深度油炸过程中油脂劣变对薯条中油脂和水分含量的影响及水分替代规律

为研究马铃薯条对不同油脂的吸收规律,使用深度油炸1、3、5 d后的大豆油、油茶籽油及两种油脂不同比例调和油煎炸马铃薯条,测定马铃薯条在油炸过程中总油脂、表面油脂、结构油脂、水分含量的变化。结果发现:对于同一种油脂来说,马铃薯条中总油脂含量随油炸时间的延长而增加;对于各新鲜油脂处理组马铃薯条,当油炸时间小于150 s时,总油脂含量随油炸时间的延长而明显增加,当油炸时间超过150 s时,总油脂含量随油炸时间的延长变化不明显,油炸240 s后的总油脂含量接近0.22 g/g。油脂劣变程度对油炸马铃薯条的油脂含量有明显影响,对于相同劣变程度的油脂,随油炸时间延长,油脂黏度增大,马铃薯条对油脂吸附能力增强,表现为所有处理组马铃薯条的表面油脂含量的升高。在油炸过程中,当油炸时间小于120 s时,水分含量变化速率随着反复油炸时间的延长而降低;油炸150～240 s时,总油脂含量与水分含量的比值随着油炸时间的延长差异逐渐增加,其中在使用深度油炸3、5 d的油处理时,油茶籽油油炸组最高。     

不同煎炸阶段薯条和煎炸油中关键风味成分分析（网络首发、推荐阅读）

风味是薯条受欢迎程度的决定性感官特征。煎炸油一旦加热,油脂的变化会直接影响食物的风味。在高油酸菜籽油(RO)煎炸过程中,煎炸薯条(FF)的风味发展表现出三个明显的阶段,包括诱导阶段(总极性化合物(TPC)的含量为3.0%~8.0%)、最佳阶段(TPC的含量为8.0%~20%)和降解阶段(TPC的含量为22%以上)。为了区分各阶段的关键香气化合物,选择了极性化合物为3.0%(FF1)、10.5%(FF2)和27%(FF3)的高油酸菜籽油制备的薯条及其相关油(RO1、RO2、RO3)进行感官分析。结果表明,FF1中,(E,E)-2,4-癸二醛(油炸气味)含量较低,这可能是FF1样品感官评分较低的原因。与FF1和FF2相比,FF3具有较高的己酸(汗臭味)、庚酸、壬酸、苯乙醛和反式-4,5-环氧-(E)-2-癸烯醛(金属气味),导致FF3的风味恶化。此外,FF3中2,5-二甲基吡嗪和2-乙基-6-甲基-吡嗪的减少导致了较低的烘焙风味,可能使得感官评分下降。同样,RO3中(E)-2-十一烯醛、己酸、庚酸和壬酸含量较高,其酸败评分增加,从而降低感官评分。当TPC含量超过22%时,油的过氧化作用会引起酸败味,因此煎炸后期应加以控制,通过研究煎炸过程中关键风味物质的变化,对开发具有最佳风味的油炸产品有借鉴意义。     

石榴皮醇提物对薯条深度油炸过程中煎炸油氧化稳定性及丙烯酰胺含量的影响

考察不同添加量（0.01%、0.02%、0.03%、0.07%、0.14%）石榴皮醇提物（ethanol extract of pomegranate peel,EEPP）对薯条深度油炸过程中煎炸油的氧化稳定性和丙烯酰胺（acrylamide,AA）生成情况的影响。结果表明EEPP表现出较高的1,1-二苯基-2-三硝基苯肼自由基抑制率（20%～97%）、2,2’-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐阳离子自由基抑制率（16%～91%）和铁离子还原力（0.3～8.24 mmol/g）;其总酚含量为20.14 mg/g。相较于低添加量的EEPP,添加量为0.14%的EEPP对煎炸油中酸价、过氧化值和极性组分含量的增长速率延缓效果最好,从而表现出最高的氧化稳定性。另外,在此添加量下,对薯条和煎炸油中的AA也具有良好的抑制作用（抑制率达83%）。所以,EEPP具有成为新型抗氧化剂的潜在能力,以延缓薯条油炸过程中煎炸油的氧化劣变速率和有效抑制薯条油炸过程中AA的产生,确保煎炸食品的安全性。     

A Comparative Study of the Characteristics of French Fries Produced by Deep Fat Frying and Air Frying

Air frying is being projected as an alternative to deep fat frying for producing snacks such as French fries. In air frying, the raw potato sections are essentially heated in hot air containing fine oil droplets, which dehydrates the potato and attempts to impart the characteristics of traditionally produced French fries, but with a substantially lower level of fat absorbed in the product. The aim of this research is to compare: (1) the process dynamics of air frying with conventional deep fat frying under otherwise similar operating conditions, and (2) the products formed by the 2 processes in terms of color, texture, microstructure, calorimetric properties, and sensory characteristics. Although, air frying produced products with a substantially lower fat content but with similar moisture contents and color characteristics, it required much longer processing times, typically 21 min in relation to 9 min in the case of deep fat frying. The slower evolution of temperature also resulted in lower rates of moisture loss and color development reactions. Differential scanning calorimetry (DSC) studies revealed that the extent of starch gelatinization was also lower in the case of air fried product. In addition, the 2 types of frying also resulted in products having significantly different texture and sensory characteristics.     

Effect of the Addition of Basil Essential Oil on the Degradation of Palm Olein during Repeated Deep Frying of French Fries

The potential antioxidant power of basil essential oil under frying conditions was explored. Two concentrations (200 or 500 ppm) were added to palm olein (PO) to evaluate their effect on fat oxidation/degradation during repeated frying of French fries at 180 °C. A higher oxidative stability index was detected for PO with basil essential oil at 200 ppm. Both concentrations showed lower p‐anisidine values than PO without basil essential oil after 5 d of frying. Addition at 500 ppm resulted in the lowest total polar compounds and free fatty acids contents. Thus, the addition of basil essential oil improved the performance of PO during repeated frying of French fries.     

The influence of frying medium degradation on fat uptake and texture of French fries

The purpose of the present investigation was to study the influence of the degree of degradation of different kinds of oils used as a frying medium on fat uptake and texture of frozen pre‐fried French fries. As has been found, the degradation degree of the frying medium depends on the kind of oil and processing time. Liquid hydrogenated rapeseed oil exhibited the best thermo‐oxidative stability among the oils under investigation. The kind of oil influenced fat uptake and the texture of French fries. The lowest fat uptake was observed with French fries fried in solid oil. Some correlations between fat uptake and changes in fatty acid content were found in the frying medium during frying. Fat absorption increased with increasing unsaturated fatty acids and decreasing saturated fatty acid content. The texture of French fries fried in hydrogenated oils was harder than that exhibited by French fries fried in liquid rapeseed oil. The hardness of French fries fried in liquid oils decreased during frying while the hardness of French fries fried in solid oil increased. Some correlations between the texture of French fries and iodine value and fatty acids content of frying media were found. The hardness of French fries increased with increasing content of saturated fatty acids and decreasing unsaturated fatty acids and trans isomer fatty acid content. Copyright © 2005 Society of Chemical Industry     

三种多羟基醇协同海藻酸钠处理对油炸薯条吸油量和品质的影响

为了减少油炸薯条吸油量,探讨不同浓度多羟基醇协同1%海藻酸钠溶液预处理薯条对油炸薯条脂肪含量的影响,利用不同浓度的多羟基醇(木糖醇、山梨醇及丙三醇)溶液协同1%海藻酸钠溶液预处理自制薯条与商业冷冻薯条,研究薯条吸油量、质构、色差的变化。结果表明:在自制薯条中,经木糖醇、山梨醇与丙三醇协同1%海藻酸钠溶液分别处理的薯条,与不做任何处理的油炸薯条相比,脂肪含量分别减少了20.45%(1%海+0.5%木)、53.00%(1%海+0.25%山)、48.72%(1%海+0.75%丙),而与仅仅涂抹1%的海藻酸钠溶液的油炸薯条相比,脂肪含量分别减少了18.35%(1%海+0.5%木)、51.75%(1%海+0.25%山)、47.37%(1%海+0.75%丙)。而商业冷冻薯条,与不做任何预处理的油炸鲜样和仅涂抹1%海藻酸钠溶液组相比,脂肪含量反而分别增加了12.29%和29.11%(1%海+1%木)。同时,木糖醇处理还能显著提高薯条L^*(p<0.05)和咀嚼性(p<0.05)。木糖醇对自制薯条具有减油效果,且作用效果是山梨醇 > 丙三醇 > 木糖醇,三种多羟基醇能改善自制薯条的色差与质构。     

Effect of frying variables on French fry properties

This work focuses on the effect of frying variables (repeated frying, potato‐to‐oil ratio, potato distribution in the fryer, oil type and potato variety) on French fry properties (water content, oil content, crust thickness and shrinkage). Furthermore, the rate of change in French fry properties during a frying batch is investigated. The temperature was acquired in several positions within the oil and the potato. It was found that when repeated frying was conducted up to regulation limits for frying oil use, the examined French fry properties were not significantly affected. On the contrary, the potato‐to‐oil ratio, potato distribution and potato variety significantly affected the water content of French fries. The most significant changes occurred during the first 1–2 min of a frying batch. According to the temperature measurements, the crust‐core front continued to advance after this first frying period. However, there was no observable crust thickness increase; this was attributed to crust shrinkage.     

添加不同成分的外裹糊鱼块深度油炸过程中的传质动力学

将大豆纤维、黄原胶和乳清蛋白分别添加到基本外裹糊（中筋小麦粉、玉米淀粉、泡打粉、食盐）中制成 外裹糊鱼块,在170 ℃大豆油中油炸30、60、90、120、150 s和180 s,测定油炸外裹糊鱼块的水分及油脂、表面油 脂和表面渗透油脂质量分数,采用菲克第二定律和一级动力学方程分析油炸过程中的传质动力学,通过苏丹红染 色实验模拟油脂吸收。结果显示：大豆纤维组、黄原胶组和乳清蛋白组外壳水分质量分数均随油炸时间的延长而降 低,而鱼块水分质量分数先降低后升高再降低;油炸0～120 s时,大豆纤维组、黄原胶组和乳清蛋白组外壳油脂质 量分数均升高,油炸120～180 s时降低。菲克第二定律拟合大豆纤维组、黄原胶组和乳清蛋白组水分扩散系数分别 为0.003 8、0.003 3 s－1和0.003 9 s－1;一级动力学方程拟合大豆纤维组、黄原胶组和乳清蛋白组油脂吸收的传质系数 分别为0.062、0.059 s－1和0.061 s－1。油炸30～60 s,3 组外裹糊鱼块的油脂渗透幅度差异不显著;油炸90～180 s, 乳清蛋白组油脂渗透最深,黄原胶组最浅。表明外裹糊中分别添加大豆纤维、黄原胶和乳清蛋白影响了外裹糊鱼块 深度油炸过程中的水分蒸发和油脂吸收,导致传质系数差异明显。     

煎炸薯条条件对高油酸葵花籽油中饱和型甘油酯核心醛生成的影响

为对煎炸过程中甘油酯核心醛(GCAs)的调控提供指导,以高油酸葵花籽油煎炸薯条实验为例,探讨煎炸方式、频次、温度以及油料比对煎炸过程中9-氧代壬酸酰基甘油三酯(9-oxo)、8-氧代辛酸酰基甘油三酯(8-oxo)两种饱和型GCAs生成的影响。结果表明：间歇煎炸较连续煎炸更易导致GCAs的生成;每小时煎炸1批次薯条所产生的饱和型GCAs低于每小时煎炸2批次和4批次的;随着煎炸温度的降低,两种饱和型GCAs含量均减少;油料比为10∶1时,两种饱和型GCAs含量整体较低。综上,为控制饱和型GCAs的生成,需采用连续煎炸方式,尽量降低煎炸温度和煎炸频次,控制油料比为10∶1。     

小麦淀粉和谷蛋白互作对油炸外裹糊鲢鱼鱼糜块油脂分布的影响

采用小麦淀粉和谷蛋白以质量比15∶1、13∶1、11∶1、9∶1和7∶1为外裹糊制作油炸外裹糊鲢鱼鱼糜块,测定外壳中谷蛋白的表面疏水性（H0）、游离巯基含量、二硫键含量及二级结构、小麦淀粉的晶体结构、油炸外裹糊鱼糜块的表面油脂及表面渗透油脂含量,观察外壳的微观结构和油脂分布;探讨小麦淀粉与谷蛋白相互作用对油炸外裹糊鱼糜块油脂分布的影响。结果显示：随着小麦淀粉和谷蛋白质量比减小,H0先升高后降低,游离巯基含量逐渐减少,二硫键含量逐渐增加;谷蛋白的β-转角结构向β-折叠转化;表面油脂、表面渗透油脂的含量和小麦淀粉的相对结晶度呈先降低后升高的趋势;外壳中的孔隙先减小后增大,油脂分布呈先减少后增加的趋势。小麦淀粉和谷蛋白质量比为11∶1时,H0(8 990)最高,小麦淀粉的相对结晶度（17.8%）、表面油脂（2.1%）和表面渗透油脂的含量（5.8%）最低,外壳的结构最紧密,油脂分布最少。以上结果表明,外裹糊中小麦淀粉和谷蛋白质量比改变了其相互作用,最终影响了油炸外裹糊鱼糜块中的油脂分布。     

亲水胶体对油炸外裹糊鱼块油脂含量及品质的影响

通过分析外裹糊中添加瓜尔豆胶、卡拉胶、海藻酸钠、黄原胶和羧甲基纤维素钠（carboxymethylcellulosesodium,CMC-Na）的油炸外裹糊鱼块油脂含量、水分含量、裹糊率以及色度、质构和微观结构,探讨亲水胶体对油炸外裹糊鱼块品质的影响。结果显示,与未添加亲水胶体组（外壳油脂含量22.67 g/100 g,鱼块油脂含量1.58 g/100 g）相比,添加0.3%（质量分数,下同）瓜尔豆胶、卡拉胶、海藻酸钠或0.4%黄原胶、CMC-Na时,油炸外裹糊鱼块的外壳和鱼块的油脂含量较低,外壳和鱼块的水分含量及裹糊率较高。其中添加0.4%黄原胶组的减油效果最好（外壳和鱼块的油脂含量分别为17.96、1.01 g/100 g）,且油炸外裹糊鱼块外壳金黄色、酥性值较高、硬度较低,鱼块的弹性、咀嚼性好;苏丹红染色幅度较轻,外壳微观结构紧密,鱼块无较大气孔形成。     

基于传质特性研究油种类对煎炸薯条质构的影响（网络首发、推荐阅读）

以"荷兰十五"品种的马铃薯和4种食用油为研究对象,考察煎炸过程中油种类对薯条质构、失水吸油动力学常数、水分空间分布、晶体结构以及微观结构的影响。结果表明:棕榈油和米糠油炸制薯条的表面硬度高于其它两种油。水分损失动力学结果表明使用棕榈油炸制薯条的表面水分损失速率最快(0.053 6 s^-),其次是米糠油(0.027 5 s^-),高油酸葵花油最慢(0.021 6 s^-1)。核磁共振影像也证实了这一结果。X-射线衍射结果表明米糠油和棕榈油炸制薯条的淀粉-脂质复合物含量高于其它两种油。扫描电镜结果表明棕榈油和米糠油炸制薯条的表面比其它油更致密。表面失水快、淀粉-脂质复合物含量高以及表面的致密性对薯条质构的增加起到重要的作用。     

Effect of pre-drying and par-frying conditions on the crispness of French fries

An experimental design was used to study the effect of pre-drying (to 10, 15 and 20% weight loss) and par-frying conditions (160, 170 and 180 °C) on the crispness of French fries. Par-frying time was adjusted with a software program to obtain equal moisture content and internal texture for all samples. Crispness was evaluated with a sensory panel. Furthermore, samples were analysed with a texture analyser and with confocal scanning laser microscopy (CSLM). Par-frying at 180 °C resulted in a crispier product than at 160 and 170 °C. Pre-drying to 20% weight loss lead to blisters and reduced crispness in comparison with pre-drying to 10 and 15% weight loss. Instrumental texture measurements showed a good correlation with sensory crispness. Large differences in cell structure, such as blisters, could be observed with CSLM. CSLM was useful to explain results from the instrumental and sensory texture evaluation.     

薯条煎炸工艺参数对高油酸葵花籽油中不饱和型 甘油酯核心醛生成的影响

为调控煎炸过程中非挥发性甘油酯核心醛（GCAs）的生成,更合理地进行煎炸,通过高油酸葵花籽油煎炸薯条实验,探究煎炸方式、煎炸批次、煎炸温度以及油料比对10-氧代-8-癸烯醛酸酰基甘油三酯（10-oxo-8）和11-氧代-9-十一碳烯醛酸酰基甘油三酯（11-oxo-9）两种不饱和型GCAs生成的影响。结果表明：与间歇煎炸相比,连续煎炸产生更少的11-oxo-9,两种煎炸方式下10-oxo-8的含量总体上差异不大;每小时煎炸1批次薯条较煎炸多批次薯条生成的不饱和型GCAs更少,且煎炸油中的10-oxo-8和11-oxo-9含量与煎炸批次整体呈正相关;煎炸温度为160 ℃时较140 ℃和180 ℃生成的不饱和型GCAs更少;油料比为30∶ 1时,不饱和型GCAs总体含量较低。综上,为降低高油酸煎炸油中GCAs的含量,可采用连续煎炸方式并尽量控制煎炸批次,保持煎炸温度在160 ℃,控制油料比为30∶ 1。     

可食性膜降低油炸鱼块含油量的研究

通过研究3 种可食性膜对降低油炸鱼块含油量的影响,探讨不同可食性膜、可食性膜在挂糊时的添加次序、可食性膜的质量分数以及不同比例的混合可食性膜复配后对油炸鱼块含油量的影响及其抑油效果。研究表明：3 种可食性膜与对照组相比均有显著的抑油效果(P ＜ 0.05),其中羧甲基纤维素钠(CMC-Na)效果最好,海藻酸钠次之,阿拉伯胶最小,其质量分数2% 的抑油率分别达到21.33%、16.97% 和9.99%;3 种可食性膜均在挂糊中添加的抑油效果最好;复配后按照CMC-Na:海藻酸钠=1:2 的比例配制的挂糊液抑油效果最好,其1% 质量分数的抑油率达到34.54%。     

Effect of an Ethanol Extract from Summer Savory (Saturejae hortensisL) on the Stability of Sunflower Oil at Frying Temperature

The effect of the ethanol extract from Saturejae hortensis L on the oxidative and thermal processes occurring in sunflower oil during its high-temperature treatment (180°C) was investigated. The changes during simulated deep fat frying were monitored by determination of the oxidation stability at 100°C, as well as by determination of unchanged triacylglycerols. It was established that the addition of 1 and 5 g kg^-1 ethanol extract from S hortensis L leads to a decrease in the oxidative and thermal changes in the oil. The ethanol extract from S hortensis L improved the oxidative stability of sunflower oil even after 50 h at 180°C and it inhibited the oxidative processes more than the thermal processes under these conditions. © 1997 SCI.