指纹图谱技术在植物油鉴定和掺假中的应用

指纹图谱技术是指利用现代仪器分析手段获得的能够代表该物种特征的各种图谱数据资料的一种技术。它主要建立在对物质成分的系统研究之上,评价样品质量的真实性和稳定性。近年来,指纹图谱技术也逐渐应用到植物油的鉴定和掺假中。文中对植物油中各种化学成分的指纹图谱在植物油品种鉴定和掺假方面的应用做了详细介绍。     

基于双重聚合酶链式反应技术检测掺假驴乳中的牛乳

目的 建立双重聚合酶链式反应(polymerase chain reaction,PCR)技术检测驴乳中掺假的牛乳的鉴别方法 。方法 将牛乳按比例掺入驴乳制备掺假乳,经热处理提取DNA,以驴和牛的12S-RNA、16S-RNA为靶标设计特异性引物,进行相应的PCR扩增,优化双重PCR退火温度,同时考察该方法 在巴氏杀菌、高温灭菌和冷冻干燥条件下的适用性及灵敏度。结果 牛和驴的引物特异性均良好,与非目标物种DNA不发生交叉反应,DNA检出限最低为10 ng;优化后的双重PCR最佳退火温度为55.7℃;单重PCR由于干扰因素少,对驴乳中牛乳的掺假检出限均为0.1%,而双重PCR也表现出较好的适用性及灵敏性,在原料乳中检出限为0.5%,巴氏杀菌乳、高温灭菌乳和冷冻干燥驴乳中检出限均为2.0%。相较于单重PCR,双重PCR大大缩短了检测时间成本。结论 本研究为驴乳中牛乳的掺假检测提供了一种准确、灵敏和经济的方法 ,具有实际参考价值。     

光谱法在食品掺假检测中的应用研究进展

食品掺假是影响食品安全的一个重要因素,除了需要有健全的法律法规外,食品安全的监管还需要依靠先进的技术手段。由于光谱法具有特征性强、快速、操作简单、样品状态不受限制等优点,被人们广泛用于食品掺假的检测中。对光谱法在各类食品体系掺假检测的具体应用方面进行了综述。     

原料乳中铵盐掺假检测方法

通过向原料乳中人为添加定量铵盐测试试剂,研究原料乳中铵盐掺假物质定性检测的方法。实验结果表明,该方法用于检测原料乳中铵盐质量分数在0．025％以上,具有良好的可操作性,同时方法操作简单,结果便于观察,适用于在养殖、收购、乳制品企业等进行原料乳质量验收检验。     

原料乳中碳酸钙掺假的检测方法

研究了原料乳中碳酸钙掺假的检测方法,样品通过离心沉淀出的碳酸钙遇盐酸生成二氧化碳,产生气泡,根据是否有气泡产生定性判定牛乳中是否掺有碳酸钙.结果表明,该方法用于检测原料乳中碳酸钙含量在0.1％的浓度添加量.以上含量具有良好的重现性,同时方法操作简单,结果准确,适用于乳品企业进行原料中碳酸钙含量的检测.     

原料乳中硫氰酸钠掺假定性检测方法

研究了原料乳中硫氰酸钠掺假快速定性检测方法,通过向原料乳样品中加入一定量的铁盐溶液,乳样与铁盐溶液接触面的颜色变化与硫氰酸钠掺入量有关,通过显色判定乳样中是否掺有硫氰酸钾。结果表明,该方法用于检测原料乳中硫氰酸钾质量分数在0．01％以上具有良好的重现性,同时方法操作简单,结果准确,适用于乳品企业进行原料乳质量验收检验。     

肉类掺假检测技术研究进展

肉类是我国居民消费最大的食品之一,然而掺假事件时有发生,这不仅对消费者的经济利益造成损害,更有甚者会对人类身体健康造成影响,因此对肉类掺假进行检测鉴别显得十分重要。本文综述了各种肉类掺假检测技术的应用和特点,并探讨其发展趋势。目前,国内外最常用的检测方法有PCR检测技术、酶联免疫法(ELISA)、近红外光谱技术、色谱技术等。在这些技术中,以PCR为主的检测技术包括长度多态性PCR、随机扩增多态性PCR以及实时PCR等最为成熟,应用得也最为广泛。近红外光谱检测虽然检测速度比较快,但是准确度方面还有待改进。ELISA方法虽然已有商品化试剂盒出现,但由于受蛋白活性影响,其应用范围也受限。色谱分析方法近年来有了更深入的研究,随着高分辨质谱的出现,通过多肽鉴定肉类品种将是一个新的研究方向。随着科技的发展,多种技术相结合将会使掺假检测更加快速、可靠。     

原料乳硫氰化物掺假定性检测方法

研究原料乳中硫氰化物掺假物质定性检测的方法,通过向原料乳中人为添加定量硫氰化物,在酸溶液中硫氰酸根与三价铁离子反应生成可溶于水及乙醚的血红色化合物,根据样品中硫氰酸根含量的多少,所显示的颜色不同。通过颜色反应判定原料乳中是否添加硫氰化物掺假物质。实验结果表明,该方法用于检测原料乳中硫氰化物质量分数在0．005％以上,具有良好的可操作性,同时方法操作简单,结果便于观察,适用于乳制品企业进行原料乳质量验收检验。     

原料乳中尿素掺假检测方法的研究

研究原料乳中尿素含量的定性检测,结果表明,该方法用于检测原料乳中“尿素”含量在0.5g/L以上具有良好的可操作性,同时方法操作简单,结果便于观察,适用于在养殖、收购、乳制品企业等进行原料乳质量验收检验.     

肉类掺假检测技术的研究进展

肉类品质的好坏直接影响着人们的生活质量和健康安全,同时也影响着整个肉品行业的发展.在高额利益驱动下,市场上肉类品质不容乐观,肉类生产加工过程中掺假现象层出不穷.本文介绍了市场上肉类掺假的主要方法 ,综述了目前采用的实时荧光PCR定量检测方法 、电子鼻结合统计学分析、酶联免疫分析、近红外特征光谱技术、高光谱技术和核磁共振...     

掺假羊乳及其制品中牛乳的检测技术研究进展

羊乳具有营养价值高、蛋白质组成更接近人乳、脂肪球直径小及致敏性低等优点,更利于人体消化吸收,受到消费者和乳品企业的青睐.近年来我国羊乳产业发展迅速且潜力巨大,但由于受羊乳产量和养殖规模的限制,羊乳价格昂贵,市场中存在羊乳及其制品掺假牛乳的现象,且掺假手段多样,难以辨别.为了保证消费者的健康和权益,保障羊乳市场良性发展,...     

综合型传感器阵列对掺杂生乳的识别

以钯、铂、金、钛、钨和银6种自制电极组为工作电极,与Ag/AgCl参比电极和铂对电极组成非选择性传感器组,再结合pH电极、电导率电极和钠度计电极3种选择性电极组成综合型传感器阵列,连接到电化学工作站和安装SPSS统计学软件电脑后,构成生乳掺杂检测系统。对荷斯坦牛生乳及掺杂不同浓度尿素和三聚氰胺,碳酸氢钠的样本乳、陈放乳、巴氏乳、酸败乳采用电化学方法进行检测,获得开路电位、交流阻抗谱、微分脉冲伏安数据,非选择性与选择性传感器组数据分别采用模式识别法进行计算,并获得各被测样本与生乳标准数据库的欧氏距离,再以不同权重得出综合欧氏距离,通过图表得到表达。结果表明,非选择性传感器阵列组对掺杂生乳具有良好的判别能力,在此基础上构建的加装有选择性传感器的综合型传感器阵列对掺杂的甑别效果优于前者。      

基于旋光法的原料乳中乳糖掺伪鉴别技术研究

旨在建立一种简便、高效的原料乳乳糖掺伪鉴别方法。以三氯乙酸为沉淀剂进行前处理,借助旋光仪,在589.30⁵89.44nm下,测定标准乳糖溶液的旋光度,绘制标准曲线,建立了一种基于标准曲线的原料乳乳糖掺伪定量鉴别法。所得回归方程的线性相关系数R2=0.9993,平均回收率达99.0%,相对标准偏差（RSD）为0.67%。与莱因-埃农氏法进行比对实验,结果无差异,但更快捷,成本更低。研究结果提示,本文所建方法实用、可靠。      

Use of MALDI-TOF MS technology to evaluate adulteration of small ruminant milk with raw bovine milk

Detection of adulteration of small ruminant milk is very important for health and commercial reasons. New analytical and cost-effective methods need to be developed to detect new adulteration practices. In this work, we aimed to explore the ability of the MALDI-TOF mass spectrometry to detect bovine milk in caprine and ovine milk using samples from 18 dairy farms. Different levels of adulteration (0.5, 1, 5, 10, 20, 40, 60, and 80%) were analyzed during the lactation period of goat and sheep (in May, from 60 to 90 d in milk, and in August, from 150 to 180 d in milk). Two different ranges of peptide-protein spectra (500–4,000 Da; 4–20 kDa) were used to establish a calibration model for predicting the concentration of adulterant using partial least squares and generalized linear model with lasso regularization. The low molecular weight part of the spectra together with the generalized linear model with lasso regularization regression model appeared to have greater potential for our aim of detection of adulteration of small ruminants' milk. The subsequent prediction model was able to predict the concentration of bovine milk in caprine milk with a root mean square error of 11.4 and 17.0% in ovine milk. The results offer compelling evidence that MALDI-TOF can detect the adulteration of small ruminants' milk. However, the method is severely limited by (1) the complexity of the milk proteome resulting from the adulteration technique, (2) the potential degradation of thermolabile proteins, and (3) the genetic variability of tested samples. Additionally, the root mean square error of prediction based only on one individual sample adulteration series can drop down to 6.34% for quantification of adulterated caprine milk and 6.28% for adulterated ovine milk for the full set of concentrations or down to 2.33 and 4.00%, respectively, if we restrict only to low concentrations of adulteration (0, 0.5, 1, 5, 10%).     

原料乳掺假现场检测箱的设计与检测项目组合

提出了原料乳掺假现场检测箱的设计思路,利用若干化学反应的基本原理和现象,可检测出原料乳中21种掺假物质。通过系统的评价各种检测方法的检测限,给出了优化后试剂组合。该检测箱适用于现场检测,便于携带。     

原料乳与乳制品中碳水化合物质量控制研究进展

原料乳与乳制品中碳水化合物具有极高的营养价值,对人体健康具有重要作用,但其掺伪现象较普遍,严重影响了原料乳与乳制品的品质。文章综述了原料乳与乳制品中碳水化合物及其掺伪物质检测技术研究进展,旨在为做好原料乳与乳制品中碳水化合物质量控制提供科学依据。      

河北省21个养牛小区生乳中硫氰酸盐含量及来源分析

为了调查生乳中硫氰酸盐的含量,对中国河北21个养牛小区(牧场)的930个生乳样品进行了硫氰酸盐含量的跟踪检测。检测结果表明930个生乳样品中硫氰酸盐检出率为100%,含量在1.86～11.92mg/L;生乳中的硫氰酸盐全部来源于本底,不存在人为添加,且生乳中硫氰酸盐含量的季节分布不存在显著差异。文章对生乳中硫氰酸盐的来源进行了分析,并提出了控制生乳中硫氰酸盐含量的建议。     

水牛乳及其乳制品中掺入牛属动物乳源的检测方法研究进展

综述了电泳、色谱、免疫化学、DNA技术等在掺假水牛乳检测中的研究进展及各自优劣,旨在为我国开展类似研究提供理论依据。     

Direct sandwich ELISA to detect the adulteration of human breast milk by cow milk

The demand for commercially available human breast milk has significantly increased in recent years. For various reasons, a significant amount of commercially available human breast milk is being adulterated with other types of milk. This fraudulent practice poses a threat to consumers' health due to potential adulterants such as cow milk, which may put the infant at risk due to intolerance or allergy. A direct sandwich anti-bovine IgG ELISA has been developed for the sensitive and specific detection of cow milk in adulterated human breast milk. This assay uses polyclonal anti-bovine IgG antibody as a capture antibody and monoclonal anti-bovine IgG-alkaline phosphatase antibody as a detection antibody. Once optimized, the assay was found to be highly sensitive, and specific to bovine IgG. The assay had no significant cross-reaction with human breast milk, indicating that it was highly specific. The anti-bovine IgG ELISA was able to detect the presence of cow milk in adulterated human breast milk with a detection limit of 0.001% cow milk. The developed assay was highly reproducible (coefficient of variation <10%). The developed direct sandwich anti-bovine IgG ELISA is simple, reliable, and reproducible, making it an ideal test for this purpose.     

Simultaneous detection for adulterations of maltodextrin,sodium carbonate,and whey in raw milk using Raman spectroscopy and chemometrics

To achieve rapid on-site identification of raw milk adulteration and simultaneously quantify the levels of various adulterants, we combined Raman spectroscopy with chemometrics to detect 3 of the most common adulterants. Raw milk was artificially adulterated with maltodextrin (0.5–15.0%; wt/wt), sodium carbonate (10–100 mg/kg), or whey (1.0–20.0%; wt/wt). Partial least square discriminant analysis (PLS-DA) classification and a partial least square (PLS) regression model were established using Raman spectra of 144 samples, among which 108 samples were used for training and 36 were used for validation. A model with excellent performance was obtained by spectral preprocessing with first derivative, and variable selection optimization with variable importance in the projection. The classification accuracy of the PLS-DA model was 95.83% for maltodextrin, 100% for sodium carbonate, 95.84% for whey, and 92.25% for pure raw milk. The PLS model had a detection limit of 1.46% for maltodextrin, 4.38 mg/kg for sodium carbonate, and 2.64% for whey. These results suggested that Raman spectroscopy combined with PLS-DA and PLS model can rapidly and efficiently detect adulterants of maltodextrin, sodium carbonate, and whey in raw milk.