Abstract:The Central Committee of the Communist Party and State Council attach great importance to people's health. The 19^th Communist Party of China National Congress formulated “implementing the strategy of healthy China”, which is aim to comprehensively improve people's health level and promote people's healthy development. Plenty and proper nutrition of national people is conducive to promoting the health of Chinese people, which is an inevitable requirement for sustainable economic and social development, continuous improvement of the people's sense of gain, happiness and security. It is both the basic condition for decisively building a moderately prosperous society in all respects and the common pursuit for all of the people. The article deeply studied and elaborate the strategic significance and current challenges of improvement of national people nutrition, as well as the corresponding measures be taken in next stage. It is hoped that the present article can give some enlightenment to the efforts of further improvement of national nutrition and the boost of health China in future.

Abstract:Objective The aims of this study were to investigate the antibiotic resistance, disinfectant resistance and their associations in 302 Salmonella enterica Typhimurium (S. Typhimurium) isolates from retail meats, food animals and humans. Methods Antibiotic susceptibility testing was performed according to the Kirby-Bauer disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined by broth microdilution method, and disinfectant resistance genes were detected by polymerase chain reaction (PCR) amplification. Results Antibiotic susceptibility testing demonstrated that 96.03% (290/302) of S.Typhimurium isolates were resistant to at least one antibiotic and 79.80% (241/302) were multidrug resistant (MDR). Tested isolates showed the highest resistance to streptomycin (78.81%,238/302), followed by compound sulphonamides (78.15%,236/302), tetracycline (75.50%,228/302) and ampicillin (71.85%,217/302). All isolates were sensitive to cefepime and imipenem. The resistance of S. Typhimurium from food to compound sulphonamides, tetracycline, ampicillin, nalidixic acid, and gentamicin were significantly higher than those from human and animal origin (P<0.05). The resistance of animal isolates to ciprofloxacin and ofloxacin was significantly higher than that of food and human isolates (P<0.05). The resistance of human isolates to cefotaxime and ceftazidime were higher than those of food and animal isolates. The MICs of benzalkonium chloride (BC), triclosan (TCS), trichloroisocyanuric acid (TCCA) and povidone iodine (PVP-I) for S.Typhimurium isolates were 2-64,0.031 25-1,32-1 024 and 256->1 024 mg/L, respectively. In addition, the frequency of resistance to PVP-I, BC and TCS was observed significantly higher in food and animal isolates than human isolates (P<0.05). The qacEΔ1, sugE(p) and qacE disinfectant resistance genes were detected in 56.95% (172/302), 20.53% (62/302) and 2.65% (8/302) of all the isolates, respectively. Notably, qacEΔ1 gene was significantly associated with β-lactam, aminoglycoside, tetracycline, sulfonamide, quinolone and chloramphenicol resistance (P<0.01). Conclusion It was indicated that antibiotic and disinfectant resistance were common among S. Typhimurium isolates and the use of disinfectants or antibiotics may contribute to co-selecting isolates with acquired resistance to other antimicrobials, which could pose significant threats to food safety and public health.

Abstract:Objective To analyze the virulence genes and antimicrobial resistance of 140 Vibrio parahaemolyticus strains from shellfish collected from farms and markets. Methods Virulence genes and antimicrobial resistance genes were detected by PCR amplification method, and antimicrobial resistance was determined by disk diffusion test. Results None of the 140 strains carried tdh gene, and trh gene was detected in one strain. All strains were resistant to ampicillin, some strains were resistant to cefazolin, cefuroxime sodium, streptomycin, amikacin, sulphamethoxazole/trimethoprim, tetracycline and florfenicol. All strains were sensitive to cefepime, gentamicin, imipenem, meropenem, ofloxacin and doxycycline. Six strains showed multi-antimicrobial resistance to two or more categories of antimicrobials. The resistance genes strA and strB were detected in streptomycin resistant strains, tetA was detected in tetracycline resistant strains, sul2 was detected in sulphamethoxazole/trimethoprim resistant strains, and floR was detected in florfenicol resistant strain. Conclusion Most of Vibrio parahaemolyticus strains didn't carry virulence genes and showed antimicrobial resistance to a certain extent. Some strains had more than one antimicrobial resistance gene, which exhibited multi-antimicrobial resistance. These results indicated that enhancing the monitoring of pathogenicity and antimicrobial resistance of Vibrio parahaemolyticus in aquatic products should be continued.

Abstract:Objective To identify the natural protein arginine kinase (AK) extracted from oysters, and to understand its basic properties and homology. Methods AK was isolated and purified from oysters by ammonium sulfate salting out and anion exchange, and the relative molecular mass and secondary structure were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and circular dichroism (CD) spectroscopy. Its stability was also studied. The amino acid sequences of oyster AK and 11 other crustacean and mollusk allergens were compared by bioinformatics software, and their homology was analyzed. Results The natural protein with a relative molecular weight of 40 kDa was oyster AK. AK was neither heat-resistant nor acid-resistant. Oyster AK has high homology of mollusk allergen AK amino acid sequence, and homology of crustacean amino acid sequence is 55%-60%. Conclusion Natural AK is extracted from oysters, and the stability and homology are basically understood. It will lay the foundation for comprehensive research on sensitization and sensitization mechanism of oysters.

Abstract:Objective To understand the composition of microbiota on the surface of fresh eggshell and its change over time. Methods The samples were collected from three cities and tested at different time points. The diversity and similarity of bacteria were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and sequencing method. Results The Shannon index and Dice index of bacteria on eggshell surface of Hanzhong were statistically significant different from Yulin and Xi'an. The bacteria were mainly Firmicutes and Actinobacteria, and the dominant genera were Staphylococus, Streptomyces and Lactobacillus. Conclusion There were different bacteria on the surface of eggshell in different areas, but the microbiota in the early and late stage of storage time was very similar.

Abstract:Objective To establish a digital polymerase chain reaction(PCR)method for hepatitis A virus (HAV) in shellfish and berry foods. Methods After sample enrichment by proteinase K digestion polyethylene glycol method, RNA was extracted by high purity virus nucleic acid kit, and then digital PCR was used to detect HAV. Results This method had typical amplification, good repeatability and stability for HAV. The sensitivity of HAV in strawberry, raspberry and shellfish samples was 25.30 CCID₅₀/20 g, 6.32 CCID₅₀/20 g and 12.54 CCID₅₀/2 g respectively, which means that the detection sensitivity of HAV was high. Conclusion This method is rapid, accurate, sensitive, and is suitable for the determination of HAV in shellfish and berry foods.

Abstract:Objective To establish a new and rapid GeXP(GenomeLabTM eXpress Profiling)based multiplex polymerase chain reaction (PCR) assay for the detection of five common foodborne pathogens. Methods Nucleotide sequences of specific gene(invA, rfbE, PfrA, IpaH, tlh) of the five pathogens (Salmonella, Escherichia coli O157∶H7, Listeria monocytogenes, Shigella, Vibrio parahaemolyticus) were obtained and compared. The primers were then designed and the multiplex PCR assay was evaluated. Optimized assay was further validated with the detection of the unknown strains and artificially contaminated samples. Results The GeXP multiplex PCR with five sets of specific primers can be used to detect five foodborne pathogens simultaneously within 5 hours. The specificity was examined by specimens confirmed previously. The detection limit was 10³ CFU/mL. Conclusion The results suggested this GeXP multiplex PCR assay was a fast, high throughput test for foodborne bacterial pathogens.

Abstract:Objective To develop a multiwalled carbon nanotube (MSPE) method coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)by preparing a magnetic multiwall carbon nanotube composite nanoparticles modified with 3-aminobenzeneboronic acid for simultaneous determination of 9 kinds of microcystins in aquatic products. Methods Magnetic multiwall carbon nanotubes (Fe₃O₄/MWCNTs) composite nanoparticles were prepared by hydrothermal synthesis. Then, the 3-aminobenzeneboronic acid was modified on the prepared magnetic carbon nanotubes through the chemical oxidation method. The nanoparticles have been characterized by transmission electron microscopy and infrared spectroscopy. The main factors influencing the extraction efficiency were optimized. And then a preprocessing method with acetic acid-PBS buffer solution-methanol (2∶49∶49, V/V) was selected as the extraction solution, and 50 mg magnetic nanomaterials were used for extraction for 15 min, 5% ammoniated methanol was used as the eluting solvent within 10 min. Results The calibration curves of microcystins showed a good linearity in the range of 5-200 ng/mL with correlation coefficients above 0.998.The detection limits(LOD)of the method were in the range of 0.15-8.71 μg/kg. The average relative recoveries of three spiked levels ranged from 91.8% to 103.2% with the relative standard deviations of 3.1%-9.5%. Conclusion The method has the characteristics of simple pretreatment, high sensitivity and high recoveries, superior to national standard method. It could simultaneously determine 9 kinds of microcystins in aquatic products and provides a powerful technical guarantee for the monitoring of microcystins in aquatic products.

Abstract:Objective The rapid yeast and mold count plate (RYM) method and the national standard (GB 4789.15-2016) method were compared for the consistency in three types of food detection. Methods 90 pastry, bread and biscuits samples, 30 milk beverage, vegetable protein beverage and solid drink samples, 30 health foods samples, three types of artificially contaminated food samples were detected by the RYM method and the GB method, then the data of the two method were analyzed by the paired t test and the log difference (|dlog|). Results The statistics were made for the data of three types of food samples and three types of artificially contaminated food samples. The paired t test gave P>0.05, and the ratio of |dlog|≤0.50 were 100.0%. There was no significant difference between the result of the two method. Conclusion There is no significant difference between the results of the RYM method and the GB method in detecting three types of food samples and three types of artificially contaminated food samples.

Abstract:With the development of the food industry and the progress of related research in recent years, the application of “probiotics” in food products and its health claim in label and advertisement which have a very important influence on consumers' cognition and choices becomes a continuous concern by both industries and administration department. This article summarizes and analyzes the definition of probiotics and the management of related health claims in international organizations and countries or regions such as China, the European Union, the United States, Canada and Japan. The similarities and differences of the use of “probiotics” concept and its health claims in various food types, relevant requirements and management frameworks which can be used for the management modification of probiotics food in China were studied and discussed. The aim of this article is to provide reference for improving the management and promoting the industry development of probiotics in China.

Abstract:Objective The objective is to reveal the epidemiological burden and predictors of acute gastroenteritis in Heilongjiang Province. Methods A multi-stage stratified random sampling method was used to collect the incidence of acute gastroenteritis in the past 4 weeks. Results A total of 19 171 people were investigated. The monthly prevalence of acute gastroenteritis was 3.51% [95% confidence interval(95%CI):3.25%-3.77%], the annual incidence rate was 37.24%, and the incidence rate was 0.466 times per person-year. The weighted monthly prevalence rate was 3.61%, the weighted annual incidence rate was 38.07%, and the weighted incidence rate was 0.479 times per person-year. It was estimated that the average annual incidence of acute gastroenteritis in this province was 14.423 million people per year, with a total of 18.147 million cases. Multivariate Logistic regression analysis showed that the nature of the residence, season, age, whether they had left their residence due to business or trips in the past 2 weeks, and the annual per capita income of the family were the influencing factors.58.66% of acute gastroenteritis cases were attributed to contaminated food. Conclusion Acute gastroenteritis in Heilongjiang Province had a heavy epidemiological burden and a high proportion of foodborne diseases, which should be paid more attention to.

Abstract:Objective To investigate the contamination and distribution of cadmium(Cd)in crabs sold in Wenzhou, and instruct consumers to eat healthily. Methods Three crab species were collected from 51 markets in 6 counties and districts of Wenzhou. The content of Cd was determined by inductively coupled plasma mass spectrometry based on GB 5009.268-2016. Results The detection rate of Cd was 100% in 235 samples. The Cd pollution in Portunus crab increase during 2013,2015 to 2017. The Cd content of muscle and hepatopancreas in Portunus crab and Scylla serrata was higher than that in Eriocheir sinensis Milne-Edwards(P<0.05). There was no significant difference in the Cd content between Portunus crab and Scylla serrata (P>0.05). The distribution of Cd in Portunus crab was hepatopancreas and gonad> pectoral muscle > leg muscle, there was no significant difference of cadmium content in different parts between female and male crabs (P>0.05). Conclusion Cd was mainly concentrated in hepatopancreas, which was irrelevant to crab species, sex and individual difference. Cd content of Portunus crab and Scylla serrata exceeded the standard seriously, especially in hepatopancreas. People should pay more attention to the Cd pollution of crabs, and reduce the intake of hepatopancreas if necessary.

Abstract:Objective To understand the types and extent of mycotoxins in grains and its products sold in Henan Province. Methods During 2018-2019,16 kinds of mycotoxins were detected by isotope dilution ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The results were evaluated and analyzed according to GB 2761-2017 national food safety standard mycotoxin limit in food. Results Fumonisin, zearalenone, aflatoxin and deoxynivalenol were the main mycotoxins in 100 corn flour, corn dregs and corn kernels, the detection rate ranged from 0.0% to 95.7%. The detection rates of deoxynivalenol in 220 wheat flour, noodles and steamed bread were 78.0%(124/159), 64.3%(18/28) and 87.9%(29/33) respectively, and the content of other mycotoxins was very low or not detected. Conclusion There were different levels of mycotoxin pollution in grain and its products in Henan Province, especially fumonisin in corn and its products. It is necessary to carry out traceability investigation in time and take corresponding control measures as soon as possible.

Abstract:Objective To identify the epidemiological characteristics of nontyphoid Salmonella infection in Shanghai, and provide scientific basis for the prevention and control. Methods The descriptive epidemiological method was used to analyze the epidemiological information of the collected diarrhea cases and the nontyphoid Salmonella test result from 26 foodborne disease surveillance sentinel hospitals in Shanghai. Results A total of 5 580 infectious diarrhea cases and specimens were enrolled. The positive detection rate of nontyphoid Salmonella was 4.19% (234/5 580). The serotypes were mainly Salmonella Enteritidis and Salmonella Typhimurium. There was no difference in the positive detection rate of nontyphoid Salmonella among different genders, ages and occupations. Spring and summer were the seasons when nontyphoid Salmonella positive detection rate was high. The positive rate of nontyphoid Salmonella in patients with fever or watery stool was significantly higher than in patients without fever or waterless stool. The positive rate of nontyphoid Salmonella was relatively high among the patients from small and medium-sized catering service and canteen. Conclusion Salmonella Enteritidis and Salmonella Typhimurium were the main serotypes of nontyphoid Salmonella in Shanghai, and the peak of nontyphoid Salmonella infection occured in spring and summer. The authorities should strengthen the supervision and management of catering service and canteen.

Abstract:Objective To monitor the contamination of Norovirus and Rotavirus in scallops sold in Beijing and analyze their genetic characteristics. Methods A total of 72 scallops were collected during November 2014 and October 2015. The digestive tissues of scallops were excised, Norovirus was enriched using the polyethylene glycol (PEG)8000 precipitation method. The virus RNA were extracted and tested for Norovirus and Rotavirus using the real-time reverse transcription-polymerase chain reaction(RT-PCR). The capsid gene of Norovirus was amplified by the semi-nested RT-PCR. PCR products were sequenced directly. Sequence alignment was performed using BioEdit 7.0.9.0 software and the phylogenetic tree was constructed by MEGA 6.06 software. Results Among 72 scallops, Rotavirus was detected negative, and the detection rate of Norovirus was 27.8% (20/72), including 16 strains of genogroup GⅡ, 2 strains of genogroup GⅠ, and 2 strains of mixed genogroups GⅠ and GⅡ. The highest detection rate of Norovirus (61.1%, 11/18) was found in winter, and none was detected in summer. A total of 8 strains were sequenced successfully and identified as GⅡ.17 genotype. These strains all belonged to the Cluster Ⅲb branch of GⅡ.17 genotype, among which 6 strains shared 100.0% sequence similarity with strains detected in Chinese people in 2015, in Japanese people in 2016 and 2017, in water samples in South Korea in 2017 and 2018, and in oysters in Japan in 2015. Conclusion Norovirus contamination existed in some scallops sold in Beijing, eating uncooked scallops would indicate a risk of viral acute gastroenteritis.

Abstract:Objective To evaluate the exposure of aflatoxins and their potential health risks of residents in Guangxi. Methods The concentration data of aflatoxins from food safety monitoring in Guangxi in 2013-2017 and the food consumption data from nutrition and health investigation in 2012 were obtained. Based on deterministic assessment model and margin of exposure(MOE), the dietary exposure to projected risks for liver cancer was calculated. Results The average dietary exposure and the highly exposure (P95) of aflatoxins B₁ (AFB₁) were 10.38 and 25.49 ng/kg BW, respectively. The MOE values were 16 and 7, the average risk for hepatocellular carcinoma(HCC)was 0.37 cases/10⁵ people, and the risk for HCC in highly exposed was 0.92 cases /10⁵ people. It was indicated that the main dietary sources of AFB₁ were vegetable oil(mainly peanut oil), which was contributed more than 72.17%. Assuming that the standard limit was strictly implemented, the average exposure of AFB₁ was 5.13 ng/kg BW, with a 50.58% reduction. Conclusion It should be paid more attention to the potential health risks caused by dietary exposure of AFB₁ of residents in Guangxi, especially the low age group and vegetable oils.

Abstract:Objective To study caffeine concentration level in the main beverages, and evaluate the caffeine intake through beverages in Shandong population and its potential health risks. Methods Caffeine concentration levels of 319 beverages samples were determined. Consumption data of beverages were obtained from a survey of 2 523 Shandong residents conducted in 2013. The deterministic assessment model was used to calculate dietary intake of caffeine in Shandong population. Results The average caffeine concentration level in 8 kinds of beverages was 9 210.06 mg/kg, and the maximum value was 49 059.60 mg/kg. The average intake of caffeine from beverages by Shandong population was 61.62 μg/kg BW per day, well below the safe level of 6.7 mg/kg BW. The dietary intake of caffeine in men aged 60 years old and older was the highest, with an average of 166.55 μg/kg BW per day, 2.49% of the comparator of 6.7 mg/kg BW. The 97.5^th percentile (P97.5) of daily caffeine intake was 476.82 μg/kg BW per day, well below the comparator of 6.7 mg/kg BW. The range of the 97.5^th percentile (P97.5) of daily caffeine intake in each gender and age group was from 0.00 to 3 104.70 μg/kg BW per day. The maximum exposure of the 97.5^th percentile was that of the 13-17 women group. Main food source of caffeine was tea, with a contribution rate of 74.19% in Shandong. The cola was the main source of caffeine intake in 3-12 years old. Conclusion The caffeine intakes through beverages by Shandong population do not rise to safety concerns. Tea and cola were the main food contributor of caffeine dietary intake for adults and children, respectively.

Abstract:Objective To describe the content of nutrients and three environmental contaminants for “overseas online shopping” infant formulas. Methods 18 kinds of “overseas online shopping”infant formula and 14 kinds of domestically purchased infant formula were collected, and their nutritional composition and 3 environmental chemicals were analyzed and compared. Results Four kinds of “overseas online shopping” infant formula did not meet the GB 10765-2010, and the nutrient contents of “overseas online shopping” infant formulas were significantly different from those domestic purchased(P<0.05). The 5 main different indictors were energy(68.09,66.77 kcal/100 mL), protein(2.00,2.32 g/100 kcal), fat(5.51,5.15 g/100 kcal), pantothenic acid(676.33,910.84 μg/100 kcal), and iodin(20.60,17.41 μg/100 kcal). Di-2-ethylhexyl phthalate (DEHP), bisphenol A (BPA) and perfluorooctanoic acid (PFOA) were not detected in any infant formula. Conclusion “Overseas online shopping” infant formulas did not completely meet the GB 10765-2010, further studies were needed to investigate the adaption of “overseas online shopping” infant formula to China's infants.

Abstract:Objective In order to promote and guide the development of beverage industrialization and standardization in China, this paper studies the management of beverage regulations and standards by international organizations and other countries, to summarize the problems and differences in domestic and foreign beverage standards, to put forward suggestions for the improvement of China's beverage quality and safety standards, and to provide references for the revision of China's beverage safety standards. Methods Comparing the standards and regulations of China, Codex Alimentarius Commission(CAC), the European Union, the United States, Australia/New Zealand, Canada and Korea, analyzing the categories, heavy metals, mycotoxins, microorganisms and other indicators, studying the existing problems in the current beverage standards in China, and putting forward some useful suggestion. Results The management of beverage standards in other countries is different from that in China. The formulation of food safety standards of beverage in China is relatively reasonable and basically identical to international standards. We should pay more attention to the colony count indicators, the ready-to-consume drinks, the improvement of standards in beverage categories, and the effective coordination between quality and safety standards. Conclusion China's beverage standard management system conforms to China's domestic situation. The beverage food safety standards is relatively reasonable. China should take good measures to the food safety standards and quality standards revision on beverages, and promote the healthy and harmonious development of the beverage industry.

Abstract:Objective To investigate the pathogenic characteristics of Clostridium perfringens isolated from two diarrhea outbreaks. Methods Samples and specimens of patients, chefs, cooking utensils and suspicious foods involved in 2 diarrhea outbreaks were collected. The real-time polymerase chain reaction (PCR), bacteria isolation and culture were performed on the samples. The number of CPs in the specimens was counted. Toxicity genes, pulsed-field gel electrophoresis (PFGE) and drug resistance detection were performed on the isolated CP strains. Results After real-time PCR and bacterial isolation, CP was detected in some patients specimens, food and smear samples, and other common viruses and bacteria were negative. In most cases, the CP count of the specimens exceeded 1.0×10⁶ CFU/g. The 10 strains of CP isolated were all carrying toxin-producing genes. The PFGE fingerprints of the 10 strains were divided into 7 bands, of which 3 were the same band in the first outbreak, and 2 bands were the same in the second outbreak. Those strains were sensitive to imipenem, metronidazole, ceftriaxone and penicillin. Six strains were resistant to clindamycin, one strain was intermediated, and six strains were intermediated to chloramphenicol. Conclusion PCR could be used for rapid screening of CP virulence genes. PFGE could also help determine food poisoning events caused by CP. At the same time, the daily monitoring of CP and the prevention of its drug resistance should be strengthened.

Abstract:Objective To investigate a food poisoning caused by wild mushrooms and to identify the risk factors.MethodsEpidemiological investigation,morphological and phylogenetic identification, and laboratory testing were taken to analyze the poisoning event. Results All the three cases complained of abdominal pain, vomiting and diarrhea after ingesting the poisonous mushrooms, and liver function impairment was found later. One case died after 5 days. The mushroom was identified as Galerina sulciceps by morphological and phylogenetic identification. Three kinds of toxins, include α-amanitin,β-amanitin and γ-amanitin were detected in laboratory. Conclusion The incident was caused by ingesting the poisonous mushroom, Galerina sulciceps. Public education,market supervision, foodborne disease surveillance should be enhanced, and the ability of medical institutions to diagnose and treat poisonous mushrooms should be improved.

Abstract:Traditional clinical nutrition research mostly stay at the stage of human and animal experiments. Cell model experiment has gradually become an important way in clinical nutrition research nowadays. Firstly, this review mainly summarizes the cells commonly used in nutrition research and gives a general introduction of diseases in clinical nutrition using cell models such as atherosclerotic cardio-cerebrovascular disease, sarcopenia, kidney diseases, tumor, gastrointestinal diseases, liver damage, allergic inflammation, burns and so on. Then it focuses mainly on the diseases which are the leading death causes of the Chinese residents, reviewing the use of cell models the advantages as well as their scientific significance and the development and application trend of cell model (3D cell, cytome, microfluidic, high throughput and high content). Finally, the limitations of cell model experiments in clinical nutrition are summarized, and new technologies used in cell model experiments of clinical nutrition are prospected.