原料奶的生产和管理

本文分析了当前我国原料奶生产和管理面临的形式,从政府、企业、农户角度分析了加强原料奶生产和管理应采取的措施以及奶源基地建设的方向、趋势     

商品奶与原料奶中农药与亚硝酸钠残留分析

采用高效气相色谱(GC)分析法对商品奶和原料奶中农药和亚硝酸钠残留进行分析,并分析不同饲养模式对原料奶中农药残留的影响。结果表明:在所测定的5种农药中,甲胺磷、敌敌畏和马拉硫磷等3种农药残留检出率较高,商品奶为45.0%～67.5%,原料奶为46.8%～71.2%。商品奶和原料奶中甲胺磷、敌敌畏、敌百虫、马拉硫磷和倍硫磷检出率和残留量差异不显著(P﹥0.05);而商品奶和原料奶中亚硝酸钠检出率和残留量差异极显著(P﹤0.01)。原料奶中5种农药加权平均检出率、农药加权平均残留量和加权残留总量均为规模化饲养显著低于农户散养和合作社饲养(P﹤0.05),后两者之间无显著差异(P﹥0.05)。     

奶源质量安全控制措施——加强奶源控制确保乳品质量

乳品质量安全是大家广泛关注的问题,乳品质量安全在加工过程中比较容易控制,而奶源质量的控制却较为复杂（主要表现在奶牛散养户难以控制奶源质量,存在药物残留以及饲料的安全问题）,并且不少企业为了争夺奶源,经常放松对原料奶质量和安全的控制。因此,原料奶的质量和安全成为影响乳品质量安全的关键所在,奶源数量和质量已成为制约乳品企业发展的共同难题。     

酸奶中持久性有机污染物残留影响因素浅析

为探究影响酸奶中POPs残留的因素,采用化学提取预富集与GC-ECD相结合的方法,测定了产自北京六个不同区域以及产自中国不同城市相同品牌酸奶中和酸奶及其原料奶中OCPs、PCBs的残留水平。结果显示:北京地区酸奶中OCPs残留水平呈西南>>南部、城区>>东南、东北的分布,PCBs残留呈城区>>西南>南部、东南>>东北的分布;产自不同城市相同品牌酸奶中OCPs、PCBs残留水平与组成因地而异,表明奶源环境是影响酸奶中POPs残留水平的重要因素之一;酸奶中HCHs、DDTs、PCBs残留水平低于其原料奶,原因可能与酸奶生产过程中的加热灭菌环节和微生物发酵过程有关。     

奶源质量管理计价系统软件的开发

0引言 生鲜牛乳是乳品加工企业的主要原料,其质量好坏直接关系到产品的风味、感观状态、理化和卫生指标以及营养价值.如果原料不合格、那么再先进的工艺、再优良的设备、再严格的管理也是徒劳的.因此、保证鲜奶的高质量对乳品企业是至关重要的.为了加强对原料奶的质量管理,目前国内的大多数企业都采取不同程度的以质论价体系,对原料奶进行等级划分,以价格促进质量.     

绿色原料奶的生产及质量控制

从奶牛的饲料构成，饲料基地的大气、水和土壤的环境监测控制，农药和化肥的使用，对饲料种植农户的一体化管理．奶牛饲料的采购、饲料加工工艺、生产和贮存过程中的质量控制，奶牛场的卫生与消毒，兽药的管理，奶牛常见疾病的防治，牛群的检疫与防疫以及原料奶的贮存和运输等方面，讨论了生产绿色原料奶所应具备的必要条件和实行“从土地到餐桌”的全程质量控制。     

直接提取-超高压液相色谱-电喷雾串联质谱法检测原料奶及奶制品中的四环素类抗生素

目的 建立直接提取-超高压液相色谱-电喷雾串联质谱法(UPLC-ESIMS/MS)同时测定原料奶及奶粉中土霉素、四环素、金霉素、强力霉素4种四环素类药物的分析方法。方法 原料奶及奶粉样品经少量高氯酸沉淀蛋白、低温冷冻除脂后, 用C18色谱柱分离, 以0.1%甲酸水和乙腈为流动相进行梯度洗脱, 电喷雾串联质谱正离子模式扫描, 多反应监测模式(MRM)检测, 外标法定量。结果 4种四环素族药物在1~1000 ng/mL浓度范围内线性关系良好, 相关系数r均在0.993以上。本方法的定量限为(S/N≥10)为原料奶5μg/kg, 奶粉25 μg/kg, 在10、50、100 μg/kg三个加标水平下, 加标回收率为73.4%~99.4%, 相对标准偏差为0.8%~14.3%(n≥6)。结论 该方法简便快速、灵敏可靠、经济有效, 适用于原料奶及奶粉中土霉素、四环素、金霉素和强力霉素4种四环素族药物残留的测定。     

原料奶抗生素的控制方法

就如何进行原料奶抗生素的控制进行了初步探讨，借鉴国外乳品企业和国内企业对抗生素管理的经验，结合公司的实际情况，建立了一套原料奶抗生素控制体系。     

原料奶嗜冷菌快速检测方法研究进展

嗜冷菌作为冷藏原料奶中生长的优势菌群,在原料奶贮存过程中会大量繁殖,并产生及其耐热的脂肪酶和蛋白酶,这些酶类在高温处理后仍会有残留,并在奶制品储藏过程中继续分解其中的脂肪和蛋白质,导致产品的风味和质地产生变化。因此,研发出一种即快速又实用的嗜冷菌计数技术成为乳品行业关注的焦点。本文主要介绍了国内外对原料奶中嗜冷菌快速检测的一些方法,并将各个方法在工业应用上的优缺点进行了比较。     

乳中残留LPS保鲜剂的检测及对乳制品性能的影响

研究了生鲜奶中过氧化氢酶系激活剂残留量的检测方法，以及巴氏杀菌或超高温（UHT）处理后该添加剂残留情况．并评价了原奶中添加该添加剂对液态奶产品风味的影响，最后，还考察了酸奶发酵前、后该添加剂的残留情况，并评价了生鲜奶中添加该添加剂对酸奶发酵和酸奶产品风味的影响。结果表明，应用适当的方法可以检测出乳中残留的LPS保鲜剂成分NaSCN（硫氰酸钠），但H2O2（过氧化氢）很快就检不出残留。合理的添加LPS保鲜剂不会影响巴氏杀菌奶、UHT奶和酸奶产品的加工及产品的风味。     

高分辨质谱定性筛查牛奶和奶粉中兽药残留

目的 建立高分辨质谱定性筛查牛奶和奶粉中兽药残留的高通量方法。方法 样品经乙腈、QuEChERS盐包提取, 采取改良的3种不同方式[QuChERS、高分辨质谱(high resolution mass spectrometry, EMR)、固相萃取(solid phase extraction, SPE)]净化提取液, 用液相色谱联用高分辨质谱(liquid chromatography-high resolution mass spectrometry, LC-HRMS)筛查了牛奶和奶粉中138种兽药残留, 建立兽药信息数据库, 并用截断值(Vcut-off, 判断阳性和阴性样品的临界值)作为评估筛查方法的指标。结果 改良的QuChERS可以获得更高的回收率, 当截断值(Vcut-off)设定为0.2时, 在2种加标水平下, 有109种兽药通过了筛查方法验证的要求, 假阳性和假阴性概率均低于5%。结论 此方法适用于牛奶和奶粉中多兽药残留的定性筛查, 一针进样可以得到109种兽药残留的筛查信息, 方法假阳性和假阴性概率在规定的目标物浓度下都低于5%。     

免疫分析技术在乳及乳制品抗生素类兽药残留检测中的应用

为了预防与治疗乳牛疾病,抗生素类兽药被广泛应用于乳牛的饲养过程中。而滥用抗生素导致牛奶中抗生素残留超出最大允许残留量,不仅会对牛奶品质造成影响,而且可能会危害到牛奶饮用者的身体健康。因此,如何快速、准确地检测乳与乳制品中抗生素类兽药残留是乳品检测行业和企业亟需解决的问题。本文主要介绍了牛乳中兽药残留的来源、危害及其现状,阐述了酶联免疫分析技术、胶体金免疫层析技术的检测原理及其在应用过程中所具有的不同特点,最后对2种方法的优势与不足进行简要总结,并对免疫分析法在乳与乳制品抗生素类兽药残留检测中的应用前景做出展望。     

Novel in vitro systems for prediction of veterinary drug residues in ovine milk and dairy products

A new in vitro tool was developed for the identification of veterinary substrates of the main drug transporter in the mammary gland. These drugs have a much higher chance of being concentrated into ovine milk and thus should be detectable in dairy products. Complementarily, a cell model for the identification of compounds that can inhibit the secretion of drugs into ovine milk, and thus reduce milk residues, was also generated. The ATP-binding cassette transporter G2 (ABCG2) is responsible for the concentration of its substrates into milk. The need to predict potential drug residues in ruminant milk has prompted the development of in vitro cell models over-expressing ABCG2 for these species to detect veterinary drugs that interact with this transporter. Using these models, several substrates for bovine and caprine ABCG2 have been found, and differences in activity between species have been reported. However, despite being of great toxicological relevance, no suitable in vitro model to predict substrates of ovine ABCG2 was available. New MDCKII and MEF3.8 cell models over-expressing ovine ABCG2 were generated for the identification of substrates and inhibitors of ovine ABCG2. Five widely used veterinary antibiotics (marbofloxacin, orbifloxacin, sarafloxacin, danofloxacin and difloxacin) were discovered as new substrates of ovine ABCG2. These results were confirmed for the bovine transporter and its Y581S variant using previously generated cell models. In addition, the avermectin doramectin was described as a new inhibitor of ruminant ABCG2. This new rapid assay to identify veterinary drugs that can be concentrated into ovine milk will potentially improve detection and monitoring of veterinary drug residues in ovine milk and dairy products.     

Screening of veterinary drug residues in food by LC-MS/MS. Background and challenges

Regulatory agencies and government authorities have established maximum residue limits (MRL) in various food matrices of animal origin for supporting governments and food operators in the monitoring of veterinary drug residues in the food chain, and ultimately in the consumer’s plate. Today, about 200 veterinary drug residues from several families, mainly with antibiotic, antiparasitic or antiinflammatory activities, are regulated in a variety of food matrices such as milk, meat or egg. This article provides a review of the regulatory framework in milk and muscle including data from Codex Alimentarius, Europe, the U.S.A., Canada and China for about 220 veterinary drugs. The article also provides a comprehensive overview of the challenge for food control, and emphasizes the pivotal role of liquid chromatography-mass spectrometry (LC-MS), either in tandem with quadrupoles (LC-MS/MS) or high resolution MS (LC-HRMS), for ensuring an adequate consumer protection combined with an affordable cost. The capability of a streamlined LC-MS/MS platform for screening 152 veterinary drug residues in a broad range of raw materials and finished products is highlighted in a production line perspective. The rationale for a suite of four methods intended to achieve appropriate performance in terms of scope and sensitivity is presented. Overall, the platform encompasses one stream for the determination of 105 compounds in a run (based on acidic QuEChERS-like), plus two streams for 23 β-lactams (alkaline QuEChERS-like) and 10 tetracyclines (low-temperature partitioning), respectively, and a dedicated stream for 14 aminoglycosides (molecularly-imprinted polymer).     

原料乳中药物残留和掺假物质检测方法的研究进展

原料乳中药物残留或掺假物质的存在造成的安全事件屡屡发生,这使我国乳品行业面临着巨大的挑战。本文主要综述了常规检测法、免疫分析法、仪器检测分析法、生物传感器和蛋白质芯片技术等对原料乳中常见聚醚类抗生素、类固醇激素、苯二氮卓类药物、苯基脲类除草剂、四环素类抗生素和青霉素类抗生素等药物残留、物理性质与原料乳相近的物质、常见电解质、非电解质、防腐剂等掺假物质的检测方法,以及对单一成分掺假物和多种成分掺假物的检测方法,并比较了不同检测方法的准确度、灵敏度、成本等优缺点,以期为相关检测部门进行质量监测或生产厂家牛乳收购提供技术参考。     

Multiresidue method for pesticides and veterinary drugs in bovine milk using GC/MS and LC/MS/MS

A simple, sensitive and selective method with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed to detect 342 pesticides and veterinary drugs contaminating bovine milk at the maximum residue limits (MRLs) defined in the "positive list system". Sample preparation was performed by extracting the analytes with acetonitrile, followed by salting-out with sodium chloride. For some pesticides, the extract was further cleaned up by n-hexane partitioning and PSA cartridge column chromatography. GC/MS-EI or -NCI was used to determine pesticide residues, while LC/MS/MS-ESI was applicable to the determination of pesticide and veterinary drug residues. The variation of the recoveries of these drugs at MRL was relatively wide; however the relative standard deviations of the recovery of each drug were within 28%, suggesting that the present method is good enough for use as a screening test for contaminants at the MRLs. These results show that this method is useful for multiresidue analysis of numerous pesticides and veterinary drugs in bovine milk.     

Multiclass methods for the analysis of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry: A review

Milk is an important and beneficial food from a nutritional point of view, being an indispensable source of high quality proteins. Furthermore, it is a raw material for many dairy products, such as yoghurt, cheese, cream etc. Before reaching consumers, milk goes through production, processing and circulation. Each step involves potentially unsafe factors, such as chemical contamination that can affect milk quality. Antibiotics are widely used in veterinary medicine for dry cow therapy and mastitis treatment in lactating cows, which can cause the presence of antimicrobial residues in milk. In order to ensure consumers’ safety, milk is analyzed to make sure that the fixed Maximum Residue Limits (MRLs) for antibiotics are not exceeded. Multiclass methods can monitor more drug classes through a single analysis, so they are faster, less time-consuming and cheaper than traditional methods (single-class); this aspect is particularly important for milk, which is a highly perishable food. Nevertheless, multiclass methods for veterinary drug residues in foodstuffs are real analytical challenges. This article reviews the major multiclass methods published for the determination of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry, with a special focus on sample preparation approaches.     

超高效液相色谱-串联质谱法测定牛乳中6种兽药残留

目的:建立高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)测定牛奶样品中6种兽药残留(硝碘酚腈、碘醚柳胺、氯氰碘柳胺、托曲珠利、三氯苯达唑、水杨酸钠)的检测方法.方法:样品经过乙腈溶液提取,以...     

高效液相色谱-串联飞行时间质谱高通量筛查生鲜乳中兽药残留

建立了一种高通量检测生鲜乳中兽药残留的高效液相色谱-串联飞行时间质谱方法,包括17大类兽药,共174?种。样品用乙腈和乙酸乙酯提取,冷冻净化后,目标化合物经过Poroshell 120 EC-C18柱（3.0?mm×150?mm,2.7?μm）分离,经0.1%甲酸溶液和甲醇流动相洗脱,采用电喷雾正离子模式进行采集。结果显示,114?种兽药化合物在质量浓度0～200?ng/mL范围线性良好（R2＞0.990?0）,检测限为1～10?ng/g。此外,回收率在70%～130%范围内的质控加标样品达99?种,相对标准偏差为1.03%～9.65%。该方法检测速度快、灵敏度高,大大提高了生鲜乳中兽药筛查的效率。     

生乳中体细胞数对乳品质量安全的影响研究进展

体细胞数增加会改变乳成分、影响牛乳风味及缩短乳制品货架期,并且使乳中抗生素和药物残留的风险增加。乳中体细胞数是衡量乳畜健康、乳品质量与安全的标准,也是国际判定隐形乳房炎的重要指标。为了保障乳品质量和安全,许多国家规定了生乳中体细胞数的限量。本文从体细胞数和乳品质量与安全的关系、不同国家对生乳中体细胞数的限量及影响体细胞数的因素和体细胞数的检测方法等方面作一综述。