Effect of menadione (vitamin K3) addition on lipid oxidation and tocopherols content in plant oils

The effect of added menadione (vitamin K3) on stored corn and wheat germ oil on the dissolution and dimerization of natural tocopherols and autoxidation of triacylglycerols was investigated. Samples of corn and wheat germ oils pure and with added menadione were stored at +20 degrees C in brown and transparent glass bottles. During storage their peroxide value, changes of the content of fatty acids and dissolution of tocopherols were measured. Destruction of individual tocopherols in tested oils with menadione stored in both dark and transparent glass bottles was greater than in the oil samples without menadione. However, the degradation of individual tocopherols was different in each oil. Addition of menadione to the both oils resulted in accelerated the process of autoxidation of these oils. The corn oil stored in transparent bottles was oxidized faster than the one stored in brown bottles. The pro-oxidant activity of menadione was additionally activated by light. In contrast, in the case of germ oil, the process of autoxidation was very fast regardless of sort of container. Addition of menadione to the plant oils influenced the dissolution of natural tocopherols but did not influence the dimerization of tocopherols. As from the experiment, the addition of menadione to the oils decreased their nutritive value.     

Effect of menadione (vitamin K3) addition on lipid oxidation and tocopherol content in plant oils

The effect of added menadione (vitamin K₃) to stored corn and wheat germ oil on the dissolution and dimerization of natural tocopherols and auto‐oxidation of triacylglycerols were investigated. Samples of corn and wheat germ oils pure and with added menadione were stored at +20°C in brown and transparent glass bottles. During storage their peroxide value, changes of the content of fatty acids and dissolution of tocopherols were measured. Destruction of individual tocopherols in tested oils with added menadione stored in both dark and transparent glass bottles was greater than in these oil samples without menadione. However, the degradation of individual tocopherols was different in each oil. Addition of menadione to the both oils resulted in accelerated the process of auto‐oxidation of these oils. The corn oil stored in transparent bottles was oxidized faster than the one stored in brown bottles. The pro‐oxidant activity of menadione was additionally activated by light. In contrast, in the cause of germ oil, the process of auto‐oxidation was very fast regardless of sort of container. Addition of menadione to the plant oils influenced the dissolution of natural tocopherols but did not influence the dimerization of tocopherols. As from the experiment, the addition of menadione to the oils decreased their nutritive value.     

蒙脱土对植物油脱色效果的综合评价北大核心CSCD

为了开发高效、环保的食用油脱色剂,以一种环保方法(半干法)生产的蒙脱土为研究对象,研究其在不同脱色条件(脱色温度、脱色时间和脱色剂添加量)下对大豆油、葵花籽油和菜籽油品质的影响。结果表明:该蒙脱土具有吸附色素和过氧化物从而降低油脂红值和过氧化值的作用,与脱色前相比,大豆油、葵花籽油和菜籽油的红值最大降幅分别为77.4%、92.3%和87.2%,过氧化值最大降幅分别为82.7%、83.2%和91.2%;蒙脱土用于3种植物油的脱色,植物油中总甾醇和总生育酚含量下降,而酸值总体上缓慢上升。进一步研究发现,在相同的脱色条件下,蒙脱土对大豆油、葵花籽油和菜籽油的酸值、总甾醇含量和吸油率的影响结果均优于活性白土,尤其是吸油率几乎是活性白土的一半。蒙脱土可替代活性白土用于对色泽要求不是很高的植物油脱色中。     

谷维素对3种食用植物油的抗氧化效果研究

从米糠油皂脚中提取纯化谷维素,按不同比例添加到大豆油、菜籽油和油茶籽油中,分别采用Schaal烘箱法和油脂氧化分析仪对3种植物油氧化稳定性进行测定,同时考察在植物油氧化过程中,谷维素对其脂肪酸组成的影响,并与常见的油脂抗氧化剂进行对比。结果表明:油脂中分别添加0.1%和0.5%谷维素均对大豆油、菜籽油和油茶籽油的氧化诱导期具有延长作用,其中对油茶籽油的作用最显著;在Schaal烘箱实验中,谷维素能够有效延缓大豆油和油茶籽油过氧化值的升高,并且对油中多不饱和脂肪酸的氧化有抑制作用,但对菜籽油的抗氧化作用不显著。     

基于脂肪酸和生育酚组成的油茶籽油掺假判别可行性分析

从脂肪酸和生育酚的组成分析以及所得色谱数据的系统聚类分析(HCA)和主成分分析(PCA)方面考察了10种植物油的异同点。气相色谱分析10种植物油的脂肪酸组成,鉴别得到12种脂肪酸。对脂肪酸组成数据的HCA分析结果表明,油茶籽油与橄榄油和菜籽油具有相似的脂肪酸组成,而与其他植物油的脂肪酸组成差异显著;而PCA分析结果可以进一步区分油茶籽油与橄榄油和菜籽油。高效液相色谱分析10种植物油的生育酚组成,测得4种异构体的相对含量。对生育酚组成数据的HCA、PCA分析结果表明,油茶籽油和菜籽油的生育酚组成差异显著。因此,基于脂肪酸和生育酚组成分析可以作为油茶籽油掺假判别的依据。     

Stability and Antioxidant Activity of Beta Carotene in Conventional and High Oleic Canola Oil

Conventional canola oil (CO) and high oleic canola oil (HOCO) were stored under autoxidative and photooxidative conditions, β-carotene was added at 0 to 120 ppm. The oils were diluted in mobile phase and injected onto an HPLC column to track β-carotene changes over time. Peroxide values were followed to assess the oxidative stability of the oils. β-carotene was more stable in HOCO than in CO under autoxidative conditions, but no difference between oils was observed under photooxidative conditions. The HOCO was more stable against autoxidation, and CO was more stable against photo-oxidation. Antioxidant activity was shown by β-carotene in both oils, which contained natural tocopherols, during both autoxidative and photooxidative conditions.     

Temperature dependence of the autoxidation and antioxidants of soybean, sunflower, and olive oil

Effects of temperature on the autoxidation and antioxidants changes of soybean, sunflower, and olive oils were studied. The oils were oxidized in the dark at 25, 40, 60, and 80 °C. The oil oxidation was determined by peroxide (POV) and p-anisidine values (PAV). Polyphenols and tocopherols in the oils were also monitored. The oxidation of oils increased with the oxidation time and temperature. Induction period decreased with the oxidation temperature; 87 and 3.6 days at 25 and 60 °C, respectively, for sunflower oil. The activation energies for the autoxidation of soybean, sunflower, and olive oils were 17.6, 19.0, and 12.5 kcal/mol, respectively. Olive oil contained polyphenols at 180.8 ppm, and tocopherols were present at 687, 290, and 104 ppm in soybean, sunflower, and olive oils, respectively. Antioxidants were degraded during the oil autoxidation and the degradation rates increased with the oxidation temperature of oils; for tocopherols, 2.1 × 10⁻³ and 8.9 × 10⁻²%/day at 25 and 60 °C, respectively, in soybean oil.     

Loss of tocopherols and formation of degradation compounds at frying temperatures in oils differing in degree of unsaturation and natural antioxidant content

Samples of oils of different degrees of unsaturation, namely palm olein, olive oil, high‐linoleic sunflower oil, high‐oleic sunflower oil, rapeseed oil and soybean oil, were heated at 180 °C for 2, 4, 6, 8 and 10 h in the presence or absence of their natural antioxidants. Also, tocopherol‐stripped oils were supplemented with α‐tocopherol (500 mg kg^?1), δ‐tocopherol (500 mg kg^?1) or a mixture of α‐, β‐, γ‐ and δ‐tocopherols (250 mg kg^?1 each) and heated under the same conditions. Losses of tocopherols and formation of polymeric triacylglycerols were followed. Total polar compounds were also evaluated after 10 h of heating. Results demonstrated that tocopherols were lost very rapidly, in the expected order, with α‐tocopherol being the least stable. Polymeric and polar compound formation during heating was inhibited to a variable extent, being more dependent on the natural content and type of tocopherols than on the degree of unsaturation of the oil. For example, polymeric and polar compound contents in soybean oil were significantly lower than those found in high‐linoleic sunflower oil. However, the expected influence of the degree of unsaturation was evident when oils were unprotected or possessed identical initial antioxidant contents. Finally, levels of degradation compounds after 10 h of heating were not dependent on the remaining content of antioxidants. © 2002 Society of Chemical Industry     

Physico-Chemical Properties,Composition, and Oxidative Stability of Olive and Soybean Oils Under Different Conditions

Commercial olive and soybean oils have been analyzed periodically in order to evaluate the influence of storage conditions on quality. The following parameters were determined every 10 days of storage: peroxide, saponification and acid values, absorption coefficients K₂₇₀ and K₂₃₂, phenols, chlorophylls and carotenoids contents, DPPH scavenging ability, and total antioxidant activity. Edible oils were exposed to daylight and stored at room temperature in different containers with the same surface area of exposure to air either in clear glass or opaque glass bottles. Changes in oils properties were also examined after the addition of Vit-E as an antioxidant in oil samples. The results showed a gradual loss of quality during storage, especially in clear glass bottles. The addition of the antioxidant, however, significantly reduced the deterioration and oxidation rate in the oil. The best containers for commercial packing of oil were opaque glass bottles containing antioxidant products.     

稳定煎炸油的天然抗氧化剂及应用效果研究进展

综述了可用于提高煎炸油稳定性的内源性天然抗氧化剂,来自具有独特内源性抗氧化剂植物油,农业加工副产物、香料和药草、水果和浆果的外源性天然抗氧化剂和主体自生的天然抗氧化剂及其这些天然抗氧化剂在棕榈油、菜籽油、大豆油和葵花籽油煎炸中的应用效果,为天然抗氧化剂在煎炸油中的应用提供了有效信息。     

Classification of edible oils using synchronous scanning fluorescence spectroscopy

Total luminescence and synchronous scanning fluorescence spectroscopy techniques were tested as regards their ability to characterize and differentiate edible oils, including soybean, sunflower, rapeseed, peanut, olive, grapeseed, linseed and corn oils. Total luminescence spectra of all oils studied as n-hexane solutions exhibit an intense peak, which appears at 290 nm in excitation and 320 nm in emission, attributed to tocopherols. Some of the oils exhibit a second long-wavelength peak, appearing at 405 nm in excitation and 670 nm in emission, belonging to pigments of the chlorophyll group. Additional bands were present in the intermediate range of excitation and emission wavelengths in some oils, arising from unidentified compounds. Similarly, bands attributed to tocopherols, chlorophylls and unidentified fluorescent components were detected in the synchronous-scanning fluorescence spectra. Classification of oils based on their synchronous fluorescence spectra was performed using a non-parametrical k nearest neighbours method and linear discriminant analysis. Both methods provided very good discrimination between the oil classes with low classification error. The results presented demonstrate the capability of the fluorescence techniques for characterizing and differentiating vegetable oils.     

6种食用植物油及其生物柴油中脂肪酸成分的比较研究

采用毛细管气相色谱法，以氢火焰为检测器，测定了菜籽油、花生油、玉米油、棉籽油、芝麻油和大豆油及其相应生物柴油中脂肪酸的组成。比较发现，植物油及其生物柴油中脂肪酸组成基本一致。因此，可以通过测定植物油中脂肪酸的组成来预测生物柴油中脂肪酸甲酯的分布。     

油样短期存放条件对过氧化值测定的影响

对两种食用植物油取样后,分装于塑料瓶和玻璃瓶且装样量不同,置实验室条件的不同光照和温度短期存放40d,其间每隔10 d测定过氧化值.研究结果表明,各种存放条件下短期存放的油样过氧化值都在增长变化,装具及装样量、光照和温度条件对短期存放的油样过氧化值测定都具较大影响.     

食用油使用过程中存贮条件对其氧化稳定性的影响研究

研究了大豆油、菜籽油、棕榈油等几种食用油在使用过程中不同存贮条件下的氧化稳定性。将食用油启封,放置在不同的环境里,检测其过氧化值和酸值的变化。结果表明:避光存贮31 d,食用油的过氧化值均低于8 mmol/kg,酸值(KOH)达到0.26~0.35 mg/g;而在室内日光直接照射的条件下存贮31 d,各食用油的过氧化值均高于10 mmol/kg,酸值(KOH)达到0.35~0.45 mg/g。实验表明,启封后的食用油,存贮于避光处可以连续使用30 d以上,而置于室内日光直接照射条件下,其连续使用期只有3周。对比实验中,棕榈油氧化稳定性优于其他油脂。     

Effects of Sesame Oil Addition to Soybean Oil During Frying on the Lipid Oxidative Stability and Antioxidants Contents of the Fried Products During Storage in the Dark

ABSTRACT: Effects of sesame oil addition to soybean oil during frying on the lipid oxidative stability and antioxidants contents of fried products during storage in the dark were studied. Flour dough pieces (2 cm × 2 cm × 0.1 cm) were fried at 160 °C for 1 min in sesame oil-added soybean oil. Concentrations of sesame oil in the frying oil were 0%, 10%, and 20% by volume. Fried products were put into a glass bottle, and the bottles were tightly sealed and stored at 60 °C in the dark for 18 d. Lipid oxidation of fried products was determined by fatty acid composition changes and conjugated dienoic acid (CDA) and p -anisidine (PA) values. Tocopherols and lignan compounds in the fried products were determined by high-performance liquid chromatography. Relative content of linolenic acid decreased, and CDA and PA values increased during storage of the fried products in the dark. Fatty acid composition change and CDA and PA values during storage were lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil. The results clearly showed that addition of roasted sesame oil to soybean oil at 10% and 20% during frying decreased the lipid oxidation of fried products during storage in the dark for 18 d by extension of induction period and decrease in decomposition of oxidized lipids. Fried products contained 134 to 267 ppm tocopherols and 0 to 148 ppm lignans before storage; however, their contents decreased during storage in the dark. Lignan compounds were more stable than tocopherols, and the rate of tocopherols degradation was lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil, which could be because of protection of tocopherols from degradation by lignan compounds.     

几种常见植物油中主要醛类物质含量随温度的变化规律研究

目的建立气相色谱-质谱联用技术(gas chromatography-mass spectrometry,GC-MS)测定常用5种植物油中主要醛类物质含量的分析方法,探究植物油中主要醛类物质含量随温度变化的规律,同时测定5种植物油的不饱和度。方法采用碘值法测定了5种植物油的不饱和度,利用GC-MS法测定植物油中主要醛类物质丙烯醛、己醛、庚醛的含量,并研究其随温度变化的情况。结果 5种植物油的碘值由大到小依次为红花籽油、菜籽油、棉籽油、葵花籽油、大豆油,随着温度升高,植物油中主要醛类物质的含量逐渐增多,以丙烯醛的含量最高。结论本方法操作简便,灵敏度较高,适用于植物油中醛类物质的含量测定。在植物油加热过程中,应尽可能缩短加热时间、控制加热温度,以减少醛类物质的生成。     

橄榄油市场行情及其与其他植物油的脂肪酸组成和微量营养成分比较

旨在更全面、深入地了解橄榄油,对2010—2021年世界橄榄油的产量和消费量以及2015—2019年中国橄榄油的进口量进行了统计分析,测定不同品牌和不同等级市售橄榄油(特级初榨橄榄油、混合橄榄油和混合油橄榄果渣油)与9种其他植物油的脂肪酸组成和微量营养成分,并分析比较其差异。结果显示：世界橄榄油的产量和消费量常年维持在300万t左右,其中欧盟占比最大,分别为58.71%～76.68%和48.73%～62.15%;2015—2019年中国橄榄油产量仅在0.5万～0.7万t,而消费量和进口量分别达到了3.9万～5.75万t和3.86万～5.37万t;不同品牌和不同等级市售橄榄油的脂肪酸组成整体差异不大,但微量营养成分存在明显差异,其中特级初榨橄榄油的角鲨烯、多酚含量明显高于混合橄榄油和混合油橄榄果渣油,而混合油橄榄果渣油的甾醇和总生育酚含量最高;与一级菜籽油、一级玉米油、一级葵花籽油、一级大豆油和亚麻籽油等其他植物油比较,特级初榨橄榄油的油酸、角鲨烯和多酚含量最高,而甾醇和总生育酚含量偏低。     

Authentication of edible vegetable oils adulterated with used frying oil by Fourier Transform Infrared Spectroscopy

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.     

Triple-TOF-MS /MS法检测植物油中甘油三酯

建立了一种高分辨质谱(Triple-TOF-MS/MS)测定芝麻油、葵花籽油、大豆油、菜籽油、花生油和玉米油等常见食用植物油中甘油三酯的方法,分析并确定不同食用植物油中每种碳原子当量(ECN)下的甘油三酯组成与含量。结果表明:采用Triple-TOF-MS/MS法可以根据一级质谱母离子(加氢母离子、加钠离子和加氨母离子)相对分子质量以及二级质谱的碎片离子([DAG]~+)对相同ECN的甘油三酯进行定性分析。采用该方法对芝麻油、葵花籽油、大豆油、菜籽油、花生油和玉米油进行甘油三酯检测,结果共获得35种甘油三酯,均含有LnLL、LLL、LLO、PLL、LOO、PLO和OOO 7种甘油三酯。     

Temperature Dependence of Autoxidation of Perilla Oil and Tocopherol Degradation

Abstract: Temperature dependence of the autoxidation of perilla oil and tocopherol degradation was studied with corn oil as a reference. The oils were oxidized in the dark at 20, 40, 60, and 80 °C. Oil oxidation was determined by peroxide and conjugated dienoic acid values. Tocopherols in the oils were quantified by HPLC. The oxidation of both oils increased with oxidation time and temperature. Induction periods for oil autoxidation decreased with temperature, and were longer in corn oil than in perilla oil, indicating higher sensitivity of perilla oil to oxidation. However, time lag for tocopherol degradation was longer in perilla oil, indicating higher stability of tocopherols in perilla oil than in corn oil. Activation energies for oil autoxidation and tocopherol degradation were higher in perilla oil (23.9 to 24.2, 9.8 kcal/mol, respectively) than in corn oil (12.5 to 15.8, 8.8 kcal/mol, respectively) indicating higher temperature-dependence in perilla oil. Higher stability of tocopherols in perilla oil was highly related with polyphenols. The study suggests that more careful temperature control is required to decrease the autoxidation of perilla oil than that of corn oil, and polyphenols contributed to the oxidative stability of perilla oil by protecting tocopherols from degradation, especially at the early stage of oil autoxidation.