Analysis on unqualified items of infant formula food by supervision and sampling inspection in China / 上海预防医学

Objective:To describe the unqualified situation of infant formula food by supervision and sampling inspection in China， and then recommend appropriate countermeasures. Methods:The results of supervision and sampling inspection of infant formula food were summarized from 2015 through 2020 in China， and the unqualified items were classified and analyzed. Results:From 2015 through 2020， a total of 30 252 batches of infant formula food were sampled and examined in China， in which 187 batches were determined to be unqualified with an overall unqualified rate of 0.62% （187/30 252）. Content of items in 82 batches of samples did not meet the national standards for food safety， accounting for 43.85% （82/187） of the total number of unqualified batches. Labels in 105 batches were unqualified， accounting for 56.15% （105/187）. Generally， the unqualified rate of infant formula food showed an overall downward trend over years， with a 1.8% of decrease between 2020 （0.03%） and 2015 （1.83%）. The main problems in the unqualified infant formula food in China were minerals， vitamins， optional ingredients， microorganisms and conventional nutrients， which accounted for 39.50% （94/238）， 15.97% （38/238）， 14.29% （34/238）， 10.50% （25/238） and 10.08% （24/238） of the total unqualified items， respectively. Conclusion:Food manufacturers should strictly implement the principal responsibility of food safety， and government regulatory sectors should continue to strengthen the supervision to ensure the quality and safety of infant formula food.

Vibro parahemolyticus contamination surveillance and virulence genes analysis on commercial marine products during 2008-2013 in Shanghai / 上海预防医学

Objective To investigate and characterize the contamination of Vibrio parahaemolyticus(V.parahaemolyticus) in commercial seafoods on Shanghai markets.Methods Based on the method of GB/T 4789.7-2008 from "Microbiological Examination of Food Hygiene: Examination of V.parahaemolyticus",the contamination of V.parahaemolyticus in seafoods from different predetermined monitoring sites in Shanghai was quantitatively determined and the occurrence of virulence genesthermostable direct hemolysin (tdh) and TDH-related hemolysin (trh),in 192 seafoods separated V.parahaemolyticus strains were detected by PCR.Results A total of 2 643 seafood samples from wholesale markets,retail markets,supermarkets,catering industries and online shopping were collected from January to December in the years of 2008 to 2013.V.parahaemolyticus was found in 192 samples (7.3%).Among 192 separated strains,2.6%(5/192) that carried tdh or trh.2.1%(4/192)were positive for tdh,and 0.5% (1/192) were positive for trh.The geometric mean densities of V.parahaemolyticus were different significantly in varied seafood species,sampling months,as well as locations(P<0.05).Especially,geometric mean densities of V.parahaemolyticus in June to October were significantly higher than those in other months(P<0.05).The detection rate (8.4%) and geometric mean densities(0.209 MPN/g) of V.parahaemolyticus in fishes were significantly higher than those in other seafood(P<0.05).The geometric mean densities of V.parahaemolyticus in seafoods from wholesale markets,retail markets,supermarkets were higher than those from other sampling resources (P<0.05).Conclusion The contamination of V.parahaemolyticus in seafoods during summer and fall was relatively higher from Shanghai markets.Some separated V.parahaemolyticus strains carry virulence genes tdh and trh.Thus the contamination of V.parahaemolyticus in seafood needs to be intensively monitored and environmental impact factor should be searched for implementing risk assessment and management on high risk points for V.parahaemolyticus contamination.

Bacillus cereus growth model established in cooked rice / 上海预防医学

Objective Establishment of growth model of Bacillus cereus in cooked rice.Methods To study the effects of temperature (10,15,20,25,30,34,37 and 43℃) on the growth of Bacillus cereus in rice.And then the SGompertz and SLogistic models were selected as the primary growth models to fit the growth curve of Bacillus cereus in cooked rice at variable storage temperatures.Using the fitness (R2),accuracy factor (Af) and deviation factor (Bf) as evaluation index,quadratic polynomial model and square root model were selected further to fit and to establish the secondary growth models of Bacillus cereus in cooked rice.Results The SGompertz model could be better fitting the growth of Bacillus cereus at different temperatures,and therefore was chosen as the primary growth model of Bacillus cereus in rice.For the developed square root model,Af was 1.12 and 1.24,Bf was 0.99 and 1.03,R2 values were 0.9537 and 0.8503;respectively.For the developed quadratic polynomial model,Af was 1.24 and 1.11,Bf was 0.92 and 0.92,R2 values were 0.9550 and 0.9462;respectively.Conclusion The quadratic polynomial model can well predict the growth of Bacillus cereus in cooked rice,which proves to be reliable.

Perchlorate contamination exposure assessment on commercial foods in Shanghai / 上海预防医学

Objective To ascertain the perchlorate contamination level in commercial foods and health risks so as to provide reference for perchlorate standard formulation and risk management.Methods Perchlorate risk survey was done on commercial foods in Shanghai;in combination with the survey results of residents'' food consumption,the exposure assessment on the presence of perchlorate in commercial food was performed by probability assessment approach.Results A total of 80 food samples from 8 food categories were analyzed,including grain,vegetables,fruits,dairy products,meat,eggs,aquatic products and teaand perchlorate detection rate was 78.8% with a mean value as 13.0±26.4 μg/kg.The highest mean value of perchlorates was 59.0±51.9 μg/kg in tea,and the lowest mean value was 3.4±2.3 μg/kg in fruits.With protection of human life and health as the maximum principle (there were supposed to be no losses of perchlorate during food processing),it was found that the estimated average dietary intake of perchlorate from the 8 food categories was 0.25 μg/kgbw.However,the 95 percentile exposure estimates reached up to 0.44 μg/kgbw,which exceeded the tolerable daily intake value of 0.3μg/kgbw established by European Food Safety Authority for healthy adults.Therefore,potential health risk may exist to certain groups of people.Conclusion Due to its high water-solubility,degradation of perchlorate in food processing probably occurs to certain extent.Therefore,there is need to carry out further actual exposure study.

Quantitative risk assessment of the contamination of Vibrio parahaemolyticus in aquatic products / 上海预防医学

Objective To estimate the health risk due to the consumption of aquatic products contaminated by Vibrio parahaemolyticus in Shanghai , and provide the basis for control of foodborne diseases associated with this pathogen . Methods According to the guidelines provided by Codex Alimentarius Commission ( CAC) , we performed a quantitative microbial risk assessment model with four steps :hazard identification , hazard characterization , exposure assessment and risk characterization .The surveillance data of Vibrio parahaemolyticus concentration in aquatic products from Shanghai during 2011 and 2013 and Shanghai residents ’ aquatic products consumption data were added in the model .And the parameters were set in this model based on the FAO/WHO scientific literature .A Monte Carlo simulation method was employed to analyze the increase of Vibrio parahaemolyticus concentration in aquatic products from market to table, and quantify the exposure and health risk of Vibrio parahaemolyticus by consuming aquatic products in Shanghai . Results The mean value of probability of infectious illness caused by aquatic products contaminated by Vibrio parahaemolyticus in Shanghai was 1.2 ×10 -6 .That indicated the number of infectious illnesses associated with Vibrio parahaemolyticus in Shanghai might reach 10 746 cases every year based on the population data from Shanghai Statistical Yearbook in 2014 . Conclusion There is the certain health risk of suffering from the disease due to the consumption of aquatic products contaminated by Vibrio parahaemolyticus in Shanghai .Decreasing the occurrence of eating raw aquatic products and controlling the temperature and time of aquatic products processing and storage were determined as the critical factors for suppressing foodborne diseases caused by Vibrio parahaemolyticus.