湿米粉加工环节微生物污染情况调查

监测了2011年全年湿米粉在调浆、蒸粉、切粉和贮存四个加工环节微生物污染情况,检测了菌落总数、大肠菌群、总大肠菌群、致病菌等指标。监测结果表明,全年144个样品的致病菌均为未检出,说明湿米粉在加工环节受到沙门氏菌、志贺氏菌和金黄色葡萄球菌三种致病菌污染的概率极低。加水调浆是湿米粉生产过程中容易受到微生物污染的一个加工环节。全年监测的湿米粉在切粉环节基本上能达到90MPN/(100g)的标准,仅在5、7、8、9月份由于设备故障或手工切粉环节污染造成微生物超标。全年监测的销售点湿米粉仅在1、2月份和11、12月份这些低温月份达到了230MPN/(100g)的标准。贮存是湿米粉微生物污染最严重的环节,湿米粉安全生产的关键控制点为手工切粉和贮存。     

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。     

市售冷饮制品卫生状况调查

对市售三大类冷饮制品随机抽取的６０个品种１２０份检样的卫生状况调查显示：冰淇淋的细菌总数和大肠菌群超标率为２０％，金黄色葡萄球菌的检出率达３０％；雪糕的细菌部数超标率为３０％，大肠菌群超标率为４０％，金黄色葡萄球菌检出率达２０５，少门氏菌检出率为１０％；棒冰的细菌总数和大脾性菌群均符合卫生指标，未检出致病菌     

天津地区市售面制品微生物污染调查分析

2020年在天津市16个区共采集278份面制品,菌落总数不合格率为5.4%(15/278),大肠菌群不合格率为1.8%(5/278),霉菌、酵母菌检出率分别为14.7%(41/278)和5.0%(14/278),蜡样芽胞杆菌检出率为8.6%(24/278),金黄色葡萄球菌检出率为0.7%(2/278),奇异变形杆菌检出率为0.7%(2/278),其余致病菌均未检出。本次抽检结果显示,天津地区市售面制品卫生质量亟待提高,建议企业有针对性的防控微生物污染,防止食源性疾病暴发,监管部门应加强对生产经营企业的监督管理,保障食品质量安全。     

汽水微生物污染状况的调查分析

汽水是常用的饮料。近年来,各地制售的品种繁多,销量逐增。由于生产设备条件及工艺流程不同,所产汽水的质量和污染微生物的情况也不相同。为了了解汽水的微生物污染状况及影响因素,我们作了一些分析研究,现报告如下:     

饮料包装瓶微生物污染情况调查分析

对浙江台州地区58个饮料厂使用的饮料包装瓶的洗消方法,洗消效果进行调查和检测,同时对各种洗消方法进行模拟实验。具备完善的洗消工艺占37．94%,各种瓶子洗前平均污菌量22458个/ml,洗后5099个/ml,(P＜0．01);霉菌总数洗前8206个/ml,洗后3193个/ml(P＜0．01)．如按细菌菌落总数和霉菌总数每毫升100个作为合格标准,洗消后的瓶子,细菌菌落总数合格率为58．62%,霉菌总数合格率为72．72%．模拟实验证明,用0．5%氢氧化钠溶液浸泡5－10分钟→刷瓶→200ppm漂白粉液浸泡5－10分钟→反冲的操作工艺达到较好的洗消效果。     

部分市售粮食制品微生物污染状况监测分析

为明确我国市售大米、小麦粉和挂面这三大类粮食制品中储藏危害微生物的污染状况,确定是否存在潜在安全风险因子,抽检了市场上59个米类产品、37个小麦粉类产品和25个挂面类产品中的霉菌和菌落总数两个微生物指标。霉菌检测结果显示,米类产品污染数量分布于≤10 CFU/g,典型数值为<10 CFU/g;小麦粉类产品污染数量分布于<10～10³ CFU/g,典型数值为10² CFU/g;挂面类产品污染数量分布于<10～10² CFU/g,典型数值为10² CFU/g;菌落总数检测结果显示,米类产品污染数量分布较广,为10～10⁴ CFU/g,典型数值为10² CFU/g;小麦粉类产品污染数量分布于10～10³ CFU/g,其中在10² CFU/g和10³ CFU/g两个数量级的分布比例相等;挂面类产品污染数量分布于10²～10⁴ CFU/g,...     

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.     

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。     

市售羊肉微生物状况调查

以超市的冷鲜羊肉和农贸市场的热鲜羊肉为研究对象,对其微生物污染状况进行了实地抽查,并对其菌落总数进行了检测和分析。结果表明:(1)不同取样地点羊肉微生物污染状况有显著性差异,超市冷鲜羊肉的菌落总数明显高于农贸市场热鲜羊肉菌落总数;(2)在12处取样地点中,76.36%的羊肉菌落总数分布在7.6×104j1.43×106cfu/g,26.36%的羊肉微生物污染极其严重,超过国家标准(GB184060.3)。     

Microbial contamination of harvested colostrum on Czech dairy farms

The objective of this study was to perform a quantitative and qualitative evaluation of microbial contamination of harvested colostrum on 39 Czech dairy farms. The study identified the proportion of colostrum samples that met the recommended goals for total plate count (TPC), total coliform count (TCC), and gram-negative noncoliform count (NCC), and evaluated the effect of the farm, breed, parity, season of the year, time of calving, and colostrum volume on these 3 microbiological parameters. Colostrum samples from cows (n = 1,241; 57.6% from Czech Fleckvieh, and 42.4% from Holstein breed) were collected on dairy farms between autumn of 2015 and spring of 2017. The samples were collected after the first milking directly from milking buckets. In 155 out of 1,241 colostrum samples (26 farms, 6 samples each, except 1 farm), the species of microorganisms obtained by culture were determined, and the findings were classified into 4 groups according to the probable source of contamination as follows: (1) normal inhabitants of bovine skin and mucosa, (2) fecal contaminants, (3) environmental contaminants, and (4) potential gram-positive mammary pathogens. Our results showed heavy microbial contamination of collected colostrum samples (TPC median = 408,000 cfu/mL; TCC median = 200 cfu/mL; NCC median = 80 cfu/mL). Only 28.4% of samples met the requirement for TPC (<100,000 cfu/mL), 88.2% for TCC (<10,000 cfu/mL), and 86.0% for NCC (<5,000 cfu/mL). Among the tested factors, we found that farm had a significant effect on all 3 microbiological parameters, volume of colostrum had an effect on TPC (the highest TPC in <3.0 L of colostrum), and season had an effect on TCC and NCC (higher TCC in summer than in autumn and winter; the highest NCC in summer and higher in autumn than in spring and winter). Our results showed that most microbes isolated from colostrum belonged to normal inhabitants of bovine skin and mucosa, fecal, or environmental contaminants (i.e., 82.6%, 81.9%, and 75.5% of colostrum samples, respectively). Potential gram-positive mammary pathogens were found in 13.5% of samples. Escherichia coli was isolated from 9.0% of colostrum samples, and Streptococcus uberis and Streptococcus parauberis were each isolated from 5.2% of samples. Our study showed high microbial contamination of colostrum collected on dairy farms. Therefore, better hygiene and sanitation around colostrum harvest should be addressed by farmers.     

拉萨地区牦牛屠宰过程中的微生物污染

为探明拉萨地区牦牛胴体屠宰过程中的微生物污染程度,明确微生物关键控制点,对拉萨地区某具有代表 性的规范屠宰企业屠宰前车间空气中的微生物、各屠宰工艺环节牦牛胴体表面以及人员用具的菌落总数和大肠菌群 数量进行测定。结果表明：屠宰前车间微生物污染严重;随着剥皮和去内脏工艺的进行,牦牛胴体的菌落总数和大 肠菌群数量显著增加;斧劈四分体后胴体的菌落总数和大肠菌群数量均显著高于剥皮和去内脏后;牦牛屠宰过程中 微生物的主要来源是垫板和斧头。     

贮藏过程中冷却牛肉微生物模型的建立

冷却牛肉贮藏过程中易受微生物的污染,通过建立微生物数学模型,可以预测冷却牛肉的污染情况。实验以自然污染下的冷却牛肉为介质,对0、4、7、10、15、20℃恒温条件下的菌落总数进行计数,利用SAS软件拟合Modified Compertz方程,并对比生长率和时间拟合了平方根二级模型,最后在波动温度下对模型进行了验证。结果显示,Modified Compertz方程能很好地反映冷却牛肉中菌落总数的污染情况,恒定温度下的模型拟合度都在0.95以上,对波动温度条件下的菌落总数的预测值与实测值进行比较,偏差度为0.90,准确度为1.12,表明菌落总数生长模型可以可靠地预测冷却牛肉的微生物污染情况。     

肉牛屠宰过程中胴体表面及接触环境污染情况分析

为研究肉牛屠宰场屠宰过程中牛胴体表面污染及接触环境污染变化情况,选取某牛屠宰场采集样品共计322 份,分别在剥皮扯皮、去内脏、修整称质量、冲洗及排酸环节对牛胴体后腿、背部、胸部、前腿及颈部以及屠宰前后的工人手部及刀具进行采样,测定菌落总数、乳酸菌、大肠菌群、金黄色葡萄球菌及假单胞菌的污染情况。结果表明：胴体表面污染情况总体呈现先上升后下降的趋势,修整称质量环节污染最为严重,菌落总数可达到2.82（lg（CFU/cm2））;胸部为屠宰过程中污染最严重的部位,平均菌落总数可达到2.10（lg（CFU/cm2））;屠宰空气在冲洗时污染最为严重,空气沉降菌落总数高达271.33 CFU/皿;屠宰工人的手部及刀具也是胴体污染的主要来源。     

姜黄素介导的光动力冷杀菌方法对牡蛎杀菌的效果研究

通过光动力疗法（photodynamic therapy,PDT）对牡蛎肉匀浆及牡蛎肠道中的细菌进行杀灭处理,探究PDT可否杀灭牡蛎中的细菌。结果表明,以姜黄素为光敏剂的光动力冷杀菌处理对牡蛎中细菌具有非常好的灭活效果,3、6 h光敏剂富集组对牡蛎的杀菌率可达90%以上。同时该方法处理简便,且具有广谱杀菌特性。     

Effect of High-Pressure Processing on Vibrio parahaemolyticus Strains in Pure Culture and Pacific Oysters

Different strains of Vibrio parahaemolyticus (Vp) in broth cultures and Vp‐inoculated live Pacific oysters (Crassostrea gigas) were subjected to high‐pressure processing (HPP) at 241, 276, 310, and 345 MPa. Results showed Vp numbers were reduced by HPP in both pure culture and whole oysters. Vp inactivation was dependent on time and pressure. Optimum conditions for reducing Vp in pure culture and oysters to nondetectable levels were achieved at 345 MPa for 30 and 90 s, respectively. Resistance variations were detected between Vp in pure culture and in oysters. HPP proved to be an efficient means of reducing Vp in oysters.     

中式肉品加工中常用香辛料的微生物学研究

本文研究了中式肉制品中常用香辛料微生物污染情况和适当杀菌方式。结果显示黑胡椒粉不论在细菌总数、霉菌、酵母菌及耐酸菌、好气性嗜热菌、大肠杆菌群等，其微生物数目均为最高。而白胡椒粉测试结果其细菌总数、霉菌、酵母菌及耐酸菌、好气性嗜热菌的对数值分布在1～5之间，不同商号来源，其污染情形也不尽相同。此外其它香辛料如五香粉、甘草粉、大蒜粉、红辣椒粉、肉桂粉等的细菌总数、霉菌、酵母菌及耐酸菌、好气性嗜热菌以及大肠杆菌群的对数值也会随着商品的不同而有差异。另外分别经过伽玛射线照射(放射剂量27～30kGy)以及包装于耐热袋中的香辛料经高温灭菌(121℃、0．1MPa、15min)后，都显示无微生物存活。     

豆豉中蜡样芽孢杆菌污染情况分析

对来自武汉市售的50份豆豉样品进行微生物污染情况调查,主要检测豆豉中蜡样芽孢杆菌,以及菌落总数、霉菌与酵母和芽孢杆菌数.结果表明,豆豉中蜡样芽孢杆菌检出率很高,为94.0％,阳性样品含菌量为3.6c fu/g～1100cfu/g,几何均数为75.8cfu/g.不同地区的豆豉中蜡样芽孢杆菌的几何均数不同(21.2c fu/g～466.0cfu/g).本调查分析对我国豆豉中蜡样芽孢杆菌污染的溯源奠定基础.     

上海市市售带壳牡蛎微生物污染状况调查

目的了解上海市市售带壳牡蛎的微生物污染状况。方法2005年4月至2006年3月在上海市水产品批发市场每月2次采集牡蛎样品,共抽取了24份。按照GB/T4789—2003《食品卫生微生物学检验》中检验规程进行微生物检测。结果所有抽检样品均不合格,污染最严重的是大肠菌群,所检样品均超标,最高污染量达1·4×106MPN/g;其次是菌落总数,超标率达41·7%,最高污染量达2·6×107CFU/g;副溶血性弧菌污染也比较严重,检出率达29·2%,污染量在3·0×102~7·4×102MPN/100g;单核细胞增生李斯特菌未检出。结论上海市市售带壳牡蛎的微生物污染状况不容乐观,已对消费者健康构成了潜在威胁。     

Surveillance of Enteric Viruses and Microbial Indicators in the Eastern Oysters (Crassostrea virginica) and Harvest Waters along Louisiana Gulf Coast

Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter‐feeding molluscan shellfish exposed to sewage‐contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male‐specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log₁₀ genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P < 0.05); however, weak correlations were found in oysters (r < 0.45) and between oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences.