高效液相色谱法测定芝麻油中芝麻素及芝麻林素

建立高效液相色谱(HPLC)法测定芝麻油中芝麻素和芝麻林素的方法。结果表明：方法以甲醇-水为流动相，梯度洗脱；提取溶剂为乙腈；净化剂为50 mg硅胶键合乙二胺-N-丙基(PSA)+50 mg C₁₈;芝麻素和芝麻林素在1～100μg/mL范围内呈线性关系，相关系数(r)均大于0.998;方法检出限(LOD)为0.03 mg/g、定量限(LOQ)为0.06 mg/g。加标回收率和相对标准偏差(RSD)均符合GB/T 27417—2017的要求。方法前处理操作简单、重复性好，适用于芝麻油中芝麻素和芝麻林素的测定。     

正相高效液相色谱法同时测定芝麻油中生育酚、芝麻素及芝麻林素含量

建立了正相高效液相色谱法同时测定芝麻油中生育酚(α-、β-、γ-、δ-生育酚)、芝麻素及芝麻林素含量的方法。样品经正庚烷溶解后,在二醇基硅胶色谱柱上以四氢呋喃-正庚烷溶液洗脱、荧光检测器分析。结果表明:芝麻素及芝麻林素荧光特性良好,样品分析在20 min内完成;方法学评价结果显示生育酚在1.0~5.0μg/m L、芝麻素及芝麻林素在0.1~5.0μg/m L范围内线性关系良好,相关系数R~2均大于0.99;生育酚、芝麻素以及芝麻林素的检出限为0.29~0.74 mg/kg,定量限为0.91~2.10 mg/kg;6种化合物加标回收率为83.47%~104.57%,相对标准偏差为0.38%~6.55%。采用该方法分析了12个芝麻香油、冷榨芝麻油、浸出成品芝麻油中生育酚、芝麻素以及芝麻林素含量,发现芝麻油中生育酚以γ型为主,芝麻素、芝麻林素含量较高。该方法简单、灵敏度高、重复性好,可用于芝麻油中生育酚、芝麻素及芝麻林素含量的同时检测。     

超声波辅助-HPLC测定芝麻油中木脂素含量

以超临界CO2流体萃取的芝麻油为原料,采用超声波辅助甲醇萃取法对芝麻油进行前处理,并通过高效液相色谱法测定芝麻油中木脂素含量。结果表明,芝麻素和芝麻林素色谱峰分离效果好,干扰峰少,芝麻素与芝麻林素平均加标回收率分别为99.3%、96.2%,相对标准偏差分别为0.87%、1.71%。与皂化法前处理方法相比,此方法的前处理简便快速、结果准确、灵敏度高、稳定性好,适用于芝麻油中芝麻素和芝麻林素含量的测定。     

芝麻油中芝麻素、芝麻林素的研究

本文利用高效液相色谱测定不同芝麻样本提取油以及市购芝麻油中芝麻素、芝麻林素的含量。色谱柱为HibarRT250-4(C18,250mm×4.6mm,填充粒度5μm);流动相:甲醇:水=75:25(V/V);流速:1ml/min;检测波长:280nm。测定结果表明:被测两峰完全分离,且峰形较好,线性范围10～100μg/ml,芝麻素、芝麻林素平均回收率分别为101.1%、100.2%重现性(n=5)分别为芝麻素RSD=2.31%、芝麻林素的RSD=3.05%,最低检出限:芝麻素为1.5μg/ml,芝麻林素为2.5μg/ml(以进量浓度计)。油样中芝麻素的含量范围为0.35%～0.72%、芝麻林素的含量范围为0.32%～0.48%,制油工艺中焙炒工序强度对芝麻林素含量变化具有一定影响。     

不同产地黑芝麻及其油脂品质研究

选取7个产地的黑芝麻为原料，压榨制备黑芝麻油，分别对黑芝麻组成和黑芝麻油品质指标进行分析。结果表明：7种黑芝麻油均以油酸、亚油酸、棕榈酸和硬脂酸为主，且不饱和脂肪酸含量达到80%以上。7种黑芝麻油的总酚含量为2.31～7.35 mgGAE/g、芝麻素含量为3.05～10.75 mg/g、芝麻林素含量为2.14～5.30 mg/g。芝麻素、芝麻林素和总酚含量与DPPH·清除能力具有显著正相关性(P<0.05),芝麻林素和总酚含量对氧化诱导时间具有极显著正相关性(P<0.01)。7个产地的黑芝麻油中，产自多哥的黑芝麻油中功能性成分含量综合得分最高，有较强的抗氧化性和氧化稳定性。     

芝麻油生产工艺对细辛素形成的影响研究

通过对不同制油工艺制得的28个芝麻油样中芝麻木酚素组分含量(尤其是细辛素含量)进行的检测分析,研究制油工艺对芝麻油中细辛素含量的影响。结果发现：2个浸出精炼芝麻油样中细辛素含量平均119.45 mg/100g,其他26个油样中仅有3个检测出少量细辛素,分别为17.25 mg/100g、7.43 mg/100g、0.58 mg/100g,冷榨芝麻油中未检出细辛素。对不含细辛素的冷榨芝麻油进行水化脱胶、碱炼脱酸、吸附脱色、蒸馏脱臭等精炼处理,并对处理后的芝麻油进行细辛素含量检测分析。结果表明：添加磷酸进行水化脱胶和添加活性白土进行吸附脱色能造成芝麻油中细辛素的形成,且随脱胶时磷酸添加量和脱色时白土添加量的增加,细辛素含量增加(磷酸添加量1%时为131.22 mg/100g,白土添加量5%时为50.73 mg/100g);碱炼脱酸、活性炭脱色、水蒸汽蒸馏脱臭过程只降低了芝麻木酚素总量,没有细辛素形成。据此,细辛素可作为区别冷榨芝麻油和其他芝麻油尤其是浸出精炼芝麻油的特征指标。     

芝麻林素的酸催化反应与抗氧化性分析

采用石油醚、甲醇和乙醇溶解芝麻林素,研究不同溶剂体系芝麻林素酸催化反应的现象;以1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力评价芝麻林素及其分解产物的抗氧化能力;采用磷钨杂多酸（phosphotungstic heteropoly acid,HPW）催化芝麻油中芝麻林素的转化,研究芝麻林素酸催化对冷榨芝麻油氧化稳定性的影响。结果表明：芝麻林素在3 种溶剂体系中酸催化反应的产物不尽相同,芝麻酚是共同产物,石油醚体系产生Semin和芝麻素酚,甲醇和乙醇体系均出现不同未知物;芝麻林素和芝麻素的DPPH自由基清除能力远低于特丁基对苯二酚、丁基羟基茴香醚、丁基羟基甲苯和芝麻酚,但石油醚体系芝麻林素酸催化产物的DPPH自由基清除能力大幅提高,为HPW催化芝麻林素提高冷榨芝麻油氧化稳定性提供了理论依据;随着HPW催化剂添加量的增加,冷榨芝麻油中的芝麻林素含量逐渐减少,芝麻酚和芝麻素酚的含量逐渐升高,同时冷榨芝麻油的氧化诱导时间逐渐延长,氧化稳定性增强。     

芝麻渣油脂浸出条件及芝麻渣油质量研究

研究了对水代法芝麻渣进行油脂浸出的最佳工艺条件以及所得芝麻油的质量指标。通过单因素试验和正交试验得到的芝麻渣油脂浸出的最佳工艺条件为:浸出温度55℃、浸出次数7次、浸出时间90 min、液料比(w/w)为1.4∶1、入浸料水分含量11%。干燥芝麻渣浸出毛油的酸价4.7 mgKOH/g、过氧化值5.37 mmol/kg、色泽(25.4mm槽)Y9.3 R9.2,除酸价稍高于芝麻油国标中原油酸价≤4.0 mgKOH/g的要求外,其他指标符合国标要求,可以作为生产食用芝麻油的原料;然而发霉变质的芝麻渣浸出毛油的酸值高达95mgKOH/g,不能再作为生产食用芝麻油的原料。干燥芝麻渣浸出毛油中芝麻木脂素和维生素E含量分别为,芝麻素764.7 mg/100 g、芝麻林素306.4 mg/100 g、芝麻酚50.6 mg/100 g、维生素E33.1 mg/100 g,与通常的芝麻油相比,芝麻素、芝麻林素含量有所提高,维生素E含量有所降低,而芝麻酚含量呈数倍提高。     

紫外光谱法测定芝麻素与芝麻林素含量

本实验采用紫外分光光度法测定芝麻油中木酚素类物质芝麻素与芝麻林素的含量.根据木酚素类化合物在200～400nm紫外区有特征吸收,利用其吸收的强弱,以芝麻油中含量最高的芝麻素为对照品,通过标准曲线的绘制和假设检验,得到芝麻素的浓度与吸光度之间的显著的线性关系,由回归方程计算芝麻素的最低检测极限为1.95μg/mL,平均加样回收率为99.31%,RSD为1.87%;在提取后的40分钟内进行稳定性试验,RSD（%）为0.3%.重现性试验结果RSD为2.85%,精密度试验结果RSD为0.22%.     

UPLC-MS/MS法测定食品中的4种木酚素

建立超高效液相色谱-串联质谱法同时测定食品中4种木酚素(包括亚麻木酚素、芝麻素、芝麻林素和芝麻酚)的分析方法。试样采用含1 mol/L氢氧化钠(NaOH)的70%乙醇水溶液提取,盐酸调节pH至4~4.5,用70%乙醇水定容。以甲醇和0.1%甲酸水为流动相梯度洗脱,经C18色谱柱分离;采用电喷雾电离源,正离子模式(ESI+),选择反应监测模式扫描(SRM),外标法定量。结果表明:4种木酚素在0.040~10μg/mL浓度范围内线性关系良好,相关系数R在0.9995~0.9999之间;相对标准偏差(RSD)为1.0%~3.1%;在50~2.00×103 mg/kg的加标浓度范围内,回收率为95.0%~101%。亚麻木酚素、芝麻酚、芝麻素、芝麻林素的检出限分别为0.1,0.1,0.03和0.1 mg/kg。该方法分离效果好,灵敏度和准确度高,简单快速,适用范围广。     

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.     

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press