基于智舌的水产品中创伤弧菌快速检测体系的构建

以创伤弧菌为研究对象,探讨智舌在致病性弧菌快速检测中的可行性。首先用基于脉冲伏安法的智舌监测创伤弧菌的生长趋势,并以常规的浊度法验证其可行性;再用智舌鉴别11种致病性弧菌的液体培养物,以确定智舌结合主成分分析法能否将致病性弧菌区分开及其所需的最短时间;最后用智舌结合SIMCA法构建创伤弧菌的模式识别单元。结果显示,可用智舌监测液体培养基中创伤弧菌的生长情况;当在特异性培养基中培养弧菌8h后,智舌能很好地区分11种致病性弧菌;7种电极与其频率段组合下的PCA模型,对所有样本的判别准确率达到100%,说明所建模型可用于创伤弧菌的快速筛检。智舌快速检测创伤弧菌的方法切实可行。     

智舌检测出血性大肠埃希氏菌O157:H7和金黄色葡萄球菌

目的:探究一种快速检测出血性大肠埃希氏菌O157:H7、金黄色葡萄球菌的新方法。方法:基于多频大幅脉冲伏安法的智舌检测微生物生长过程中营养肉汤成分的综合信息,并结合主成分分析方法和簇类的独立软模式识别技术,对检测得到的数据进行分析。结果:在智舌的钯电极1 Hz频率段检测出血性大肠埃希氏菌O157:H7、金黄色葡萄球菌和1%葡萄糖营养肉汤区分效果较好,通过独立软模式识别技术能很好地判别、区分有菌生长的培养基和纯培养。结论:智舌能够有效检测、区分两种菌及培养基,有望成为检测出血性大肠埃希氏菌O157:H7、金黄色葡萄球菌的一种新技术。     

智舌对同属5种产毒曲霉的快速鉴别研究

为探究智舌(电子舌)是否能够鉴别同属中不同种的霉菌,以构建快速鉴别霉菌的新技术。用基于多频脉冲伏安法的智舌,结合主成分分析,对在相同基质中培养30、40h和50h的5种主要产毒曲霉菌的液体培养物进行鉴别研究,筛选能够鉴别它们的最佳电极和频率段组合。结果显示,5种产毒曲霉不同时间段的培养物的鉴别效果不同,30h的稍有鉴别趋势,但不能彼此鉴别;40h的鉴别趋势稍好,也仅有W电极100Hz和Ag电极100Hz能够鉴别;50h的5种产毒曲霉菌的培养物,多数电极和频率段组合都能有效鉴别,其中Pt电极100Hz、Au电极1Hz和10Hz、Pd电极1Hz和10Hz、W电极10Hz和100Hz、Ag电极1Hz和100Hz的鉴别效果最好。同时利用判别依据的d值,均为dmin﹥2.000。研究结果表明,智舌结合主成分分析法快速鉴别同属不同种的产毒曲霉菌是可行的。     

多频脉冲电子舌鉴别食源性致病菌

为了解能够显示被检测液体食品综合信息的电子舌,是否也能显示细茼液体培养物的综合信息,探讨一类新型食品致病菌的快速检测新技术.基于伏安法的多频脉冲电子舌,结合主成分分析,对8种食源性致病性茼进行区分研究,得到最佳电极阵列和频率段组合,再对亲缘关系较近的4种肠道致病菌进行区分.结果显示,区分食源性致病菌效果好的电极和频率段分别是:钯电极的100 Hz、金电极的1 Hz、钛电极的100 Hz、银电极的100 Hz和钨电极的10 Hz:区分肠道致病菌效果好的电极和频率段分别是:钛电极的100 Hz、银电极的100Hz和铂电极的1 Hz、10 Hz.研究结果表明.多频脉冲电子舌伏安法结合主成分分析法区分食源性致病菌是可行的,具有很大的研究价值,有望成为一类具有发展优势的快速检测食源性致病菌的新技术.     

智舌在白酒区分辨识中的应用研究

采用智舌对白酒进行区分辨识.采用铂电极、金电极、钯电极、钛电极、钨电极和银电极作为工作电极.在1Hz、10Hz、100Hz脉冲频率下进行检测.采用主成分分析进行数据处理.结果表明,智舌能够将各种不同品牌、香型的白酒很好地区分开;在白酒行业,智舌具有很大的应用潜力.     

基于电子舌及一维深度CNN-ELM模型的普洱茶贮藏年限快速检测

采用伏安电子舌对不同贮藏年限的普洱茶进行快速检测。将深度学习技术引入到电子舌的模式识别中,提出一种基于一维卷积神经网络(1-D CNN)与极限学习机(ELM)组合的模式识别模型(1-D CNN-ELM)。采用该模型结合伏安电子舌对5种不同贮藏年限的普洱茶进行分类鉴别,结果表明,与传统基于离散小波变换(DWT)结合支持向量机(SVM)或极限学习机(ELM)的模型相比,1-D CNN-ELM对普洱茶贮藏年限的分类效果更优,其测试集准确率、精确率、召回率和F1-Score分别达到98.32%,98.0%,98.0%,0.98。试验表明深度学习方法适用于对电子舌信号进行模式识别处理,且具有较高的分类准确性和泛化能力。     

电子鼻技术结合化学计量学用于卷烟包装纸VOCs残留量的表征

为建立更加简便快速、环保和低成本的卷烟包装纸品质判别方法,结合卷烟包装纸挥发性有机化合物(VOCs)的质量分数和电子鼻检测结果,用判别因子分析(DFA)、主成分分析(PCA)和簇类独立软模型分析(SIMCA)3种方法分别构建苯残留量判别模型和15种VOCs总量判别模型,并对比了3种方法的建模结果。结果表明:采用DFA构建苯残留量判别模型,以及采用DFA或SIMCA构建15种VOCs总量判别模型,均可较好地实现卷烟包装纸品质的快速判别。     

基于多频脉冲电子舌的茶饮料区分辨识

多频脉冲电子舌是一种采用多频率大幅脉冲作为激发扫描信号,用几种不同的非修饰金属电极组成传感器阵列,检测被测物质的整体响应信号,辅以主成分分析数学方法的新型电子舌系统.实验中采用铂电极、金电极、钯电极、钛电极、钨电极作为传感器阵列,在1、10、100Hz三个频率段下进行检测,数据采用主成分分析的方法对六种不同的茶饮料进行区分辨识.结果显示,钛10Hz钨10Hz组合电极能够对六种茶饮料有较好的区分辨识效果.可见,多频脉冲电子舌在饮料的区分、辨别真伪方面有很大的潜力.     

拉曼光谱结合模式识别方法鉴别大米种类

为实现大米种类准确、快速的鉴别,选购72份大米样品,粉碎,采集粒度为100-140目米粉的拉曼光谱,对谱图数据进行去噪、归一化和特征提取后,综合运用主成分分析（PCA）、层次聚类分析（HCA）和支持向量机（SVM）三种方法对粳米、籼米和糯米进行聚类与模式识别研究。三种大米经PCA分析可直观地归为三簇,籼米和糯米可被区分开,但粳米与糯米、粳米与籼米不能区分。HCA结果表明粳米与籼米较难区分,糯米与其它两种米有较大差异,三种大米经HCA聚类分析准确率为81.94%。而采用SVM判别方法经10次运行后的平均识别率达98.86%。实验证明：拉曼光谱法结合支持向量机用于大米种类的分类与识别简单快速,在分析数据相对复杂的情况下,可快速建立分类模型并实现大米种类间的鉴定与识别。     

2种弧菌的实时荧光PCR快速检测

目的为快速、特异、灵敏的检测致病性弧菌,建立致病性弧菌的实时荧光PCR方法。方法针对霍乱弧菌的种特异性基因ompW、毒力基因tcpA、ctxA和副溶血性弧菌的种特异性基因tl、毒力基因tdh设计引物和Taqman荧光探针,建立实时荧光PCR检测方法。结果该方法能够特异性地检出副溶血性弧菌或霍乱弧菌,并进一步确定其是否携带tdh、tcpA或ctxA毒力基因,检测的灵敏度可达到10CFU/ml或0.1716μg/ml(pg/μl)DNA模板浓度。结论该方法特异性强、灵敏度高,适用于食品中致病性弧菌的快速检验。     

Prevalence of potentially pathogenic Vibrio species in the seafood marketed in Malaysia

Seafood samples obtained in seafood markets and supermarkets at 11 sites selected from four states in Malaysia were examined for the presence of nine potentially pathogenic species from the genus Vibrio between July 1998 and June 1999. We examined 768 sample sets that included shrimp, squid, crab, cockles, and mussels. We extensively examined shrimp samples from Selangor State to determine seasonal variation of Vibrio populations. Eight potentially pathogenic Vibrio species were detected, with overall incidence in the samples at 4.6% for V. cholerae, 4.7% for V. parahaemolyticus, 6.0% for V. vulnificus, 11% for V. alginolyticus, 9.9% for V. metschnikovii, 1.3% for V. mimicus, 13% for V. damsela, 7.6% for V. fluvialis, and 52% for a combined population of all of the above. As many as eight Vibrio species were detected in shrimp and only four in squid and peel mussels. The overall percent incidence of any of the eight vibrios was highest (82%) in cockles (Anadara granosa) among the seafoods examined and was highest (100%) in Kuching, Sarawak State, and lowest (25%) in Penang, Pulau Penang State, among the sampling sites. Of 97 strains of V. cholerae isolated, one strain belonged to the O1 serotype and 14 to the O139 serotype. The results indicate that the various seafood markets in Malaysia are contaminated with potentially pathogenic Vibrio species regardless of the season and suggest that there is a need for adequate consumer protection measures.     

RECOVERY OF VIBRIO METSCHNIKOVII FROM MARKET SEAFOOD

Vibrio metschnikovii, a potentially pathogenic marine bacterium, was recovered from a wide variety of finfish and shellfish purchased at fish markets and supermarkets. Because limited information is available on the occurrence of this organism in food products and human disease, the observations may be relevant to public health considerations of seafood consumption .     

Der PCR-gestützte Nachweis von Vibrio cholerae in klinischen und nicht klinischen Proben

Although classical microbiological methods for the detection and identification of pathogenic Vibrio cholerae are sufficiently and reliably available today, the successful development and application of PCR-based assays for species diagnostics, determination of relevant serotypes, discrimination of pathovars and virulent variants were carried out in the last couple of years. The currently available PCR-based assays for V. cholerae are summarised and discussed in the present paper.     

基于微间隙阵列电极传感器检测副溶血性弧菌的方法初探

目的建立电化学免疫传感器法快速检测副溶血性弧菌的分析方法。方法采用微间隙阵列电极作为基础电极,运用双抗夹心酶联免疫反应和酶催化银沉积反应实现分析信号放大,检测副溶血性弧菌。结果该方法特异性良好,对非目标菌株无交叉反应,对副溶血性弧菌的检出限为10~5 CFU/mL,线性范围为10~5~10~8CFU/mL,传感器的电导率与副溶血性弧菌浓度之间呈良好的线性关系,线性相关系数r~2=0.955。增菌6h后,只需2h即可完成检测。结论该方法具有检测速度快、操作简便、检测成本低等特点,为副溶血性弧菌的快速检测提供了一种有效手段。     

致病性弧菌检测新技术研究进展

随着人们对水产品需求的增加及致病性弧菌引发的食源性疾病的流行，致病性弧菌对水产养殖业及人类健康造成了巨大威胁，基于此，致病性弧菌检测新技术的开发变得尤为迫切。本文介绍了包括免疫学方法、核酸检测方法、基于生物芯片的检测方法、基于核酸适配体的检测方法、基于肽质量指纹图谱技术的检测方法、基于生物传感器技术的检测方法在内的六项检测技术，分析了其优缺点及其在致病性弧菌中的应用。最后，总结了致病性弧菌检测新技术的研究现状，结合新兴技术指出未来研究方向，为致病性弧菌的快速检测提供参考。     

基于电子鼻的食用油氧化判别分析

为实现食用油氧化快速判别分析,以市场上常见的食用油为原料,对其进行氧化处理,根据国标中过氧化值和酸值划分为氧化油与未氧化油并作为模型样品和验证样品,采用电子鼻技术测定食用油气味,同时结合聚类分析（cluster analysis,CA）、主成分分析（principal component analysis,PCA）和线性判别分析（linear discriminantanalysis,LDA）方法对不同氧化程度的食用油进行判别,并建立油脂氧化的快速判别模型。同时将检测判别结果与国标规定进行比较分析,结果表明：3 种方法建立模型判别正确率均为100%,CA、PCA和LDA模型验证的判别正确率分别为95.8%、98.9%和100%,说明基于电子鼻技术的食用油氧化判别检测是可行的。     

Rapid classification of virgin and recycled EPS containers by Fourier transform infrared spectroscopy and chemometrics

ABSTRACT

A rapid and sensitive method for classification of virgin and recycled expanded polystyrene (EPS) food containers was developed using Fourier transform infrared spectroscopy (FTIR) and chemometrics. This method includes preparing a transparent film by dissolution, examining by FTIR and developing classification models. The degradation of EPS containers occurring during the recycling process was reflected by the carbonyl region of the infrared spectrum which was used as variables for multivariate data analysis. PCA was used to reduce the data dimension and view the sample similarities. Soft independent modelling of class analogy (SIMCA), partial least squares-discrimination analysis (PLS-DA) and linear discrimination analysis (LDA) were applied to construct three classification models. The best discrimination results were obtained by an LDA model, with all samples correctly classified. PLS-DA and SIMCA could not classify the recycled EPS samples with low levels of adulteration. When applying this method to commercially available EPS containers, about 45% of samples were shown to contain recycled polystyrene resins. It is concluded that the carbonyl region of the infrared spectra coupled with chemometrics could be a powerful tool for the classification of virgin and recycled EPS food containers.     

两种致病性弧菌二重LAMP-熔解曲线检测方法的建立

应用环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP),建立了食品中产毒素性霍乱弧菌和副溶血性弧菌二重LAMP-熔解曲线快速检测方法。本方法针对产毒素性霍乱弧菌ctx A基因和副溶血性弧菌gyr B基因分别设计引物组进行二重LAMP扩增,并利用熔解曲线法分析扩增产物,从而判断DNA模板中所含目标菌。应用本方法对9株目标菌和17株非目标菌的检测结果与预期一致,并可通过熔解曲线的特征峰准确分析DNA模板中所含目标菌。对二重LAMP扩增产物的测序分析表明,扩增所得序列与目的基因序列吻合,从而进一步验证了该方法的特异性。经测试,本方法对两种目标菌的检测灵敏度均可达100 fg DNA/反应管。实验证明所建立的方法具有良好的特异性,并可为食品中两种致病性弧菌的快速检测提供一种重要技术手段。     

Cheddar cheese classification based on flavor quality using a novel extraction method and Fourier transform infrared spectroscopy

Analysis of Cheddar cheese flavor using trained sensory and grading panels is expensive and time consuming. A rapid and simple solvent extraction procedure in combination with Fourier transform infrared spectroscopy was developed for classifying Cheddar cheese based on flavor quality. Fifteen Cheddar cheese samples from 2 commercial production plants were ground into powders using liquid nitrogen. The water-soluble compounds from the cheese powder, without interfering compounds such as fat and protein, were extracted using water, chloroform, and ethanol. Aliquots (10 μL) of the extract were placed on a zinc selenide crystal, vacuum dried, and scanned in the mid-infrared region (4,000 to 700 cm⁻¹). The infrared spectra were analyzed by soft independent modeling of class analogy (SIMCA) for pattern recognition. Sensory flavor quality of these cheeses was determined by trained quality assurance personnel in the production facilities. The SIMCA models provided 3-dimensional classification plots in which all the 15 cheese samples formed well-separated clusters. The orientation of the clusters in 3-dimensional space correlated well with their cheese flavor characteristics (fermented, unclean, low flavor, sour, good Cheddar, and so on). The discrimination of the samples in the SIMCA plot was mainly due to organic acids, fatty acids and their esters, and amino acids (1,450 to 1,350 and 1,200 to 990 cm⁻¹), which are known to contribute significantly to cheese flavor. The total analysis time, including the sample preparation time, was less than 20 min per sample. This technique can be a rapid, inexpensive, and simple tool to the cheese industry for predicting the flavor quality of cheese.     

水产品中副溶血性弧菌实时荧光PCR检测方法

建立了一种特异、灵敏、稳定的副溶血性弧菌(Vibrio parahemolyticus,VP)致病基因的检测方法。对已建立的副溶血性弧菌致病基因tdh、trh和tlh荧光PCR方法的特异性、灵敏度和重复性进行检测,以验证该方法的有效性。该方法与副溶血性弧菌反应良好,与其他弧菌属和非弧菌属的6株常见食源性致病菌无交叉反应;检测了6株副溶血性弧菌标准菌株和分离株,3种致病基因检出限分别为tlh 6～43 CFU/mL,tdh 97～1 700 CFU/mL,trh 1 100～4 000 CFU/mL;3种致病基因20次重复组内变异系数在0.96%～1.50%,组间变异系数在2.70%～4.10%。该方法操作简便,特异性强,灵敏度高,能够准确、快速、灵敏地检测水产品中副溶血性弧菌。