测定油脂极性组分不同柱层析技术的比较

以现行的油脂极性组分检测ISO 8420(2002)为依据,对GB/T 5009.202—2003《食用植物油煎炸过程中的极性组分(PC)的测定》的柱层析法,GB 5009.202—2016《食品安全国家标准食用油中极性组分(PC)的测定》中的制备型快速柱层析法和柱层析法进行比对实验。结果发现:GB/T 5009.202—2003的柱层析法的检测结果与ISO标准的检测结果差异较大,一致性差;而GB 5009.202—2016中的制备型快速柱层析法和柱层析法的检测结果与ISO标准的检测结果基本一致。     

Rapid determination of polar compounds in frying fats and oils using image analysis

Fats and oils were exposed to high temperature at 145°C for 80 h with frying steamed noodles, and the polar compounds were determined using a standard column chromatography and a novel image analysis method. The image was separated into polar and nonpolar component on TLC plate, and recorded with a camera. When the original image was transformed into 3 monochrome components of red, green and blue, respectively, pseudo-mass (the intensity-weighted area) ratio of image processed with a red-frame was highly correlated with real mass determined by column chromatography. The content of polar compounds for respective frying oils was calculated with the standard curves of first order regression that showed the determination coefficients of R²>0.8 (P<0.001). Consequently, it seemed that image analysis on polar compound could replace the extremely time and chemical consuming standard method for estimating the quality of frying fats and oils.     

介电常数在煎炸油极性组分快速检测中的应用

介电常数与煎炸油中极性组分含量有较好相关性,用于评价煎炸油品质,具有快速、便捷、安全等优点。本文分析了液体介电特性的测试原理和煎炸油介电特性机制,列出极性组分和介电常数的相关性拟合模型。以商业化应用广泛的FOS、FOM 310、Testo 270三类快速检测仪器为对象,对其内部构造、仪器操作和数据可靠性进行评价,结合餐饮业实践经验总结了影响其检测准确度的主要因素,包括煎炸油品种、校准体系、悬浮物、操作规范性。最后,提出此快速检测技术未来的两大发展方向:对信号处理参数的特异性优化和对数据处理技术或红外在线检测技术的引入结合。     

不同煎炸用油制备河豚鱼汤挥发性风味成分的差异性

采用顶空固相微萃取-气相色谱-质谱联用技术分析不同煎炸用油制备的河豚鱼汤中挥发性风味物质,利用相对气味活度值结合主成分分析确定其特征风味成分。结果表明,不同煎炸用油制备的河豚鱼汤中挥发性风味物质种类与相对含量差别较大,5种不同鱼汤中共检出69种挥发性物质,其中清汤,猪油、大豆油、花生油、橄榄油煎炸后熬煮制得鱼汤分别检测出46、30、38、32、32种。主成分分析能较好地区分不同组鱼汤,清汤的特征风味物质为庚醛、壬醛、癸醛、反-2-癸烯醛、反,反-2,4癸二烯醛、三甲胺;猪油煎炸后熬煮制得鱼汤的特征风味物质为己醛、庚醛、反-2-辛烯醛、壬醛、癸醛、反-2-癸烯醛、反,反-2,4-癸二烯醛、反-2-十一醛、2-戊基呋喃;大豆油、花生油、橄榄油煎炸后熬煮制得鱼汤的特征风味物质为壬醛、癸醛、反-2-癸烯醛、反,反-2,4-癸二烯醛。     

制备型快速柱层析检测煎炸油极性组分含量

采用制备型快速柱层析,建立快速分离制备并检测煎炸油中极性组分含量的技术。利用油脂极性组分专用中压制备液相色谱技术,用专用的商品化FLASH柱为分离制备色谱柱,以体积比8713的石油醚—乙醚为洗脱液,洗脱液流速25mL/min,发现当非极性组分洗脱11 min时,恰好能实现煎炸油中极性与非极性组分的分离,且分离速度快,仅需41min,检测重复性RSD5%,均优于传统人工柱层析技术,与传统人工柱层析技术的相比,其相对偏差也±6%,表明基本一致。     

Effects of frying on polar material and free fatty acids in soybean oils

The purpose of this study was to investigate the quality deterioration of pressed soybean oil (PSBO), first grade solvent extracted soybean oil (FG‐SESBO) and third grade solvent extracted soybean oil (TG‐SESBO) with respect to time at 180 °C. It was found that there was a significant increase in total polar material (PM; P < 0.01) and free fatty acids (FFA; P < 0.05) in PSBO, FG‐SESBO and TG‐SESBO with increased time of frying. After forty‐five frying cycles, the final concentration of total PM was significantly higher in TG‐PSBO (30.39%) than in PSBO (21.10%) and FG‐SESBO (25.93%; P < 0.05). During frying cycles, the final acid value (AV) was significantly higher in PSBO (0.84 ± 0.02 mg KOH/g fat) than in TG‐SESBO (0.59 ± 0.01 mg KOH/g fat) and FG‐SESBO (0.56 ± 0.03 (mgKOH/g oil; P < 0.05). The content of saturated fatty acids in the three types of frying oils was significantly increased after forty‐five cycles of frying. However, even larger changes were observed in the content of unsaturated fatty acids, with decreases in C18:2, 9 c 12 c and C18:3, 9c 12c 15c and increase in C18:1, 9 c. The highest increasing slopes of PM and AV were observed in the TG‐SESBO.     

Comparison of different methods to determine the spreadability and firmness of processed cheese

Summary Current texture-measuring instruments and a recently developed measuring method (two-dimensional measuring of the force necessary to spread a sample) were compared in measuring the spreadability of processed cheese. How far subjective assessment by a qualified panel correlates with the instrumental results in determining spreadability and firmness was also investigated. Samples of processed cheese with various consistencies were measured by an Universal testing machine, a buttermeasuring instrument (DIN 10331), a rotational-type rheometer (oscillation mode) and a two-dimensional force measuring instrument. The evaluation of the results shows that an oscillating rheometer is most suitable to measure the spreadability of processed cheese; the correlation coefficient (r) between the dynamic Weissenberg number, calculated from parameters of the rheometer, and the subjective judgement by the panel wasr=0.91. For the determination of firmness the two-dimensional force measuring instrument is most suitable. The correlation coefficient between the parameter tangential energy (S _t) and the sensorially evaluated firmness wasr=0.95.

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Vergleich verschiedener Bestimmungsmethoden für die Streichfähigkeit und Festigkeit von Schmelzkäse

Zusammenfassung Verschiedene gebräuchliche Meßinstrumente und ein neu entwickeltes Gerät zur zweidimensionalen Messung der Kräfte, die zum Ausstreichen einer Probe erforderlich sind, wurden vergleichend zur Charakterisierung der Streichfähigkeit von Schmelzkäse erprobt. Dabei wurde auch geprüft, inwieweit die subjektiven Beurteilungen eines qualifizierten Prüferpanels mit den Meßwerten für Streichfähigkeit und Festigkeit korrelierten. Gemessen wurde mit einer Universalprüfmaschine, dem Butterprüfgerät (DIN 10331), einem Rotationsrheometer und mit dem zweidimensional registrierenden Kraftmeßgerät. Dabei zeigte sich, daß das Rheometer im oscillierenden Modus die Streichfähigkeit am besten zu charakterisieren vermag. Die Korrelation zwischen den Rheometerwerten, berechnet als dynamische Weissenbergzahl, und den sensorisch ermittelten Werten für die Streichfähigkeit betrugr=0,91. Zur Bestimmung der Festigkeit ist das zweidimensional registrierende Kraftmeßgerät am besten geeignet, was sich in einem Korrelationskoeffizienten vonr=0,95 zwischen dem ParameterS _t und den im Sensoriktest ermittelten Werten für dieFestigkeit ausdrückt.

     

便携式煎炸油极性组分快速检测仪的设计

介绍了一种采用传感器方法检测煎炸油极性组分的检测仪。该仪器利用叉指电极式电容传感器检测煎炸油介电常数的变化情况,通过一个电容/频率转换电路将电容的变化量转换为便于测量的频率形式,测得输出频率的变化情况反映煎炸油介电常数的变化情况。最后实验结果表明:使用该仪器测得的输出频率变化量与柱层析法测得的煎炸油极性组分变化量之间具有较好的相关性。这种检测方法可用于实际检测,且该仪器便于携带、检测速度快,便于现场检测。     

煎炸油中反式脂肪酸和极性化合物检测方法及防控措施研究进展

油脂在煎炸过程中会产生反式脂肪酸（TFA）和极性化合物（TPC）等危害因子,长期摄食会在体内蓄积,影响婴幼儿生长发育,引发心脏病、血栓、2型糖尿病、癌症等。对煎炸油中TFA和TPC的分析检测方法、危害及防控措施进行综述,旨在寻找快速有效的分析检测方法,并通过相应措施降低其含量。提出选择合适的煎炸温度,缩短煎炸时间,减少反复煎炸次数,选择饱和程度较高、氢化程度较低的煎炸油,选择合适的煎炸食品,添加适当种类和浓度的抗氧化剂等可降低煎炸油中TFA和TPC的含量。     

煎炸时间对不同食用油脂品质的影响

目的探讨煎炸时间对不同油脂的热稳定性的影响,通过对不同种油脂观察对比,选择适合煎炸食品使用的油脂。方法以酸价(acid value,AV)、过氧化值(peroxide value,POV)羰基价(carbonyl group value,CGV)为指标,对于不同油脂在不同煎炸时间下,观察油脂理化指标和品质的裂变程度的变化。结果随着煎炸时间的增加,油脂的酸价、过氧化值、羰基价呈现增加趋势。结论 4种油脂对煎炸时间的稳定性为:花生油玉米油大豆油葵花籽油。     

煎炸油中极性物质与酸价之间的相关性研究

本实验以油茶籽油、橄榄油和棕榈油为研究对象,研究经过180℃下油炸薯条后三种油的酸价与极性物质的相关性以及主要脂肪酸的变化。发现,三种油随着油炸时间的增加酸价(p<0.05)显著增大。油茶籽油、橄榄油和棕榈油的最终酸价分别为0.32、0.66、0.58mg/g。经过20次油炸,三种油的总极性物质(TPC)显著增加,油茶籽油、橄榄油和棕榈油总极性物质分别为16.01%、20.91%和17.66%。随着油炸时间的增加,三种煎炸油的饱和脂肪酸含量显著增加。不饱和脂肪酸的含量变化较大,C18∶2和C18∶3显著下降,而C18∶1逐渐下降。      

Chemistry of deep-fat frying oils

ABSTRACT:  Deep-fat frying produces desirable or undesirable flavor compounds and changes the flavor stability and quality of the oil by hydrolysis, oxidation, and polymerization. Tocopherols, essential amino acids, and fatty acids in foods are degraded during deep-fat frying. The reactions in deep-fat frying depend on factors such as replenishment of fresh oil, frying conditions, original quality of frying oil, food materials, type of fryer, antioxidants, and oxygen concentration. High frying temperature, the number of fryings, the contents of free fatty acids, polyvalent metals, and unsaturated fatty acids of oil decrease the oxidative stability and flavor quality of oil. Antioxidant decreases the frying oil oxidation, but the effectiveness of antioxidant decreases with high frying temperature. Lignan compounds in sesame oil are effective antioxidants in deep-fat frying.     

硅胶柱层析分离煎炸油中极性和非极性组分的研究

用硅胶柱层析分离煎炸油脂中的极性组分和非极性组分,对其中非极性组分洗脱剂的使用体积进行优化,通过研究各个洗脱馏分中非极性组分洗脱质量的变化,用薄层色谱(TLC)对分离效果进行验证并对油脂标准极性组分和标准非极性组分进行回收率的试验,发现当非极性组分洗脱剂的使用量为200 m L时,不仅实现了油脂极性组分和非极性组分的分离,而且油脂的极性组分和非极性组分的回收率都几乎是100%。     

电导率法快速检测前炸油中极性化合物含量的研究

为了研究煎炸油中极性化合物含量的电导率法快速捡测技术,对不同煎炸油极性化合物含量与其电导率之间的关系、电导率法的重复性及准确度进行了实验.结果表明,四种煎炸油的极性化合物含量与其电导率之间均存在较好的相关性,相关系数R2分别为0.9737、0.9835、0.9611、0.9645.煎炸油的电导率测定具有较好的重复性,随机选择5组煎炸油样进行电导率的重复测定,测定结果的相时标准偏差为2.78%～4.27%,均小于5%.柱层析法测定的煎炸油极性化合物舍量与电导率法测定的煎炸油极性化合物含量之间具有较好的相关性,相关系数R2为0.9862,方法的准确度较好.电导率的测定方法具有快速、简便的特点,可以代替柱层析法时煎炸油的极性化合物含量进行测定.     

Analysis of trans fatty acids in deep frying oils by three different approaches

Simulated frying experiments were performed on three different types of oils with French fries as the fried food. Comparison of frying oil samples was then made with their control counterparts (i.e. oil samples heated without food). Three different methods, gas chromatography (GC), attenuated total reflection (ATR) AOCS method Cd 14d-99 and attenuated total reflection negative second derivative absorbance (−2D ATR), were applied to quantify total trans fats. The total trans fats were found to be higher in the frying oil samples as compared to the control samples, which might be due to the presence of a high amount of trans fats in the pre-fried and frozen French fries. In general, the ATR AOCS method Cd 14d-99 produced lower amounts of trans fatty acids and the −2D ATR absorbance method produced higher amounts when compared with those obtained by gas chromatography.     

不同取样方法测定果醋饮料中的挥发性成分

试验采用贮藏一段时间瓶装果醋饮料的顶空取样、光照后顶空取样、固相微萃取三种取样方法,运用气相色谱-质谱对饮料中的挥发性成分进行了分析.结果表明,对于果味较强的瓶装果醋饮料挥发性成分的定性分析,无需用固相微萃取,而采用瓶装果醋饮料顶空取样就可达到分析的目的.     

Composition, stability and acceptability of different vegetable oils used for frying peanuts

The purpose of this work was to determine the chemical stability of vegetable oils in the frying process and the consumer acceptance of fried-salted peanuts prepared in different vegetable oils. Fatty acids composition was determined in sunflower, corn, soybean, peanut and olive oils. A chemical study (free fatty acid and p-anisidine values) of these oils at frying temperature (170 °C) was developed during 96 h. Consumer test of fresh products was performed on fried-salted peanuts prepared in the different oils. Peanut oil and virgin olive oil presented oleic acid as predominant fatty acid (44.8% and 64.2%, respectively), making it more resistant to lipid oxidation at frying temperature than the other refined vegetable oils (sunflower, corn and soybean oils). Virgin olive and peanut oils showed less increment of free fatty acids and p-anisidine value than the other oils along the heating essay. In addition, fried-salted peanuts prepared with refined peanut oil showed higher consumer acceptance than those prepared with other vegetable oils such as sunflower, corn, soybean and olive oils. Peanut oil could be used to fry peanuts obtaining products with higher consumer acceptance and shelf-life, thus preventing loss of their sensory and nutritional quality.     

3种油脂煎炸过程极性组分与甘油三酯聚合物及多环芳烃相关性研究

以花生油、菜籽油和葵花籽油的连续煎炸油条的试验为例,对煎炸过程极性组分(PC)、甘油三酯聚合物(TGP)及多环芳烃(PAHs)形成及相关性进行研究。结果表明:3种油脂中PC、TGP及PAHs含量均随煎炸时间的延长而增加;经过32 h的煎炸,花生油中PC、TGP与PAH16含量分别从未煎炸时的3.34%、0.43%、169.88μg/kg增至29.00%、16.92%、282.66μg/kg,菜籽油中PC、TGP与PAH16含量分别从4.02%、0.51%、18.85μg/kg增至25.80%、15.55%、42.92μg/kg,葵花籽油中PC、TGP与PAH16含量分别从2.43%、0.42%、21.49μg/kg增至34.19%、24.76%、51.95μg/kg;煎炸过程菜籽油PC增幅最小,至32 h煎炸结束,PC含量未超出国标限量(≤27%);煎炸过程中PC与TGP、PC与PAH4含量间均呈显著的正相关,根据相关性方程可以通过PC含量对煎炸油中TGP与PAH4含量进行预测。综合考虑煎炸在用油的安全性,除根据国标对PC含量进行检测和控制之外,还应关注TGP及PAHs在煎炸过程的变化情况。