1-月桂酸-3-棕榈酸甘油二酯纳米结构脂质载体对麝香草酚的包埋与缓释特性

为了开发基于功能性脂质1,3-甘油二酯的纳米结构脂质载体,研究了以1-月桂酸-3-棕榈酸甘油二酯和葵花籽油分别为固液脂质基质的纳米结构脂质载体对麝香草酚的包埋及缓释特性。结果表明：吐温-80与大豆卵磷脂质量比为1∶ 1时能很好地稳定1-月桂酸-3-棕榈酸甘油二酯与葵花籽油复合的纳米结构脂质载体,1-月桂酸-3-棕榈酸甘油二酯与葵花籽油质量比为4∶ 1、1∶ 1、1∶ 4条件下均能高效包埋麝香草酚,且载药率大于95%,但仅两者质量比4∶ 1条件下能使麝香草酚的载药量达到脂质质量的20%,并具有很好的稳定性;FTIR、荧光光谱和TEM表征表明包埋麝香草酚的1-月桂酸-3-棕榈酸甘油二酯纳米结构脂质载体具有很好的分散性和均一度;缓释实验表明,更高含量的1-月桂酸-3-棕榈酸甘油二酯会减慢麝香草酚的释放速率,可通过调节1-月桂酸-3-棕榈酸甘油二酯与葵花籽油的质量比达到控释效应。     

氢化大豆油中反式脂肪酸气相色谱分析方法的研究

建立了氢化大豆油中反式脂肪酸的毛细管气相色谱分析方法,着重考察了色谱柱温对反式脂肪酸分离效率的影响.最佳色谱条件为:H2压力60 kPa,空气压力50 kPa,柱前压220 kPa,程序升温120℃保留3 min、8℃/min升温至175℃保留28min、3 ℃/min升温至215℃保留20min,进样口温度260℃,检测器温度260℃.方法最小检测量≤5.50μg/mL,线性范围为饱和脂肪酸(18:0,20:0)8.0×10-3～5.4×10-1 mg/mL,不饱和脂肪酸(9t-18:1、9t 12t-18:2、9c-18:1、9c 12c-18:2)1.66×10-2～1.06 mg/mL(R2＞0.993),相对标准偏差为0.28%～0.93%,t检验结果无显著差异(α=0.05).     

枸杞子中玉米黄素双棕榈酸酯及枸杞酸的测定

目的:建立枸杞子中脂溶性活性成分玉米黄素双棕榈酸酯及水溶性活性成分枸杞酸（AA2βG,即2-O-(β-葡糖苷)-抗坏血酸）的液相含量测定方法。方法:采用高效液相色谱法,色谱条件为Luna C₁₈（2）色谱柱（4.6 mm×250 mm,5 μm）,流动相丙酮: 甲醇=55:45,等度洗脱,流速1.0 mL/min,柱温25 ℃,检测波长450 nm;枸杞酸检测:UPLC,Waters二醇基柱Torus TM Diol Column（3 mm×100 mm,1.7 μm）,流动相为乙腈?66.7 mmol/L醋酸铵（体积比85:15）,等度洗脱,流速为0.4 mL/min,柱温40 ℃,检测波长260 nm。结果:玉米黄素双棕榈酸酯在0.01~0.1 mg/mL范围内线性关系良好,r为0.9990;平均回收率为99.44%,RSD为4.04%。枸杞酸在3.125~100 μg/mL范围内线性关系良好,r为1.0000;平均回收率为96.30%,RSD为3.61%。22批枸杞样品中,玉米黄素双棕榈酸酯含量最高可达0.51%,枸杞酸含量最高可达1.33%。结论:该方法均准确可靠,重现性良好,可用于枸杞子的质量控制。     

橄榄油甘油二酯异构体的HPLC-ELSD测定方法建立及其应用

目的:建立一种用于测定橄榄油中甘油二酯异构体的方法,并应用于评价橄榄油的新鲜度。方法:采用正相高效液相色谱法,以异丙醇-正己烷为流动相进行梯度洗脱,应用蒸发光散射检测器进行检测。结果:1,3-甘油二酯(1,3-DAG)和1,2-甘油二酯(1,2-DAG)在20 min内实现分离,分别在11.16～111.62 μg/mL和9.50～95.00 μg/mL范围内线性关系良好,平均回收率分别为103.2%和101.4%,重复性及日间精密度RSD均低于4.0%;应用该方法测定了6批特级橄榄油的甘油二酯异构体含量,测定结果与橄榄油氧化情况相关性较好。结论:该方法能够准确、快速地测定橄榄油甘油二酯异构体的含量。     

Silver-ion HPLC测定1,3-二油酸-2-棕榈酸三酰甘油的含量

准确测定1,3-二油酸-2-棕榈酸三酰甘油(OPO)的含量,建立了一种以高效液相色谱结合银离子交换柱(Silver-ion HPLC)的测定方法。以ChromSpher 5 Lipid(25 cm×4.6 mm,5μm)银离子交换柱通过HPLC正相系统分离三酰甘油,配合蒸发光散射检测器(ELSD),以毒性较小的二氯甲烷和丙酮为流动相。流速0.6 mL/min,柱温30℃。漂移管温度30℃,空气压力0.35 MPa。在此条件下,1,3-二油酸-2-棕榈酸三酰甘油和1,2-二油酸-3-棕榈酸三酰甘油两种同分异构体基本达到分离,样品出峰完整,峰形良好。OPO色谱峰面积的自然对数与浓度的自然对数呈良好的线性关系(R2=0.998 8)。用该方法测定了母乳脂肪、实验室合成结构油脂样品、商品结构油脂、棕榈油和山茶油中OPO的含量。结果表明该方法的灵敏度高、重现性良好。     

壳聚糖甘油二酯微乳液的制备、表征及稳定性研究

以壳聚糖为壁材制备壳聚糖甘油二酯微乳液,在单因素试验基础上,采用响应面试验优化制备条件,并对壳聚糖甘油二酯微乳液的表面性质与温度稳定性、贮藏稳定性、氧化稳定性进行了研究。结果表明,壳聚糖甘油二酯微乳液最佳制备工艺条件为:壳聚糖质量浓度3.44 mg/mL,三聚磷酸钠(TPP)质量浓度1.5 mg/mL,壳聚糖与1,3-甘油二酯乳脂质量比1∶2.79,壳聚糖溶液与TPP溶液体积比2∶1。在最佳制备工艺条件下,所制备的壳聚糖甘油二酯微乳液包埋率为66.53%,粒子分布均匀,粒径可达93.7 nm;壳聚糖甘油二酯微乳液有明显的壳核结构;壳聚糖甘油二酯微乳液在20~70℃的范围内有相对较好的稳定性,最佳贮藏温度为4℃,且包被很好地延缓了1,3-甘油二酯乳脂的氧化。     

反相高效液相色谱法手性分析和制备全反式虾青素3种异构体

目的建立反相高效液相色谱法(reversed-phase high performance liquid chromatography, RP-HPLC)检测全反式虾青素三种异构体(3R,3′R、3R,3′S和3S,3′S)的分析方法。方法采用了固定相填料为纤维素-三(3,5-二甲基苯基氨基甲酸酯)的手性色谱柱(Ultimate Cellu-DR column),综合考察了流动相和柱温对全反式虾青素3种异构体的分离效果,并采用半制备液相色谱法获得全反式虾青素的3种异构体。结果得到最佳的分析色谱条件:流速为0.80 mL/min,柱温30℃,流动相为甲醇,等度洗脱,检测波长为480 nm。在此条件下,全反式虾青素的3种异构体达到良好分离,分离度均大于2。优化后的半制备色谱条件为:制备柱Ultimate Cellu-DR,流动相为纯甲醇,流速为15.00 mL/min。获得的3种异构体纯度均大于97%。结论该分析方法能有效地区分全反式虾青素的3种异构体,可用于不同来源虾青素的鉴定。     

红江橙皮渣提取果胶的工艺研究

对红江橙皮渣提取果胶的最佳工艺进行了研究.结果表明:Al2(SO4)3为最优果胶沉淀剂;酸提条件为在水料比20:1(m/V)、85 ℃和pH 2.0下酸提120 min;盐析条件为在pH 7.0和75 ℃下每100 g果胶粗提液(由10 g红江橙皮渣制成)中加入5 mL的饱和Al2(SO4)3盐析60 min;脱盐条件为每1 g 果胶粗品用20mL的混合液(VHCl/V乙醇/V水=47/50/3)脱盐30min.最终果胶得率为6.70%,含盐量为4.34%;成品中半乳糖醛酸含量为47.3%,甲氧基含量为33.3%,胶凝度109.     

HPLC-ELSD法测定L-抗坏血酸棕榈酸酯

建立高效液相色谱—蒸发光散射检测法检测L-抗坏血酸棕榈酸酯的方法。L-抗坏血酸棕榈酸酯样品用甲醇溶解,0.22μm微滤膜过滤,仪器条件:用C_(18)反相色谱柱进行分离,流动相:甲醇和水(含0.01%甲酸),流速:0.8mL/min,漂移管温度60℃,氮气压力:25psi,梯度洗脱。实验结果表明L-抗坏血酸棕榈酸酯峰面积的常用对数与其进样浓度的常用对数呈现良好线性关系(R~2=0.9972),加标回收率在97.23%~102.05%范围内,RSD5%。该方法不需对样品进行衍生化处理,能准确、快速定量L-抗坏血酸棕榈酸酯含量。     

Silver-ion HPLC测定1,3-二油酸-2-棕榈酸甘油三酯的含量

为准确测定1,3-二油酸-2-棕榈酸甘油三酯（OPO）的含量,建立了一种以高效液相色谱结合银离子交换柱（Silver-ion HPLC）的测定方法。以ChromSpher 5 Lipid （25 cm*4.6 mm, 5 μm）银离子交换柱通过HPLC正相系统分离甘油三酯,配合蒸发光散射检测器（ELSD）,以毒性较小的二氯甲烷和丙酮为流动相。流速0.6 mL/min,柱温30℃。漂移管温度30℃,空气压力0.35 MPa。在此条件下,1,3-二油酸-2-棕榈酸甘油三酯和1,2-二油酸-3-棕榈酸甘油三酯两种同分异构体基本达到分离,样品出峰完整,峰形良好。OPO色谱峰面积的自然对数与浓度的自然对数呈良好的线性关系( R2 = 0. 998 8)。用该方法测定了母乳脂肪、实验室合成结构油脂样品、商品结构油脂、棕榈油和山茶油中OPO的含量。结果表明该方法的灵敏度高、重现性良好。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

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.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.