即食凉拌菜中单增李斯特菌的风险评估与管理

发布时间：2018-04-26 07:48

本文选题：即食凉拌菜 + 单增李斯特菌　；参考：《上海理工大学》2012年硕士论文

【摘要】：即食凉拌菜一般不会经过高温处理，而单增李斯特菌生长的温度范围较宽，尤其在低温时也能生长，所以消费者很容易通过食用被单增李斯特菌污染的即食凉拌菜而中毒，因此对即食凉拌菜中单增李斯特菌的危害进行评估并制定相应的风险管理措施就显得极为重要。本研究通过拟合即食凉拌菜中单增李斯特菌在不同温度下的生长数据，通过数学检验，选出最适的次级模型。通过对某市即食凉拌菜中单增李斯特菌的定量检测及对该市人群的膳食调查，确定其阳性污染率及人群的消费数据，进而建立数学模型进行定量风险评估，并根据敏感性分析对风险因素进行排序。根据单增李斯特菌的污染情况、人群消费数据及风险评估结果，对食品安全目标（FSO）值进行了假设性研究，并提出了相应的风险管理措施。同时本研究开发了快速风险评估软件，以便使用者能够方便快速的了解食用某种菌而患病的大概风险。具体研究结果如下：第一，为使实验菌株更具代表性，从即食凉拌菜中分离得到李斯特菌株，再接种到即食凉拌菜中以获得Combase数据库中缺少的35℃生长数据，结合Combase数据库里生菜中单增李斯特菌在5℃、10℃、15℃、20℃、25℃的生长数据构建即食凉拌菜中单增李斯特菌的初级模型和次级模型，着重将最大比生长率的观测值与各个模型的预测值进行比较，通过数学检验和分析讨论，确定用Logistic模型作为初级模型，Ratkowsky模型作为次级模型来对即食凉拌菜当中单增李斯特菌的生长状况进行预测。第二，按照ISO11290-2的检测与计算方法对某市100份样品进行了定量检测，确定其初始污染水平；通过预测生长模型确定食用时单增李斯特菌的摄入量。使用@Risk5.7软件，定量评估人群因消费即食凉拌菜而患单增李斯特菌病的风险，并进行敏感性分析。结果表明，大约有0.80%的即食凉拌菜中单增李斯特菌量超过风险阈值（4lg cfu/g），可知市民因食用即食凉拌菜导致单增李斯特菌病的风险较低。敏感性分析结果表明，初始污染水平与单增李斯特菌量的相关性最高，是消费者和食品监管部门需要重视的主要风险控制因素。第三，分别开发了较为方便快捷的快速风险评估软件（sQMRA）和基于预测微生物模型的食品微生物风险评估软件。前者使用VB程序编写，，设置了11个基本问题，使用者分别输入后即可得出污染水平及患病概率等；后者以微软Excel的加载宏模式为载体，使用VBA程序编写，将预测微生物模型与风险评估相结合，使用者根据预测模型拟合出的生长参数，输入对应单元格即可求得患病概率。使用者可根据实际情况选择软件进行初步的风险评估，同时，本研究为后续风险评估软件的开发提供了新思路。第四，对目前主要国家和组织对即食食品中单增李斯特菌的风险管理现在进行了总结归纳。根据即食凉拌菜中单增李斯特菌的不同污染水平和分布情况，对FSO值进行了假设性研究。通过估算不同限量值所导致人群患单增李斯特菌病的概率及病例数，并综合各方面因素考虑，建议主管部门将FSO值定为100cfu/g，同时提出风险管理建议措施。
[Abstract]:It is generally not treated by high temperature, but the temperature range of the growth of Lester bacteria is wide, especially at low temperature. So the consumer is easily poisoned by eating the instant salad with the mushroom contaminated by Lester bacteria. Therefore, the harm of Lester bacteria in the instant salad is evaluated and the corresponding is formulated. The risk management measures are very important. By fitting the data of the growth of Lester bacteria at different temperatures in the instant salad, the optimum secondary model is selected through the mathematical test. Through the quantitative detection of the single increase of Lester bacteria in the instant salad of a city and the dietary survey of the population in this City, the positive pollution is determined. A mathematical model was established for quantitative risk assessment, and the risk factors were sorted according to the sensitivity analysis. According to the pollution situation of the single Lester bacteria, the population consumption data and the risk assessment results, the food safety target (FSO) value was hypothesized and the corresponding risk management was put forward. At the same time, this study developed a rapid risk assessment software that allows users to quickly and quickly understand the risk of eating a certain bacterium. The results are as follows:
First, in order to make the experimental strain more representative, the Lester strain was isolated from the instant salad, and then inoculated to the instant vegetable to obtain the 35 degrees of growth data in the Combase database, and combined with the growth data of 5 C, 10, 15, 20, 25 centigrade in the lettuce in the Combase database. The primary and secondary models of monocytogenes were compared with the predicted values of the maximum specific growth rate and the prediction values of each model. Through the mathematical test and analysis, the Logistic model was used as the primary model and the Ratkowsky model was used as the secondary model for the growth of the single increase of Lester bacteria in the food cold food. Make a prediction.
Second, according to the detection and calculation method of ISO11290-2, 100 samples in a city were quantified to determine the initial pollution level, and the intake of single increase of Lester bacteria was determined by predicting the growth model. The @Risk5.7 software was used to quantify the risk of a single increase of Lester's disease due to the consumption of instant cold dish. The results showed that the amount of single increasing Lester bacteria in about 0.80% of the instant salad was higher than the risk threshold (4LG cfu/g). It was known that the risk of single increasing Lester's disease caused by edible cold food was lower. The sensitivity analysis showed that the correlation between the initial pollution level and the single increase of Lester bacteria was the highest, which was the consumer and the consumer. The main risk control factors that food regulators should pay attention to.
Third, the fast fast risk assessment software (sQMRA) and the food microorganism risk assessment software based on the predictive microorganism model are developed respectively. The former uses the VB program to set up 11 basic problems. The user can get the pollution level and the probability of illness after input, and the latter is loaded with the Microsoft Excel. As a carrier, the VBA program is used to combine the predicted microorganism model with the risk assessment. The user can get the disease probability according to the growth parameters fitted by the predicted model and input the corresponding cell. The user can choose the software for the initial risk assessment according to the actual situation. At the same time, this study is the follow-up risk assessment software. The development provides a new way of thinking.
Fourth, the risk management of the single increase of Lester bacteria in instant food by the main countries and organizations is now summarized. According to the different level and distribution of the different contamination level and distribution of the single increase of Lester bacteria in the instant salad, the FSO value is hypothesized. By estimating the value of different limits, the population of monocytogenes is caused by the single increase of Lester's disease. In terms of probability and case number, and considering all factors, it is recommended that the FSO be set to 100cfu/g and the risk management measures proposed.

【学位授予单位】：上海理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R155.5

【参考文献】