肉鸡屠宰加工及冷藏中的微生物污染来源及菌相分析

研究了商业屠宰及冷藏过程对肉鸡胴体天然茵落的影响,结果表明,空气、预冷水与环境中各种接触面均是禽类生鲜产品的潜在污染源.尽管加工过程能减少胴体表面各种腐败茵、致病茵污染,但某些工序也增加了特定细菌的污染程度,细菌交叉污染发生在加工过程中的所有阶段.总的说来净膛操作会导致胴体污染程度上升,冲洗、预冷过程对减菌都有很好效果.但预冷过程也可能导致嗜冷茵污染的发生,并且加工过程中存活的细菌能在冷藏阶段继续增殖进而导致产品腐败.     

2010年江苏省肉鸡沙门菌污染专项监测分析

目的了解肉鸡养殖和屠宰过程中沙门菌的污染状况,为确定从生产到销售各环节沙门菌分布和疾病可能传染源、制定公共卫生措施并评价其有效性提供科学依据。方法按照《全国食源性致病菌监测工作手册》中专项监测的采样和实验室检测要求,2010年共采集活体肉鸡肛拭样本210份,胴体样本204份,监测沙门菌污染情况。结果肛拭样本检出沙门菌23份,检出率10.95%;胴体样本检出沙门菌71份,检出率34.80%。两类样本的血清学分型构成比不同(χ2=15.7,P<0.001),肛拭样本检出的23株沙门菌中有22株印第安纳沙门菌,胴体样本中检出的71株沙门菌中有35株为印第安纳沙门菌,22株为奥尔巴尼沙门菌。结论肉鸡活体肛拭和胴体样本沙门菌检出率差异有统计学意义(χ2=33.5,P<0.001),胴体高于活体检出率,活体和胴体的沙门菌来源不同,胴体可能存在交叉污染。     

冰鲜鸡预冷过程中微生物菌群多样性动态分析

为了对肉鸡屠宰预冷过程中预冷水、鸡胴体的微生物群落结构进行动态分析,研究二者优势菌群的消长规律。本文对第一批屠宰鸡通过预冷水0、2、4、6、8 h时预冷池中一阶、二阶预冷水以及鸡胴体进行菌落总数(TVC)检测,然后采用高通量测序的方法对二者的群落结构进行动态分析。菌落总数测定结果表明:在预冷过程中,一阶预冷水菌落总数由103 CFU/mL增长到105 CFU/mL,二阶预冷水菌落总数由102 CFU/mL增长到104 CFU/mL,在预冷前,鸡胴体的菌落总数为4.53 lg CFU/g,经预冷后在6~8 h内,鸡胴体表面菌落总数高于预冷前,说明预冷水已经失去了清洗减菌的作用,还可能会对鸡胴体造成交叉污染。高通量测序发现:在预冷过程中,一阶预冷水中气单胞菌属减少,假单胞菌属、链球菌属增加;二阶预冷水的不动杆菌属减少,假单胞菌属增加;与预冷前相比,预冷过程中鸡胴体的魏斯氏菌和漫球菌属减少,金黄杆菌属和假单胞菌属增加。本研究表明预冷后期预冷水失去减菌作用,对鸡胴体造成污染,预冷工艺主要对气单胞菌属、魏斯氏菌和漫球菌属有较好的减菌效果,对金黄杆菌和假单胞菌属减菌效果不佳。这为宰后胴体预冷工艺的优化提供参考依据,同时为冰鲜鸡产品的质量安全提供保障。     

生猪屠宰加工过程中微生物的污染及减菌措施

为确保屠宰加工肉类产品的安全和卫生,主要对生猪在屠宰加工过程中微生物污染和减菌措施进行了总结,旨在对屠宰行业在预防和减少屠宰线上胴体污染方面提供参考。     

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。     

生肉的微生物污染和对策(上)

<正>胴体上的微生物引人注目的原因有两个,其一是肉在烹煮和供餐过程中处理不当,引起食物中毒,例如沙门氏菌:其二主要是假单胞菌的耐冷菌使肉发生腐败变化,而不可食用.减少胴体微生物污染的目的就是减少疾病(从动物递给人)的危害,使生产的胴体达到商业要求的货架期.本文讨论污染来源的鉴别和减少污染方面的进展,屠宰场卫生的评价以及在加工结束时消除胴体污染的可能性.     

基于传统培养和高通量测序方法分析羊肉加工过程中的菌群多样性

通过传统培养和高通量测序分析了羊肉加工过程中的菌群多样性及其变化,确定了羊肉加工过程主要的污染菌群组成。传统培养结果表明在羊肉加工过程中,初始胴体表面菌数在103~104 CFU/cm2之间,而在后续的分割过程中其菌数增长到105~106 CFU/cm2,说明加工过程可能会造成羊肉二次污染。从不同选择性培养基中分离得到43株菌,通过16S rDNA序列分析鉴定为嗜水气单胞菌、肠杆菌、变形杆菌、葡萄球菌和大肠杆菌,结晶紫染色测定成膜能力结果发现上述肠杆菌的成膜能力最强。高通量测序发现,胴体和台面表面的腐败菌均有莫拉菌科、嗜水气单胞菌科、嗜冷杆菌科、希瓦氏菌科、普雷沃氏菌科、假单胞菌科、李斯特菌科、葡萄球菌科、肠杆菌科等,说明胴体和加工环境间存在交叉污染。本研究发现羊肉加工过程中的优势菌群复杂,并且污染菌株也具有较强的成膜能力,为冷鲜羊肉的保鲜技术开发提供了理论基础。     

冷鲜肉加工的关键技术及微生物控制

冷鲜肉是指经过严格的检疫检验后,屠宰的猪胴体经过预冷、排酸等工艺环节,最后胴体的中心温度达到0～4℃。主要的技术在于工厂生产过程采用了两段式预冷,即第一段为快速冷却,条件为胴体置于-15℃以下的环境温度中1～1.5h;第二段为预冷,条件为胴体置于0～4℃的环境温度中16～24h,产品最终的中心温度达到0～4℃。在生产加工和销售的过程中,为了控制微生物的繁殖采取减菌技术来提高产品的质量,延长产品的货架期。     

肉鸡屠宰加工中减菌处理前后细菌菌相分析

基于16S rDNA V6～V8可变区的聚合酶链式反应-变性梯度凝胶电泳（polymerase chain reaction-denaturinggradient gel electrophoresis,PCR-DGGE）技术分析肉鸡屠宰加工过程中减菌处理前后胴体或产品细菌多样性。在预冷环节前采用50 ℃、1.5%乳酸溶液对肉鸡胴体冲淋15 s进行减菌处理,采集屠宰加工环节中减菌处理前后的胴体或分割产品表面样品,提取样品中的细菌总DNA,通过16S rDNA V6～V8可变区的PCR扩增,变性梯度凝胶电泳,对PCR扩增片段割胶回收、克隆测序分析减菌前后细菌菌相变化。结果表明,减菌前,胴体清洗环节DGGE条带的数量最多、亮度最强,细菌污染最严重,其次是分割环节,而预冷环节细菌种类及数量最少,污染程度最低;减菌后,各屠宰加工环节细菌种类与数量较减菌前均有所减少,其中胴体清洗环节与分割环节细菌的种类与数量减少量最多,预冷环节细菌的种类及数量最少,不同屠宰加工环节细菌种类并不完全一致;乳杆菌属细菌在整个肉鸡屠宰加工过程中均有出现,与肠杆菌科和假单胞菌属细菌为肉鸡屠宰加工过程中的优势腐败菌。     

黄羽肉鸡屠宰过程中胴体表面腐败菌的变化

为了分析黄羽肉鸡屠宰加工环节的肉鸡胴体污染菌的菌群组成,本试验利用平板倾注法及Illumina MiSeq高通量测序高效地测定黄羽肉鸡屠宰过程中加工环境和胴体表面腐败菌的多样性。结果表明,净膛、预冷及分级是黄羽肉鸡菌落总数增长的主要污染来源工序,分级秤、分级车间工人手套、预冷槽及净膛工人手套为以上三个工序中污染来源接触面,且分级秤及分级车间工人手套所污染菌群是黄羽鸡胴体菌群的主要来源,使黄羽鸡胴体表面菌落总数及假单胞菌增长率高达24.13%、41.27%,经过分级秤及分级车间工人手后黄羽鸡菌落总数显著（P<0.05）增加至4.63 lg(CFU/g)。打毛后（DM）、净膛后（JH）、净膛消毒后（CH）黄羽鸡胴体优势菌主要为链球菌属（Streptococcus）,大肠杆菌属（Escherichia）和气单胞菌属（Aeromonas）。黄羽鸡经预冷槽预冷后气单胞菌属丰度大幅增加,链球菌属次之。经过分级秤分级后黄羽鸡胴体菌群中不动杆菌属（Acinetobacter）为主要优势菌,巨球菌属（Macrococcus）次之。添加次氯酸电解水减菌后,黄羽肉鸡胴体表明气单胞菌属和链球菌属丰度大幅...     

Yeast populations associated with processed poultry

The bacterial contamination of poultry carcasses during and after processing is well documented, however, little attention has been given to the composition and incidence of yeast populations of this product. A study was undertaken with the objective of identifying predominant yeasts associated with the skin of fresh and spoiled processed poultry carcasses. A total of 159 representative yeast isolates obtained from fresh and spoiled processed carcasses were identified according to conventional methods. Species ofCandida, Cryptococcus, DebaryomycesandYarrowiawere isolated from fresh and spoiled carcasses.RhodotorulaandSaccharomycesspp. were isolated from fresh samples only andTrichosporonspp. from spoiled samples only.     

2002年北京市市售鲜鸡蛋和生鸡肉的沙门菌污染情况调查

为了了解北京市市售鲜鸡蛋、生鸡肉的沙门菌污染情况,并为建立食物污染及中毒的预警系统提供数据基础,2002年7、8和9月从北京市四个区的集贸市场、超市、商场和街边小商店共采集鲜鸡蛋100件,生鸡肉100件,进行了沙门菌的定性、定量检测及血清分型。结果表明鲜鸡蛋蛋液中未检出沙门菌,生鸡肉的沙门菌阳性检出率为30%,沙门菌在生鸡肉中的污染情况与销售温度有关。因此,控制沙门菌的污染来源和生鸡肉销售的温度条件是控制沙门菌污染的手段之一。然而,还需要进一步研究的是鲜鸡蛋外源性污染情况的调查;销售温度与污染情况之间相关性的进一步证实。     

开封市畜禽沙门菌污染状况及血清学鉴定分析

了解开封市畜禽肉中沙门菌的污染状况及血清学分布,为沙门菌引起的食源性疾病的防控提供依据。方法 依据GB 4789.4—2010《中华人民共和国国家标准食品卫生微生物学检验方法》和2011年国家食源性疾病监测网监测方案,定期对开封市畜禽养殖场和屠宰场进行随机采样监测。结果 在691份样品中,沙门菌检出率为35.9%(248/691);分离出沙门菌253株,有17个血清型。结论 开封市生鸡肉和生猪肉不同程度受到沙门菌的污染,以生鸡肉污染最严重。应加强禽畜类养殖、屠宰加工等过程的卫生监管,减少食源性疾病的发生。     

Tracking spoilage bacteria in commercial poultry processing and refrigerated storage of poultry carcasses

Four trials were conducted to examine the effect of commercial processing and refrigerated storage on spoilage bacteria in the native microflora of broiler carcasses. Prescalded, picked, eviscerated, and chilled carcasses were obtained from a commercial processing facility, and psychrotrophs in the bacterial flora were enumerated on Iron Agar, Pseudomonas Agar, and STAA Agar. The size of the population of spoilage bacteria on processed carcasses stored at 4 degrees C for 7, 10, or 14 days was also determined. Bacterial isolates were identified and dendrograms of the fatty acid profiles of the isolates were prepared to determine the degree of relatedness of the isolates. Findings indicated that although some processing steps increased the level of carcass contamination by selected bacteria, the number of spoilage bacteria recovered from processed carcasses was significantly (P< or = 0.05) less than the number of bacteria recovered from carcasses entering the processing line. Acinetobacter and Aeromonas spp. were the primary isolates recovered from carcasses taken from the processing line. During refrigerated storage, there was a significant (P < or =0.05) increase in the population of bacteria on the carcasses, and Pseudomonas spp. were the predominant bacteria recovered from these carcasses. Dendrograms of the fatty acid profiles of the isolates indicated that bacterial cross-contamination of carcasses occurs during all stages of processing and that some bacteria can survive processing and proliferate on carcasses during refrigerated storage. Furthermore, cross-contamination was detected between carcasses processed on different days at the same facility. Findings indicate that although poultry processing decreases carcass contamination by psychrotrophic spoilage bacteria, significant levels of bacterial cross-contamination occur during processing, and bacteria that survive processing may multiply on the carcasses during refrigerated storage.     

Control of campylobacter in poultry industry from farm to poultry processing unit: A review

Campylobacter is an emerging zoonotic bacterial threat in the poultry industry. Most of the human cases of campylobacteriosis recorded have revealed their poultry origins. Various control measures have been employed both at the farm and processing levels to combat with it. The antibiotic treatment, phage therapy, competitive exclusion, and vaccination have been adapted at the farm level to reduce colonization of Campylobacter in poultry gut. While prevention of intestinal spillage, scheduled slaughter, logistic slaughter, chemical decontamination of carcasses are recommended to reduce contamination during processing. The postharvest interventions such as heat treatment, freezing, irradiation of contaminated carcass can effectively reduce Campylobacter contamination. Thus, integrated approaches are required to tackle infection of Campylobacter in humans.     

Comprehensive Review of Campylobacter and Poultry Processing

Campylobacter has been recognized as a leading bacterial cause of human gastroenteritis in the United States, with 40000 documented cases annually. Epidemiological data suggest that contaminated products of animal origin, especially poultry, contribute significantly to campylobacteriosis. Thus, reduction of contamination of raw poultry would have a large impact in reducing incidence of illness. Contamination occurs both on the farm and in poultry slaughter plants. Routine procedures on the farm such as feed withdrawal, poultry handling, and transportation practices have a documented effect on Campylobacter levels at the processing plant. At the plant, defeathering, evisceration, and carcass chillers have been documented to cross‐contaminate poultry carcasses. Carcass washings and the application of processing aids have been shown to reduce populations of Campylobacter in the carcasses by log₁₀ 0.5 log₁₀ 1.5; however, populations of Campylobacter have been shown to enter a poultry processing plant at levels between log₁₀ 5 colony‐forming units (CFU)/mL and log₁₀ 8 CFU/mL of carcass rinse. The purpose of this article is to review Campylobacter, the infection that it causes, its association with poultry, contamination sources during processing, and intervention methods.     

鲜肉中小肠结肠炎耶尔森菌的半定量风险评估

目的:分析南京市售鲜肉中小肠结肠炎耶尔森菌的风险程度。方法:将国内外文献报道及市场调查数据的统计分析相结合,运用经典的半定量风险评估软件"Risk Ranger"进行风险分级。结果:南京市售猪肉和牛肉中小肠结肠炎耶尔森菌的风险评分分别为31和24,每人每天因食用污染该菌的鲜肉造成食物中毒的概率分别为3.62×10-9,3.12×10-10,前者为后者风险的11.6倍。通过进一步研究发现,加工后采取有效的控制体系,均使两者的风险均降低到10%。结论:南京市售牛肉中小肠结肠炎耶尔森菌的风险程度较低,而市售猪肉中已接近中等程度,需做好预防措施,加强监管。     

Continuous online processing of fecal- and ingesta-contaminated poultry carcasses using an acidified sodium chlorite antimicrobial intervention

The objective of this study was to determine the effectiveness of the combined use of an inside-outside-bird-washer for the removal of visible contamination and an online acidified sodium chlorite (ASC) spray system in reducing microbial levels on contaminated poultry carcasses. Specifically, we attempted to determine if this technique (referred to as continuous online processing [COP]) would (i) eliminate the need for offline reprocessing of contaminated carcasses, (ii) meet Zero Fecal Tolerance standards, and (iii) attain significant reductions in titers of some of the commonly found bacterial species. Carcasses were sampled for Ercherichia coli, Salmonella, and Campylobacter at five stations along the processing lines in a series of five commercial plant studies to compare the efficacy of the COP system to that of offline processing. The microbiological quality of fecally contaminated carcasses was found to be significantly better following COP treatment (E. coli, 0.59 log10 CFU/ml; Salmonella, 10.0% incidence) than after standard offline reprocessing (E. coli, 2.37 log10 CFU/ml; Salmonella, 31.6% incidence). Zero Fecal Tolerance requirements were met by all but 2 (0.2%) of the 1.127 carcasses following COP. COP also significantly reduced the titers of Campylobacter; residual titers were 1.14 log10 CFU/ml (49.1% incidence) following COP, compared to 2.89 log10 CFU/ml (73.2% incidence) in carcasses that underwent offline reprocessing. These results support the combined use of an inside-outside-bird-washer for the removal of visible contamination and an online ASC spray system to reduce microbial levels in commercially processed poultry.     

Reduction of Campylobacter spp. by commercial antimicrobials applied during the processing of broiler chickens: a review from the United States perspective

A reduction in Campylobacter spp. has been associated with use of commercial antimicrobial technologies during the processing of broiler chickens. This review is focused on commercial interventions that have received approval by both the U.S. Food and Drug Administration and the U.S. Department of Agriculture for use on raw poultry in the United States. Most of these interventions are currently applied prechill. The limited number of publications on the topic suggests that the application of antimicrobials in commercial settings results in Campylobacter reduction of 1 to 2 log CFU/ml of carcass rinse. However, postchill counts of 0.5 to 1 log CFU/ml of carcass rinse (approximately 4,000 CFU per carcass) are still common. Thus, antimicrobial interventions are not a complete solution for the control of Campylobacter on raw poultry. New postchill interventions are needed, as are (i) improvements in the methodology for detection and enumeration of Campylobacter, (ii) additional surveys on the contamination of processed poultry, and (iii) an understanding of possible resistance to antimicrobials by Campylobacter spp. Research addressing these topics will lead to better control of Campylobacter in commercial poultry carcasses.     

Current and future interventions for improving poultry health and poultry food safety and security: A comprehensive review

Poultry is thriving across the globe. Chicken meat is the most preferred poultry worldwide, and its popularity is increasing. However, poultry also threatens human hygiene, especially as a fomite of infectious diseases caused by the major foodborne pathogens (Campylobacter, Salmonella, and Listeria). Preventing pathogenic bacterial biofilm is crucial in the chicken industry due to increasing food safety hazards caused by recurring contamination and the rapid degradation of meat, as well as the increased resistance of bacteria to cleaning and disinfection procedures commonly used in chicken processing plants. To address this, various innovative and promising strategies to combat bacterial resistance and biofilm are emerging to improve food safety and quality and extend shelf-life. In particular, natural compounds are attractive because of their potential antimicrobial activities. Natural compounds can also boost the immune system and improve poultry health and performance. In addition to phytochemicals, bacteriophages, nanoparticles, coatings, enzymes, and probiotics represent unique and environmentally friendly strategies in the poultry processing industry to prevent foodborne pathogens from reaching the consumer. Lactoferrin, bacteriocin, antimicrobial peptides, cell-free supernatants, and biosurfactants are also of considerable interest for their prospective application as natural antimicrobials for improving the safety of raw poultry meat. This review aims to describe the feasibility of these proposed strategies and provide an overview of recent published evidences to control microorganisms in the poultry industry, considering the human health, food safety, and economic aspects of poultry production.