高效液相色谱法测定保健食品原料和产品中角鲨烯的含量

目的建立高效液相色谱法测定保健食品和保健食品原料中角鲨烯的含量。方法样品经乙腈提取,经过Waters Xbridge C18色谱柱分离以甲醇为流动相,流速为1.0 mL/min,柱温为40℃,在紫外检测器210 nm波长下测定角鲨烯的含量。结果当角鲨烯浓度在0.5～300μg/mL范围内线性良好(r=0.9999),方法检出限为0.719mg/kg,方法定量限为2.398mg/kg,相对标准偏差为3%,在复杂基质中方法平均回收率为92.4%,在单一基质中方法平均回收率为114.9%。使用市售样品和原料对该方法进行验证,检测值在商品标识值的97%～106%范围内。结论此方法操作便捷,适用性广,验证结果良好,适合对保健食品和保健食品原料中角鲨烯的含量检测。     

高效液相色谱-二极管阵列检测器测定橄榄油中角鲨烯含量的条件优化

目的:检测橄榄油中角鲨烯的含量。方法:利用高效液相色谱-二极管阵列检测器法测定特级压榨橄榄油中角鲨烯的含量。结果:测得特级压榨橄榄油中角鲨烯的含量为6.5 mg/g,回收率为95.68%,相对标准偏差为0.57%。线性范围为(0~1.20)mg/mL,在上述范围内能够呈现出良好的线性关系,检出限的值为0.01 mg/mL。实验最佳的条件为萃取剂选用石油醚,层析柱中的填充物选择硅藻土,流动相选择乙腈:叔丁基甲醚(75:25)作为流动相,检测器的检测波长210nm,盐酸的浓度选择5 mol/L,检测器温度25℃,二极管阵列检测器中二极管选用50个。结论:高效液相色谱-二极管阵列检测器法分析灵敏度高、速度快、准确度高,精密度和回收率结果都符合国家标准要求。     

高效液相色谱法同时测定护眼保健品中叶黄素和玉米黄质

目的 建立高效液相色谱法(high performance liquid chromatography, HPLC)同时测定护眼保健品中叶黄素和玉米黄质的分析方法。方法 样品用胰酶氯化钠预处理后, 经无水乙醇及石油醚提取, 在55 ℃水浴中用40%氢氧化钾-甲醇溶液皂化30 min, 无水乙醇稀释后, 选用色谱柱YMC Carotenoid S-5 (250 mm× 4.6 mm, 5 μm), 以甲醇:三氯甲烷(4:1, V:V)为流动相, 流速为1.5 mL/min, 柱温为25 ℃, 于445 nm波长处测定样品。结果 叶黄素在0.3906~12.4979 μg/mL范围内线性关系良好, 相关系数r2为0.9999, 平均回收率为91.5%~95.2% (n=9), 检出限为0.0075 μg/g; 玉米黄质在0.1474~4.7184 μg/mL范围内线性关系良好, 相关系数r2为1, 平均回收率在98.6%~110.2% (n=9), 检出限为0.0120 μg/g。结论 该方法快速、稳定, 能够适用于护眼保健品中叶黄素和玉米黄质的同时测定。     

气相色谱法测定脱臭馏出物中角鲨烯的含量

建立了气相色谱法测定植物油脱臭馏出物中角鲨烯含量的方法。样品用内标液稀释,采用HP-5毛细管色谱柱,内标法定量。结果表明,角鲨烯质量浓度在10~400μg/m L范围内,方法的线性关系良好,相关系数为0.9998,最低检测限为2.0μg/m L;在10、15及20g/kg的加标水平下,角鲨烯的平均回收率为99.2%~102.8%,相对标准偏差(RSD)为1.5%~2.6%。并以此方法检测了6组不同植物油脱臭馏出物样品,其角鲨烯含量在1.75%~26.10%之间。该方法分析时间短,重现性好,灵敏度高,定量准确,样品不需要特殊处理,具有较强的实用价值,适用于植物油脱臭馏出物中角鲨烯含量的测定。     

气相色谱法测定生湿面制品中的乙二醇、 1,2-丙二醇和1,3-丙二醇

目的 建立对生湿面制品中乙二醇、1,2-丙二醇和1,3-丙二醇含量同时测定的气相色谱方法。方法 样品经粉碎, 加适量的海砂研磨成干粉状, 加入无水乙醇提取, 离心, 过滤后用气相色谱测定其中乙二醇、1,2-丙二醇和1,3-丙二醇的含量。采用石英毛细管色谱柱(HP-INNOWAX), 进样口为240 ℃, 分流比为20:1, 流速为1.0 mL/min, 程序升温为: 初始100 ℃, 维持4 min, 再以50 ℃/min升温至200 ℃, 维持8 min。检测器为氢火焰离子化检测器(FID), 检测器温度为280 ℃。结果 该方法在2.39~2500 μg/mL浓度范围内呈良好的线性关系, R2＞0.9993, 检出限为0.72~0.87 mg/kg。在5.0、10.0、50.0 mg/kg三个添加水平下, 平均回收率为87%~106% (n=6), 相对标准偏差(RSD)为1.3%~5.4% (n=6)。结论 该方法简便、快速、灵敏度好、准确度高, 所使用的试剂毒性小, 可同时检测大量样品, 能满足实际样品的检测要求。     

气相色谱法同时检测食品中9种常见食品添加剂

通过对样品前处理、色谱条件的优化,建立一种气相色谱仪同时检测9种食品添加剂的高效检测方法。结果表明：硫酸浓度为200 g/L,用量5.0mL;亚硝酸钠浓度为50 g/L,用量5.0 mL;衍生温度为25℃;冰浴衍生时间30 min为最优。气相色谱仪条件：氢火焰光度检测器（FID）;色谱柱：HP-5柱（30 m×0.35 mm×0.25 μm）;进样口温度：220℃;检测器温度：260℃;柱温：程序升温70℃（3 min）→30℃/min→190 ℃（2 min）→30℃/min→250℃（10 min）。9种食品添加剂在15min内有限分离,各组分线性范围在10 μg/mL~500 μg/mL（r=0.9998）,平均加标回收率在85.9 %~108.3 %之间,相对标准偏差（RSD,n=6）在2.32 %~8.54 %之间。在此条件下检测回收率高、精密度较好、效率高,节约人力物力,可满足各类食品的检测要求。     

高效液相色谱-高分辨质谱-同位素内标法测定乳粉中的胆碱

目的 建立高效液相色谱－高分辨质谱-同位素内标法测定乳粉中胆碱的含量。方法 奶粉样品用水溶解, 加入硫酸铜溶液(70 g/L)和氢氧化钠溶液(40 g/L)沉淀蛋白, 离心后过0.45 μm粒径的微孔膜, 经ZORBAX SB-Aq C18色谱柱, 以0.1%甲酸水和乙腈为流动相进行梯度洗脱, 流速0.60 mL/min; 柱温箱温度30 ℃。质谱采用正离子模式分析, 同位素内标法定量。结果 该方法在0.5~10 μg/mL范围内线性关系良好, 相关系数为0.9998。平均加标回收率为91.4%~99.7%, 相对标准偏差为1.0%~3.2%(n=5), 检出限为0.2 mg/100 g, 定量限为0.5 mg/100 g。结论 该方法预处理简单, 分析速度快, 检测成本低, 能满足奶粉中胆碱的检测要求。     

毛细管气相色谱法测定方便面中抗氧化剂的含量

建立了方便面中抗氧化剂(BHT、BHA、TBHQ)含量的毛细管气相色谱测定方法.采用WBI进样口,毛细管色谱柱J&W DB1701(中等极性30m×0.53 mm×lμm),FID检测器进行检测.进样口温度:230℃,载气流速:10 mL/min,柱室温度:150℃保持5 min,以5℃/min升至230℃,保持10 min.检测器温度:250℃,样品用无水乙醇提取定容后直接进样测定.方法简单、快速、重现性好,平均回收率大于90％,RSD小于3.0％,线性范围BHT、BHA为10～200 μg/mL,TBHQ为25～500μg/mL.     

高效液相色谱-蒸发光法测定保健品中盐酸氨基葡萄糖的含量

目的建立高效液相色谱-蒸发光法测定一种保健品中盐酸氨基葡萄糖含量的分析方法。方法采用Waters Xbridge Amide柱(4.6mm×150mm,3.5μm),以乙腈:0.2%三乙胺水(V:V,75:25)为流动相,流速为1.0 mL/min,柱温为40℃。蒸发光散射检测器检测条件为漂移管温度105℃,载气N_2,压力12.5 bar。结果盐酸氨基葡萄糖进样量在0.12886～1.03088μg时与峰面积呈良好线性关系(r~2=0.9998),平均加样回收率为101.91%,相对标准偏差为1.43%。结论此方法简单、准确,精密度和重现性良好,可用于保健品中盐酸氨基葡萄糖含量的测定。     

气相色谱法快速测定含薄荷产品中薄荷脑的含量

目的:采用气相色谱法建立含薄荷产品中薄荷脑含量快速测定的方法。方法:从市场上选择2种薄荷糖及含薄荷的漱口液,优化出正己烷提取方法;采用AT.OV-1301毛细管柱,将提取液分流进样2μL。分流比为10:1,进样口温度220℃,检测器温度220℃,柱温110℃,保持2min;以5℃/min程序升温,升至150℃,保持5min;选择FID检测。结果:薄荷脑在5.0~1500μg/mL范围内线性良好。检测下限为1μg/mL;日内精密度RSD为1.30%~1.80%;3种样品加样回收率分别为103.44%、101.87%和107.26%。测得3种样品中薄荷脑的含量分别为(4.09±0.24)mg/g、(3.78±0.21)mg/g和(0.41±0.01)mg/mL。结论:该方法快速、准确,样品前处理简单,适用于薄荷制品中薄荷脑含量的测定。     

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.     

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。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

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

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status