可见/近红外光谱技术无损检测新鲜鸡蛋蛋白质含量的研究

鸡蛋是一种重要的食品,蛋白质是鸡蛋的主要营养成分。本研究利用可见近红外反射光谱技术无损检测新鲜鸡蛋的蛋白质含量。使用光谱仪获取新鲜鸡蛋在400~1100 nm波段范围内的漫反射光谱;分别使用多元散射校正(MSC)法和一阶导数法(1-D)对反射光谱进行预处理;对反射光谱、MSC处理光谱和1-D光谱,使用逐步回归法判别法选择最优波长组合,建立多元线性回归模型,使用全交叉验证法验证模型。结果表明,可见/近红外反射光谱经过多元散射校正后,确定的10个最优波长(400、403.16、407.9、714.6、715、715.58、970.4、970.75、973和974.45 nm)组合建立模型的校正和验证结果最好:选定模型的校正结果为R=0.92,SEC=0.42%;验证结果为Rcv=0.89,SECV=0.47%。研究表明可见/近红外反射光谱技术可以较好的预测新鲜鸡蛋的蛋白质含量,本研究可为可见近红外光谱技术在鸡蛋营养成分的快速检测提供一定的理论基础。     

基于多元散射校正和偏最小二乘(MSC/PLS)的傅里叶变换近红外光谱检测蜂蜜中还原糖

为快速无损测定蜂蜜的还原糖,提出一种用近红外光谱技术进行检测的新方法.选用SN/T0852-2000铁氰化钾滴定法作为光谱还原糖测定的标定方法,用不同光谱预处理方法对模型的影响进行比较.首先用MSC对光谱数据进行校正,在经过Norris导数平滑法对原始光谱进行预处理消除噪声.利用光谱专用分析软件TQ Analyst7.2,建立偏最小二乘(PLS)校正模型.最优光谱模型校正相关系数(R)、校正相关均方差(RMSEC)、预测相关均方差(RMSEP)、交互验证相关系数(Rcv)、交叉验证均方差(REMSECV)分别为0.970 56,1.21,1.54,0.962 67,1.36.结果表明,应用多元散射校正(MSC)处理,并经过Norris二阶导数平滑后的PLS模型优于经典PLS算法所建立的模型. 用MSC对光谱数据进行校正,在经过Norris导数平滑法对原始光谱进行预处理消除噪声.利用光谱专用分析软件TQ Analyst7.2,建立偏最小二乘(PLS)校正模型.最优光谱模型校正相关系数(R)、校正相关均方差(RMSEC)、预测相关均方差(RMSEP)、交互验证相关系数(Rcv)、交叉验证均方差(REMSECV) 别为0.970 56,1.21,1.54,0.962 67,1.36.结果表明,应用多元散射校正(MSC)处理,     

利用可见/近红外光谱判别干枣品种

目的利用可见/近红外反射光谱技术快速判别干枣的品种。方法使用光谱仪获取山西永和枣、山西板枣和新疆和田枣3种干枣在345~1100 nm波段范围内的漫反射光谱;分别使用多元散射校正(MSC)法和一阶导数法(1~(st)-D)和二阶导数法(2~(st)-D)对反射光谱进行预处理;对预处理光谱进行主成分分析,全交差验证法确定最佳主成分数量,提取主成分,结合马氏距离法和线性判别法建立品种判别模型,建立模型过程中使用全交叉验证法确定最佳主成分数,将模型应用于干枣的品种判别。结果可见/近红外反射光谱经过MSC处理后提取主成分建立品种预测模型对枣的品种判别结果最好,利用前4个主成分结合马氏距离法建立的判别模型和利用前5个主成分结合线性判别法建立判别模型,对于3个品种的枣的校正和验证判别准确率都达到了100%。结论可见/近红外反射光谱技术可以较好地判别干枣品种,本研究可为可见/近红外光谱技术在于枣品种和产地的快速鉴别和溯源中的应用提供一定的技术基础。     

近红外光谱法快速检测带鱼肉中的水分和蛋白质含量

应用傅立叶变换近红外光谱分析技术对带鱼肉中水分和蛋白质含量进行了研究。分别建立原始光谱、间隔2点一阶导数(dblg2)、3点平滑(sa3)、标准归一化(SNV)和多元散射校正(MSC)的偏最小二乘回归(PLS)模型,比较定标相关系数(Rc)、预测相关系数(Rv)、定标标准差(SEC)和预测标准差(SEP),建立了MSC预测模型,水分和蛋白质近红外检测模型的相关系数均在0.9以上。SEC分别为0.74和0.68,SEP分别为0.81和0.73。将确定的模型进行了外部验证,水分和蛋白质NIR预测值和化学分析值的配对t检验差异均不显著。说明近红外光谱法应用于带鱼肉中水分和蛋白质含量的快速检测是可行的。     

南疆鲜羊肉水分含量的近红外光谱法无损检测

本文在近红外反射光谱780~1700 nm的波长范围内采集新宰杀的同一品种的羊的后腿肉134个样本的光谱数据,来实现快速无损的南疆生鲜羊肉含水量的检测。这些光谱数据经中值平滑滤波、多元散射校正、一阶导数、标准化处理、中心化变换和S-G平滑等预处理方法对原始光谱进行降噪处理;然后以13:1的比例将样本分为训练集和测试集,并采用PLSR建立预测模型,使用所建模型对生鲜羊肉水分含量进行预测。结果为:训练集的预测相关系数Rc为0.94、标准差MSEC为0.04,预测成功率为97.6%,测试集的预测相关系数Rv为0.89、标准差MSEV为0.07,预测成功率为96.4%。实验结果证实结合中值平滑滤波、多元散射校正、一阶导数、标准化处理、中心化变换和S-G平滑等多种预处理方法建立的基于近红外光谱PLSR模型,可以对南疆鲜羊肉的水分含量进行精确的快速无损评价,并且能为南疆生鲜羊肉水分含量的快速无损检测技术的应用提供理论上的指导。     

酸奶中非脂乳固体的近红外定量分析模型建立

采用偏最小二乘回归PLS建模算法,建立酸奶中非脂乳固体的近红外定量分析模型,并对模型进行验证评估。收集92组酸奶样品,并用漫反射方法采集得到近红外扫描光谱,光谱经过MSC、一阶导数、S-G平滑等预处理,选取波数范围6 000~10 000 cm-1,用PLS法建立得到了较优模型,其相关系数R为0.99078,均方根校正误差RMSEC为0.152,均方根预测误差RMSEP为0.330,性能指数PI为83.1。用此模型对25组酸奶样品进行了预测,预测效果较好。     

可见/近红外光谱技术无损检测新鲜鸡蛋pH及蛋白质的研究

本文利用可见/近红外光谱技术检测新鲜鸡蛋p H和蛋白质。分别采集新鲜鸡蛋在400~1000 nm和900~1700 nm波长范围的漫反射光谱,使用多元散射矫正(MSC)、标准正态变量变换(SNV)等光谱预处理技术,选择最佳的预处理方法,使用偏最小二乘法(PLS)建立p H和蛋白质模型并对其进行评价。结果表明,基于900~1700 nm波长范围的光谱获得的p H模型较好,其校正集相关系数为0.948,预测集相关系数为0.855;基于400~1000 nm波长范围的光谱获得的蛋白质模型较好,其校正集相关系数为0.927,预测集相关系数为0.906。研究表明,可见/近红外光谱技术可以较好的预测新鲜鸡蛋的p H和蛋白质,为鸡蛋营养成分的快速无损检测提供新的思路和方法。     

利用可见/近红外光谱技术对小米产地进行溯源研究

目的利用可见/近红外光谱技术对产自不同地区的晋谷21号小米进行溯源研究。方法使用近红外光谱仪获取产自洪洞、浮山、沁县3个不同地区的晋谷21号小米400~1004nm波段范围内的漫反射光谱;对光谱分别进行多元散射校正法(multiple scattering correction,MSC)、一阶导数法(first derivative,1St-D)预处理;对预处理光谱进行主成分分析,全交叉验证确定最佳主成分数量,获取主成分;同时选择预处理光谱特征波长。使用马氏距离法、线性判别法建立判别模型,最后用未知样品的验证准确率来表示模型的判别效果。结果原始光谱和MSC处理光谱提取特征波长分别建立的产地判别模型对3个不同产地的小米判别完全准确;1St-D处理光谱基于7个主成分结合马氏距离法和基于9个主成分结合线性判别法建立的2种判别模型对3个不同产地的小米亦实现完全准确判别。结论可见/近红外反射光谱技术用于小米产地的判别具有可行性,本研究可为小米产地的快速判别应用中提供技术基础。     

基于近红外光谱技术快速检测贵州红薯粉丝中薯粉含量

采用近红外光谱技术结合偏最小二乘法建立预测红薯淀粉及全粉粉丝中薯粉含量的定量模型,实现薯粉含量的在线快速检测。分别制作180份红薯淀粉粉丝和红薯全粉粉丝样品,以一阶导数、最大最小归一化处理、移动平均平滑、多元散射校正、标准正态化等计量学方法预处理光谱。结果表明,选择波数9403.6～7498.2 cm^–1、6101.9～4246.7 cm^–1+消除常数偏移量所建的红薯淀粉粉丝模型效果最好,波数9403.6～4597.6 cm^–1+减去一条直线所建的红薯全粉粉丝模型效果最好,预处理后2个模型相关系数分别为0.9875和0.9892,交叉验证均方根误差(RMSECV)分别为1.23和1.13,校正后预测相对分析偏差(RPD)分别为6.83和7.42。外部验证预测相关系数为0.9625和0.9714,相对标准偏差(RSD)均小于1,模型具有较高的准确度。近红外光谱技术可以实现贵州红薯粉丝中薯粉含量的快速检测。     

基于近红外漫反射光谱的面包老化过程中非冻结水含量无损检测

目的 建立一种基于近红外光谱技术快速无损测定面包老化过程中的非冻结水含量的方法。方法 应用近红外漫反射光谱技术采集新鲜面包在放置2h、2d、3d、4d、5d、6d、7d时的光谱，对比导数、S-G平滑(Savitzky Golay smooth)、标准正态变量变换(Standard normal variable transformation，SNV)及多元散射校正(Multiplicative scatter correction，MSC)预处理方法，利用偏最小二乘回归法(Partial least square regression，PLSR)和多元线性回归法（Multiple Linear Regression，MLR）建立面包老化过程中的非冻结水含量的预测模型，并对比两种模型预测结果。结果 利用PLSR建模相较MLR建模结果较好，建立的模型预测结果较好，模型的校正集相关系数（Rc）和均方根误差（RMSEC）分别为0.9386和0.0236 , 验证集相关系数（Rv）和均方根误差（RMSEP）分别为0.9271和0.0245。结论 通过近红外光谱技术结合偏最小二乘法建立面包老化过程中的非冻结水含量模型可作为面包老化过程中的非冻结水含量无损快速测定的可行性方法，其含量变化可以有效预测面包老化，为面包老化的无损检测提供了新的可行方案。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.