部分食品煎炸用油的反式脂肪酸比较

为探究不同品种食用油和煎炸食品对反式脂肪酸形成的影响,本文使用5种食用油(葵花油、大豆油、菜籽油、棕榈油、花生油),在一定温度下炸制14批次油条,又依次使用大豆油炸制豆腐、油条和鸡腿,对2种情况下产生的煎炸油进行气相色谱分析,比较反式脂肪酸含量。结果表明:炸油条过程中,食用油中反式脂肪酸的含量均随着煎炸时间的延长而增加,葵花油中反式亚油酸总含量最多(约12 mg/g),花生油中反式油酸含量最低(约0.6 mg/g),在煎炸过程中,大豆油中反式脂肪酸的含量无显著变化,保持在3.5 mg/g左右。比较可知,不同种类食用油在加热过程中产生的反式脂肪酸含量有较大差异,而使用大豆油分别炸制豆腐、油条和鸡腿时,煎炸油中的反式脂肪酸无显著差异,说明油炸过程中的反式脂肪酸主要来源于食用油中不饱和脂肪酸的氧化裂解和异构化,与煎炸食品关系不大。从反式脂肪酸的生成量来看,烹饪过程中长时间煎炸建议使用大豆油,而不适宜使用葵花油。     

食用油加热过程中反式脂肪酸的形成和变化

对花生油、大豆油、菜籽油、玉米油和葵花籽油分别进行加热试验,采用气相色谱法测定其不同加热温度和不同加热时间脂肪酸组成,分析研究食用油中反式脂肪酸形成和变化特点及其影响因素。结果表明食用油加热至300℃时,其反式脂肪酸含量是未加热时的2倍以上;随着加热温度的升高或加热时间的延长,食用油中反式脂肪酸种类和含量都增加。加热温度、加热时间和食用油中脂肪酸组成均是影响反式脂肪酸形成和变化的因素;而反式脂肪酸受影响的程度因其种类的不同而变化。     

加热对油茶籽油中反式脂肪酸形成的影响

通过研究不同加热条件下(200、260、300℃)油茶籽油中脂肪酸组成,来分析反式脂肪酸形成和变化特征。结果表明,加热温度和加热时间是导致油茶籽油中反式脂肪酸形成和变化的影响因素。随着加热温度的升高和时间的延长,反式脂肪酸含量和种类有增加的趋势;而且反式脂肪酸的种类和含量还受未加热油茶籽油中顺式脂肪酸的影响。因此,在油茶籽油烹饪过程中,应掌握好加热温度和时间,以避免形成反式脂肪酸。     

煎炸条件对精炼光皮树油中反式脂肪酸的影响

研究了煎炸过程中加热温度、加热时间对光皮树油中反式脂肪酸的影响,以及鸡脯肉、油条煎炸过程中光皮树油中反式脂肪酸含量及类型的变化。结果表明:加热温度对光皮树油中反式脂肪酸的生成量影响显著,当温度升至270℃时,反式脂肪酸总量最高达到1.77%;在较低的加热温度下,加热时间对其影响较为缓和。鸡脯肉、油条煎炸过程中,光皮树油中反式脂肪酸的变化复杂,反式脂肪酸总量变化范围较小,但其类型变化较大。     

高温条件下食用油脂脂肪酸的变化

研究不同加热时间和加热温度对食用油中脂肪酸各组分及其指标的影响.利用气相色谱检测了加热后油脂的反式脂肪酸生成量和各个脂肪酸含量变化,利用2,4-二硝基苯肼对羰基值进行了检测.结果表明,随着加热温度和加热时间的增加,不饱和脂肪酸的含量缓慢下降,饱和脂肪酸的含量上升,其中C16:0经过210℃3h后含量增加了0.572 9 g/L,与此相反,C18:2则下降了2.084 9 g/L.反式脂肪酸的含量和羰基值都呈上升趋势,反式C18:1和反式18:2含量经过210℃3h后分别增加了0.074 3 g/L和0.071 6g/L,经过210℃3h加热后羰基值为52.81 meq/kg,并且这种趋势随着温度的升高,变化更加剧烈,尤其在150℃后油脂的品质开始下降迅速,这样不利于人体健康.因此,建议日常烹饪过程中油温控制在150℃以下.     

长时间高温加热食用油反式脂肪酸的形成和变化

通过研究不同加热温度(180℃,220℃和260℃)及不同加热时间(0.5~10 h)对家庭用菜籽油及工业用棕榈油中脂肪酸的组成研究,分析工业用油与家庭用油反式脂肪酸形成和变化特点及其影响因素。结果表明两种油加热至260℃时,其反式脂肪酸含量是原油的5倍以上,随着加热温度的升高或加热时间的延长,食用油中反式脂肪酸种类和含量都增加。因此,通常家庭用油不会长时间加热,但工业用油的长时间加热会使油脂中反式脂肪酸的含量明显上升。     

初榨橄榄油在加热过程中品质变化研究

初榨橄榄油营养丰富且具保健价值，研究初榨橄榄油在烹调加热过程中品质的变化具有重要意义。采用仪器分析和化学分析法研究初榨橄榄油在加热过程中品质指标的变化。研究结果表明，初榨橄榄油在180℃加热过程中，脂肪酸值、过氧化值、羰基值、黏度逐渐增加，饱和脂肪酸和反式脂肪酸含量增加，不饱和脂肪酸含量下降。初榨橄榄油在180℃加热300 min时，过氧化值开始超标；加热480 min时，脂肪酸值、羰基值、反式脂肪酸含量仍未超标或超过推荐量。初榨橄榄油在180℃下加热烹调食品不宜超过240 min。如果要延长烹调加热时间，可以适当降低加热温度。该研究为初榨橄榄油在食品中的煎炸及含初榨橄榄油食品的高温处理提供科学参考。     

一种家庭用营养均衡型配方食用油的加热及烹饪稳定性北大核心CSCD

通过模拟加热(180℃加热15、30 min)及家庭烹饪(炒青菜)过程,研究了一种富含不饱和脂肪酸、n-6/n-3脂肪酸比例适宜且有益脂质伴随物含量丰富的配方食用油的加热及烹饪稳定性。结果表明:配方食用油在加热或烹饪青菜时其酸值、过氧化值略有上升,但均远低于GB 2716—2018的规定;加热和炒菜过程中不会造成反式脂肪酸含量的增加,且苯并(a)芘含量远低于国标限量,说明在加热和炒菜过程中该配方食用油能够保持安全稳定;此外,配方食用油脂肪酸组成在加热或烹饪前后变化不大,n-6/n-3脂肪酸比例稳定,生育酚和总酚含量在加热和烹饪后下降幅度在35%以内,植物甾醇含量下降约12%。由此可知,配方食用油能够在常规家庭烹饪过程中保持稳定,是一种日常补充n-3多不饱和脂肪酸和有益脂质伴随物的有效途径。     

高温油茶籽油中苯并芘和反油酸产生规律研究

为了探讨高温条件下油茶籽油中苯并芘和反式脂肪酸的形成规律进行了研究。试验测定了不同温度、时间、煎炸不同食材后2种油茶籽油中苯并芘和反油酸以及烟气中苯并芘的含量。结果表明高温条件下,油茶籽油中苯并芘含量未随加热时间延长而明显提高;但反油酸含量随加热时间和温度上升趋势明显。油茶籽油在180℃下煎炸香蕉、面条、瘦肉、豆腐等食材12 h后苯并芘含量大幅上升,且煎炸豆制品上升速度最快;压榨毛油煎炸香蕉和豆腐24 h后油中反油酸仍低于检出限(0.05%),而煎炸面条和瘦肉后,油中反油酸上升明显,分别达到1.9%和0.6%;浸提精炼油中煎炸4种食材后反油酸含量均有显著上升,上升幅度依次是面条豆腐香蕉瘦肉。     

高温加热对牡丹籽油脂肪酸和理化性质的影响

通过研究牡丹籽油经不同温度（90、120、150、180、210、240 ℃）加热30 min后脂肪酸组成、含量以及 理化性质的变化,探究高温加热对牡丹籽油品质的影响。结果表明：牡丹籽油在高温加热后会生成脂肪酸异构体、 环状脂肪酸以及中、短碳链脂肪酸,且温度越高种类越多。虽然上述高温加热后牡丹籽油各理化指标均符合食用油 标准,但是随着温度的升高,牡丹籽油不饱和脂肪酸含量下降,富含营养价值的α-亚麻酸含量在温度超过180 ℃时 迅速下降。可见,在理化指标上牡丹籽油具有良好的热稳定性,但是从营养角度其不适合用于高于180 ℃的高温煎 炸等烹调方式。     

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.     

马铃薯煎炸过程中食用油稳定性的研究

采用马铃薯作为食材,菜籽油、胡麻油和米糠油3种常用食用油作为煎炸用油,测定不同煎炸温度、不同煎炸时间下3种食用油酸值、碘值、过氧化值,评价不同食用油煎炸过程中的稳定性。结果表明:经过5 h的连续加热,3种食用油的酸值、过氧化值含量都随加热温度和加热时间的增大有逐渐上升的趋势,碘值随着加热温度和加热时间的增大逐渐下降,3种食用油在125℃、150℃、175℃、200℃温度梯度下连续加热5 h后的酸值均低于5 mg/g。依据过氧化值含量的增加幅度和碘值的降低幅度来评判煎炸油的煎炸品质结果为:胡麻油>菜籽油>米糠油。     

生育酚抑制油脂氧化机制研究进展

生育酚是天然脂溶性抗氧化剂维生素E的重要组成部分,广泛存在于各种食用油中。但在加热条件下,油脂中生育酚在参与延缓油脂氧化反应过程中自身会发生损耗、转化和迁移,其转化产物是否还具备抗氧化活性成为研究热点。针对中餐食用油以高温煎炸为主的使用习惯,研究生育酚在高温煎炸条件下的转化及抗氧化活性维持十分重要。结合油脂氧化机理,主要总结了油脂中生育酚的抗氧化机制,重点对加热条件下生育酚抑制油脂氧化机制相关研究进展进行综合分析,旨在为合理及正确使用脂溶性抗氧化剂维生素E、发挥其营养保健功效、维持油脂品质提供一定参考。     

基于主成分分析法评价两种餐饮用油的煎炸性能

目的 分析两种常见餐饮用油(餐饮调和油A和餐饮调和油B)煎炸性能的差异,并对餐饮用油煎炸品质进行综合评估。方法 在模拟西式快餐实际油炸条件下进行煎炸薯条实验,考察了餐饮用油在油炸过程中十项品质指标,并利用主成分分析法(PCA)对两种餐饮用油在油炸过程中的煎炸性能进行综合评价。结果 餐饮用油品质指标间存在不同程度的相关性,PCA将10个品质指标缩减成2个综合性评价指标,累计贡献率达87.920%,反映了餐饮用油煎炸品质的大部分信息,并进一步提取出评估餐饮用油煎炸性能的5个关键指标,即过氧化值、极性组分、碘价、羰基值以及亚油酸/棕榈酸比值。主成分分析综合得分表明,在油炸过程中,餐饮调和油A得分较高,具有较好的煎炸性能。结论 本研究建立的餐饮用油煎炸性能评价体系为煎炸油的筛选和质量控制提供借鉴。     

Comparison of the Frying Performance of Olive Oil and Palm Superolein

Abstract: Deep‐fat frying is an important method of food preparation in which foods are immersed in hot oil. Repeated use of frying oils is a common practice, and in the presence of atmospheric oxygen it produces various undesirable reactions in used oils. Stable frying oils usually require low linolenic acid (LnA < 3%), increased oleic acid (OA > 40%), and decreased linoleic acid (LA < 50%). The aim of this study was to establish the behavior of palm superolein (PSO) (OA 45%; LA 12.5%; LnA 0.2%) and olive oil (OO) during repeated, discontinuous deep frying of French fries. The behavior of the oils under controlled heating conditions was also studied by maintaining all of the process variables the same as those in deep frying, except that there was no food in the oil. The PSO selected to be tested in this study may represent an alternative to OO as a frying medium. Although PSO presented a faster increase in some oxidation indices, such as free fatty acid and total polar compounds, for other indicators, PSO showed better behavior than OO (less formation of C8:0 and lower peroxide value). Practical Application: The super palm olein selected for use in this study can be suggested as a suitable replacement for olive oil for frying and cooking purposes because it provides higher oxidative stability besides the beneficial effects of olive oil on human health. In fact, several studies have indicated that palm oil exhibits similar frying performance to high‐oleic oils, with the advantages of greater availability in the market and a lower price.     

食用油与氯化钠模型反应中氯丙醇酯的消长规律

为研究热加工过程中食用油与NaCl反应产生3-氯-1,2-丙二醇酯(3-monochloropropane-1,2-diol ester,3-MCPD酯)和2-氯-1,3-丙二醇酯(2-monochloropropane-1,3-diol ester,2-MCPD酯)的变化规律,分别建立食品和煎炸油2个体系模型,考察食用油种类、NaCl含量、反应温度、反应时间、含水量和pH值等因素对2-MCPD酯和3-MCPD酯的含量影响。结果表明:2种模型反应中,食用油种类、反应时间、反应温度和NaCl含量对2-MCPD酯和3-MCPD酯的含量变化有着较大的影响;通过比较发现,在食品模型中,2-MCPD酯和3-MCPD酯的含量随反应温度的增加(100~190℃)呈现下降趋势,分别下降5%和20%,然而在煎炸油模型中,随反应温度的增加(100~220℃)两者呈现增加趋势,分别增加7倍和8倍。另外,随NaCl含量和反应时间的增加,2个模型反应中的2-MCPD酯和3-MCPD酯的含量变化趋势不完全一致。这说明2-MCPD酯与3-MCPD酯虽然结构近似,但消长规律不同。该研究结果可为有效减少热加工食品中氯丙醇酯的含量提供参考。     

影响煎炸油中极性组分含量的研究

目的为更好地根据不同煎炸时间和煎炸食材选择合适的煎炸油,并确定合理的煎炸油更换频率,以最大程度降低煎炸油的劣化程度,保持煎炸油的良好卫生质量。方法本实验采用食用油品质检测仪对常用植物油中的总极性组分含量进行测定,对影响煎炸油极性组分含量的几点因素进行考察研究。结果不同煎炸时间、不同煎炸食材对总极性组分含量影响不同;不同植物油品种在煎炸过程中极性组分含量变化趋势不同;当已知极性组分含量初始值的油品以一定比例相互混合时,其极性组分含量初始值会发生可预期的改变。结论不同油品在煎炸过程中的极性组分含量与煎炸时间、油品中单不饱和脂肪酸含量、煎炸食品中碳水化合物含量和煎炸数量正相关;选择合适的煎炸油需要综合考虑油品极性组分初始值、极性组分在煎炸过程中的变化情况;根据不同品种食用油极性组分含量初始值的不同,可初步判断油品是否与其声称成分相符。     

Application of protein-based edible coatings for fat uptake reduction in deep-fat fried foods with an emphasis on muscle food proteins

BackgroundDeep-fat frying is a common cooking method where fat or oil is used as the heat transfer medium, in direct contact with the food at a temperature above the boiling point of water. During the deep fat frying method, oil not only serves as a heating medium but also absorbs into food, increasing the total fat content. As a result, consumption of deep-fat fried foods has been associated with coronary heart diseases, obesity and type 2 diabetes. Selection of an appropriate food coating before frying may act as a barrier to moisture loss, which is important commercially, and also reduce fat uptake during frying.Scope and approachThis paper succinctly reviews different protein sources for edible coatings and compare them with muscle food proteins which were used in deep-fat fried foods.Key findings and conclusionsProtein-based coatings have been explored as potential coating materials in fat-uptake reduction. Comparatively, proteins are able to form films with better mechanical and barrier properties than polysaccharides. Application of muscle food proteins (myofibrillar proteins) as coatings, which are rich in these proteins, is novel and could be product-friendly for deep-fried muscle foods.