微波对植物油中维生素E抗氧化性能的作用

阐述维生素Ｅ结构的及其抗氧化机理,综述微波作用下植物油中维生素Ｅ抗氧化性能的变化。     

我国食用植物油维生素E含量研究

通过对中国市场上的13种食用植物油,包括100多个品牌,共326个样品的维生素E含量进行检测分析．采用的检测方法为AOCS Official Method Ce8-89方法,结果表明：各种食用植物油按总维生素E平均含量的从大到小的排列顺序为大豆油（105．91mg／100g）、玉米油（88．65mg／100g）、葵花籽油（74．45mg／100g）、菜籽油（69．37mg／100g）、芝麻油（51．66mg／100g）、葡萄籽油（42．35mg／100g）、花生油（42．12mg／100g）、亚麻籽油（37．71mg／100g）、红花籽油（32．91mg／100g）、米糠油（32．27mg／100g）、橄榄油（22．03mg／100g）、核桃油（20．94mg／~OOg）、茶籽油（12．78mg／100g）。     

食用植物油掺入矿物油的鉴别

重点叙述食用植物油掺（混）入矿物油食用后对人体的危害,所引发的食物中毒案例以及对矿物油的鉴别检验方法。     

反相高效液相色谱法快速测定植物油中的维生素E

建立了快速测定植物油中维生素E含量的高效液相色谱法。采用VP-ODSC18色谱柱,流动相为甲醇/水(体积比为98∶2),流速为1ml/min,柱温为35℃,荧光检测激发波长为290nm,发射波长为340nm。在上述实验条件下,维生素E的线性范围为0.1～25mg/kg,检出限为2.7×10-2mg/kg,回收率为87.2%～97.3%,RSD为2.6%。该法测定样品,快速准确,重复性好。     

HPLC法同时测定植物油中维生素A和不同构型维生素E含量

以石油醚为溶剂,用索氏提取法提取了黑芝麻、白花生、黑花生、葵花籽、大豆、棉花籽的油脂。油样品先用正己烷溶解,然后用甲醇定容,其中正己烷含量为20%(v/v),用Hypersil ODS2 5μm色谱柱,甲醇为流动相,对所提油脂中维生素A、α-维生素E、γ-(β)维生素E、δ-维生素E含量进行检测。实验结果表明,在204nm波长下,维生素A、α-维生素E、γ-(β)维生素E、δ-维生素E在0~200μg/m L范围内与峰面积有良好的线性关系,标准曲线相关系数r均大于0.9978。维生素A、α-维生素E、γ-(β)维生素E、δ-维生素E加标平均回收率分别为97.83%、98.58%、98.75%、99.93%。     

HPLC法同时测定植物油中维生素A和不同构型维生素E含量

以石油醚为溶剂,用索氏提取法提取了黑芝麻、白花生、黑花生、葵花籽、大豆、棉花籽的油脂。油样品先用正己烷溶解,然后用甲醇定容,其中正己烷含量为20%（v/v）,用Hypersil ODS2 5μm色谱柱,甲醇为流动相,对所提油脂中维生素A、α-维生素E、γ-（β）维生素E、δ-维生素E含量进行检测。实验结果表明,在204nm波长下,维生素A、α-维生素E、γ-（β）维生素E、δ-维生素E在0²00μg/m L范围内与峰面积有良好的线性关系,标准曲线相关系数r均大于0.9978。维生素A、α-维生素E、γ-（β）维生素E、δ-维生素E加标平均回收率分别为97.83%、98.58%、98.75%、99.93%。      

微波辐射下植物油中维生素E抗氧化性能的变化

在阐述维生素Ｅ的抗氧化机理的基础上,重点综述了微波辐射作用下植物油中维生素Ｅ抗氧化性能的变化情况,并讨论了将来的研究方向     

常见食用植物油中维生素E异构体含量调查研究

通过查阅国内外官方食物成分数据库,同时综合近年来国内对成品食用植物油中不同生育酚和生育三烯酚含量进行分析的文献,建立常见食用植物油维生素E异构体成分表。结果表明:国内外现有数据库中食用植物油种类及其生育酚和生育三烯酚数据均不全,且不同地区含量存在明显差异。通过对国内最新研究汇总,共收集22种合计659个常见食用植物油的α-、β-、γ-、δ-生育酚数据,同时收集17种合计183个食用植物油的α-、(β+γ)-、δ-生育三烯酚数据。生育酚广泛存在于植物油中,以α-生育酚和γ-生育酚为主,但不同植物油中含量情况存在明显差异;生育三烯酚主要存在于棕榈油、米糠油和葡萄籽油中,在其他植物油中分布很少。不同类型食用植物油的选择会明显影响人体活性VE总量和不同异构体的摄入情况,目前国内外食用植物油VE异构体数据库有地区差异且均不能覆盖目前常见的食用植物油种类,更新常见成品食用植物油VE数据库很有必要。     

高效液相色谱法同时测定植物油中3种维生素A和9种维生素E

建立1种通过高效液相色谱法同时测定植物油中3种维生素A(维生素A-全反式酯、维生素A-醋酸酯、维生素A-棕榈酸酯)和9种维生素E(δ-生育三稀酚、β-生育三稀酚、γ-生育三稀酚、α-生育三稀酚、δ-生育酚、β-生育酚、γ-生育酚、α-生育酚、d-α-醋酸酯)的方法,并对13种植物油进行检测。结果表明：方法的色谱柱为CAPCELL PAK PFP(150 mm×4.6 mm, 5μm)、提取剂为乙醇、2,6-二叔丁基对甲酚(BHT)添加量为0.01g、流动相为乙醇-水,梯度洗脱。建立的方法在质量浓度0.5～20μg/mL范围内,线性关系良好(R²> 0.999),方法的检出限为0.100～2.80 mg/kg、定量限为0.332～13.32 mg/kg、相对标准偏差(RSD)≤5.27%、回收率为80.67%～98.42%。建立的方法可用于植物油中3种维生素A和9种维生素E的同时检测。     

不同微波时间下植物油品质的变化情况

研究了微波平均辐射时间对植物油中硫代巴比妥酸（ＴＢＡ）值和维生素Ｅ含量的变化情况,结果表明,当微波参数变化时,植物油的上述指标也随之而变,且其受影响程度与植物油的不饱和度有关。     

Tocopherol speciation as first screening for the assessment of extra virgin olive oil quality by reversed-phase high-performance liquid chromatography/fluorescence detector

A method based on reversed-phase high-performance liquid chromatography with fluorescence detector has been developed for the determination of tocopherols in vegetable oils. Oils were diluted in acetonitrile/tetrahydrofuran (THF) and injected directly onto HyPurity C₁₈ column. Methanol and THF (90:10) mixture was used as a mobile phase. Tocopherols were detected by fluorescence detector. The method had good limit of detection (LOD) (7 ng/g for α-tocopherol and 6 ng/g for β-, γ- and δ-tocopherols) and reproducibility (CV% < 2.8%).     

Detection of olive oil adulteration with some plant oils by GLC analysis of sterols using polar column

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.     

Effects of chemical interesterification on solid fat content and slip melting point of fat/oil blends

Fat/oil blends, formulated by mixing fully hydrogenated palm oil stearin or palm oil stearin with vegetable oils (canola oil and cottonseed oil) in different ratios from 30:70 to 70:30 (w/w %), were subjected to chemical interesterification reactions on a laboratory scale. Fatty acid (FA) composition, iodine value, slip melting point (SMP) and solid fat content (SFC) of the starting blends were analysed and compared with those of the interesterified blends. SMPs of interesterified blends were decreased compared to starting blends because of extensive rearrangement of FAs among triacylglycerols. These changes in SMP were reflected in the SFCs of the blends after the interesterification. SFCs of the interesterified blends also decreased with respect to the starting blends, and the interesterified products were softer than starting blends. These interesterified blends can be used as an alternative to partial hydrogenation to produce a plastic fat phase that is suitable for the manufacture of margarines, shortenings and confectionary fats.     

贵州威宁短柱油茶与册亨红球油茶籽油品质分析

为探明我国贵州地区独特的高寒山区和低热河谷区2个自然环境下本地特有油茶物种的油茶籽油品质的差异性,同时选育优质木本油料品种,从威宁短柱油茶和册亨红球油茶种质资源中筛选出稳产、抗病的优株共计14份,对2种类型油茶单位冠幅产量、茶籽油脂肪含量、脂肪酸组成与功能性活性物质含量进行测定,并应用主成分分析方法对油脂质量进行综合评价。结果表明,威宁短柱油茶脂肪含量显著高于册亨红球油茶,而单位冠幅产量低于册亨红球油茶;2种茶籽油的脂肪酸均由SFA、MUFA和PUFA组成,3种成分含量最高的分别为WN-8(14.72%)、QXN-5(84.75%)和QXN-4(11.17%);茶籽油功能性活性物质主要包括α-VE、总酚、角鲨烯和β-谷甾醇,含量变化范围分别为17.90 mg/100 g(WN-1)～34.27 mg/100 g(QXN-3)、3.41 mg/kg(WN-9)～40.46 mg/kg (WN-8)、79.33 mg/kg (QXN-2)～364.73 mg/kg (WN-7)、204.40 mg/kg (WN-6)～350.10 mg/kg (WN-7)。主成分分析结果表明,油脂质量排名...     

高效液相色谱法测定食品中维生素E的研究进展

该文综述了维生素E的发现、研究发展、医疗保健功效以及各种食品中维生素E的高压液相色谱分析方法等。     

Comparison of Rapid Reversed Phase High-Performance Liquid Chromatography (RP-HPLC) Method with Rapid Reversed Phase Thin Layer Chromatography Method for Detecting Vegetable Oils in Ghee (Clarified Milk Fat)

An efficient, fast, and reliable reversed phase high-performance liquid chromatography based method was developed to detect specific adulterant in premium and pure ghee (clarified butterfat) samples. The method is based on the detection of cholesterol and β-sitosterol as markers in the unsaponifiable matter of pure ghee and adulterated ghee samples, respectively. The reversed phase high-performance liquid chromatography method resolved cholesterol, stigmasterol, campasterol, and β-sitosterol at Rt values of 17.681 ± 0.122, 19.7 ± 0.2, 20.2 ± 0.2, and 22.7 ± 0.2 min., respectively. β-sitosterol served as an indicator for the adulteration in ghee by plant and specific adulterant oil at dose dependent manner (1–5 g/100 g of ghee). Validation of the method revealed that it was fast, economical, highly reliable, and comparable with the reversed-phase thin layer chromatography method with no false negatives.     

高温加热对植物油脂品质的影响

本文对几种常见植物油（大豆油、花生油、菜籽油、芝麻油）进行微波加热和常规加热处理，然后测其酸价和过氧化物值，与未加热的样品进行比较；结合气相色谱法测定植物油的脂肪酸组成，考察了高温加热对植物油脂品质的影响。并研究了生育酚（ＶＥ）对油脂加热过程中品质的影响。实验结果表明：两种加热方法都会使植物油的酸价和过氧化物值升高，而微波加热条件下两指标的升高是常规加热条件下的两倍左右；ＶＥ对延缓植物油脂品质下降有一定的作用。