煎炸老油对小鼠耐缺氧能力与抗疲劳能力的影响

新鲜精炼菜籽油煎炸薯条3 d(60锅),检测煎炸过程中菜籽油的过氧化值、黏度和极性化合物含量,将煎炸老油按低(10 mL/(kg·d))、中(20 mL/(kg·d))、高(40 mL/(kg·d))剂量对小鼠进行灌胃,另设阴性对照组(10 mL/(kg·d)新鲜精炼菜籽油灌胃)和正常对照组(10mL/(kg·d)蒸馏水灌胃),灌胃4周后,测定各组小鼠体重、耐缺氧生存时间和游泳力竭时间,考察煎炸老油对小鼠耐缺氧能力与抗疲劳能力的影响。结果表明:新鲜精炼菜籽油经过反复煎炸后,随着煎炸时间的延长菜籽油的过氧化值先升高后降低,黏度和极性化合物含量升高,油脂品质发生劣变;各组小鼠的体重没有显著差异;阴性对照组与正常对照组在各个指标上都没有显著差异;与阴性对照组相比,低剂量组小鼠耐缺氧生存时间和游泳力竭时间都没有显著差异,而中、高剂量组小鼠耐缺氧生存时间和游泳力竭时间都显著下降(p 0. 05)。     

潲水油、煎炸老油与合格食用植物油的鉴别研究

近年来潲水油(或地沟油)事件时常出现，为寻找鉴别潲水油的方法，防止潲水油回流到食用油市场，本文采集到的潲水油、煎炸老油及合格食用植物油的理化指标与国家规定的食用油标准进行对比，同时比较三种油的水分含量，发现潲水油及煎炸老油的酸价远远高于国家食用油最高允许值，因此，可作为辨别潲水油、煎炸老油与合格食用植物油的理化指标。     

薄层色谱法快速鉴别潲水油和煎炸老油的研究

潲水油被炼制并流回食用油行列的事件逐年增多,为防止此类有害油品流回食用油行列,寻找快速而准确的鉴别方法,对从市场购买的常见食用植物油以及采集到的潲水油、煎炸老油进行薄层色谱分析,发现潲水油和煎炸老油的薄层色谱有明显的拖尾斑,而食用植物油则没有.拖尾斑成分经柱色谱分离并进行红外分析,结果表明,潲水油、煎炸老油的拖尾成分是合格食用油所不含的醛、酮类化合物.薄层色谱法可以作为鉴别合格食用植物油与潲水油、煎炸老油的快速方法.     

煎炸老油掺伪大豆油的高场核磁检测

通过高场核磁共振仪检测了纯大豆油和掺伪了煎炸老油的大豆油并对谱图进行积分。通过谱图对比发现了三个鉴别指标,第一个鉴别指标是在δ=1.58处,纯大豆油有明显特征峰,而煎炸老油在该处无特征峰;第二个鉴别指标是在δ=2.77~2.84处,纯大豆油特征峰的积分面积高于掺伪了煎炸老油的大豆油(添加50%煎炸老油积分面积为1.51,纯大豆油积分面积为2.04),并且随着煎炸老油添加量的增加积分面积逐渐减小;第三个鉴别指标是在δ=5.25~5.42处,纯大豆油特征峰的积分面积明显高于掺伪了煎炸老油的大豆油(添加50%煎炸老油积分面积为3.98,纯大豆油积分面积为4.87),而且也随着煎炸老油添加量的增加积分面积逐渐减小。     

离子迁移谱法快速鉴别煎炸老油

目的建立基于离子迁移谱的快速鉴别煎炸老油的鉴别方法。方法油样经正己烷50倍稀释、混匀,进样量为4.0μL,在进样口温度为170℃,迁移管温度为60℃的离子迁移谱条件下进行检测,样品测试时间为20 s。将采集的油样离子迁移谱图利用化学计量学方法进行分析,建立煎炸老油鉴别模型。结果运用主成分分析法(PCA)对两类油脂的谱图信息进行分类,两类油脂能明显分开,效果良好。采用递归支持向量机法(R-SVM)对煎炸老油建立判别模型,十折交互检验正确判别率最高达98.8%。结论本方法无需复杂前处理、检测时间短,有机试剂用量小,操作简单快速,结合化学计量学的分析方法建立的煎炸老油的鉴别模型准确度高,适用于煎炸老油的快速鉴别,为我国食用油质量安全监管提供了一种新方法。     

甲硫氨酸对小鼠毛发生长和脏器指数的影响

选择血缘和体重相近的昆明小白鼠80只,随机分成4组,分别以0.12%(对照组),0.80%,1.60%,2.40%的甲硫氨酸(Met)处理,每个处理5个重复、每个重复雄雌鼠各2只。在毛发退行期和休止期分别采集毛发纤维、心脏、肝脏、脾脏、肺脏、肾脏和胸腺等,用于测定毛发直径和长度及各脏器指数。结果表明:0.80%,1.60%,2.40%3种处理能显著降低退行期毛发直径(P0.05),但对休止期毛发直径无显著影响(P0.05);0.80%,1.60%2种处理能显著降低退行期和休止期毛发长度(P0.05),显著提高退行期脾指数、肺指数和肾指数(P0.05),但对心指数、胸腺指数均无显著影响(P0.05);1.60%Met处理能显著提高休止期肝指数和肾指数(P0.05),但对心指数、脾指数无显著影响(P0.05)。综上,0.80%,1.60%2种处理能显著降低小鼠毛发直径、长度,并能显著提高小鼠退行期脾指数、肺指数和肾指数。     

高温煎炸对于牡丹籽油品质变化的影响

对牡丹籽油在煎炸过程中过氧化值、酸值、色泽、脂肪酸组成等4项评价指标的变化进行了试验研究,目的在于探讨反复煎炸对牡丹籽油质量变化的影响。结果表明,牡丹籽油煎炸12次后(每次温度220℃,时间20min),感官指标变化明显,卫生指标酸值过氧化值符合食品安全国家标准,油脂中的α-亚麻酸相对百分比含量前4次变化不明显,第5~12次逐渐呈下降趋势。     

以稻米油为基油的煎炸调和油品质研究

以稻米油、棕榈油(24℃)和棉籽油为原料调配以稻米油为基油的煎炸调和油,并对其品质进行研究。通过对调和油脂肪酸组成和氧化稳定性的检测,确定稻米调和油配方。在土豆条连续煎炸试验中,对比稻米油和稻米调和油在煎炸过程中理化指标(酸价、过氧化值、碘值、极性组分含量)和营养物质(脂肪酸组成及维生素E、植物甾醇、谷维素含量)变化,综合评估其煎炸性能。结果表明:稻米油含量低于70%的调和油多不饱和脂肪酸含量不超过30%,氧化诱导时间最长的是稻米油含量为60%的调和油(配方2),其次为稻米油含量为50%的调和油(配方1);稻米油、调和油(配方1、配方2)在煎炸30 h后,酸价(KOH)分别增加了1.01、1.21、1.19 mg/g;与配方1相比,配方2的过氧化值初始值(1.78 g/100 g)和峰值(7.48 g/100 g)较小;煎炸30 h,稻米油的碘值(I)从101.66 g/100 g降低到90.57 g/100 g,降幅为10.91%,配方1的碘值(I)从80.23 g/100 g降低到76.34 g/100 g,降幅为4.85%,配方2的碘值(I)从84.56 g/100 g降低到79.47 g/100 g,降幅为6.02%;稻米调和油的极性组分含量超标时间延长,饱和脂肪酸增长率较稻米油低,而多不饱和脂肪酸的降幅略高于稻米油;稻米调和油较稻米油的维生素E损耗率高。综合来看,稻米调和油的煎炸稳定性较好,并且也一定程度保留了稻米油的营养特性,配方2的煎炸性能更为优越。     

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。     

边滤对棕榈油煎炸品质的影响

分析了过滤过程中添加滤油粉对棕榈油煎炸品质的影响。实验表明,滤油粉可使深度煎炸的油脂透光率明显升高,能在一定程度上延长棕榈油的氧化稳定时间;在煎炸过程中适当使用滤油粉,可在一定程度上延长棕榈油的使用时间;但滤油粉不能使深度煎炸的棕榈油品质发生显著的改变。     

油脂饱和度对油炸马铃薯片品质的影响

以玉米油、花生油、大豆油、大豆棕榈调和油、棕榈油5种不同饱和度油脂作为煎炸用油,以马铃薯片为煎炸内容物,于140℃循环煎炸。考察马铃薯片的油脂含量、水分含量、色泽、酥脆性以及感官评分的变化,综合分析油脂饱和度对油炸马铃薯片品质的影响。结果表明:煎炸油脂的饱和度显著影响油炸马铃薯片的品质(p 0.05),随着煎炸油脂饱和度的增加,油炸马铃薯片的油脂含量呈降低的趋势,水分含量呈增加的趋势,L值呈增大的趋势,表明马铃薯片颜色随着煎炸油脂饱和度的增加而越发鲜亮;油炸马铃薯片的酥脆性、感官评分亦随煎炸油脂饱和度的增加呈显著增加的趋势(p 0.05)。由此可知,相对于不饱和度较高的玉米油、花生油、大豆油,饱和度较高的棕榈油更加适合马铃薯片的煎炸。     

煎炸花生油中的总极性组分对脂质代谢的影响

花生油在煎炸过程中发生一系列化学反应,产生了氧化甘油三酯、聚合甘油三酯和游离脂肪酸等极性大于甘油三酯的极性组分。用煎炸花生油的极性组分处理人肝癌细胞(HepG2),通过油红染色评估细胞内脂肪的含量,通过RT-PCR测量与脂质合成密切相关的基因(SREBP-1c、FAS、ACC、HMGCR)的mRNA相对表达含量评估脂质代谢情况。结果表明:随着极性组分的增多,细胞内脂肪含量明显增多;在极性组分质量浓度为2. 0 mg/mL时,SREBP-1c、FAS、ACC的mRNA水平分别增加为对照组的2. 95±0. 08(P 0. 05)、3. 24±0. 16(P 0. 05)、1. 77±0. 18(P 0. 05)倍,表明花生油中的极性组分会上调脂质合成相关基因的表达,进而导致HepG2细胞的脂质聚积。研究结果说明煎炸花生油中的极性组分在细胞层面导致脂质代谢紊乱。     

Effect of food surface roughness on oil uptake by deep-fat fried products

The aim of this work is to examine the relationship between surface roughness and oil uptake in fried fabricated products. Two product categories were studied, using formulations based either on potato flakes or wheat gluten. Products were deep-fat fried at 170 °C and two oil fractions, penetrated oil and surface oil, were determined at the beginning and at the end of cooling period. The surface of fried products was measured using a scanning laser microscope and characterized by an area-scale fractal analysis. Within each product category, products with higher surface roughness retained more oil. However, this relationship could not be extended when comparing products of different categories. Potato-flake-based products were rougher than gluten-based products, but retained less oil. Further, gluten-based products absorbed most of the oil during frying, whereas potato-flake-based mostly absorbed oil during cooling. Certainly, surface roughness is a key factor in oil absorption, but other food-related properties, such as the micro-structure of the crust, may explain differences among product categories and should be examined in future studies.     

Effect of turanose on the rheology and oil uptake of instant fried noodles

Effects of turanose on the functional properties of instant fried noodles were assessed mainly in terms of rheology- and oil uptake-related characteristics. The Mixolab results showed that the water absorption of dough decreased as the turanose level increased, whereas the gel stability and starch retrogradation increased. Also, the use of turanose lowered the storage and loss moduli of the dough, showing a more viscous nature. These viscoelastic characteristics were correlated with the decreased resistance to extension and increased extensibility. NMR spin–spin relaxation analysis showed three distinct water populations in the turanose noodle doughs whose relaxation times were varied depending on the level of turanose. After frying, the noodles with turanose exhibited a continuous and smooth surface as well as a less porous structure. These microstructural characteristics were correlated with the reduced oil uptake by 20.8%, the enhanced oxidative stability and furthermore the improved breaking stress.     

Effect of oxidation of frying oil on the sensory value of fried fish fillet

Fresh sunflower seed oil and used oil were compared as media for deep fat frying of cod fillet. The oxidized oil had more rancid, varnish like and intensive fried flavours. Hydroperoxides present in used frying oil were decomposed into benzidine-active compounds. The sample fried in used oil had lower overall sensory quality, especially poorer flavour and odour. The flavour profile of the fried product was modified by oxidation products in used oil as well. The latter profile consisted of significantly more intensive rancid and stale flavours and significantly stronger old meat flavour. In contrast to this, the product fried in fresh oil had slightly stronger meat flavour. There was no difference in the intensity of fish flavour.     

走油蹄膀的制作技术

走油蹄膀为深受大众喜爱的传统名菜,具有软糯粘齿的表皮、香酥可口的肌肉,给人以油而不腻的口感而受到消费者欢迎。制作的关键在于使绉纱更多的出现在皮上。一般认为其越浓密,越均匀则口感越好。而用冷冻原料制作,在皮面胀发上会受到一定影响,为使面上的绉纱肥厚且又分布均匀,本制作方法在传统工艺的基础上作了些更新,能较好的达到目的。绉纱,其实是猪皮真皮层中的胶纤维,在不同传热介质中先受热软化,接着的高温又使纤维中所含的气体急剧膨胀,后又突然遇冷收缩。这二热一冷的温差变化很快改变了纤维结构,使猪皮表面产生大大小小的泡状凸起,在结构改变的同时,又赋予新的口感。     

油炸食品吸油过程的机制分析

以油炸冷冻土豆条为研究对象,研究了油炸过程和冷却过程中,样品表面温度和内部温度的变化,以及因温度变化引起的蒸汽压力的变化。测量数据表明:在油炸过程中,食品的内部温度升至水的沸点后不再增加,食品的表面温度很快升至比油温低20～30℃左右就不再变化;在冷却过程中,食品的表面温度很快下降;而食品内部温度降低较慢。对吸油的两种驱动机制进行了比较分析,最终确定毛细吸力对吸油的影响较小,大部分的吸油是因为食品内水蒸汽冷凝而带来的表面壳层孔洞内外压力差而导致的。