牦牛屠宰过程中菌落总数和大肠菌群污染状况的分析

为了掌握牦牛屠宰过程中菌落总数和大肠菌群的污染状况,本实验对甘肃玛曲某牦牛屠宰场在牦牛屠宰过程中的屠宰前、屠宰中和分割后三个阶段以及牦牛胴体等14个采样点进行采样,进行菌落总数和大肠菌群的测定。研究发现,屠宰前的各采样点中,菌落总数在5.45logCFU/g以上,大肠菌群在3.25logCFU/g以上;屠宰中的各采样点中,菌落总数在3.37logCFU/cm2以上,大肠菌群在1.63logMPN/100cm2以上;在分割后的各采样点中,菌落总数在3.68logCFU/cm2以上,大肠菌群在1.74logMPN/100cm2以上;在胴体的剥皮、劈半和分割三个时期中,分割后的菌落总数(3.49logCFU/cm2)和大肠菌群(1.61 logMPN/100cm2)污染最严重,剥皮后的菌落总数(2.47logCFU/cm2)和大肠菌群(1.53logMPN/100cm2)污染最小。结果表明,屠宰前环境污染最严重,胴体随着剥皮、劈半和分割的进行,菌落总数显著增加,分割后胴体的大肠菌群显著高于剥皮和劈半。      

肉牛屠宰工序微生物污染状况分析和喷淋减菌技术

以减少冷却后牛胴体表面的微生物数量为目标,在企业实际生产条件下,以菌落总数为指标分析屠宰过程中各工序胴体表面的微生物变化状况,探讨不同喷淋方式的减菌效果。结果表明,屠宰工序中初始剥皮操作对胴体造成的污染最严重,其次为去脏工序。高压清水清洗对全胴体的减菌量为0.62(log10CFU/cm2);2%的乳酸喷淋对胸口部位菌落总数的减少量为1.06(log10CFU/cm2)。采用2%的乳酸喷淋可以有效减少肉牛屠宰过程中的胴体污染。     

屠宰过程中滩羊胴（屠）体表面微生物污染水平的变化

为了促进盐池滩羊产业的进一步发展,降低宰后滩羊胴体表面的微生物污染水平,延长生鲜滩羊肉产品的货架期,对当地某滩羊屠宰加工企业日常生产过程中6个环节（剥皮扯皮、取白脏红脏、修整称重、去尾燎毛、冲洗和冷却）共300个滩羊胴（屠）体的5个部位（后腿、背部、胸部、前腿和颈部）表面的菌落总数（aerobic plate count,APC）进行采样和检测,以胴（屠）体平均APC作为指示指标进行统计和分析,探究滩羊胴（屠）体表面微生物污染水平在屠宰加工过程中的变化规律。结果显示,剥皮扯皮后,屠体平均APC为（2.27±0.43）lg（CFU/cm2）;取白脏红脏、修整称重和冷却后,胴（屠）体平均 APC 均显著上升（P＜0.05）,分别达到（2.52±0.45）、（3.01±0.44）、（2.28±0.41）lg（CFU/cm2）;去尾燎毛和冲洗后,胴体平均 APC 均显著下降（P＜0.05）,分别达到（2.28±0.37）、（2.28±0.41）lg（CFU/cm2）。     

2016~2018年广东省膨化食品微生物污染状况分析

目的 了解广东省膨化食品受卫生指标菌(菌落总数、大肠菌群)污染状况, 为防控食源性疾病提供依据。方法 按照GB 4789.2-2016《食品安全国家标准食品微生物学检验菌落总数测定》、GB 4789.3-2016《食品安全国家标准食品微生物学检验大肠菌群计数》中的方法对广东省2016~2018年共1672批次膨化食品进行检验。结果 2016~2018年监督抽检中, 膨化食品卫生指标菌不合格率分别为2.29% (2016年)、4.08% (2017年)、6.31% (2018年), 其中不合格样品生产单位所在地市不合格率最高连续3年均为潮州市。结论 2016~2018年广东省膨化食品受微生物污染的程度有逐年加重的趋势, 尤其潮州市的生产企业, 监管部门应强化膨化食品安全监督力度, 督促落实企业主体责任, 确保食品卫生安全。     

北京市餐饮业食用冰块微生物污染水平调查

评估北京市餐饮业食用冰块微生物污染的风险。方法 在北京市场抽检了63份餐饮业食用冰块样品,冰块独立分装在无菌采样袋中,2 h内完成采样到检测的过程。按照国家标准方法检测其中的菌落总数、大肠菌群、沙门菌、志贺菌和金黄色葡萄球菌。结果 63份餐饮业食用冰块样品均未检出沙门菌、志贺菌和金黄色葡萄球菌等致病菌。连锁快餐店和咖啡店食用冰块的菌落总数和大肠菌群等指示菌计数较低,部分饮品甜品店食用冰块菌落总数和大肠菌群较高。结论 检测的食用冰块样品均是安全的。部分饮品甜品店用食用冰块指示菌较高,提示生产过程中可能存在微生物污染,需要严格执行卫生操作规范的程序。     

津晋地区原料奶中微生物污染程度分析与鉴定

沙门氏菌是一种重要的人畜共患肠道疾病致病菌,它引起的食物中毒已成为一类最常见且危害性较大的细菌性食物中毒。本研究对我国津晋地区原料奶中微生物污染情况进行分析与鉴定,主要包括菌落总数、大肠菌群和沙门氏菌的检测。结果显示：津晋地区原料奶来源不同,奶源质量有较大差别。菌落总数平均在104～107CFU/mL之间,存在许多超标奶;大肠菌群数差别较大,晋奶源质量很好,大肠菌群数均低于110MPN/mL,天津地区乳品厂A大肠菌群数最高为1100MPN/mL,乳品厂B受到大肠菌群的严重污染,几乎均大于或等于11000MPN/mL;沙门氏菌未检出。研究证实了津晋地区原料奶的质量和安全性不容忽视。     

一起花旗参茶生产过程微生物污染事故的分析及对策

针对花旗参茶生产过程中出现的微生物污染问题,该研究对原料处理、生产流程、生产车间空气、食品接触面及产品微生物指标进行动态观察和分析。结果表明,污染的主要原因是原料处理不当、操作现场空气洁净度差、消毒不到位、二次污染等,对此采取原料三道清洗、加强消毒、提高灌装间洁净度等相应纠正措施,使生产处于全面有效的控制和管理状态。     

腐乳中微生物污染状况分析

腐乳在我国具有几千年的食用历史,是一种传统的发酵大豆制品,但腐乳中细菌总数较高,可能带来一定的安全隐患并影响腐乳出口.本研究采集了全国各地生产的27份腐乳,分别对其菌落总数和耐热菌菌落数进行了检测,结果表明:不同类型及采用不同标准的腐乳中耐热性微生物数量占细菌总数的98％,最低的仅为0.8％.根据检测结果说明腐乳的安全问题需要引起重视,以促进腐乳行业的健康发展.     

豆干加工的微生物污染途径研究

微生物污染是豆干加工过程中的一种潜在危害,是影响豆干产品质量的主要因素之一.试验通过对豆干各加工环节及主要接触面上的微生物菌落总数的动态监测和分析,确立了豆干生产过程中的微生物污染途径及主要来源,主要是原辅材料(包括原料大豆、生产用水、凝固剂、调味料)、加工用的机械及器具、车间操作人员、车间空气环境等,这将为下一步对豆干加工过程中的微生物污染控制起到重要作用.     

基于高通量测序的黄羽肉鸡屠宰过程中菌群多样性分析

利用传统培养和高通量测序技术分析黄羽肉鸡打毛、净膛、预冷和包装屠宰过程中鸡胴体表面和预冷水的微生物污染情况。结果表明：经打毛、净膛和预冷后的鸡胴体菌落总数分别为4.82、5.03、4.68(lg(CFU/g)),说明该屠宰工艺未起到较好的减菌效果,宰后胴体微生物污染严重;高通量测序技术分析发现,肉鸡屠宰加工过程中的胴体表面和预冷水的优势腐败菌在属水平上为莫拉氏菌属、假单胞菌属、葡萄球菌属、乳杆菌属、巨大球菌属、嗜冷杆菌属和不动杆菌属等。主成分分析表明,一阶、二阶预冷水、预冷后鸡胴体及包装后鸡胴体相距较近,差异性不大,但与打毛鸡胴体和净膛后鸡胴体2组样品有较大差异,说明预冷水中的污染菌组成决定了宰后胴体的污染菌种类。本研究说明不同屠宰流程后的黄羽肉鸡胴体污染菌的组成与丰度存在差异,需针对不同屠宰流程特性采取对应的控制手段保障黄羽肉鸡制品的质量与安全。     

食品中菌落总数和六肠菌群检验的质量控制

分析了实际检测菌落总数和大肠菌群两指标存在的问题，提出了保证检验结果正确性的控制措施。     

食品中菌落总数和大肠菌群检验的质量控制

分析了实际检测菌落总数和大肠菌群两指标存在的问题,提出了保证检验结果正确性的控制措施.     

湛江东海岛文蛤模拟加工的细菌学分析

用行业标准分别对文蛤原料、清洗并热烫后和冷冻0.5 h后等加工工序中文蛤细菌总数、大肠菌群数、粪大肠菌群数、副溶血性弧菌、金黄色葡萄球菌和沙门氏菌进行了检验.结果发现,湛江东海岛近海文蛤原料的细菌总数为(4.0±0.1)×105 cfu/g,清洗并热烫和再冷冻0.5 h后对细菌总数的影响不明显.文蛤原料大肠菌群数为(790.7±21.3)MPN/g,清洗并热烫后大肠菌群数明显降低至(19.4±1.3)MPN/g,再冷冻0.5 h后大肠菌群数为(18.3±1.1)MPN/g.文蛤原料粪大肠菌群数为(817.5±19.8)MPN/g,清洗并热烫后粪大肠菌群数明显降低至(194.2±10.2)MPN/g,再冷冻0.5 h后粪大肠菌群数为(180.6±11.3)MPN/g.文蛤原料、清洗并热烫后和再冷冻0.5 h后副溶血性弧菌的检验结果均为＜3 MPN/g;均未检出凝固酶阳性的金黄色葡萄球菌和沙门氏菌.可见湛江东海岛近海文蛤的细菌污染主要是大肠菌群和粪大肠菌群,经清洗并热烫和再冷冻0.5h处理,能明显降低大肠菌群和粪大肠菌群数量.     

西瓜汁超高压均质杀菌效果研究

研究西瓜汁超高压均质处理与微生物存活量的关系。西瓜汁样品在0～150MPa 的压力条件下经均质处理后检测各项微生物指标。结果表明：西瓜汁在均质压力150MPa 时,菌落总数下降2.1～2.3 个对数单位,霉菌及酵母菌菌落总数下降2.0～2.3 个对数单位,大肠菌群菌落总数下降3.1～3.5 个对数单位,但芽孢菌的数量变化不明显。在初始菌落总数为1.0 × 104CFU/mL 的情况下,经150MPa 均质处理1 次,可达到国家食品卫生标准,综合感官评估与鲜榨西瓜汁相近。初始菌落较高时,可均质处理多次以达到国家食品卫生标准,但综合感官评估有所下降。     

Manageable risk factors associated with bacterial and coliform counts in unpasteurized bulk milk in Flemish dairy herds

Associations between herd management practices and both bacterial counts (BC) and coliform counts (CC) from 254 and 242 dairy herds in Flanders (Belgium), respectively, were studied. Data were analyzed using multivariable, multilevel linear regression analysis, allowing variance components analyses. Both BC and CC fluctuated throughout the year, although the milk quality parameters followed an opposite pattern. Bacterial count values decreased with each increase of the cleaning frequency of the cubicles (once per week, once per day, twice per day, or more than twice per day) between January and March. Herds with a conventional milking parlor had substantially lower BC than herds where the cows were milked using an automatic milking system. Lower BC were observed when the milking parlor was equipped with an automatic cluster removal system, when premilking teat disinfection was applied, when the dry cows were supplemented with a mix of minerals and vitamins, and when the teats were prepared either first wet and dried or via an automatic milking system. Milking cows with a high-pipeline milking parlor setup or with an automatic milking system was associated with substantially higher CC values. Herds where prepartum heifers were often treated with antimicrobials before calving had a lower CC than farms where heifers were either not or only rarely treated. Most variation in BC and CC resided at the herd level rather than at the observation level, indicating that management is important in the control of both BC and CC. Still, only a small proportion of the total variance was explained by factors capturing information related to the milking, herd health, and dry cow management, which suggests that the bacteriological milk quality and, in particular, CC is primarily driven by other factors than the ones included in this study.     

Milk quality on Danish farms with automatic milking systems

The bulk-milk quality of 98 Danish farms with automatic milking systems was analyzed from 1 yr before introduction of automatic milking until 1 yr after. Bulk-milk total bacterial count, spores of anaerobes, somatic cell count (SCC), and freezing point increased when automatic milking was introduced and the frequency of milk-quality failures almost doubled. Milk-quality failures were most frequent in the first 3 mo after the start of automatic milking. The increase in spores of anaerobes indicated that the increase in total bacterial count originated partly from contamination of milk from the teat surface and partly from lack of cleaning of the milking equipment or cooling of the milk. The increase in bulk-milk SCC indicated that milk from clinically infected cows and cows with high cell counts was not diverted to the same degree, milking automatically rather than milking conventionally. A self-monitoring program including survey of the bulk-milk quality was established to help farmers in the transition period going from conventional to automatic milking. The program was introduced on 84 farms. Farms on the self-monitoring program reduced bulk-milk cell count. Application of the program did not reduce the frequency of high total bacterial counts and freezing points of the bulk milk to the level of conventional milking. However, the program reduced the overall frequency of milk-quality failures.     

冷冻饮品微生物检验中一些问题的分析与探讨

在按照GB/T4789-2003《食品卫生微生物学检验》对冷冻饮品进行检验分析时,注意到了影响结果准确性的几个问题,同时发现卫生标准的微生物指标存在一些缺陷,影响到检验结果的准确性。对这些问题进行了分析和探讨,并提出了修改建议。     

Bulk milk somatic cell counts are related to bulk milk total bacterial counts and several herd-level risk factors in dairy goats

The aim of this study was to describe the temporal variation in bulk milk somatic cell count (BMSCC) on Dutch dairy goat farms and to assess the correlation of BMSCC with bulk milk total bacterial counts (BMTBC) and with several herd management factors. Bulk milk somatic cell count and BMTBC data were recorded from 90% of the dairy goat farms in the Netherlands over the years 2005 to 2007. Farm characteristics and management information was collected by means of questionnaires. The bulk milk data and the questionnaire data were linked and linear mixed models were used to identify risk factors for increased BMSCC and BMTBC. Bulk milk somatic cell count was found to display a distinct pattern throughout the year, being highest around December and lowest around June. Bulk milk somatic cell count correlated to BMTBC (r = 0.4). Significant factors in the BMSCC model were month in lactation, treating mastitic animals instead of culling, caprine arthritis encephalitis status, milk fever prevalence, and liner material. Month in lactation and treating mastitic animals instead of culling were also significant in the BMTBC model. In the high-BMSCC period, a higher number of goats with an extended lactation significantly reduced the BMSCC. Thus, this study indicates that mastitis-related factors account for some of the variation in BMSCC and BMTBC levels between dairy goat herds. It shows that intramammary infection is probably the most important factor driving the correlation between BMSCC and BMTBC, suggesting that programs to improve udder health may have a positive effect on both BMSCC and BMTBC.