食用油中掺入低价动物油脂鉴别方法的研究进展

动物油脂是动物脂肪组织经提取精炼而成的油脂。动物油脂因资源丰富,具有独特风味,广泛应用于食用油、起酥油、制备肉味香精,同时也是生产肥皂、甘油和饲料的重要原料。因动物油脂成本低廉,不法商贩受利益驱使在食用植物油或高价动物油脂中掺加低价动物油脂,严重扰乱了市场秩序,侵害消费者合法权益和身体健康。近年来,近红外光谱法与拉曼光谱等光谱法、气相色谱与液相色谱及其质谱联用技术、实时分析质谱、低场核磁共振等技术应用于动物油脂掺假鉴别技术研究。本文对主要动物油脂掺假鉴别技术进行综述,并对其发展趋势进行了综述,以期为动物油脂的掺假鉴别技术研究提供参考。     

Distinguishing lard from other animal fats in admixtures of some vegetable oils using liquid chromatographic data coupled with multivariate data analysis

Detection of animal fat adulterants in vegetable oils is of great importance from commercial and health perspectives. Distinguishable identification of lard contamination in some vegetable oils has been attempted in this study. Vegetable oils, namely palm oil (PO), palm kernel oil (PKO), and canola oil (CLO), were spiked with different proportions of animal fats, such as lard (GLD), beef tallow (BT), and chicken fat (CF). High-performance liquid chromatographic (HPLC) analyses were performed to monitor the triacylglycerol (TAG) compositional changes in the oil samples before and after adulteration. The results showed that qualitative determination of lard contamination in PKO was possible by a visual comparison of TAG profiles of PKO adulterated with different animal fats with those of the animal fats. This approach was not useful for PO and CLO. However, by subjecting liquid chromatographic data to multivariate procedures, distinguishable grouping of lard-contaminated samples was achieved for all three oils.     

Speciation of animal fat: Needs and challenges

The use of pork fat is a concern for Muslims and Jews, who for religious reasons avoid consuming anything that is pig-derived. The use of bovine materials, including beef fat, is prohibited in Hinduism and may also pose a risk of carrying the infectious agent for bovine spongiform encephalopathy. Vegetable oils are sometimes adulterated with animal fat or pork fat with beef fat for economic gain. The development of methods to determine the species origin of fat has therefore become a priority due to the complex and global nature of the food trade, which creates opportunities for the fraudulent use of these animal fats as food ingredients. However, determining the species origin of fats in processed foods or composite blends is an arduous task as the adulterant has a composition that is very similar to that of the original fat or oil. This review examines some of the methods that have been developed for fat speciation, including both fat-based and DNA-based methods, their shortcomings, and the need for additional alternatives. Protein-based methods, specifically immunoassays targeting residual proteins in adipose tissue, that are being explored by researchers as a new tool for fat speciation will also be discussed.     

红花籽油中脂肪酸组成评价与分析

建立有效的红花籽品质评价方法,筛选发掘红花籽优异资源,为优质红花品种选育及品质改良提供理论基础。以82 份不同产地的红花籽为实验材料,测定红花籽油中的脂肪酸和9 种组分含量,采用隶属函数转化和主成分分析（principal component analysis,PCA）方法,综合评价红花籽油的主要营养品质特征。82 份红花籽油脂肪酸和9 种组分含量各有差异,变异系数在0.98%～111.99%之间;脂肪酸平均含量为22.16～27.23 mg/100 g,亚油酸平均质量分数为78.54%～82.45%。相关性分析发现,脂肪酸与亚油酸（C18:2）和棕榈酸（C16:0）呈显著正相关,与油酸（C18:1n12、C18:1n9）分别呈极显著和显著负相关。PCA将9 个营养组分指标简化为3 个PC因子,PC1包括亚油酸（C18:2）、油酸（C18:1n9）、硬脂酸（C18:0）和二十四烷酸（C24:0）;PC2包括棕榈酸（C16:0）和亚麻酸（C18:3）;PC3包括油酸（C18:1n12）、二十碳烷酸（C20:0）和二十碳一烯酸（C20:1）。3 个PC贡献率分别为42.721%、30.426%和16.435%,累计贡献率为89.852%。根据各因子隶属函数值和权重,分析红花籽油主要营养品质综合评价排名,筛选出综合品质评价得分靠前的10 份种质：09新疆红花、24云南红花、05四川红花、41辽宁红花、66封丘红花、55卫辉红花、32河北红花、71亳州红花、22延津红花、78江苏红花。     

水酶法提取油脂研究进展

油脂来源十分广泛,因而高效、安全、环保的提取技术在油脂工业化生产中具有重要的意义。水酶法提取油脂条件温和、绿色、安全、生产工艺简单且所得油脂营养价值较高,在不同油脂原料的提取中具有应用潜力。对水酶法提取油脂的原理和优缺点进行了介绍,重点综述了水酶法在植物油脂、动物油脂和微生物油脂提取中的应用研究进展,以及水酶法与其他辅助手段的联用,以期为水酶法油脂提取技术的发展和应用提供参考。     

超高效液相色谱-四极杆/静电场轨道阱质谱快速筛查和定量检测食用油脂中的天然辣椒素、合成辣椒素和二氢辣椒素

建立超高效液相色谱-四极杆/静电场轨道阱质谱(UHPLC-Q/Orbitrap)快速筛查和定量检测食用油脂中天然辣椒素、合成辣椒素和二氢辣椒素的分析方法。结果表明,前处理最佳条件为:样品经二氯甲烷溶解,氢氧化钠水溶液提取,硫酸酸化,PRiME HLB固相萃取小柱净化;液质最佳条件为:0.1%甲酸水-0.1%甲酸乙腈梯度洗脱,Thermo Scientific Accucore Vanquish C₁₈+色谱柱(100 mm×2.1 mm,1.5 μm)分离,静电场轨道阱质谱分析检测。结果表明:3种辣椒素在0.1~40 μg/L范围内线性关系良好,R2≥0.999;3个加标水平(n=6)的平均回收率在66.7%~112.8%范围内,相对标准偏差在3.2%~9.7%范围内;检出限在0.02~0.05 μg/kg之间,定量限在0.1~0.2 μg/kg之间。该方法可在无标准物质的情况下对食用油脂中3种辣椒素进行快速筛查及确证,同时可在有标准物质下进行准确定量,为食用油脂中非法添加回收油脂的筛查确证和准确定量检测提供新的技术和思路。     

Properties of Low-Fat Frankfurters Containing Monounsaturated and Omega-3 Polyunsaturated Oils

Properties of low-fat (<18%) frankfurters containing high-oleic acid sunflower oil (HOSO) and fish oil were studied. Replacement of animal fats by the oils had little effect on emulsion stability. Frankfurters with 5% fish oil had very low sensory scores due to undesirable fish flavor. Incorporation of maximum amounts of HOSO into low-fat beef/pork and all-beef frankfurters increased oleic acid by 34% and 62%, respectively, and the monounsaturated/saturated fatty acid ratio by 178% and 468%, respectively, compared to a regular (30% fat) product containing only animal fats. Sensory evaluation and instrumental texture profile analysis showed that the reduction in total fat caused texture problems, especially increased firmness and springiness and decreased juiciness.     

Three-year study of fenthion and dimethoate pesticides in olive oil from organic and conventional cultivation

Residues of fenthion and dimethoate pesticides were determined in organic and conventional olive oils by liquid-liquid and solid-phase extractions with subsequent gas chromatography and mass spectrometric analysis. The olive oil samples were collected from Crete during 1997-99. The average concentrations of fenthion in conventional olive oils were 0.1222, 0.145 and 0.1702 mg kg^-1, and for dimethoate were 0.0226, 0.0264 and 0.0271 mg kg^-1 for 1997, 1998 and 1999, respectively. The average concentrations of fenthion in organic olive oils were 0.0215, 0.0099 and 0.0035 mg kg^-1 for 1997, 1998 and 1999, while for dimethoate they were 0.0098, 0.0038 and 0.0010 mg kg^-1, respectively. All the olive oils contained residue levels lower than the maximum resi-due levels according to the FAO/WHO Codex Alimentarius. The organic olive oil contained significantly lower concentrations of the two pesticides. The levels of fenthion and dimethoate in organic olive oils exhibited a decreasing trend following the implementation of the new cultivation method. We propose procedures that should be established in the organic cultivation in order to maximize its effectiveness.     

Organochlorine content of milks, dairy products and animal feed ingredients: Ireland 1971-1972.

Milks (bovine and human) and dairy products (butter, cheese, skim and whey powders, calf-replacer, casein, butter-oil and dietetic food) were collected during 1971/2 throughout Ireland together with a more limited samples of the 10 major animal feed ingredients, and analysed for organochlorine insecticide residues using electron-capture gas chromatography. The different materials contained low or negligible levels of chlorinated insecticides. Apart from some of the animal feed ingredients the DDT residues were generally the predominant contaminants detected together with lower levels of gamma-BHC (lindane), aldrin/dieldrin and heptachlor/heptachlor epoxide. The maximum levels of these insecticides in the bovine milk and dairy products (511, 100, 62 and 21 mug/kg fat respectively) constitute only 50% or less of the Codex Tolerance Limits. The correspondingly low residue levels in the human milk (maxima of 128, 1, 1, and 5 mug/kg fat respectively) which at most represent insecticidal ingestion by infants equivalent to 13, 0-05, 5 and 5% respectively of the WHO/FAO acceptable daily intake for DDE, gamma-BHC, aldrin/dieldrin and heptachlor/heptachlor epoxide again pose no obvious health hazards and are strongly indicative of negligible organochlorine contamination in the general diet. The samples of animal feed ingredients examined also contained trace levels of ogranochlorines (maxima of 0-9, 0-1, 1-6 and 1-0 mug/kg respectively). More extensive monitoring of the residues in animal feed ingredients (the most probable source of milk contamination is advocated, and the desirability of tolerance limits for insecticides in animal feeds discussed.     

Eggs and poultry meat as tocopherol sources in dependence on tocopherol supplementation of poultry diets

One feeding trial with broilers and three feeding experiments with layers were carried out to investigate the influence of various vitamin E supplementations on α-tocopherol concentration of foods of poultry origin. Vitamin E content of basal diets amounted to ≈20 mg per kg feed; 0, 100, 1000, 10 000 and 20 000 mg vitamin E per kg feed were added. Broilers were fed for 30 days and slaughtered, layers were kept for one laying year (13×28 days), eggs were collected daily. Vitamin E concentration was determined in muscle (breast, legs), liver, fat and eggs by HPLC. Tocopherol concentration increased with vitamin E supplementation in all samples. The highest tocopherol concentration was measurement in egg yolk (254.9) followed by liver (44.8) and muscle (12.2 mg/100 g). Vitamin E supply of poultry feed depends on costs of vitamin E and financial benefits for the farmer.     

我国油脂化工、精细化工生产现状与发展建议

以动植物油脂为原料通过直接反应或调配、水解等可生产出品种繁多的化工、精细化工产品，这类产品由于对环境友好及具有可生物降解等特点而得到人们的青睐。我国肥皂、甘油、天然脂肪酸、脂肪酸酯、脂肪胺和脂肪酰胺、油脂基表面活性剂及其他油脂化工产品等大宗油脂化工产品与国外相比相差不大，但在油脂精细化工方面与发达国家有一定的差距，主要表现在技术相对落后、自主开发创新能力较低、产品结构不合理且未形成系列等。我国油脂化工、精细化工的发展趋势是巩固和深化现有的油脂化工产品、以特种技术为基础发展油脂精细化工产品，利用资源优势开发特种油脂精细化学品、研发与市场对路的专用油脂化学品。     

HPLC法测定食用动物油脂中丙二醛残留量

建立柱前衍生高效液相色谱法测定动物油脂中丙二醛残留量的方法。试样经三氯乙酸混合液提取,与硫代巴比妥酸(TBA)进行衍生化反应后,采用Thermo Syncronis C₁₈色谱柱(250 mm×4.6 mm,5μm),以0.01 mol/L乙酸铵-甲醇(体积比65︰35)为流动相,等度洗脱,二极管阵列检测器检测。结果表明,丙二醛在0.01~2.0μg/mL范围均有良好线性关系,相关系数(r)为0.9999;方法检出限为0.0064 mg/kg;3个不同水平(0.1,0.2和0.6 mg/kg)的加标平均回收率为97.41%~102.25%,RSD值为1.08%~2.15%。方法具有操作简便、灵敏度高、重现性佳等特色,适用于动物油脂中丙二醛残留量检测。     

提取方法对奇亚籽油品质特性的影响

以奇亚籽为原料,分别采用压榨法、溶剂浸提法、水酶法和超临界CO₂萃取法提取奇亚籽油,对比分析不同方法提取奇亚籽油的理化性质、脂肪酸组成、油脂氧化稳定性、酚类物质含量及体外抗氧化能力等品质特性。结果表明:4种方法中,超临界CO₂萃取法的油脂得率最高(85.5%),其次是溶剂浸提法(65.8%)和压榨法(40.9%),水酶法最低(33.2%)。超临界CO₂萃取的奇亚籽油品质最佳,色泽为黄值70红值4.3灰值0.3,酸价为1.10 mg KOH/g、过氧化值为0.0137 g/100 g,含有不饱和脂肪酸总质量分数为88.22%,其中亚油酸18.36%,亚麻酸69.86%;其氧化速度最慢在30 h后过氧化值达到0.25 g/100 g;总酚含量为106.45 mg/kg,黄酮含量为222.09 mg/kg。超临界CO₂萃取的奇亚籽油在相同质量浓度下的DPPH自由基清除能力(IC₅₀ 28.04 mg/mL)与ABTS+·清除能力(IC₅₀ 33.70 mg/mL)优于压榨法、溶剂浸提法和水酶法;对超氧阴离子自由基清除能力(IC₅₀ 10.08 mg/mL)优于溶剂浸提法、水酶法,略低于压榨法。     

婴配食品中氯丙醇酯的污染状况及检测方法研究进展

氯丙醇酯类污染物对人体具有潜在的危害,目前已被发现普遍存在于精炼植物油、含油脂性食品及动物乳汁及母乳中,其中精炼植物油尤其是精炼棕榈油中的污染水平较高。婴配食品中脂肪的主要来源是精炼植物油及动物脂肪,对于以婴配食品为主要食物来源的婴儿来说,此类污染物的暴露水平较高可能造成潜在的健康危害。目前婴配食品中氯丙醇酯类污染物的研究数据有限,且国内外相关法律法规不足,造成监管及生产环节关注有限。本文以婴配食品为关注点,综合介绍了国内外婴配食品中的氯丙醇酯污染状况及暴露危害、相关法律法规,并简要介绍了婴配食品中常用的氯丙醇酯检测方法,以帮助监管机构、生产企业及检测机构全面了解行业氯丙醇酯污染现状并及时做出改善。     

Polychlorinated dibenzo-p-dioxins,dibenzofurans and dioxin-like polychlorinated biphenyls in food and feed in Latvia in 2009–2011

During 2009–2011 a monitoring programme for 17 polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and 12 dioxin-like polychlorinated biphenyls (DL-PCBs) was conducted in the Latvian food and feed market. Using ISO 17025-accredited analytical methodology, investigation of 121 food (milk, dairy products, meat, eggs, fish, fish products) and 66 feed samples (fish meal and oil, compound and mineral feed, vegetable and animal fats) was performed. Most samples showed contamination below the European Commission (EC) Regulation No. 1881/2006 and Commission Directive 2006/13/EC limits. Average total toxicological equivalent (total-TEQ₍₁₉₉₈₎) concentrations within the food sample groups, except fish and fish products, ranged between 0.41 and 15.1 pg total-TEQ₍₁₉₉₈₎ g^?1 fat. Fish and fish products showed contamination levels from 0.18 to 46.0 pg total-TEQ₍₁₉₉₈₎ g^?1 fresh weight (f.w.). Fifty-seven per cent of cod liver samples were non-compliant. The most contaminated feed samples were fish meal and fish oil. A comparison with WHO-TEF₍₂₀₀₅₎ data is given.     

加热条件下α-生育酚在油脂中的抗氧化活性、损耗及其对油脂全氧化值的影响

以大豆油、棕榈油、茶油和猪油为材料,以α-生育酚为研究对象,采用Rancimat法（110～130?℃）和烘箱法（120～180?℃）研究在加热条件下α-生育酚在油脂中的抗氧化活性、损耗情况及其对油脂全氧化值的影响。Rancimat结果表明：110 ℃条件下,α-生育酚（200～1?000?mg/kg）能显著延长猪油、茶油和棕榈油的氧化诱导期（P＜0.05）,且添加量越大,油脂的氧化诱导期越长,而在大豆油中,α-生育酚则表现出促氧化现象,即添加量越大,大豆油氧化诱导期越短;烘箱实验结果表明：α-生育酚在油脂中的损耗率,与加热温度呈正相关,与其添加量呈负相关;180?℃条件下,α-生育酚（1?000?mg/kg）能有效抑制大豆油、茶油和猪油在加热过程中全氧化值的增长;而在棕榈油中,α-生育酚促进了棕榈油全氧化值的增大,添加量越大,促进作用越强。     

Varietal differences in the fatty acid composition of oils from cowpea (Vigna unguiculata) and limabean (Phaseolus lunatus)

The fatty acid composition of the extracted oils from ten varieties of cowpea, eighteen varieties of limabean and two of soyabean were determined by gas-liquid chromatography. All the seeds, with the exception of soyabean, were poor sources of oil. The major fatty acids in the cowpea and limabean varieties were linoleic (C_18:2), palmitic (C_16:0) and linolenic (C_18:3) acids. In the soyabeans, linoleic and oleic (C_18:1) acids were the major fatty acids. Traces of gadoleic (C_20:1), erucic (C_22:1) and lignoceric (C_24:0) acids were obtained in Cowpea Kano 1696, Farv-13 and Nigeria B₇ and in limabean TPL 2 and TPL 187. Considerable variability was encountered among the different fatty acids in the different varieties of cowpea and limabean. This is indicated by the differences in fatty acid composition and the high coefficient of variation obtained for ether extract (28·6 and 46·2% in cowpea and limabean, respectively), lauric acid (100 and 50%, respectively), oleic acid (35·1 and 37·7%, respectively), myristic acid (30 and 30·8%, respectively) and behenic acid (39·4 and 30·4%, respectively). Some of these differences may be genetic.     

植物油中角鲨烯的提取与高效液相色谱法分析

建立了硅胶柱提取,高效液相色谱法分析植物油中角鲨烯的方法.样品用石油醚溶解,过硅胶柱净化,经C18柱分离,紫外检测(210 nm).结果表明,角鲨烯与其他杂质峰得到良好分离,在2～1 000 mg/L浓度范围内,峰面积与浓度呈良好线性,线性相关系数(R2)0.998.在大豆油中添加5.0、100、500和1 000mg/kg水平的角鲨烯,平均加标回收率为82.4％～ 89.3％,相对标准偏差小于7.1％(n=8),方法测定低限(LOQ)5 mg/kg.本方法准确、灵敏、可靠,已应用于实际样品分析.     

Mineral oil and PCB/dioxin analysis in some European food contamination episodes

Following a contamination of the animal food chain in Belgium with PCBs, we investigated if there was a link between the presence of PCBs and the mineral oil content. The concentrations of mineral oil hydrocarbons in samples highly contaminated with PCBs were identical with those observed in samples with very low concentrations of PCB collected from non-contaminated farms or supermarkets. We concluded that the introduction of PCBs in the animal food chain was done by the use of pure transformer oil and not by waste oils (used edible, hydraulic or motor oils) collected at the recycling centres. The concentrations of mineral oil were lower than samples collected and analysed in Switzerland during the summer of 1999 when relatively high levels were measured.