3种食用油在薯条煎炸过程中的品质变化

以大豆油、葵花籽油、棕榈油为研究对象,探讨在(180±5)℃条件下煎炸薯条,每天连续煎炸4h,共煎炸5d后各食用油理化指标的变化。结果表明:随着煎炸时间延长,3种食用油的色泽加深、黏度增加;酸价(AV)显著增加,但未超过国家标准;碘价(IV)则随着煎炸过程进行而逐步降低;过氧化值(POV)在煎炸过程中均先上升后下降,其中大豆油和葵花籽油的POV呈波动性;煎炸3d后,大豆油、葵花籽油的羰基值(CV)超过或非常接近国家标准50meq O2/kg,煎炸4d后,两种油的极性化合物(TPM)含量超过国家标准;整个煎炸过程中棕榈油的CV和TPM含量均低于大豆油和葵花籽油。     

玉米油在油条煎炸过程中的品质变化

以玉米油在190℃下连续煎炸油条32h,每2h取一次煎炸油样,对其感官、理化指标、VE、脂肪酸等指标进行检测,研究玉米油煎炸油条过程中的品质变化。结果表明:连续煎炸32h后,玉米油的吸光度OD448nm由0.028上升到0.673,酸价从0.33mg KOH/g增大至2.40mg KOH/g,羰基价由7.78 meq/kg增大至97.40 meq/kg,极性组分由3.81%增加至30.16%。依据GB 7102.1—2003中的相关规定,玉米油在190℃下连续煎炸油条不宜超过18h。     

高油酸葵花籽油与普通葵花籽油在煎炸性能上的比较研究

对高油酸葵花籽油与普通葵花籽油的脂肪酸组成及含量进行对比研究,探讨2种葵花籽油在煎炸过程中的品质变化。结果表明:在(180±5)℃煎炸24 h过程中,高油酸葵花籽油和普通葵花籽油的极性组分、酸价和共轭二烯值(CD)都呈持续上升的趋势,2种油样丙二醛含量(MDA)都呈现升降交替变化,整体呈上升趋势。综合来看,高油酸葵花籽油与普通葵花籽油在煎炸性能上差异不大。     

棕榈油在面制品煎炸过程中的品质变化

以棕榈油作为煎炸用油,面制品为原料,在连续无添加新油的油炸模拟体系中,探究不同油炸温度和油炸时间对煎炸油中极性组分(PC)含量、酸价(AV)、甘油三酯聚合物(TGP)含量、脂肪酸组分、多环芳烃(PAH4)含量影响及相关性进行研究.结果 表明,随着煎炸时间延长,AV、TGP含量、PAH4含量、PC含量和饱和脂肪酸(SFA...     

大豆油煎炸过程中的品质变化研究

以无抗氧化剂精炼大豆油为原料煎炸冷冻薯条,研究了大豆油煎炸过程中脂肪酸组成以及理化指标酸值、羰基值、过氧化值和极性物质的变化,并对脂肪酸组成变化与理化指标变化之间的关系进行了讨论。结果表明:在40 h的煎炸过程中,大豆油饱和及单不饱和脂肪酸含量增加,多不饱和脂肪酸含量减少,且煎炸时间在0~30 h内脂肪酸增加量与减少量基本相当;过氧化值先增大后减小再增大;羰基值先缓慢增加后快速增加再缓慢增加;极性物质先缓慢增加后快速增加;酸值匀速增加;16碳脂肪酸增加量、氢过氧化物分解量及羰基值增加量的变化趋势相吻合。     

食用油煎炸过程中的品质变化研究

油炸食品是中国的传统食品,深受广大消费者的喜爱。然而食用油随着煎炸时间的延长,逐渐分解聚合,产生大量的严重影响食品品质及风味的醛、酮、酸、聚合物等物质,其对人体的健康存在着潜在的危害,甚至可以致癌。在食用油煎炸过程中,对油脂品质相关的指标(包括酸值、碘值、皂化值、过氧化值、脂肪酸组成、氧化稳定性、黏度、聚合物的含量以及甘一酯、甘二酯和甘三酯的含量)进行检测,结果表明,随着煎炸时间的延长,煎炸油中的聚合物含量大大升高,黏度增大,有少量甘二酯生成,不饱和脂肪酸含量下降,碘值、皂化值降低,酸值、过氧化值升高。     

棕榈油和棉籽油硬脂在油条煎炸过程中的品质评价

将棕榈油和棉籽油硬脂分别进行32 h 的连续深度煎炸,检测过程中的质量指标,评价其煎炸特性。结果表明,在32 h 连续深度煎炸过程中,随着煎炸时间的延长,棕榈油颜色加深更明显,其极性组分含量和酸价增加更多,碘值更低,两种油的过氧化值变化均不明显,但所有指标均在国标规定范围内。两种煎炸油的饱和脂肪酸（saturated fatty acid,SFA）的含量均增加,单不饱和脂肪酸（monounsaturated fatty acid,MUFA）和多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）的含量减少,棉籽油硬脂的SFA 增加更多。两种煎炸油的反式脂肪酸（trans fatty acid,TFA）含量均随煎炸时间的延长而增加,其中棕榈油的TFA 含量增加更多。棉籽油硬脂作为煎炸油煎炸后的食品酸价、极性组分含量、TFA 含量更低,颜色透亮,煎炸寿命长,稳定性好,食用安全,更符合现代消费者的消费观。     

亚麻籽油在煎炸过程中的品质变化

本文研究了常规煎炸条件下,经过不同煎炸时间的亚麻籽油营养成分、理化指标及有害物质含量,并通过主成分分析对其煎炸性能进行了综合评价。结果表明:未经煎炸的亚麻籽油不饱和度达81.77%,其α-亚麻酸的含量为47.50%,是一种富含多不饱和脂肪酸、高营养价值的食用油。亚麻籽油在170 ℃连续煎炸60 h（5 d）过程中,亚麻籽油的色泽、酸价、过氧化值、折光指数、羰基价、极性组分、生育酚含量、脂肪酸组成均有显著（P<0.05） 变化,煎炸全程没有产生苯并（α）芘;5种主要脂肪酸（α-亚麻酸、油酸、亚油酸、棕榈酸、硬脂酸）含量均呈下降趋势,C17:0以下的五种饱和脂肪酸（辛酸、癸酸、月桂酸、肉豆蔻酸、棕榈酸）含量均呈逐渐升高的趋势,其余脂肪酸呈下降趋势。通过煎炸性能分析,煎炸35 h后的亚麻籽油的酸价超过国家限量,其他项目均在国家限量范围以内,经综合评估30 h基本到达亚麻籽的煎炸使用极限,在30 h的煎炸时间内是一种健康良好的煎炸用油。     

石河子部分地区葵花籽油反式脂肪酸含量与品质分析

以石河子部分地区居民常食用的不同品牌、不同渠道购买的葵花籽油为样品,测定分析其反式脂肪酸的含量及品质,比较全精炼加工食用油与原生态作坊式加工食用油的反式脂肪酸含量及品质的不同。结果显示:在26个被检测产品中有7个食用油产品总反式脂肪酸的含量在1%以上,1个在2%以上,多数为全精炼油产品,过度加工带来了反式脂肪酸含量的升高。该地区的作坊式压榨制油加工程度低,品质偏低;高级精炼油加工程度高,品质较高。23.1%的产品酸值和42.3%的产品过氧化值指标不符合国家标准。抽样的产品不合格率为76.9%,经常购买散装油的居民需要注意食用油品质和卫生安全等方面的问题。     

煎炸条件对大豆油品质裂变的影响研究

研究大豆油(含0.02％TBHQ)在170℃、190℃、210℃条件下煎炸食品2、4、6h,油脂的酸值、过氧化值、p-茴香胺值、羰基值、维生素E、氧化脂肪酸、反式脂肪酸含量的变化;结果表明:煎炸温度越高、时间越长、油脂热氧化程度越大、理化特性变化及品质裂变程度越大.190、210℃煎炸6h,大豆油p-茴香胺值从原样0.36分别上升到156.3、175.8;羰基值达48.2、61.5 meq/kg;维生素E含量由89.5 mg/kg下降为8.3、5.19 mg/kg;反式脂肪酸含量由0.91％分别增加为1.76％、2.08％;氧化脂肪酸是原样0.92％的1.6倍和2.6倍以上;酸值由0.1 mgKOH/g增加到0.45、0.56 mgKOH/g.此研究结果说明:大豆油不宜在高于190℃以上的温度条件下长时间煎炸食品.     

煎炸米糠油营养成分及煎炸油条品质分析

利用米糠油连续煎炸油条32 h,通过对煎炸米糠油中谷维素、维生素E、植物甾醇含量,以及煎炸油条含油率、酸值、过氧化值、羰基值检测和感官指标评价,分析研究米糠油在煎炸过程中营养成分的变化及煎炸油条的品质。结果表明:经过32 h的连续煎炸,煎炸油条中米糠油的酸值(KOH)从0.73 mg/g逐渐增加至1.32 mg/g,过氧化值呈现波动增长的变化趋势(由0.05 g/100 g增大至0.08 g/100 g),羰基值从12.50 meq/kg逐渐增加至61.72 meq/kg;煎炸米糠油中谷维素含量相对稳定,植物甾醇含量有所降低(从1.67%降低至1.23%),维生素E含量从57.04 mg/100 g显著降低至1.18 mg/100 g;煎炸油条的平均含油率为12.38%;煎炸油条的含油率低、感官效果好。     

亚麻籽油和棕榈液油煎炸油条过程中的品质变化

为了获得亚麻籽油的最适煎炸条件,在（180±5） ℃下,以GB 2716—2018中规定极性化合物含量达到27%为煎炸终点,对亚麻籽油和棕榈液油在油条连续煎炸过程中理化指标进行检测和比较,同时对油条进行感官评定。结果表明：在连续煎炸油条过程中,两种植物油的酸值、总氧化值、极性化合物及聚合物含量均随着煎炸时间的延长而不断增加,但在4 h以内,亚麻籽油极性化合物含量较低;亚麻籽油的极性化合物含量在煎炸13 h后达到27.78%,而棕榈液油的极性化合物含量在煎炸18 h后达到27.27%;相较于棕榈液油,在油条煎炸过程中,亚麻籽油中多不饱和脂肪酸含量不断减少,尤其是α-亚麻酸下降幅度更大;亚麻籽油140 ℃下的氧化诱导期均在1 h以内,远低于棕榈液油;油条感官评定表明棕榈液油更适宜于油条煎炸。研究表明亚麻籽油适合短时（<4 h）高温煎炸,不建议长时间深度煎炸。     

高油酸葵花籽油煎炸过程中MCPD酯及缩水甘油酯的变化

以高油酸葵花籽油为煎炸用油对鱼排、鸡块和薯条进行煎炸实验,探究3-氯丙醇(3-MCPD)酯、2-氯丙醇(2-MCPD)酯和缩水甘油酯在煎炸过程中的变化。结果表明:原油中3-MCPD酯、2-MCPD酯及缩水甘油酯含量分别为0.26、0.05 mg/kg和0.58 mg/kg;在煎炸过程中2-MCPD酯含量与3-MCPD酯含量呈现极显著相关(p0.01);煎炸油中的MCPD酯在煎炸后有明显的生成;受煎炸材料的影响,3-MCPD酯含量在煎炸鱼排和鸡块体系煎炸12 h时达到最大值,分别为2.22 mg/kg和2.05 mg/kg,而后逐渐下降;3-MCPD酯含量在煎炸薯条体系中变化不大;缩水甘油酯含量则在所有体系中均下降,受煎炸材料的影响,缩水甘油酯分别在煎炸24 h(鱼排)、60 h(鸡块)和96 h(薯条)中基本降解完全。     

Oxidation of corn oil during frying of soy-flour-added flour dough

ABSTRACT:  Oxidation of corn oil during frying of soy–flour-added dough was studied. Flour dough containing soy flour at 0%, 10%, 20%, and 30% was fried in corn oil at 180 °C for 2.5 min, and a total of 60 fryings were performed every 30 min. The oxidation of oil was determined by contents of free fatty acids (FFA), conjugated dienoic acids (CDA), polar compounds, and p -anisidine values (PAV). Tocopherols and phospholipids (PLs) in the oil were determined by HPLC. Tocopherols were present in corn oil at 1000 ppm before frying and increased after the first frying of dough containing soy flour due to tocopherol transfer from soy–flour-added dough to the oil during frying. However, as the oil repeated frying, tocopherol contents decreased and its degradation rate was higher in the oil that fried soy–flour-added dough than in the oil that fried the dough without soy flour. PL was not detected in corn oil before and after frying. As the oil repeated frying, FFA, CDA, and polar compounds contents, and PAV of frying oil increased due to the oil oxidation. The values were higher in the oil which fried soy–flour-added dough than in the oil fried the dough without soy flour, indicating the acceleration of oil oxidation by soy flour added to dough. Increase in the oil oxidation by soy flour added to the dough was highly correlated with fast decomposition of tocopherol in the oil.     

Changes in quality and composition of sunflower oil during enzymatic degumming process

The objective of this study was to examine the effect of the enzymatic degumming process on composition of crude sunflower oil.     

Changes in oil and potato chips during frying

The effect of frying of potato chips (batch processing during 12 h) on the chemical characteristics and fatty acid composition of the used oil were determined. Samples of the fried oil and potato chips were taken at various time periods. The volatile carbonyl compounds of the aroma concentrate of each sample were isolated and their oxime derevatives were prepared and subsequently estimated by UV absorption for the total oximes and conjugated diene carbonyl oximes. The development of the volatile carbonyl compounds in both frying oil and fried potato chips was increased on continued frying. Concerning the frying oil this increase was found to be in coincident with the decrease in the linoleic and linolenic acid percent.     

Simultaneous monitoring of the conventional qualitative indicators during frying of sunflower oil

Deterioration of sunflower oil during a 32 h frying was studied by monitoring the levels of polar compounds (total content, TPC; triglyceride polymers, TGP; triglyceride dimmers, TGD; oxidised triglyceride monomers, oxTGM; diglycerides, DG; and free fatty acids, FFA), carbonyl value (CV), oil/oxidative stability index (OSI), and conjugated diene value (CDV). The frying process increased the level of TPC in the oil from 2.8% to 28.9%. The TGP, TGD, oxTGM, DG, and FFA increased 186.5, 29.1, 6.1, 5.1, and 5.4 times, respectively. The CV, OSI, and CDV changed from 7.9 μmol/g, 2.7 h, and 10.6 mmol/l to 70.9 μmol/g, 1.2 h, and 61.6 mmol/l, respectively. The TPC or TGDP (TGD + TGP) contents were significantly correlated with the CV, OSI, or CDV. Finally, it was recommended that the sunflower oil should be discarded at 10% TGDP, 20% TPC, or 44 mmol/l CDV.