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1.
Physicochemical properties and oxidative stability of refined coconut oil (RCO), refined soybean oil (SBO), pure olive oil (POO), and vegetable shortening (VST) during repeated frying of potato chips were determined. Polyunsaturated fatty acids of all the oils significantly decreased after frying. Tocopherols in SBO, POO and VST, and DPPH radical scavenging activities of POO and VST significantly decreased after frying. L* values of the oils significantly decreased, and a* and b* values significantly increased after 80 times repeated frying. Conjugated dienes and p-anisidine value of SBO after 80 times repeated frying were 21.8 mmol/L and 47.7, respectively, the highest among the oils. Levels of total polar compounds of all the oils after 80 times repeated frying were between 8.1 and 9.5%, not exceeding rejection limit after frying. Compositions and contents of alkanals, 2-alkenals, and 2,4-alkadienals in the oils during frying were largely affected by their fatty acid compositions. 相似文献
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Detection of olive oil adulteration with some plant oils by GLC analysis of sterols using polar column 总被引:2,自引:0,他引:2
A new method was developed to determine the presence of some refined vegetable oils in olive oil based on the sum of campesterol and stigmasterol percentages. Model systems of corn, soybean, sunflower and cotton seed oils in olive oil at levels of 5%, 10% and 20% were prepared. The unsaponifiables of these model systems were analysed by GLC using polar column with high thermal stability. An olive oil authenticity factor based on the summation of campesterol and stigmasterol percentages was established as an indicator of olive oil adulteration with vegetable oils. The results indicate the possibility to detect the presence as little as 5% of these plant oils in olive oil. 相似文献
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Refined oils including corn, sunflower, soybean, and palm oils as well as low-quality olive oil such as refined lampante and pomace olive oils are commonly used for extra-virgin olive oil (EVOO) adulteration. Indeed, K 270 could be used as a parameter for the detection of EVOO fraud for each type of the studied refined oils, 10 % olive, 4 % pomace olive, 10 % palm, 5 % corn, and 2 % soybean oils. Moreover, the adulteration could also be detected by the increase of the trans fatty acid contents with 10 % pomace olive, 3 % soybean, 3 % sunflower, 2 % corn, and 10 % palm oils. Actually, stigmasta-3,5-diene content is one of the most effective means of detecting refined oils in EVOO at low levels: 2 % olive, 0.4 % pomace olive, 1 % palm, 0.2 % soybean, 0.5 % sunflower, and 0.1 % corn oils. Finally, the application of linear discriminant analysis could represent an alternative and innovative tool for faster and cheaper evaluation of EVOO adulteration. 相似文献
4.
拉曼光谱-聚类分析法快速鉴别掺伪花生油 总被引:3,自引:3,他引:0
目的建立快速鉴别掺伪花生油的拉曼光谱.聚类分析方法。方法以不同产地、不同品牌的多批次花生油、大豆油、玉米油、菜籽油、葵花籽油、精炼棕榈油、精炼棉籽油及精炼地沟油为样品,在780 nm和532 nm激光光源下,扫描和比较其普通、扩展及导数拉曼光谱的形态。结果在532 nm激光光源的扩展光谱及一阶导数光谱中,花生油与低价植物油及精炼地沟油光谱的信息量最大,样品间光谱形态的差异显著,谱峰得到有效分离。基于此全波段光谱信息和形态建立的多步聚类分析模型及鉴别程序对36份不同花生油、105份不同低价植物油、30份仿冒花生油和38份不同精炼地沟油的判别正确率均为100%,对180份5%及以上的掺假花生油的判别正确率达86%以上,对75份5%及以上的掺杂花生油的判别正确率为92%,对72份5%及以上的掺杂植物油的判别正确率达92%以上。样品测量时无需制备样品及消耗化学试剂,测量和分析一份样品仅耗时5 min左右。结论所建立的拉曼光谱.聚类分析模型既可准确鉴定花生油,还可准确鉴定各种类型的掺伪花生油,可实现对掺伪花生油的快速、无损和准确鉴别。 相似文献
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The oxidative and thermal stabilities of genetically modified high oleic sunflower oil (87% oleic acid) were compared with those of regular sunflower (17% oleic acid), soybean, corn, and peanut oils during storage at 55 °C and simulated deep fat frying at 185 °C. Oxidative stability was evaluated by measuring the oxygen content and volatile compounds in the sample bottle headspace and peroxide value. The coefficient variations (CVs) for volatile compound, headspace oxygen, and peroxide value analyses were 2.02%, 1.41%, and 3.18%, respectively. The oxidative stability of high oleic sunflower oil was greater than those of regular sunflower and soybean oil (P < 0.05) and as good as those of corn and peanut oils (P > 0.05). The thermal stabilities of oils during deep fat frying were evaluated by measuring the infrared absorption at 2.9 μm and conjugated diene content. The CV of conjugated diene content was 1.07%. Infrared and conjugated diene results showed that the high oleic sunflower oil had greater thermal stability than had regular sunflower, soybean, corn, and peanut oils (P < 0.05). The genetically modified high oleic sunflower oil, with 5.5% linoleic acid, had better oxidative and thermal stabilities than had the regular sunflower oil with 71.6% linoleic acid. 相似文献
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Issa Javidipour Hakan Erinç Ayhan Baştürk Aziz Tekin 《International Journal of Food Properties》2017,20(7):1582-1592
The effects of microwave heating for 3, 6, and 9 min at a frequency of 2450 MHz on fatty acid composition, tocopherols, iodine value, free fatty acids (%), peroxide value, conjugated dienes and trienes, and hexanal contents of refined hazelnut, soybean, sunflower, and virgin olive oils were investigated. A significant (p < 0.05) decrease was observed in linoleic and linolenic acids contents of soybean oil during exposure to microwave heating. Tocopherol contents of oil samples significantly decreased (p < 0.05) during microwave heating. Free fatty acids of the samples slightly increased and iodine value showed reduction throughout the process. Conjugated dienes contents of samples showed an increasing trend up to the 6 min, followed by a reduction at 9 min. Conjugated triene fatty acids of all the samples significantly increased (p < 0.05) throughout the application. While peroxide value showed increasing trend up to the 3 min and sharply decreased at 9 min, hexanal contents of refined hazelnut, virgin olive, soybean, and sunflower oils increased 63, 28, 55, and 389 fold, respectively, after 9 min exposure to microwave heating. Kinetic analysis of data showed that the reaction orders for peroxide and hexanal formation were zero and first order, respectively, and in the tested oils the reaction rate followed the order: soybean oil ? sunflower oil ? hazelnut oil ? virgin olive oil for peroxide, and sunflower oil ? soybean oil ? hazelnut oil ? virgin olive oil for hexanal formation. It was concluded that hexanal could be considered as a parameter for evaluation of the quality of oils exposed to microwave heating. 相似文献
8.
气相色谱法测定常见植物油中脂肪酸 总被引:19,自引:0,他引:19
随着营养学研究发展,人们对脂肪酸认识不断增加。中国营养学会也推荐膳食中必需脂肪酸摄入理想比值,市场上也出现大量调和油,为了评估食用植物油营养价值,该研究分析常用食用植物油中脂肪酸组成和各种油营养特色。方法:用氢氧化钾-甲醇溶液将植物油皂化后,在三氟化硼作为催化剂作用下,用甲醇将样品甲酯化,正己烷提取甲酯化产物。以毛细管柱DB-23作为分离柱,用气相色谱法测定植物油脂肪酸组成。结果:大豆油,葵花籽油,玉米油中含有50%-60%亚油酸和20%-30%油酸,营养均衡合理;花生油,芝麻油中油酸、亚油酸含量约35%-45%,易于人体吸收;菜籽油中含有45%油酸和15%芥酸,芥酸对人体健康有不利作用;橄榄油,茶籽油中含有75%-80%油酸,红花籽油中含有约80%亚油酸,有降低胆固醇功效。 相似文献
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Nikolaos K. Andrikopoulos 《Food Reviews International》2002,18(1):71-102
The chromatographic, spectrophotometric, and spectroscopic methods used for detection, identification, and quantification of the triglyceride (TG) species present in common edible vegetable oils are reviewed. The TG species identified in each kind of oil and their percentage distributions reported in literature are presented in tabular form. Data on oils from the following 10 sources are reviewed: corn, cottonseed, grapeseed, linseed, olive, palm, peanut, rapeseed, soybean, and sunflower. The number of TG species identified in these vegetable oils ranged from 20 (grapeseed oil (GR)) to 79 (peanut oil (PN)), with six (GR) to 13 (PN) different fatty acyl moieties contributing to their molecular structures. The quantitative levels reported ranged from traces (below 0.1%) to 49.7% (trilinolenin in linseed oil) and 54.6% (triolein in olive oil), respectively. The highest mean values (30-35%) correspond to four predominant TG species (dipalmitoylolein, trilinolein, trilinolenin, and triolein). 相似文献
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Josep Serra Bonvehi & Francesc Ventura Coll 《International Journal of Food Science & Technology》2009,44(3):456-466
The possibilities of detecting hazelnut paste adulterated with refined and non-refined vegetable oils have been studied. Research was focussed mainly on peanut, high oleic-acid sunflower, corn and soybean oils which have a similar composition to hazelnut oil. The analytical procedures to detect fatty acid (FA), triacylglycerol (TAG) and tocopherol profiles as indicators of adulteration were determined. The better indicators experimentally determined were seven FA (palmitic, stearic, linoleic, linolenic, arachidonic, behenic and lignoceric acids) and different TAG with three unsaturated FA (the code letters used for FA are: P = C16:0 ; S = C18:0 ; O = C18:1 ; L = C18:2;; Ln = C18:3 ) (LLLn , LLL and OOO), two unsaturated FA (POL, PLL and SOO), and one unsaturated FA (PPL). As expected, when refined vegetable oils were added to hazelnut paste, the increment of stigmasta-3,5-diene allowed detection at levels of 2% oil added. Limits of detection were measured using standard and adulterated hazelnut with different amounts of non-refined vegetable oils added (5%, 10%, 20% and 30%). The distribution of tocopherols and tocotrienols is highly useful, except in the case of added sunflower oil. The differences between the experimental and theoretical values of the TAG with equivalent carbon number (ΔECN) of 42 does not improve the detection limit of hazelnut paste adulterated with peanut or sunflower oils. Similarly, tocopherols usually added to refined vegetable oils as an antioxidant were also determined. 相似文献
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Hongyan Li Ya‐wei Fan Jing Li Liang Tang Jiang‐ning Hu Ze‐yuan Deng 《Journal of food science》2013,78(4):H633-H641
The aim of this research was to evaluate the oxidative stabilities and qualities of different vegetable oils (almond, blend 1‐8, camellia, corn, palm, peanut, rapeseed, sesame, soybean, sunflower, and zanthoxylum oil) based on peroxide value (PV), vitamin E content, free fatty acid, and fatty acid composition. The vegetable oils with different initial fatty acid compositions were studied under accelerated oxidation condition. It showed that PV and n‐3 polyunsaturated fatty acid (PUFA) changed significantly during 21 d accelerated oxidation storage. Based on the changes of PV and fatty acid composition during the oxidation process, mathematical models were hypothesized and the models were simulated by Matlab to generate the proposed equations. These equations were established on the basis of the different PUFA contents as 10% to 28%, 28% to 46%, and 46% to 64%, respectively. The simulated models were proven to be validated and valuable for assessing the degree of oxidation and predicting the shelf life of vegetable oils. 相似文献
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Yongyong Li Bin Jiang Yongjiang Lou Quan Shi Rongyu Zhuang Zhao-Wen Zhan 《International Journal of Food Science & Technology》2020,55(1):165-174
Free fatty acids (FFAs) and triacylglycerols (TAGs) are the main components of edible vegetable oils. In this work, electrospray ionisation (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to characterise the molecular composition of FFAs and TAGs in various vegetable oils, including soybean, rapeseed, corn, sunflower, peanut, linseed and olive oils. Semiquantitative analysis of FFAs and structural analysis of TAGs by MS/MS were further conducted to reveal the differences in the molecular compositions of the various vegetable oils. It was found that each vegetable oil has characteristic fingerprints of FFAs and TAGs. MS/MS measurements showed that the high-abundance TAGs in each vegetable oil were mainly composed of their abundant FFAs and glycerol. FFA and TAG fingerprints of genetically modified (GM) and nongenetically modified (non-GM) vegetable oils were similar, exhibiting only subtle differences, as confirmed by principal component analysis (PCA). 相似文献
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The effect of frying oil on the lipid oxidation, antioxidants, and in vitro antioxidant activity of gim bugak was studied. Bugak was prepared by pan-frying at 180 °C in unroasted sesame, soybean, extra virgin olive, or palm oil. The degree of lipid oxidation based on conjugated dienoic acid and p-anisidine values was higher in the bugak fried in soybean or sesame oil with high contents of polyunsaturated fatty acids and tocopherols. However, the oil oxidation was lower in olive and palm oils, which showed higher degradation of tocopherols and polyphenols than in sesame or soybean oil during frying. Although the bugak fried in palm oil contained less antioxidants than that fried in soybean or sesame oil, the in vitro antioxidant activity was not different (p > 0.05). Results suggest that palm oil can replace unroasted sesame oil for the preparation of gim bugak with improved lipid oxidative stability and health functionality. 相似文献
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食用植物油的高分辨气相色谱分析 总被引:1,自引:1,他引:0
为评估食用植物油的营养价值,该文分析了常用食用植物油中的脂肪酸组成和各种油的营养特色。用KOH—CH3OH溶液将植物油皂化后,在三氟化硼作为催化剂的作用下,用CH3OH将样品甲酯化,正己烷提取甲酯化产物。以毛细管柱DB-23作为分离柱,用气相色谱法测定植物油的脂肪酸组成。大豆油、葵花籽油和玉米油中含有50%-60%的亚油酸和20%-30%的油酸,营养均衡合理;花生油和芝麻油中油酸与亚油酸含量相当,有35%-45%,易于人体吸收;菜籽油中含有45%的油酸和15%芥酸,对人体健康有不利作用;橄榄油和茶油中含有75%-80%的油酸,红花籽油中含有约80%的亚油酸,有降低胆固醇功效。 相似文献
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Authentication of edible vegetable oils adulterated with used frying oil by Fourier Transform Infrared Spectroscopy 总被引:2,自引:0,他引:2
The application of Fourier Transform Infrared (FTIR) Spectroscopy to authenticate edible vegetable oils (corn, peanut, rapeseed and soybean oil) adulterated with used frying oil was introduced in this paper. The FTIR spectrum of oil was divided into 22 regions which corresponded to the constituents and molecular structures of vegetable oils. Samples of calibration set were classified into four categories for corn and peanut oils and five categories for rapeseed and soybean oils by cluster analysis. Qualitative analysis of validation set was obtained by discriminant analysis. Area ratio between absorption band 19 and 20 and wavenumber shift of band 19 were treated by linear regression for quantitative analysis. For four adulteration types, LODs of area ratio were 6.6%, 7.2%, 5.5%, 3.6% and wavenumber shift were 8.1%, 9.0%, 6.9%, 5.6%, respectively. The proposed methodology is a useful tool to authenticate the edible vegetable oils adulterated with used frying oil. 相似文献
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气相色谱仪结合数据分析软件鉴别橄榄油掺杂 总被引:1,自引:1,他引:0
目的基于气相色谱仪和数据分析软件来鉴别橄榄油掺杂。方法取5种橄榄油分别与市售葵花籽油、大豆油、菜籽油、玉米油和花生油以不同的比例混合来模拟掺杂。运用气相色谱-氢火焰检测器检测其脂肪酸甲酯含量,结合数据分析软件(mass profiler professional,MPP)进行数据处理,以偏最小二乘判别分析法建立预测模型。结果 1%(体积比)掺杂样品的鉴别准确率在90%以上。结论通过此方法对各类掺杂橄榄油都能很好地鉴别是否掺杂。 相似文献
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Correlation of fatty acid composition of vegetable oils with rheological behaviour and oil uptake 总被引:4,自引:0,他引:4
The fatty acid compositions of seven edible vegetable oils were investigated and correlated with their rheological behaviours and the amount of absorbed oils to fried products. All oil samples showed constant viscosity as a function of shear rate, exhibiting Newtonian behaviours. The highest viscosity was observed in hazelnut oil, followed by olive, canola, corn, soybean, sunflower, and grapeseed oils. In addition, a high correlation (R2 = 0.94) demonstrated that the flow behaviours of vegetable oils were positively governed by their major components (18:1 and 18:2 fatty acids). It was also shown that a more rapid change in viscosity with temperature was observed in the oils containing more double bonds (R2 = 0.71). Furthermore, even though the overall tendency was that the potato strips fried in the oils with high viscosity appeared to cause more oil uptake, a significant effect of oil types on oil uptake was not observed. 相似文献