响,并对其食用安全性进行评价。结果表明:浸泡和水煮都能减少海带和紫菜中总砷和四种砷化合物含量。油炸和高温烘烤影响砷形态和含量的变化:油炸样品中总砷含量减少,DMA、MMA和无机砷含量变化表现出不一致性;除250℃外,其他温度烘烤的样品总砷含量均增加,二甲基砷酸(DMA)、一甲基砷酸(MMA)、无机砷含量随温度的升高而增加,到250℃时最多增加近3倍,对食用安全性有一定影响;在150℃油炸15min和200℃烘烤的样品中有新的砷化合物生成,其结构和毒性尚难确定。     

Application of cellulose- and chitosan-based edible coatings for quality and safety of deep-fried foods

Excessive oil uptake and formation of carcinogens, such as acrylamide (AA), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs), during deep-frying are a potential threat for food quality and safety. Cellulose- and chitosan-based edible coatings have been widely applied to deep-fried foods for reduction of oil uptake because of their barrier property to limit oil ingress, and their apparent inhibition of AA formation. Cellulose- and chitosan-based edible coatings have low negative impacts on sensory attributes of fried foods and are low cost, nontoxic, and nonallergenic. They also show great potential for reducing HCAs and PAHs in fried foods. The incorporation of nanoparticles improves mechanical and barrier properties of cellulose and chitosan coatings, which may also contribute to reducing carcinogens derived from deep-frying. Considering the potential for positive health outcomes, cellulose- and chitosan-based edible coatings could be a valuable method for the food industry to improve the quality and safety of deep-fried foods.     

常见蔬菜的黄酮含量及烹饪对其含量的影响

本实验目的在于了解我国辽宁省地区常见蔬菜的黄酮类物质含量及黄酮类物质在不同烹饪方式下的变化情况,为进一步估算膳食中黄酮类物质的摄入水平提供依据。结果表明,叶菜中黄酮类物质含量较高,花、果类和根、茎类次之。萝卜缨、韭菜、芹菜中黄酮类物质含量较高,分别达到39.18,36.26和32.20mg/100g。经过烹饪后,大部分蔬菜中黄酮类物质含量均有所增加,其中,中火炒制的烹饪方式使蔬菜中的黄酮含量增加得较为显著,增加幅度在12.11%～166.38%之间。增加绿叶蔬菜的摄入量,可获得充足的黄酮类物质,采用中火炒制的烹饪方式有利于黄酮类物质的释放。     

上海地区部分市售食品中反式脂肪酸含量与组成分析

目的了解上海地区部分市售食品中的反式脂肪酸(trans-fatty acids,TFAs)含量以及异构体组成,为开展TFAs的风险评估和食品选择提供参考。方法于2011年1～6月在上海市超市、面包店或快餐店中抽取具有代表性的9大类共106种市售食品,包括植物油、乳及乳制品、休闲食品、方便食品、快餐食品、饮料、小吃甜饼、调味品和畜禽肉及制品,采用银离子固相萃取(Ag+-SPE)结合气相色谱方法检测TFAs含量。结果抽检样品中的TFAs以反式油酸(t C18∶1)为主,反式多不饱和脂肪酸含量较少。除黑咖啡外,其余105种食品均检测到TFAs,其中,巧克力派的TFAs含量最高(1 711.58 mg/100 g)。反刍动物食品和含乳及乳制品的食品中11t C18∶1异构体含量较高(占总TFAs的53.9%～100.0%)。富含氢化油的休闲食品中9t C18∶1异构体含量较高(占总TFAs的14.3%～87.7%)。猪肉和牛肉经加工后TFAs含量有不同程度降低。结论市售食品中普遍检测到TFAs,食物成分和加工过程不同总TFAs含量及异构体组成存在较大差异,预包装休闲食品和西式甜饼店食品含有较多的TFAs。     

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.