近红外光谱法测定面粉的水分、脂肪、碳水化合物和蛋白质含量

应用近红外光谱技术结合不同的定量分析方法建立面粉4种组分的快速定量模型。国标法测定68种面粉样品的水分、脂肪、碳水化合物和蛋白质的含量,并采集其近红外漫反射光谱图。选取58个校正集和10个验证集样品,通过马氏距离法剔除异常样品后,对比17种光谱预处理方式所建立的基于全光谱的偏最小二乘法(partial least squares,PLS)定量模型效果,在最佳预处理方法的基础上,采用向后区间偏最小二乘法(Backward interval PLS,BiPLS)筛选特征光谱,进一步得到最佳定量模型。结果表明,所建立的模型校正集相关系数Rcv均大于0.9650,内部交叉验证均方根误差均小于0.328;验证集相关系数均大于0.9926,预测均方根误差均低于0.383。因此,模型具有较好的准确性和稳定性,能应用于面粉的多指标快速检测。     

基于ATR-FTIR结合CARS算法测定蜂王浆中水溶性蛋白质和总糖含量

采用衰减全反射-傅里叶中红外光谱法（ATR-FTIR）和竞争性自适应重加权采样法（CARS）,结合理化分析,建立快速测定蜂王浆中水溶性蛋白质、总糖含量的方法。基于CARS法,采用Savitzky-Golay平滑和一阶导数对原始光谱预处理,筛选出84个特征波长点,模型对水溶性蛋白质预测效果最好,校正集和验证集的相关系数分别为0.9631和0.9771,RMSECV和RMSEP分别为0.0913和0.0754。总糖的PLS定量模型筛选出111个特征波长点,采用Savitzky-Golay平滑和二阶导数处理后,结果最佳,校正集和验证集的相关系数分别为0.9750和0.9850,RMSECV和RMSEP仅为0.4485和0.4244,建模效果好。结论：基于CARS法筛选特征波长,采用ATR-FTIR和偏最小二乘法快速检测蜂王浆水溶性蛋白质和总糖含量是可行的,所建定量模型稳健性好,预测准确度高。     

两种近红外光谱分辨率预测牛肉营养成分的比较研究

应用近红外光谱技术在不同光谱分辨率下分析了同一批牛肉样本的蛋白质、脂肪和水分含量.样品取自16头西门塔尔杂交牛的14个部位,宰后成熟48h,绞成肉糜状后分别于不同分辨率1.6和10.0nm条件下进行近红外光谱扫描和化学成分测定.应用The Unscrambler 建模软件,采用偏最小二乘回归技术(PLSR),通过交互验证程序建立近红外数学模型,得到不同分辨率1.6和10.0nm条件下蛋白质的校正集相关系数R分别为0.94和0.93,交互验证标准差(RMSECV)分别为0.49和0.54;脂肪R分别为0.93和0.92,RMSECV分别为0.64和0.76;水分R分别为0.87和0.81,RMSECV分别为1.18和1.26研究结果表明,高光谱分辨率下的蛋白质、脂肪和水分模型精度要略优于低光谱分辨率所建模型.     

奇亚籽水分、脂肪、蛋白质和灰分的近红外 光谱快速检测模型优化

水分、脂肪、蛋白质、灰分是重要的奇亚籽品质指标,目前主要依赖于化学法测定,过程烦琐,耗时费力,且不能多指标同时监测。以103份不同产地的奇亚籽为建模样本,通过19种光谱预处理方法和最佳谱区范围的筛选分别建立了奇亚籽中水分、脂肪、蛋白质、灰分的偏最小二乘模型。结果表明:对于水分采用Savitzky-Golay滤波平滑(SG)对光谱进行预处理,脂肪采用一阶导数(1st)和多元散射校正(MSC),蛋白质采用1st、标准正态变化(SNV)和SG,对于灰分采用1st、SNV和Norris微分平滑(ND)组合光谱进行预处理,针对各参数最佳预处理光谱采用人工法进行谱区筛选建立模型,得到水分、脂肪、蛋白质和灰分的验证集相关系数分别为0. 993、0. 972、0. 925和0. 923。结果显示,利用近红外光谱可以实现对奇亚籽的水分、脂肪、蛋白质以及灰分的同时快速无损检测,在大规模奇亚籽原料的分选中提高检测效率。     

近红外法测定豆浆蛋白质、脂肪和可溶性固形物含量

利用傅里叶变换近红外光谱仪采用积分球漫反射方式对60个豆浆样品进行光谱的采集,结合常规分析结果分别建立了3种成分的近红外校正模型。结果表明:豆浆蛋白质、脂肪及可溶性固形物光谱分别经过消除常数偏移量、一阶导数和矢量归一化(SNV)预处理后建模效果最好。蛋白质、脂肪和可溶性固形物含量的校正模型决定系数(R2)分别为:0.966 4、0.950 0和0.950 7,交叉验证均方根差(RMSECV)依次为0.076 9、0.087 4和0.316;对模型进行外部验证,验证集化学值和模型预测值之间差异不显著,说明模型可以用于豆浆中蛋白质、脂肪和可溶性固形物含量的检测。     

基于近红外光谱的藏区酥油脂肪和蛋白质含量快速检测分析

为了建立藏区酥油中脂肪和蛋白质含量快速检测方法,以藏区不同产地酥油为研究对象,采用组合区间偏最小二乘法优选出脂肪和蛋白质的红外光谱特征波段,在此基础上分别对几种光谱预处理方法进行比较挑选出最佳预处理方法,最后建立脂肪和蛋白质的定量分析模型并对模型进行外部验证。结果表明:在脂肪和蛋白质的特征波段内采用SNV+数据归一化+二阶导数+S-G滤波法对光谱预处理后建立脂肪和蛋白质定量模型,模型相关系数(R)分别为0.994和0.997,交叉验证均方差(RMSECV)分别为4.09%和0.286%。对验证样本的预测值和实测值进行配对t检验,两种测量值之间没有显著性差异(P0.05),表明建立的脂肪和蛋白质的近红外定量模型具有良好的预测能力,基于近红外光谱快速测定藏区酥油中脂肪和蛋白质的含量是可行的。     

两种近红外光谱分辨率预测牛肉营养成分的比较研究

应用近红外光谱技术在不同光谱分辨率下分析了同一批牛肉样本的蛋白质、脂肪和水分含量。样品取自16头西门塔尔杂交牛的14个部位,宰后成熟48h,绞成肉糜状后分别于不同分辨率1.6和10.0nm条件下进行近红外光谱扫描和化学成分测定。应用The Unscrambler建模软件,采用偏最小二乘回归技术(PLSR),通过交互验证程序建立近红外数学模型,得到不同分辨率1.6和10.0nm条件下蛋白质的校正集相关系数R分别为0.94和0.93,交互验证标准差(RMSECV)分别为0.49和0.54;脂肪R分别为0.93和0.92,RMSECV分别为0.64和0.76;水分R分别为0.87和0.81,RMSECV分别为1.18和1.26。研究结果表明,高光谱分辨率下的蛋白质、脂肪和水分模型精度要略优于低光谱分辨率所建模型。      

基于近红外建立荞麦营养成分快速检测模型

为探索一种快速、高效测定荞麦营养成分含量的方法,从内蒙古等地收集荞麦样品66份,采集样品近红外漫反射光谱图,并参照国标法测定样品水分、灰分、脂肪、蛋白质、淀粉含量,利用样品近红外光谱指纹结合化学计量学方法建立荞麦各营养成分的快速检测模型。结果,在10 000～4 000 cm^-1波数范围内,分别对近红外光谱进行多元散射校正+一阶导数处理、一阶导数处理+标准正态变换及去趋势算法、无预处理、二阶导数+标准正态变换及去趋势算法,结合化学测定值建立的营养成分快速检测模型的校正和预测效果最佳;所建立的水分、灰分、脂肪、蛋白质、淀粉含量快速检测模型交叉验证决定系数R²分别为81.601 0%、94.086 2%、80.942 3%、99.897 5%、99.857 6%,外部验证决定系数R²分别为81.60%、94.09%、80.94%、99.97%、99.86%,且验证结果预测值及化学值差异不显著。建立的模型可以满足荞麦营养成分的快速检测。     

基于近红外光谱法快速测定许氏平鲉脂肪和 水分含量的方法研究

目的建立近红外光谱法结合偏最小二乘法测定许氏平鲉鱼肉中的脂肪和水分含量,以期简便、快速地对许氏平鲉进行品质分析与评价。方法采用常规分析手段测定70个样品的脂肪和水分含量,同时采集其近红外光谱数据,结合偏最小二乘法(partial least square,PLS)建立许氏平鲉鱼肉中脂肪和水分的定量预测模型,并对比不同光谱预处理方法、光谱范围和因子数对定量预测模型的影响。结果光谱经Savitzky-Golay(S-G)和标准正态变量变换(standardized normal variate,SNV)预处理后,在5341.85~4007.36 cm~(-1)、6556.79~5345.71cm~(-1)和8651.10~7162.33 cm~(-1)光谱范围内,选取主因子数10,建立脂肪的校正模型性能最优;光谱经过SNV预处理后,在8886.38~4061.35cm~(-1)光谱范围内,分别选取主因子数为9时,建立的水分的校正模型性能最优。脂肪和水分含量相对最优PLS模型的校正集相关系数分别为0.9918和0.9912,校正标准偏差分别为0.2680和0.3300,交叉验证相关系数分别为0.9820和0.9810,交叉验证均方差分别为0.3980和0.4850,验证集相关系数分别为0.9804和0.9798,验证集均方差分别为0.3260和0.3070。结论本方法可较为准确地预测许氏平鲉鱼肉中的脂肪和水分含量,能够满足快速分析评价许氏平鲉品质的要求。     

傅立叶变换近红外光谱法快速检测锅盔中水分含量

应用傅立叶变换近红外光谱技术,建立锅盔水分含量分析模型.测定61份锅盔的近红外光谱,经一阶导数+MSC预处理以滤去噪声,在7 501.9～4 597.6 cm-1谱段范围内,选择维数10,利用偏最小二乘法建立近红外光谱与国标参考方法测得的水分含量之间的相关模型.最终得到水分定量校正模型决定系数(R2)为99.03％,内部交叉验证均方差(RMSECV)为0.409％.用该模型对19个未知锅盔样品进行外部验证,其水分外部验证决定系数(R2)为97.99％,预测标准偏差(RMSEP)为0.341％.结果表明,近红外定量分析技术有较高的准确度,能满足锅盔水分的快速检测精度要求.     

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