基于高光谱成像技术的金银花与山银花快速鉴别

利用高光谱成像技术,研究一种快速、准确、无损的鉴别金银花与山银花的方法。通过对比3种预处理方法对偏最小二乘算法(Partial Least Squares,PLS)建模效果的影响,得到SNV为建模最优预处理方法。使用回归系数法(Regression Coefficient,RC)和连续投影算法(Successive Projection Algorithm,SPA)选择经预处理后光谱的特征波长,并分别建立极限学习机(Extreme learning machine,ELM)和最小二乘支持向量机(Last Squares Support Vector Machine,LSSVM)的判别分析模型。结果表明,光谱经SNV预处理后,应用SPA提取特征波长并建立LS-SVM判别分析模型为金银花和山银花最优判别模型,其建模集与预测集识别率均达到了100.00%。因此,利用高光谱成像技术能够无损、有效地鉴别金银花与山银花,并且在全光谱和特征波长下均能实现金银花与山银花的快速判别分析。     

基于可见/近红外高光谱成像技术的鸡蛋新鲜度无损检测

以400~1 000nm高光谱系统获得鸡蛋样本的高光谱图像,利用蒙特卡洛法检测异常样本,采用不同预处理方法处理原始光谱;应用竞争性正自适应加权算法(Competitive Adaptive Reweighted Sampling,CARS)、遗传偏最小二乘法(Genetic Algorithms PLS,GAPLS)和间隔蛙跳法(Interval Random Frog,IRF)对预处理后光谱数据提取特征波长;分别建立基于全光谱和特征波长的偏最小二乘回归(Partial Least Squares Regression,PLSR)和最小二乘支持向量机(Least Squares Support Vector Machine,LS-SVM)鸡蛋新鲜度预测模型。结果表明:标准正态变量变换(Standardized Normal Variate,SNV)法为最优预处理方法;利用CARS、GAPLS和IRF分别选出8,35,74个特征波长;基于GAPLS提取的特征波长的LS-SVM模型最优,其校正相关系数(Rc)为0.899,预测相关系数(Rp)为0.832。表明基于高光谱成像技术的鸡蛋新鲜度无损检测是可行的。     

基于可见/近红外高光谱成像技术的牛肉品种鉴别

利用可见/近红外高光谱成像技术实现荷斯坦奶牛、秦川牛、西门塔尔牛三个品种牛肉的快速无损鉴别。首先,对原始光谱进行预处理并对样本集进行划分;应用竞争性自适应重加权算法(CARS)、连续投影算法(SPA)和无信息变量消除算法(UVE)对预处理后的光谱数据提取特征波长;结合偏最小二乘判别模型(PLS-DA)、K最近邻(KNN)模型及支持向量机(SVM)模型进行全波段及特征波段鉴别分析。结果表明,一阶导数(FD)法为最优预处理方法,利用光谱-理化值共生距离法(SPXY)法划分后的样本模型预测性能最好;利用CARS、SPA和UVE分别选出24、17和19个特征波长;基于CARS法提取的特征波长所建的RBF-SVM模型的校正集与预测集正确率分别为100%、98.82%。由此可见,基于高光谱成像技术能够获得较好的牛肉品种鉴别效果。该研究可为牛肉品种的快速无损鉴别提供参考。     

高光谱成像技术对灵武长枣果皮强度的无损检测

利用高光谱技术对灵武长枣果皮强度检测进行研究,为灵武长枣外部品质无损检测提供科学方法。采集120个灵武长枣的400~1000 nm的高光谱图像,对光谱数据进行预处理;应用连续投影算法(SPA)、正自适应加权算法(CARS)和无信息变量消除法(UVE)对原始光谱数据提取特征波长;分别建立基于全光谱和特征波长的偏最小二乘回归(PLSR)和最小二乘支持向量机(LS-SVM)果皮强度预测模型。结果表明:采用标准正态变换(SNV)预处理算法效果最优,其PLSR模型的交叉验证相关系数(Rcv)为0.8207,交叉验证均方根误差(RMSECV)为9.9630;利用SPA、CARS和UVE法从全光谱的125个波长中分别选取出29个、31个和31个特征波长;而基于全光谱建立的LS-SVM模型效果最优,其预测相关系数(Rp)为0.9555,预测均方根误差(RMSEP)为3.8282;研究结果表明基于高光谱成像技术采集的灵武长枣漫反射光谱进行果皮强度无损检测具有可行性。     

基于高光谱技术的不同霉变程度籼稻快速鉴别

为解决快速、无损鉴别籼稻霉变程度问题。该文利用高光谱技术采集正常、轻度霉变、中度霉变和重度霉变共4类籼稻样本的光谱数据,经不同预处理后,通过连续投影算法(SPA)提取特征波长,采用多元线性回归判别分析(MLR-DA)建立籼稻霉变程度鉴别模型。同时,通过竞争性自适应重加权算法(CARS)筛选特征变量,采用偏最小二乘法回归判别分析(PLS-DA)建立鉴别模型。研究结果表明,SG-SPA-MLRDA和RAW-CARS-PLS-DA模型的验证集相关系数RP均大于0.950。其中,RAW-CARS-PLS-DA模型的预测效果最优,其验证集相关系数RP为0.969,均方根误差RMSEP为0.269,对未知籼稻样本的总体分类准确率为93.33%。该模型对不同霉变程度籼稻具有较强的鉴别能力,故该方法可为快速、无损鉴别籼稻霉变程度提供技术支持。     

基于微型近红外光谱仪的油菜籽含油率模型参数优化研究

为实现油菜籽含油率快速无损检测,采用微型近红外光谱仪,结合竞争性自适应重加权(CARS)、遗传算法(GA)、连续投影算法(SPA)、无信息变量消除法(UVE)、向后区间偏最小二乘法(BIPLS)、联合区间偏最小二乘法(SIPLS)等方法优选油菜籽含油率近红外光谱特征波长,建立偏最小二乘回归(PLSR)和最小二乘支持向量机(LS-SVM)定量分析模型,同时对LS-SVM模型参数进行优化。研究表明,对PLSR模型,BIPLS+GA优选的26个特征波长建模效果最好,其预测相关系数(Rp)和预测均方根误差(RMSEP)分别为0.9330和0.0075,对LS-SVM模型,SIPLS+GA优选的13个特征波长建模效果最好,预测相关系数(Rp)和预测均方根误差(RMSEP)分别0.9192和0.0055。证明了波长优选和参数优化可有效简化油菜籽含油率近红外光谱定量分析模型,提高模型预测精度和稳定性,为进一步拓展微型近红外光谱仪的应用提供技术参考。     

基于高光谱成像技术小麦籽粒霉变鉴别方法研究

小麦霉变籽粒是小麦不完善粒一种,鉴别小麦霉变粒是粮食霉变程度的重要参考。为了更精确地鉴别小麦霉变籽粒,本文利用高光谱成像技术采集不同品种小麦霉变籽粒及非霉变籽粒的光谱信息,建立小麦霉变籽粒的鉴别预测模型,实现小麦霉变籽粒快速、无损、有效、稳定的鉴别。首先收集了100粒霉变和100粒正常非霉变籽粒400-1000 nm范围的高光谱图谱,通过不同的光谱预处理方法进行处理,选出最优光谱信息预处理方法。接着,采用连续投影算法(SPA)和竞争性自适应重加权采样(CARS)提取特征波长,分别比较通过全波长范围和特征波长下建立的偏最小二乘判别分析(PLS-DA)和支持向量机(SVM)模型并进行比较。结果表明,淮麦22和宁麦13的最优预测模型分别为全波长-OSC-SVM和SPA-OSC-SVM模型,对应的R分别为0.9963和0.9998,RMSEP分别为0.0309和0.0064,R分别为0.9975和0.9995,RMSECV分别为0.0247和0.0111。     

高光谱成像技术结合优化算法窖泥总氮含量的预测

窖泥的总氮含量是窖泥质量评价的指标之一,其常规检测方法周期长且具有破坏性。为实现窖泥总氮含量的快速无损检测,提出了高光谱成像技术（HSI）结合优化算法的窖泥总氮含量的检测方法。首先,使用不同的预处理方法对可见光（Vis）光谱数据进行处理,并建立偏最小二乘回归（PLSR）模型,通过比较模型性能确定了最佳预处理。其次,综合比较了采用全光谱波长、竞争性自适应重加权采样（CARS）算法、连续投影算法（SPA）和CARS与SPA(CARS-SPA)联用策略方法优选特征波长,并作为PLSR和最小二乘支持向量机（LS-SVM）模型输入变量,研究对各模型性能的影响。最后,基于最优模型实现了窖泥样本的总氮含量可视化,直观反映不同层级的总氮含量差异。结果表明,标准正态变量变换（SNV）方法预处理后建立的PLSR模型预测总氮含量最好;CARS-SPA联用策略方法优选特征波长较其他两种方法好,且其建立的LS-SVM模型的预测性能最佳（预测集决定系数Rp2=0.987 6、预测均方根误差（RMSEP）=0.013 8 g/100 g）。高光谱成像技术结合优化算法可以快速、无损检测窖泥总氮含量,为窖泥中总氮含量检...     

基于高光谱的茄子外部缺陷检测

利用高光谱(900～1700nm)对完好、木栓化和烂果茄子进行识别研究。共采摘了252个茄子样本,包含完好茄子170个,木栓化茄子60个和烂果茄子22个,利用高光谱成像系统采集完好、木栓化和烂果3种区域一共252个样本的高光谱图像,然后提取合理的感兴趣区域(ROI)获得样本光谱数据。采用多种预处理方法进行光谱预处理,建立偏最小二乘(partial least squares method,PLS)判别分析模型,结果表明,经normalize预处理后模型的预测效果最好,因此选择normalize作为预处理方法。基于预处理后的光谱数据,采用连续投影法(SPA)、回归系数法(RC)和竞争性自适应重加权算法(CARS)提取特征波长,并分别建立偏最小二乘(PLS)和多元线性回归(MLR)判别模型进行研究。结果表明:CARS-MLR模型对3种类型样本鉴别效果最佳,其校正集决定系数Rc2为0.94,预测集决定系数Rp2为0.90,RMSEC和RMSEP分别为0.19和0.21,预测集判别准确率达到96.82%。本研究采用高光谱可以对完好、木栓化和烂果茄子进行有效鉴别,为茄子的缺陷无损检测提供了理论参考。     

基于近红外光谱的褐变板栗识别建模方法研究

为了实现褐变板栗的快速无损分选,研究了基于近红外光谱技术的褐变板栗栗仁检测方法。试验在1000~2500 nm波段范围内采集板栗栗仁的反射光谱,通过标准正态变量变换预处理后,采用K-最近邻法(KNN)、簇类独立软模式法(SIMCA)、主成分回归-线性判别分析法(PCA-LDA)、偏最小二乘回归-线性判别分析法(PLS-LDA)以及最小二乘-支持向量机判别分析法(LS-SVM)分别建立褐变板栗识别模型并进行比较分析。偏最小二乘结合最小二乘-支持向量机所建PLS-LS-SVM模型性能最优,该模型对测试集的敏感性、特异性和识别正确率分别为1.00%、0.92%和95.00%。结果表明:近红外光谱结合PLS-LS-SVM可用于褐变板栗的快速无损检测。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.