反相高效液相色谱法测定婴幼儿配方食品中的叶黄素

建立了反相高效液相色谱法测定婴幼儿配方食品中叶黄素测定方法。选用色谱柱YMC Carotenoid4.6mm×250mm,5μm,以甲醇、甲基叔丁基醚为流动相进行梯度洗脱,流速为1mL/min,于445nm波长下,测定婴幼儿配方食品中叶黄素的含量,叶黄素含量在0.0164～0.492μg/mL范围内呈线性关系,R=0.9998,平均回收率为99.2%,RSD为1.1%。该方法可以简便准确的测定婴幼儿配方食品中叶黄素的含量。     

婴幼儿奶粉中维生素B_1的检测方法研究

本文建立了一种快速测定婴幼儿奶粉中维生素B1的高效液相色谱检测方法。该方法使用C18色谱柱分离维生素B1,以离子对流动相改善色谱分离度和峰形,流速为1mL/min,在紫外检测器242nm处检测。实验表明该方法可以达到以下指标:相关系数r0.9990,精密度3%,加标回收率79%~85%,满足要求。     

高效液相色谱法测定婴幼儿配方乳粉中的维生素B1、维生素B2

目的建立高效液相色谱法快速测定婴幼儿配方乳粉中的维生素B1、B2的含量。方法样品进行前处理后,采用Waters Xbridge C18色谱柱(150 mm×4.6 mm, 5μm)进行分离。以0.05 mol/L乙酸钠溶液-甲醇为流动相等度洗脱,柱温为30℃,流速为1 mL/min,荧光检测器进行检测,外标法定量。结果在优化的实验条件下,维生素B1、维生素B2可以有效分离,线性范围为0.05～1.00μg/mL,相关系数均大于0.999。维生素B1的加标回收率为87.4%～99.1%,相对标准偏差为1.2%～3.06%,检出限为0.03 mg/100 g;维生素B2的加标回收率为90.6%～97.8%,相对标准偏差为0.97%～3.44%,检出限为0.02 mg/100 g。结论此方法简单、快捷、高效,适用于婴幼儿配方乳粉中维生素B1、维生素B2的测定。     

高效液相色谱-质谱联用测定婴幼儿配方食品中叶酸的含量

建立了婴幼儿配方食品中叶酸含量的高效液相色谱-质谱联用测定方法。采用C18色谱柱(4.6mm×250mm,5μm)进行分离,以5 mmol/L乙酸铵(含0.1%甲酸)溶液-甲醇为流动相梯度洗脱,柱温25℃,流速1.0 mL/min,进样量20μL,柱后分流比为1∶3,质谱采用多离子反应监测(MRM)方式进行检测,正离子模式,定量离子为m/z442.0→295.2。叶酸在0.001~2.500μg/mL的范围内线性关系良好(r=0.9989),该方法相对标准偏差(RSD)为2.6%~6.0%,回收率为83.9%~104.0%,检出限(S/N=3)和定量限(S/N=10)分别为1.0 ng/mL、3.3 ng/mL。该方法操作简便、灵敏度高、重复性好,可用于婴幼儿配方食品中叶酸的测定。     

HPLC法测定婴幼儿配方奶粉中维生素C

建立婴幼儿配方奶粉中Vc的高效液相色谱测定法.方法采用C18(5μm,4.6mm×250mmi.d)反相色谱柱,流速1.0 mL/min;柱温30℃;流动相:v(甲醇):v(6.8 g/L KH2PO4水溶液,用盐酸调pH2.3)=1:99;进样量5 μL;检测波长215 nm.方法的检出限50μg/g,线性范围20～200 μ/mL,加标回收率80.4～86.2%,相对标准偏差为2.90%.该法具有样品预处理简单、灵敏度高、分析时间短等优点,可用于婴幼儿配方奶粉中Vc的直接测定.     

高效液相色谱荧光法测定营养素补充制剂中维生素K2(MK-7)的含量

建立高效液相色谱荧光法（HPLC-FLD）测定营养素补充制剂中维生素K2（MK-7）的含量。样品用异丙醇超声提取30 min，提取液离心过滤后取样液10 μL注入液相色谱系统中。样液经安捷伦C18色谱柱(4.6 mm×150 mm，5 μm)或其他等效色谱柱分离，柱后采用锌粉还原柱（4.6 mm×50 mm）衍生，使样品中维生素K2（MK-7）具有荧光特性。以甲醇（含5%四氢呋喃，冰乙酸0.03%，乙酸锌1.0 g/L）为流动相，流速1.0 mL/min，检测波长 激发波长243 nm发射波长430 nm。当称取样品1.0 g，定容体积为10 mL时，MK-7的检出限为0.03 μg/g，定量限为0.1 μg/g；MK-7在浓度0~2.176 μg/mL的范围内线性关系良好，线性相关系数为R2=0.9999；重复性实验中RSD%为0.97%；样品加标回收率为93.40%。此方法操作简单，高效，准确，重现性好，可用于营养素补充制剂中维生素K2（MK-7）的含量测定。     

HPLC法有效测定发酵液中维生素B_(12)的含量

建立了一种更简便、快速、准确的测定谢氏丙酸杆菌发酵液中脱氧腺苷钴胺素(维生素B12)含量的检测方法,使用高效液相色谱直接检测.利用Apollo C18(5μm,4.6mm×25cm) 色谱柱;以乙腈-0.05mol/L磷酸二氢钾缓冲液(pH3.0)作流动相;柱温25℃;检测波长260nm;流速1.0mL/min;恒速洗脱.在所选定的液相色谱条件下,脱氧腺苷钴胺素和杂质分离良好,维生素B12在20μg/mL80μg/mL范围内线性良好,线性方程相关系数为0.99995,平均回收率为99.92%,相对标准偏差RSD为0.12%.此方法重复性好,样品预处理方法简单,分析速度快,7min内即可实现目的产物和杂质的完全分离.适用于整个发酵过程条件的优化及发酵产物提取过程的监控.     

高效液相检测婴儿配方乳粉中的维雏生素B12

目的:建立婴儿配方乳粉中维生素B12的高效液相测定方法.方法:采用BDS HYPERSIL C18柱(150mm×4.6mm,5μm),以水-乙腈为流动相;流速0.25mL/min,检测波长361am.结果:维生素B12的检出限为20ng/mL,线性范围在0.0506～3.23841μg/mL,回收率在92.23%～96.68%,相对标准偏差(RSD)为2.04%.结论:本方法快捷准确,适用于婴儿配方乳粉中添加的维生素B.2的测定.     

HPLC检测生物柴油生产过程中副产物甘油含量的研究

研究了高效液相色谱法(HPLC)测定生物柴油生产中副产物甘油的方法.生物柴油废弃物(主要含甘油)经稀释、调节pH至5.5,离心,所得下层液经微孔滤膜过滤,HPLC检测其甘油含量.最佳色谱条件色谱柱ZORBAX NH2(250 mm×4.6 mm,5 μm);检测器示差检测器;柱温30℃;流动相70%乙腈;流速1 mL/min.甘油最低检测限为2 mg/L,回收率为94.34%～99.43%,相对标准偏差为1.03%.与传统化学方法相比,高效液相色谱法快速简便,结果准确,重现性好.     

高效液相色谱法测定强化食品中维生素B6的含量

目的 建立了一种高效液相色谱法检测强化食品(婴幼儿配方食品、婴幼儿谷类辅助食品和功能饮料)中维生素B6方法。方法 利用Eclipse Plus C18(5 μm, 4.6 mm×250 mm)色谱柱, 流速1 mL/min, 流动相: 甲醇-(0.2 g/L辛烷磺酸钠, 体积分数为0.25%的三乙胺溶液, 利用乙酸调节pH=3.2±0.1)(V:V=21:79), 进样量 10 μL, 柱温30 ℃实现了对吡哆醛、吡哆醇和吡哆胺3种组分的分离; 在激发波长293 nm, 发射波长395 nm的条件下实现了对这3种组分的检测。结果 吡哆醛、吡哆醇和吡哆胺在0.1~1.0 μg/mL范围内均表现出良好的线性关系, 3种组分的相关系数均大于0.999, 检出限为0.01~0.02 mg/100 g, 定量限为0.03~0.05 mg/100 g, 均满足现行国标要求。3种维生素B6在添加水平为0.05、0.20和0.60 mg/100 g时的加标回收率为89.6%~107.1%, 相对标准偏差(n=6)为1.3%~7.0%。结论 该方法操作简便, 准确度和精密度高, 能够用于对多种常见强化食品中3种维生素B6的检测     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。