发酵乳加工过程中霉菌和酵母的控制

霉菌和酵母普遍存在于自然环境中,在食品生产加工过程中时有造成污染的情况,是造成发酵乳腐败变质的主要原因。发酵乳作为短时保质期且需低温运输、销售的产品,低水平的霉菌和酵母不会造成食品质量安全事故。但是霉菌生长会造成食品霉斑,酵母污染导致产品胀包、腐败及风味的改变,给食品质量安全带来一定的影响。介绍了霉菌和酵母的污染源以及相应的控制措施,以期更好地控制发酵乳中霉菌和酵母的污染水平。     

副干酪乳杆菌直投式菌种中霉菌和酵母菌检测方法的建立

霉菌和酵母菌是直投式菌种中常见的污染菌,严重影响直投菌种的安全使用。在副干酪乳杆菌直投式菌种的霉菌、酵母菌检测中,由于菌种本身对霉菌、酵母菌的抑制作用以及高浓度菌种对污染菌检测的干扰作用,经常造成检测结果的假阴性。本研究根据副干酪乳杆菌菌体比霉菌、酵母菌小的特点,采用抽滤的方法将副干酪乳杆菌和霉菌、酵母菌分开,通过定性和定量两步检验,结合国标检测方法,成功鉴定到副干酪乳杆菌直投式菌种污染的低丰度霉菌和酵母菌。为有效地控制副干酪乳杆菌直投式菌种的产品质量,菌种发酵产品在生产过程中的稳定性提供了有效的保证。     

我国发酵乳制品的冷链现状调研

摘要：冷链对发酵乳制品的质量有着非常重要的作用。本研究对我国发酵乳的冷链现状进行了调研,总结出发酵乳制品的生产、储存、运输、配送、销售等环节中存在以下问题：冷链控制水平参差不齐、地区间差异大;乳制品“断链”问题严重,并且存在几个主要的温度节点,即0-4℃、8-10℃、12-15℃、18-23℃、26-30℃。     

一种发酵床霉菌抑制剂的制备方法和应用研究

通过对发酵床及其特点的介绍,发现在发酵床养殖中,发酵床容易被霉菌污染,会给畜禽养殖造成巨大的危害。根据防霉剂的研究和开发方向,设计出了一种新型的针对发酵床霉菌的抑制剂,并在实际生产中进行了防霉试验,取得了较满意的效果。     

饲料霉菌污染危害与防控

饲料霉菌毒素严重危害畜禽的生理机能,同时也危及动物性食品安全。霉菌毒素主要由4种霉菌属产生即曲霉菌属、青霉菌属、镰刀菌属及麦角菌属。饲料霉菌的污染常为多种霉菌,各种霉菌毒素间有累加作用,中毒症状复杂。避免饲料霉菌污染造成的危害,必须防控4关—把好原料采购品控关、添加防霉预防关、抓好加工储存运输环节关及把控养殖饲喂关。     

霉菌毒素对动物的危害及脱霉技术研究进展

霉菌毒素是霉菌生长过程中产生的次级代谢产物,具有高毒性,是全球畜禽饲料和人类食品安全的威胁因素,很容易通过农作物和饲料原料进入动物食物链,从而造成安全危害和经济损失。对饲料中霉菌毒素的种类、污染情况、对动物的危害及霉变饲料脱毒方法等问题进行讨论。     

霉菌毒素的危害及预防

霉菌毒素是霉菌生长时自然产生的代谢产物。一般农作物在生长、收割、加工、储藏、运输等环节中极易感染霉菌,从而导致霉菌毒素污染。近几年来,气候环境改变引起的高温高湿环境越来越多,国际贸易的增长以及交通、物流业发展引起的物资频繁转运,使得农作物及饲料受到霉菌毒素的污染越来越严重。霉菌毒素引起的畜禽免疫抑制、疾病易感性提高、生产性能下降等一系列问题在严重影响动物健康和人类食品安全的同时,也给畜牧业发展带来极大的危害,应引起我们的高度重视。     

填补霉菌毒素风险评估研究空白 乳及乳制品品控技术取得突破进展

<正>乳及乳制品中霉菌毒素检测灵敏度和通量低的技术难题一直困扰乳业发展,中国农业科学院完成的"乳及乳制品中霉菌毒素防控关键技术及应用"研究成果针对乳及乳制品中霉菌毒素风险评估研究空白,即霉菌毒素污染水平、发生规律掌握不清的难题,经过8年的系统研究,建立了以"检测技术—风险评估—过程控制"为主线的乳及乳制品霉菌毒素防控技术体系,取得突破性进     

霉菌毒素对奶牛养殖的危害及防控措施

目前我国奶牛养殖业普遍存在霉菌毒素污染的情况,不仅严重影响奶牛生产性能的发挥,给我国奶牛养殖业造成巨大的损失,还直接威胁到动物食品安全及人类自身的健康,因此一直受到行业的广泛重视。本文主要概述了部分霉菌毒素对奶牛的危害以及奶牛饲料防霉、脱毒等方法,为减少霉菌毒素对奶牛养殖的影响提供参考。     

青贮饲料中霉菌毒素的产生、毒性作用及脱毒研究进展

青贮饲料是反刍动物日粮中重要的组成部分,但青贮饲料在收获前、发酵期间及青贮完成后都会受到多种霉菌毒素污染。反刍动物摄入霉菌毒素后会对其健康和生产性能产生不利影响,并对食品安全及人类健康构成威胁。青贮饲料中优势霉菌包括镰刀菌属(Fusarium)、曲霉属(Aspergillus)、青霉属(Penicillium)和链格孢属(Alternaria)真菌,所产生的主要霉菌毒素包括单端孢霉烯族毒素、伏马菌素、玉米赤霉烯酮、黄曲霉毒素、赭曲霉毒素、蓝酪霉菌毒素、霉酚酸和麦角生物碱等。本文将对上述毒素在青贮饲料中的产生、影响、预防和脱毒的方法进行简要综述,以期为生产优质青贮饲料提供理论支持。     

抗真菌植物乳杆菌的筛选及其在酸乳保鲜中的应用

以33株具有潜在抑制真菌活性的植物乳杆菌为研究对象,分别与基础发酵剂复配制备酸乳,通过测定发酵酸乳在敞口室温条件下贮藏期间霉菌、酵母菌的菌数变化及酸乳的酸度,筛选具有良好保鲜效果的植物乳杆菌.结果表明:初筛所得9株植物乳杆菌(IMAU80152、10156、80091、50045、10155、80106、10216、10996、10239)可明显抑制真菌生长,复筛出IMAU80091和IMAU80106在酸乳中酸度变化程度显著低于其他菌株及商业保鲜菌(P＜0.05),当上述2株菌以1∶1复配发酵时抑制酵母菌效果显著优于商业保鲜菌(P＜0.05).复配发酵的酸乳样品贮藏21d后,滴定酸度为(138.24±1.19)°T,显著低于商业保鲜菌组(146.41±1.18)°T(P＜0.05).IMAU80091和IMAU80106复配组合可有效抑制货架期内酸乳真菌污染,具有作为生物保鲜菌的优良特性.     

活性多糖在发酵乳中的应用研究进展

分子生物学技术已证实,活性多糖作为一种天然高分子聚合物具有多种生理生化活性功能,其中活性多糖络合水的能力、高黏度、抗氧化及抗衰老等特性奠定了其应用于食品领域的基础,将活性多糖与食品相结合生产功能性食品成为当下研究的热点。发酵乳具有良好的风味和益生性能,但是也存在诸如货架期较短、凝乳品质较差、益生性能表现一般等问题,如何进一步提升发酵乳品质成为目前的主要问题。本文重点介绍不同种类活性多糖在发酵乳中的应用及研究进展,综述活性多糖对发酵乳的理化、凝胶和益生性能方面的影响及作用机理,探讨活性多糖在发酵乳中的应用与     

牛奶中铅的污染及控制措施

随着工业的发展,空气、水和土壤中铅的含量大幅增加,加大了食品中铅污染的隐患。奶牛摄入、饮用高铅含量的饲料和水都会将其代谢到乳中,因此,消费者对牛奶中铅污染的危害应给予高度关注。对牛奶中铅的存在形式、来源、危害、限量、检测方法、防控措施等进行综述,以期增加消费者对牛奶中铅污染的科学认识。     

发酵乳中生物活性肽的研究进展

发酵乳经乳酸菌发酵水解后含有丰富的多肽类物质,发酵乳源生物活性肽不仅具有丰富的营养价值,还具有抗氧化、降血压、抗菌等多种生物功能。本文综述发酵乳中多种功能生物活性肽,阐明乳酸菌蛋白酶导致的生物活性肽多样性,解析抗氧化肽、抗高血压肽、抗菌肽和其他功能活性肽的作用机制、多肽序列及构效关系,最后介绍了生物活性肽的序列鉴定与功能预测技术,为其在功能性食品中的开发应用提供参考。     

一种肠膜明串珠菌Leuco4发酵乳的特性

制备出一种含肠膜明串珠菌Leuco4的无任何添加剂的发酵乳,采用肠膜明串珠菌Leuco4发酵乳与常规发酵乳按质量比1∶4混合,并对所得发酵乳产品进行黏度、脱水收缩敏感性、质构及感官测试.结果表明:21d保质期内,与对照组相比,含肠膜明串珠菌Leuco4的发酵乳,持水性佳,黏度、口感、稳定性均能达到理想状态,且不含任何添加剂,符合清洁标签产品的要求.     

Food safety implications of ochratoxin A in animal-derived food products

Ochratoxin A (OTA) is an important mycotoxin with potential to reach the human food chain through carry-over of contaminated, mostly cereal-based, feed into animal-derived products. Certain population groups, such as infants and children, are intensive and relatively restricted consumers of some animal-derived products, particularly milk and other dairy products, which may become contaminated with OTA. This review examines the literature on the occurrence of OTA in animal-derived products and discusses the public health and food safety implications of consumption of these products. The risk of OTA contamination of meat, milk, blood and derived products is discussed.     

牛奶中汞的风险分析

随着工业的发展,空气、水和土壤中汞的含量大幅增加,加大了食品中汞污染的隐患。奶牛摄入、饮用高汞含量的饲料和水都会代谢到乳中。因此,消费者对牛奶中汞的危害要给予高度关注。作者就牛奶中汞的存在形式、来源、危害、监管等方面进行阐述,以期增加消费者对牛奶中汞的科学认识。     

藏灵菇发酵乳生产工艺优化及其功能特性

为研究藏灵菇功能特性,以滴定酸度和感官评价为指标,通过单因素试验对藏灵菇脱脂发酵乳工艺条件进行初步优化,并通过体外实验对藏灵菇脱脂发酵乳抗氧化能力和降胆固醇能力进行测定。结果表明：确定藏灵菇接种量6%、发酵温度37 ℃、发酵时间7.5 h为藏灵菇脱脂发酵乳的最优工艺条件,此条件下制得的脱脂发酵乳酸度适宜、口感细腻、质地均匀,具有独特风味,乳酸菌数为1.48×108 CFU/mL,硬度为178.43 g,高于传统发酵乳,黏附性为－103.52 g·s,且非脂乳固体含量、蛋白质含量和滴定酸度均符合发酵乳标准GB 19302—2010《食品安全国家标准 发酵乳》,品质较好;藏灵菇发酵乳抗氧化能力虽与传统发酵乳差异不显著,但具有较好的降胆固醇能力,藏灵菇脱脂发酵乳胆固醇去除率高达37.98%,藏灵菇全脂发酵乳胆固醇去除率高达40.68%。     

Future directions in the European union for veterinary education as related to food-producing animals, with special reference to Greece

During the past 50 years, procedures for raising food-producing animals have changed. Intensification of food production was necessary to keep prices low and to fulfill market demands for the continuously increasing worldwide population. Intensification of farming procedures produced many new problems, some of which had a considerable impact on public opinion about how animals are raised and how food of animal origin is produced and preserved. "Man made diseases" of animals such as bovine spongiform encephalopathy (BSE); contamination of foods with dioxins either through contamination of animal feeds or from the environment; and increased microbial resistance to drugs used for treatment, for prophylaxis of animals from infectious agents, and for growth promotion are some well-known hazards of intensified farming. Veterinarians working on food-producing animals are faced with an increased demand for foods of high quality and safety in developed countries, and higher quantities in the rest of the world. These qualitative and quantitative changes indicate that they must adjust to these new conditions. They will be most successful if their education is adjusted to meet the challenges that the public has created for them through new concepts of the production of food of animal origin. One such concept is the production of foods under fully certified procedures from the farm to the consumer's table. Food safety measures protecting public health will better be achieved if the education of the future veterinarian includes the principles of Hazard Analysis Critical Control Points (HACCP) starting at farm level. This article provides some market-driven ideas in this direction for European Union (EU) countries, including Greece.     

Regulation of food intake in dairy cows in relation to milk production

The physiological state of the animal will influence the amount of energy it can utilize and this, in turn, will tend to affect its demand for food. Particularly when the energy concentration of the ration is not high, any effect of the physiological state on abdominal capacity will affect intake, e.g. young, fat or pregnant animals will have a reduced capacity compared to older, thin or non-pregnant animals, respectively. In general, intake of energy will increase with increasing concentration of digestible energy in the ration, but it becomes constant once the animal is able to meet its total requirement. When the energy concentration of the ration is not limiting, an increased output of energy will, in general, be matched by an increased intake. The response may not be immediate however, so that after parturition for example, peak food intake frequently occurs after peak milk yield. Correlations between intake and milk yield are generally low, whereas there is usually a marked relationship between body weight and intake in the lactating cow. Simple equations linking intake to body weight and milk yield are usually quite accurate in the general situation, but rarely of value to predict intake of an individual. More complex equations, though more accurate, are difficult to apply in the practical situation.The relationship between lactation and food intake is examined in some detail. It is concluded that efficiency of utilization of food energy for milk production could be improved by minimizing cyclic variations in liveweight of the cow during lactation. To permit this, methods are currently being examined for manipulating diet composition to enable the cow to consume enough food in early lactation to meet the requirement for milk production. If these methods are successful, it will be possible to feed the cow for constant liveweight by feeding to appetite at all times and altering the composition of the diet to match the energy demand of the cow. Allowance should be made for growth and pregnancy, but fatness should be avoided.