中国安徽阜阳劣质婴儿配方粉中阪崎肠杆菌的污染

2004年中国安徽阜阳劣质婴儿配方粉事件引起了我国政府的高度重视.为了调查婴儿配方粉中阪崎肠杆菌的污染状况,根据美国FDA和加拿大实验室的方法,建立了婴儿配方粉中阪崎肠杆菌的分离鉴定技术.从87份阜阳劣质奶粉样品中检测到11份阪崎肠杆菌阳性样品,污染阳性率为12.6%.用API 20E和Qualicon BAX(R)系统鉴定了11株阪崎肠杆菌.这是国内首次从婴儿配方粉中分离到阪崎肠杆菌菌株.     

奶粉中阪崎肠杆菌的分离与鉴定

目的了解某地区婴儿配方奶粉中阪崎肠杆菌的污染情况,为我国制定婴儿配方奶粉中阪崎肠杆菌的限量标准及为政府加强对婴儿配方奶粉的管理提供科学依据。方法常规生理生化鉴定法和实时荧光PCR法。结果检出2株阪崎肠杆菌。结论我国市售的婴儿配方奶粉中存在少量的阪崎肠杆菌污染。     

婴幼儿配方食品中阪崎肠杆菌的计数结果不确定度评定

[目的] 了解专项抽查的婴儿配方食品中的阪崎肠杆菌指标状况,并探讨阪崎肠杆菌的计数结果的不确定度评定方法。[方法] 按照GB 4789.1-2010 《食品微生物学检验 总则》和GB 4789.40-2016 《食品微生物学检验 阪崎肠杆菌检验》进行了抽样和检测, 依据JJF1059.1-2012 《测量不确定度评定与表示》及贝塞尔统计学方法对计数结果进行不确定度评定。[结果]22批次婴儿配方食品中有1批次检出阪崎肠杆菌,检出率为4.55%, 该批次样品中阪崎肠杆菌平均计数为25.5MPN/100g,计数结果扩展标准不确定度为2.72MPN/100g。[结论] 本次评估依据阪崎肠杆菌检计数检验国家标准,对4次保温培养节点进行了分析,结果表明固液混合过程,酵液取样体积,阪崎肠杆菌显色平板上可疑菌落选择和MPN法重复计数的四个不确定度较大,是记数检验过程中的重要环节。     

阪崎肠杆菌-食品安全控制的新目标

自 196 1年英国首次报道阪崎肠杆菌引起婴儿脑膜炎病例以来 ,世界上相继有多个国家报道了新生儿阪崎肠杆菌感染事件 ,婴儿配方奶粉与疾病的暴发密切相关。在 2 0 0 3年第 35次食品卫生法典大会上 ,美国和加拿大提出了有关控制婴幼儿配方奶粉中阪崎肠杆菌的危险性框架 ,指出 1岁以下的易感婴幼儿感染阪崎肠杆菌后有生命危险。 2 0 0 4年第 36次食品卫生法典大会一致通过并设立了以加拿大为首的起草工作组 ,加速修订婴幼儿食品国际卫生操作规范 ,制定阪崎肠杆菌和其它可能导致婴幼儿健康危害的相关病原菌的微生物标准。     

从进口饼干、巧克力和方便面中检出阪崎肠杆菌

目的了解食品中阪崎肠杆菌的污染状况。方法采用PCR法和全自动生化分析仪检测进出口食品中的阪崎肠杆菌。结果从新疆某实业有限公司进口的14批饼干、巧克力和新疆某食品公司等生产的11批方便面中检出5株阪崎肠杆菌,检出率分别为14.2%和27.3%。结论阪崎肠杆菌在食品中存在安全隐患。     

测试片法：实现乳品阪崎肠杆菌的快速检测

阪崎肠杆菌是寄生于人和动物肠道内的条件性致病菌,可导致新生儿出现脑膜炎、败血症及坏死性结肠炎等疾病,具有发病急、致死率高等特点。该菌的自然来源比较广泛,但是从多起阪崎肠杆菌引发的中毒事件中发现,婴幼儿配方奶粉是目前阪崎肠杆菌主要感染渠道。而2002年和2003年发生的两家国际乳业巨头因产品中检出阪崎肠杆菌主动召回产品的事件则使阪崎肠杆菌成为世界瞩目的焦点。     

LAMP法检测乳粉中的阪崎肠杆菌

据WHO最新报告显示,乳粉中的阪崎肠杆菌是导致婴幼儿感染和死亡的主要原因之一。FDA于2002年公布了婴幼儿乳粉中阪崎肠杆菌检测的推荐方法,但检测周期长达1周左右,而且操作复杂,难以满足控制该疾病暴发和传播的需要。DNA环介导等恒扩增(loop-mediated isothermal amplification,LAMP)技术是一种特异性、灵敏度高、检测时间短的新型基因扩增技术。本文以阪崎肠杆菌为研究对象,建立了一套应用于婴幼儿乳粉中阪崎肠杆菌快速检测方法。针对阪崎肠杆菌16s RNA基因设计4条引物特异性识别靶基因的六个特殊区域,并在63℃进行恒温扩增。实验结果表明,使用该方法能够在5h之内检测出复原乳样品中101CFU/mL的阪崎肠杆菌。灵敏度可以达到100fg阪崎肠杆菌基因组DNA。应用环介导等温扩增法,克服了传统检测周期长、操作复杂的缺点,不仅能够用于婴幼儿乳粉中阪崎肠杆菌的检测,而且满足了对于婴幼儿乳粉中阪崎肠杆菌快速检测的迫切需要。     

奶粉中阪崎肠杆菌的风险评估

阪崎肠杆菌能引起脑膜炎、NEC和菌血症等，约2．5％～14％婴儿配方奶粉含有阪崎肠杆菌，0％～12％的普通奶粉含有阪崎肠杆菌，含量从0．36-66．0cfu／100g。婴幼儿奶粉中的阪崎肠杆菌问题已受到了全世界的普遍关注。本文基于大量研究和调查数据，从奶粉中阪崎肠杆菌的危害识别、奶粉中阪崎肠杆菌的暴露评估、奶粉中阪崎肠杆菌危害特性以及阪崎肠杆菌的检测方法等方面客观地对奶粉中阪崎肠杆菌进行风险评估，并对降低我国婴儿配方奶粉中阪崎肠杆菌风险提出建议。     

3种方法检测婴幼儿配方奶粉中的阪崎肠杆菌

目的对市售婴幼儿配方奶粉中阪崎肠杆菌检测方法进行研究。方法分别用常规培养鉴定方法、常规PCR方法和实时荧光PCR方法对32份奶粉样品进行阪崎肠杆菌分离鉴定。结果32份样品中检出2株阳性株，阳性率为6．25％，3种鉴定方法结果相符。结论联合使用多种鉴定方法可提高阪崎肠杆菌检测的可靠性。     

新疆部分进出口食品中阪崎肠杆菌的污染调查

目的了解新疆进出口食品中阪崎肠杆菌的污染状况。方法利用PCR方法对新疆进出口食品中的11大类、253批次进行初筛,用传统方法进行分离,最后用VITEK全自动生化分析仪进行鉴定。结果分别从饼干巧克力类、方便面类、谷物类、儿童食品类、干果类和其他类食品中检出阪崎肠杆菌,阳性率分别为：13.43%、8.16%、15.79%、75.00%、11.11%、11.11%。结论 阪崎肠杆菌在上述食品尤其是儿童食品中存在,是安全隐患。     

我国婴幼儿断奶食品的发展现状

介绍了我国婴幼儿断奶食品的发展现状和存在问题,并就今后的发展方向作了一定的探讨.     

提高全民对食品营养及安全的认知是解决食品安全总是的关键

本文结合最近发生的食品安全事件及婴幼儿食品的营养及安全问题,指出食品安全问题在我国大有日趋严重之势,并建议国家有关部门、媒体和社会各界共同配合,对广大消费者和食品生产者进行食品营养和食品安全知识和法规的教育及宣传,以提高他们的认知水平,这是解决食品安全问题的关键.     

北方农村婴幼儿简易辅助食品的实验研究

研制一种原料来源广泛，价格低廉，营养合理，配制简便的婴幼儿辅助食品。配方食品以小米粉，白面粉为主，混合适量黄豆粉，鸡蛋，并强化碳酸钙，核黄素等。同时进行营养评价。结果：配方组动物的体重增长，血红蛋白，血清蛋白含量和骰，胫骨长度都与酪蛋白组无明显差异；较正ＰＥＲ为２．２４，达酪蛋白值的８９．６％；ＮＰＲ为３．９９，ＰＲＥ为６５．６７％，分别达酪蛋白值的９１％以上；ＴＤ为８６．２％；ＢＶ两组无明显差异     

Effects of repeated exposure on acceptance of initially disliked vegetables in 7-month old infants

In the weeks following the start of weaning, 70 mothers were asked to identify a vegetable purée that their infant disliked and that they normally would not offer again. The 49 who did so were then asked to offer that vegetable on alternate days for 16 days, and to offer a well-liked one (carrot purée) on the other days. Amount eaten and acceptance were measured at each meal. On the first day of exposure, mean intake of the initially disliked vegetable was 39 ± 29 g and of the liked one, 164 ± 73 g (mean ± SD). Over the following days, intake of the initially disliked vegetable increased rapidly and by the eighth exposure was 174 ± 54 g, similar to that of the liked vegetable (186 ± 68 g). A similar pattern of results was found for mother-reported liking ratings. These effects of repeated exposure appear to be long lasting because nine months later, 63% of the infants were still eating and liking the initially disliked vegetable. The present study shows that when a vegetable is initially disliked it is worth persisting in feeding it for at least eight subsequent meals.     

Food processing increases casein resistance to simulated infant digestion

The objective of this study was to determine whether processing could modify the resistance of casein (CN) to digestion in infants. A range of different dairy matrices was manufactured from raw milk in a pilot plant and subjected to in vitro digestion using an infant gut model. Digestion products were identified using MS and immunochemical techniques. Results obtained showed that CNs were able to resist digestion, particularly κ‐ and αs₂‐CN. Resistant areas were identified and corresponded to fragments hydrophobic at pH 3.0 (gastric conditions) and/or carrying post‐translational modifications (phosphorylation and glycosylation). Milk processing led to differences in peptide patterns and heat treatment of milk tended to increase the number of peptides found in digested samples. This highlights the likely impact of milk processing on the allergenic potential of CNs.     

Effects of repeated exposure to either vegetables or fruits on infant’s vegetable and fruit acceptance at the beginning of weaning

This study investigated the effects of repeated exposure to either vegetables or fruits on an infant’s vegetable and fruit acceptance during the first 18 days of weaning. We hypothesized that repeated exposure to a type of vegetable or fruit, would increase its intake. Furthermore, we expected that being exclusively weaned with vegetables would result in a higher acceptance of vegetables than being exclusively weaned with fruits. To investigate this, a 19-day intervention study was conducted in 101 healthy infants, aged 4–6 months. Infants were randomly assigned to one of four treatment groups. Two groups received exclusively vegetable purées as targets every other day for 18 consecutive days; green beans was the target for one group and artichoke for the other group. The other two groups received exclusively fruit purées including either apple or plums as the target fruit. On day 19, the vegetable groups consumed their first fruit purée and the fruit groups their first vegetable purée. At the beginning of the study on days 1 and 2 and at the end on days 17, 18 and 19, the infants were fed fruit or vegetable purée in our laboratory. On days 3–16, the parents fed their infants the fruit or vegetable purées at home.Outcome variables were vegetable and fruit intake over time. Mean vegetable intake in the vegetable group increased significantly from 24 ± 28 g (mean ± SD) on days 1 and 2 to 45 ± 44 g on days 17 and 18. Fruit intake in the fruit group increased significantly from 46 ± 40 to 66 ± 42 g. Fruit intake was significantly higher than vegetable intake from the start. Repeated exposure to fruit had no effect on the vegetable intake. The first intake of green beans in the fruit groups at day 19, was 24 ± 29 g and on average as low as the green beans intake in the vegetable groups at the 1st exposure on days 1 or 2. Similarly, the first apple intake in the fruit groups on days 1 or 2 of 47 ± 48 g did on average not differ from the first apple intake of 45 ± 49 g in the vegetable groups on day 19. The mean intake of green beans and plums increased significantly after repeated exposure. The intake of the target food artichoke stayed low and the intake of apple only increased slightly. These findings confirm that at the first exposure fruit acceptance is higher than vegetable acceptance. Weaning with vegetables, but not with fruits, may promote vegetable acceptance in infants.     

婴幼儿配方奶粉中核苷酸含量的测定方法研究

为检测婴幼儿配方奶粉中胞嘧啶核苷酸、尿嘧啶核苷酸、腺嘌呤核苷酸、鸟嘌呤核苷酸、次黄嘌呤核苷酸5种核苷酸的含量，建立了奶粉中5种核苷酸的紫外检测器液相色谱法。对试样提取、固相萃取等前处理方式和仪器检测条件进行了研究，试样经0．5％乙酸去除蛋白质，氨基固相萃取柱富集和净化，symmetry C18柱分离，254nm紫外检测器液相色谱分析方法定量检测。胞嘧啶核苷酸、尿嘧啶核苷酸、腺嘌呤核苷酸、鸟嘌呤核苷酸和次黄嘌呤核苷酸的添加回收率分别是90．0％～94．2％、86．4％～93．2％、85．7％～92．6％、90．0％和85．7％～93．3％，相对标准差分别为6．6％、3．4％、8．2％、6．8％和8．2％，检出限分别为0．04、0．05、0．05、0．06和0．04μg/mL。3年来对30件送检样品的检测显示，检测结果与标示量基本一致。该方法适用于婴幼儿配方奶粉核苷酸含量的分析。