Risk Analysis Of The Quality And Safety Of Dairy Products Sold In China And Aquatic Products Sold In Shanghai And Other Places

The quality and safety of dairy products and aquatic products has become one of the hot issues of global food safety.Hence,risk assessment and risk factors analyses of quality and safety of dairy and aquatic products provide scientific early warning information for the relevant food regulatory departments,which will be helpful to prevent the occurrence of incidents related to dairy products and aquatic products safety.In this study,Monte Carlo simulation,quantitative risk assessment and fault tree analysis?FTA?were used to assess the risk of pathogenic microorganisms and chemical hazards in domestic liquid milk.Then a safety risk early warning model of dairy product was constructed by using machine learning algorithms to qualitatively predict the safety of dairy products sold in China.In view of the quality and safety problems faced by commercial animal-derived aquatic products?hereinafter referred to as aquatic products?in Shanghai,the risk assessment method was used to study the risks of chemical contaminants and Vibrio parahaemolyticus?Vp?in aquatic products in the coastal areas of eastern China,and the corresponding risk assessment model was also built.The spatial distribution pattern and spatial-temporal characteristics of veterinary drug residues in the Yangtze River Delta of China were analyzed by global spatial autocorrelation,hot spot analysis and spatial-temporal scanning.The main research contents and conclusions are as follows:1 Risk assessment and early warning of quality and safety of dairy products sold in ChinaFirstly,the hazards of pathogenic microorganisms in liquid milk were studied,and the effects of temperature and time on the growth of Staphylococcus aureus?S.aureus?and Escherichia coli?E.coli?in the supply chain of liquid milk were analyzed.Quantitative risk assessment models for the contamination of these two bacteria in commercial liquid milk were established,respectively.The results showed that the final average contamination concentration of S.aureus in liquid milk with different p H?6.4-6.8?was higher in the non-heat treatment route and heat treatment route,and the probability of exceeding 10⁵ CFU/m L was more than 3.9%.The probability of the final average contamination concentration of E.coli in liquid milk with different p H exceeding 10⁶ CFU/m L was 0.1%,which leads to low health risk.In addition,the risk assessment model of Mycobacterium bovis in raw milk was constructed.The results showed that the average probability of carrying Mycobacterium bovis in raw milk was4.75×10^-4.The average probability of 1 kg per capita consumption of raw milk carrying Mycobacterium bovis was 0.016,which has health risk to human body.After studying the risk of pathogenic microorganisms in liquid milk,the factors in supply chain which cause chemical hazards of liquid milk were further investigated,and a fault tree of liquid milk chemical hazards incidents was constructed.It could be found that following key factors may affect chemical hazards incidents in liquid milk:the incomplete feedback mechanism of the production enterprise,neglect or absence of good monitoring of government departments,and the poor random inspections of China National Food and Drug Administration.Moreover,the vulnerability of chemical hazards in the liquid milk supply chain was analyzed.The results showed that three groups of people?consumers,production enterprises and food regulatory authorities?thought that the liquid milk supply chain was vulnerable to chemical hazards incidents.In view of various potential risks in dairy products,a qualitative prediction model of dairy products safety was constructed by using Chinese dairy product sampling data from 2014 to 2017 combined with machine learning algorithms.The results showed that the model constructed with Adaboost algorithm had better effect than other algorithms,and the sensitivity,specificity and accuracy of the model were 62.50%,91.67%and 72.22%,respectively.The model had good prediction effect and could be used for the prediction of dairy product quality and safety.Based on this prediction model,we also constructed a web server,which can be accessed by users at http://www.biotechshu.com:8080/Mpredict.2 Risk analysis of quality and safety of aquatic products sold in Shanghai and other placesThe risk of cadmium,lead,mercury,malachite green and nitrofuran in aquatic products was assessed by dietary exposure assessment method.The results showed that the average exposure of cadmium,mercury and lead in 2-4 years old male children and4-7 years old female children through the consumption of aquatic products was both higher than other age groups.The daily intake of malachite green by fish for all age groups was within the safe range?the margin of exposure was more than 10000?,and the nitrofuran in the daily intake of fish for all age groups has a certain health risk?the margin of exposure for nitrofuran metabolites was less than 10000?.According to the pollution of Vibrio parahaemolyticus in aquatic products investigated in literature,the risk of Vibrio parahaemolyticus food poisoning caused by raw aquatic products of residents in the eastern coastal area was evaluated.The results show that the probability of disease of the residents living in the eastern coastal areas suffering from raw aquatic products was 8.34×10^-7,and the risk was low.Geographic Information System?GIS?method was used to study the spatio-temporal distribution and clustering of the excess and detection rates of veterinary drug residues in aquatic products in Shanghai,Jiangsu,Zhejiang and Anhui?Yangtze River Delta Urban Agglomerations?the of China from 2017 to 2019.The results showed that the overall excess rate and detection rate of veterinary drug residues in aquatic products from 2017 to 2019 presented spatial random distribution.The results of hot spot analysis and spatio-temporal scanning analysis showed that there were clusters of veterinary drugs detected and exceeded in aquatic products.