牛奶中黄曲霉毒素M_1检测及其污染预防

黄曲霉毒素M_1(AFM_1)是由黄曲霉毒素B_1(AFB_1)在动物体内代谢产生的,是一种毒性极强的物质,主要表现在致癌性和致突变性。在实际生产中常通过检测AFM_1来判定牛奶是否被黄曲霉毒素污染。首先采用酶联免疫吸附法对某奶牛场2016年所产原奶中的AFM_1含量进行了检测分析,结果表明,所有原奶样本中均检出了AFM_1,检出率为100%,但其含量均未超过国标中的限量标准,合格率为100%,同时,3月中、下旬和11月下旬采集的原奶样本中AFM_1检出量较其他时段采集的原奶样本高;其次,对国内外乳及乳制品中AFM_1的限量标准进行了比较分析;最后,对引起原奶中AFM_1污染的主要原因及AFM_1污染的预防措施进行了探讨,以期为有效预防、控制原奶中的AFM_1污染,确保原奶质量安全提供参考。     

湖北省奶牛精料原料及牛奶中黄曲霉毒素污染调查

为研究湖北省奶牛精料原料黄曲霉毒素B_1(AFB_1)和牛奶中黄曲霉毒素M_1(AFM_1)的污染情况,试验在湖北省武汉市、黄冈市、襄阳市和十堰市等地采集162份奶牛精料原料和242份奶样,奶样包括120份超高温灭菌(UHT)奶和122份巴氏灭菌奶,应用ELISA方法分别检测AFB_1和AFM_1。结果表明:28.4%的饲料样本中检测出AFB_1,其中2.5%样本超过国家限量标准,阳性样本平均浓度28.5μg/kg;与麦麸、大豆粕、芝麻饼相比,花生饼和玉米的AFB_1污染程度更大;72.7%的牛奶样本中检出AFM1,阳性样本平均浓度为98.1 ng/kg;巴氏灭菌奶的AFM_1污染显著高于UHT奶(P<0.05),62.3%巴氏灭菌奶和1.7%UHT奶中AFM_1超过欧盟限量标准(50 ng/kg),但所有牛奶AFM_1均未超过我国限量标准(500 ng/kg)。综上,奶牛饲料生产中需要加强对易受AFB_1污染的饲料原料监测,并监测牛奶AFM_1污染情况,确保乳品安全。     

大豆蛋白在犊牛代乳料中的应用研究进展

随着人们生活水平的不断提高 ,乳制品加工业的不断兴起 ,对牛奶的需求量越来越大。如果能用营养全面、犊牛能消化吸收、成本又低的代乳料代替部分或全部牛奶 ,就能大大减少犊牛用奶 ,为乳制品加工提供更多的奶源。因此 ,研制成本低又能满足犊牛营养需要的与牛奶近似的饲用代乳料 ,已成为研究者们关注的课题。大豆蛋白以其价廉及蛋白质含量高而成为犊牛代乳料研究的主要蛋白来源。1　代乳料的发展2 0世纪 60年代 ,欧美一些国家开始使用代乳料 ,由于当时脱脂乳蛋白过剩 ,价格较低 ,因而在代乳料中几乎全部使用脱脂乳蛋白作蛋白源。到 80年代 ,…     

影响牛奶蛋白质和脂肪含量的因素及调整措施

乳蛋白质和乳脂肪的含量是衡量牛奶质量的重要标志,也是牛奶作为高营养食品的重要条件。长期以来,人们只注重追求牛奶产量和乳脂率,而对乳蛋白质含量的高低并不十分重视,随着人民生活水平的不断提高和乳制品生产的要求,乳品加工     

牛乳体细胞数对牛奶品质的影响

随着奶牛业和乳品业的迅速发展,牛奶体细胞数在牛奶生产中的重要作用越来越得到人们的重视。本文综述了影响牛奶体细胞数的因素、体细胞数在奶牛生产中的应用及其对乳及乳制品品质的影响。     

体细胞含量与牛奶质量的关系

随着我国奶牛业和乳品工业的发展．牛奶和乳制品已成为人们喜爱的食品。优质的乳制品是以优质的原料乳为基础的．没有优质的原料乳．就不可能生产好的乳制品。体细胞含量（SCC）是衡量原料乳质量的一个重要指标．它不仅可以反映牛奶质量的好坏．而且可以推测奶牛场的饲养管理状况及奶牛的健康状况。     

黄曲霉毒素B_1在奶牛体内的代谢及转化为乳中黄曲霉毒素M_1机制的研究进展

质量安全是奶业的生命线,霉菌毒素污染一直是奶业面临的主要风险因子之一,了解奶中黄曲霉毒素M_1的代谢机理是解决霉菌毒素污染的基础。本文综述了饲料中黄曲霉毒素B_1在奶牛瘤胃内的消化与代谢、在机体内的运输、在肝脏中的代谢,以及AFB_1转化为乳中AFM_1的转化率及降低措施,以期为控制乳中的黄曲霉毒素提供参考。     

热加工对牛乳品质的影响

牛乳是一种热敏性物质，研究热加工对乳及其乳制品质量的影响，对稳定提高乳及乳制品质量具有非常重大的意义。在任何一种乳制品的加工生产中，有时会不只一次地重复热加工工艺。如果掌握不好热加工工艺。即会对乳及乳制品质量带来许多不良影响二。如加热臭的产生、蛋白质的变性、乳石的生成、酶类的钝化、色泽的褐变及维生素的大量破坏等。１ 奶膜的形成奶膜即人们在加热牛奶时，在奶液表面形成的一层薄膜，也称奶皮：此膜随着加热时间的延长，其厚度逐渐增加。据研究认为，该膜的形成是由于乳液与空气接触界面层的蛋白质，在水份不断蒸发…     

乳及乳制品中激素检测方法的研究进展

随着人们的生活质量的提高,含有丰富的钙、维生素、蛋白质的乳及乳制品不仅成为人们生活中不可缺少的食物之一,而且需求量也在日益增加,促使了乳及乳制品的市场逐渐壮大,也推动了乳畜养殖业的快速发展。为了降低乳畜各种疾病的发病率及提高乳畜的乳产量,会在养殖过程中对乳畜各种疾病的预防使用各种抗生素与激素药物,大量的激素残留物会随着食物进入人体,进入生态系统,对人类的身体健康以及生态环境造成负面的影响。因此,对乳及乳制品中的激素含量进行检测就显得十分重要,本文介绍了乳及乳制品中激素检测的常用方法及其研究进展。     

奶牛日粮中增加非降解蛋白饲料提高乳蛋白率试验

近年来,随着我国人民生活水平的不断改善,人们对乳与乳制品的消费要求也日益提高,加之市场的激烈竞争,很多乳品加工企业对原料奶的收购质量越来越重视,生鲜牛奶的收购已由原来单一以牛奶比重或乳脂率计价改为乳脂率、乳蛋白率等多项指标计价。据调查,杭州地区牛奶总...     

RO反渗透膜过滤系统在乳制品工厂中的运用研究

在新冠肺炎疫情下消费者对乳制品的需求更加注重营养健康,聚焦更优质高蛋白营养的乳制品成为市场的新品类。RO反渗透膜过滤系统在低温下通过压力驱动进行浓缩,最大限度地保留了牛奶的营养成分和口感,其设备配置简单,操作方便,近两年在乳制品行业得到大力推广,成为闪蒸工艺之后牛奶浓缩的又一新工艺。本文通过对RO反渗透膜过滤系统在乳制品生产工艺流程关键控制点、膜的污染及控制措施、CIP清洗和消毒的应用进行研究,以为RO反渗透膜在乳制品工厂的运用提供参考。     

Changes in intake of milk and dairy products among elementary schoolchildren following experiential studies of dairy farming

This study intends to clarify the effects of hands‐on dairy farming experience on the consumption of milk and dairy products. A survey was conducted on 474 elementary schoolchildren and their parents at eight elementary schools that offered hands‐on dairy farming experience at four dairy farms in Hokkaido, Japan. In the survey, questionnaires were used to inquire about the children's milk and dairy product intake before and after the hands‐on experience. In addition, milk intake at school was investigated weekly for 3 months after the hands‐on experience. The parents were asked about the children's intake of milk and dairy products at home before and after the hands‐on experience. Analysis of the survey results indicated a significant increase in the amount and frequency of milk consumed and the frequency of yogurt consumed at home by the children immediately after the hands‐on experience. Accordingly, the study suggested that the hands‐on dairy farming experience had the effect of increasing children's milk and dairy product consumption at home.     

Global trends in milk quality: implications for the Irish dairy industry

The quality of Irish agricultural product will become increasingly important with the ongoing liberalisation of international trade. This paper presents a review of the global and Irish dairy industries; considers the impact of milk quality on farm profitability, food processing and human health, examines global trends in quality; and explores several models that are successfully being used to tackle milk quality concerns. There is a growing global demand for dairy products, fuelled in part by growing consumer wealth in developing countries. Global dairy trade represents only 6.2% of global production and demand currently outstrips supply. Although the Irish dairy industry is small by global standards, approximately 85% of annual production is exported annually. It is also the world's largest producer of powdered infant formula. Milk quality has an impact on human health, milk processing and on-farm profitability. Somatic cell count (SCC) is a key measure of milk quality, with a SCC not exceeding 400,000 cells/ml (the EU milk quality standard) generally accepted as the international export standard. There have been ongoing improvements in milk quality among both established and emerging international suppliers. A number of countries have developed successful industry-led models to tackle milk quality concerns. Based on international experiences, it is likely that problems with effective translation of knowledge to practice, rather than incomplete knowledge per se, are the more important constraints to national progress towards improved milk quality.     

国内外原料乳中金黄色葡萄球菌风险评估研究综述

近年来我国乳品消费量持续增加,乳品质量安全关乎着人们身体健康和生命安全.金黄色葡萄球菌及其肠毒素引起的乳品中毒事件时有发生,逐本求源地针对原料乳开展金黄色葡萄球菌风险评估研究是十分必要的.本文根据国际食品法典委员会拟定的微生物风险评估的原则和指导方针,从危害识别、危害特征描述、暴露评估、风险描述四方面综述了关于原料乳中金黄色葡萄球菌国内外风险评估的研究现状.通过国外成熟的定量风险评估案例,介绍关于原料乳中金黄色葡萄球菌定量风险评估的基本框架,提出未来应加强构建肠毒素预测模型,较为系统的对原料乳从牧场到餐桌进行全程监控和风险评估的建议.     

电子鼻在乳及其制品检测中的应用研究进展

电子鼻作为一种基于综合气味信息的气味指纹检测技术,有着快速、无损、便捷、有效、客观等多方面优势,成为了乳及其制品的热门检测技术。与常规仪器分析和感官评价方法结合,电子鼻在乳制品掺假,成分检测,乳制品加工、贮藏过程中品质变化等相关气味信息方面的研究较多,为市场监控乳制品的质量安全提供了有效保障。本文总结了电子鼻在乳制品风味成分鉴别,乳及其制品新鲜度检测,乳制品加工过程监控、掺假检测等方面应用的研究进展,并展望了电子鼻技术在乳及其制品应用方面的进一步研究方向,旨在为其在乳及其制品质量安全快速检测等方面提供参考。     

An overview of aflatoxin B1 biotransformation and aflatoxin M1 secretion in lactating dairy cows

Milk is considered a perfect natural food for humans and animals. However, aflatoxin B1 (AFB1) contaminating the feeds fed to lactating dairy cows can introduce aflatoxin M1 (AFM1), the main toxic metabolite of aflatoxins into the milk, consequently posing a risk to human health. As a result of AFM1 monitoring in raw milk worldwide, it is evident that high AFM1 concentrations exist in raw milk in many countries. Thus, the incidence of AFM1 in milk from dairy cows should not be underestimated. To further optimize the intervention strategies, it is necessary to better understand the metabolism of AFB1 and its biotransformation into AFM1 and the specific secretion pathways in lactating dairy cows. The metabolism of AFB1 and its biotransformation into AFM1 in lactating dairy cows are drawn in this review. Furthermore, recent data provide evidence that in the mammary tissue of lactating dairy cows, aflatoxins significantly increase the activity of a protein, ATP-binding cassette super-family G member 2 (ABCG2), an efflux transporter known to facilitate the excretion of various xenobiotics and veterinary drugs into milk. Further research should focus on identifying and understanding the factors that affect the expression of ABCG2 in the mammary gland of cows.     

Interaction of mammary bovine ABCG2 with AFB1 and its metabolites and regulation by PCB 126 in a MDCKII in vitro model

The ATP‐binding cassette efflux transporter ABCG2 plays a key role in the mammary excretion of drugs and toxins in humans and animals. Aflatoxins (AF) are worldwide contaminants of food and feed commodities, while PCB 126 is a dioxin‐like PCB which may contaminate milk and dairy products. Both compounds are known human carcinogens. The interactions between AF and bovine ABCG2 (bABCG2) as well as the effects of PCB 126 on its efflux activity have been investigated by means of the Hoechst H33342 transport assay in MDCKII cells stably expressing mammary bABCG2. Both AFB1 and its main milk metabolite AFM1 showed interaction with bABCG2 even at concentrations approaching the legal limits in feed and food commodities. Moreover, PCB 126 significantly enhanced bABCG2 functional activity. Specific inhibitors of either AhR (CH233191) or ABCG2 (Ko143) were able to reverse the PCB 126‐induced increase in bABCG2 transport activity, showing the specific upregulation of the efflux protein by the AhR pathway. The incubation of PCB 126‐pretreated cells with AFM1 was able to substantially reverse such effect, with still unknown mechanism(s). Overall, results from this study point to AFB1 and AFM1 as likely bABCG2 substrates. The PCB 126‐dependent increased activity of the transporter could enhance the ABCG2‐mediated excretion into dairy milk of chemicals (i.e., drugs and toxins) potentially harmful to neonates and consumers.     

乳业韧性增长下的新变化——2022年中国乳业市场回顾与分析

2022年,中国牛奶产量为3 932 万吨,同比增长6.8%;乳制品产量为3 118 万吨,同比增长2.0%。原奶产量充足,但生产量明显下降,乳业市场进入到短期的调整阶段。从消费变化来看,消费降级、消费平移、消费升级同时存在,乳品消费出现结构分化;从产品的变化看,低温鲜奶全面进入全方位的竞争阶段,将复刻常温乳品的发展路径;常温奶基础型产品增加较快,但价格竞争激烈;而中高端乳品的降价销售与价格恢复过程,品牌价值的作用明显;随着老龄化社会的到来,成人类奶粉成为市场的热点产品,越来越多的企业加入到这个品类的竞争中来;为挖掘市场新的增长点,乳品的关联类产品受到重视,比如雪糕、奶酒、奶酪等;从渠道变化看,线上渠道受到更多企业的重视,线下渠道也出现了新的业态,这些都推动着乳品企业的渠道变革。     

乳与乳制品中黄曲霉毒素检测研究进展

黄曲霉毒素（aflatoxin，AF）是霉菌产生的毒性极强的次级代谢产物，主要存在于乳与乳制品和霉变谷物中。目前研究较多的黄曲霉毒素有黄曲霉毒素B₁（AFB₁）、AFB₂、AFG₁、AFG₂、AFM₁和AFM₂，黄曲霉毒素物理与化学性质稳定，加热处理很难将其破坏，是目前公认的毒性最强的致癌物之一。黄曲霉毒素不仅会造成动物营养不良及免疫力下降等问题，进入人体后还会对人体的肝脏造成极大的损害，而且原料乳中黄曲霉毒素的存在会对整个乳制品产业链造成严重的危害。因此，建立简便的、特异性好、灵敏度高的检测乳与乳制品中黄曲霉毒素的方法具有十分重要的意义。作者综述了乳与乳制品中黄曲霉毒素的检测方法进展，介绍了国内外近年来质谱法、电化学法、光谱法、色谱法、试纸条法等方法在检测乳与乳制品中黄曲霉毒素的应用，总结以上各种方法在检测乳与乳制品中黄曲霉毒素中的优势与其面临的挑战，并对今后乳与乳制品中黄曲霉毒素检测方法的发展方向进行了展望，以期为设计新的乳与乳制品中黄曲霉毒素检测方法提供思路。     

国际标准化组织(ISO)乳与乳制品标准体系

我国和其他乳类生产、消费大国在乳与乳制品标准的制定和实施方面存在着很大的差距.本文通过收集整理国际标准化组织(international standardization organization,ISO)乳与乳制品相关标准,对ISO乳与乳制品标准体系的构成、现状及特点进行了介绍和剖析,并与我国乳与乳制品标准体系现状进行了对比分析.