Rapid testing methods for food contaminants and toxicants

Food safety is one of the major concerns in every country regardless of the economic and social development. The frequent occurrence of food scandals in the world has led the Chinese government to implement several strategies to fortify the food supply system to a high food safety standard. This relies heavily on laboratory testing services but conventional methods for detection of food contaminants and toxicants are limited by sophisticated sample preparation procedures, long analysis time, large instruments and professional personnel to meet the increasing demands. In this review, we have incorporated most of the current and potential rapid detection methods for many notorious food contaminants and toxicants including microbial agents, toxic ions, pesticides, veterinary drugs and preservatives, as well as detection of genetically modified food genes and adulterated edible oil. Development of rapid, accurate, easy-to-use and affordable testing methods could urge food handlers and the public to actively screen for food contaminants and toxicants instead of passively relying on monitoring by the government examination facility. This review also provides several recommendations including how to encourage the public to engage in the food safety management system and provide optimal education and financial assistance that may improve the current Chinese food safety control system.

Early exposure to food contaminants reshapes maturation of the human brain-gut-microbiota axis

Early childhood growth and development is conditioned by the consecutive events belonging to perinatal programming. This critical window of life will be very sensitive to any event altering programming of the main body functions.Programming of gut function, which is starting right after conception, relates to a very well-established series of cellular and molecular events associating all types of cells present in this organ, including neurons, endocrine and immune cells. At birth, this machinery continues to settle with the establishment of extra connection between enteric and other systemic systems and is partially under the control of gut microbiota activity, itself being under the densification and the diversification of microorganisms’ population. As thus, any environmental factor interfering on this pre-established program may have a strong incidence on body functions. For all these reasons, pregnant women, fetuses and infants will be particularly susceptible to environmental factors and especially food contaminants. In this review, we will summarize the actual understanding of the consequences of repeated low-level exposure to major food contaminants on gut homeostasis settlement and on brain/gut axis communication considering the pivotal role played by the gut microbiota during the fetal and postnatal stages and the presumed consequences of these food toxicants on the individuals especially in relation with the risks of developing later in life non-communicable chronic diseases.

Food Safety Risks and Contributing Factors of Cronobacter spp.

Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,and necrotizing enterocolitis in neonates and infants,with neurological sequelae in severe cases.Interest in Cronobacter has increased significantly in recent years due to its high virulence in children.In this review,we summarize the current understanding of the prevalence of Cronobacter species in several important food types.We discuss the response mechanisms enabling persistence in adverse growth con-ditions,as well as its pathogenicity.We emphasize the food safety concerns caused by Cronobacter and subsequent control methods and clinical treatments.

National Food Contamination Monitoring Programmes-Levels of Mercury, Lead and Cadmium in Chinese Foods

Six hundred and thirty-four food samples of six kinds were collected from Beijing,Shanghai, Jiangsu, Sichuan, Jilin and Guangdong areas, China and Hg, Pb, Cd contents were determined. The results showed that their levels in the Chinese foods were low; their levels in meat, egg, milk and fish were generally below the national hygienic standard. The average daily dietary intake of Hg, Pb, Cd were 7.25 μg, 103.77μg and 30.72 μg respectively and they were all less than the ADI established by WHO

Influence of Genista Tinctoria L or Methylparaben on Subchronic Toxicity of Bisphenol A in Rats

Objective To evaluate the influence of an extract of Genista tinctoria L. herba （GT） or methylparaben （MP） on histopathological changes and 2 biomarkers of oxidative stress in rats subchronicly exposed to bisphenol A （BPA）. Methods Adult female Wistar rats were orally exposed for 90 d to BPA （50 mg/kg）, BPA＋GT （35 mg isoflavones/kg） or BPA＋MP （250 mg/kg）. Plasma and tissue samples were taken from liver, kidney, thyroid, uterus, ovary, and mammary gland after 30, 60, and 90 d of exposure respectively. Lipid peroxidation and in vivo hydroxyl radical production were evaluated by histological analysis along with malondialdehyde and 2,3-dihydroxybenzoic acid detection. Results The severity of histopathological changes in liver and kidneys was lower after GT treatment than after BPA or BPA＋MP treatment. A minimal thyroid receptor antagonist effect was only observed after BPA＋MP treatment. The abnormal folliculogenesis increased in a time-dependent manner, and the number of corpus luteum decreased. No significant histological alterations were found in the uterus. The mammary gland displayed specific estrogen stimulation changes at all periods. Both MP and GT revealed antioxidant properties reducing lipid peroxidation and BPA-induced hydroxyl radical generation. Conclusion GT L. extract ameliorates the toxic effects of BPA and is proved to have antioxidant potential and antitoxic effect. MP has antioxidant properties, but has either no effect or exacerbates the BPA-induced histopathological changes.

Colorectal cancer and pollution

The incidence of colorectal carcinoma is increasing in young patients, in contrast to the well established wisdom that it is exclusively diagnosed in patients older than 40 years. In this survey, we examined all possible risk factors, and we recommend a number of measures for early detection in young patients who are at risk of developing this malignant tumor.

鼠伤寒沙门氏菌所致暴发性食物中毒的病原学研究

武汉市某单位因食用奶油糕点引起暴发性食物中毒,患者年龄为2.5～63岁,从患者肛门拭子中,分离出鼠伤寒沙门氏菌。取材78份,其中22例为阳性,分离率为28.2％,对阳性患者进行病原的追踪观察,发现成人病后带菌时间较长,而幼儿病后带菌时间较短,故成人病后的带菌现象是一个值得重视的问题。

Risk Assessment of Mycotoxins Intake through the Consumption of Maize, Peanuts, Rice and Cassava in Côte D’Ivoire

Mycotoxins are secondary metabolites of filamentous fungi that colonize a wide range of crops, including cereals and oilseeds, both in the field and after harvest, especially during storage. Several studies carried out on the occurrence of mycotoxins in crops and their derived products such as maize, peanuts, rice and attieke (cassava product), reported substantial levels of Aflatoxins (AFs), Fumonisins (FBs), Ochratoxin A (OTA) and Zearalenone (ZEA). The aim of the present study was to analyze findings available on Aflatoxins, Ochratoxin A and Fusarium toxins occurrence in maize, peanuts, rice and attieke in order to assess the exposure level and cancers risk in the Ivorian population. References and publications related to OTA in Côte d’Ivoire were searched and selected. Medline/PubMed, Elsevier Bibliographic Databases, BioInfoBank Library, DOAJ (Directory of Open Acess Journal), Australian Journal of Basic and Applied Sciences and https://medwelljournals.com/home.php were used as databases. Data available showed Estimated Daily Intake (EDI) of AFs and OTA were above of their Tolerable Daily Intake (TDI) as recommended by the Joint FAO/WHO Experts Committee on Food Additives through rice, maize, peanut and attieke consumption in Côte d’Ivoire. In addition, there is a veritable incidence of cancers with the abundant and frequent consumption of foods maize, rice, peanuts and attieke. However, maize and rice seemed to be sources of FBs

Nanobody-based immunosensing methods for safeguarding public health

Immunosensing methods are biosensing techniques based on specific recognition of an antigen-antibody immunocomplex,which have become commonly used in safeguarding public health.Taking advantage of antibody-related biotechnological advances,the utilization of an antigen-binding fragment of a heavy-chain-only antibody termed as'nanobody'holds significant biomedical potential.Compared with the conventional full-length antibody,a single-domain nanobody retaining cognate antigen specificity possesses remarkable physicochemical stability and structural adaptability,which enables a flexible and efficient molecular design of the immunosensing strategy.This minireview aims to summarize the recent progress in immunosensing methods using nanobody targeting tumor markers,environmental pollutants,and foodborne microbes.

Natural bioactive substances for the control of food-borne viruses and contaminants in food

Food-borne viruses and contaminants,as an important global food safety problem,are caused by chemical,microbiological,zoonotic,and other risk factors that represent a health hazard.Natural bioactive substances,originating from plants,animals,or microorganisms,might offer the possibility of preventing and controlling foodborne diseases.In this contribution,the common bioactive substances such as polyphenols,essential oils,proteins,and polysaccharides which are effective in the prevention and treatment of food-borne viruses and contaminants are discussed.Meanwhile,the preventive effects of natural bioactive substances and the possible mechanisms involved in food protection are discussed and detailed.The application and potential effects of natural bioactive substances in the adjuvant treatment for food-borne diseases is also described.

Research Progress on Remediation Technology Suitable for Farmland Soil Contaminated by Cd

Cd contamination range of farmland soil in China is wide,which has constituted a major threat for food safety and residents＇ health. Via multi-year development,there are more remediation methods suitable for soil contaminated by Cd among the world,but some methods are only suitable for the contaminated sites and indoor research,and can not be applied in large-range contaminated farmland. We analyze the source of Cd in farmland soil. By combining farmland＇s characteristics,three remediation techniques（ low-absorption crops plantation,soil solidification and phytoremediation） and their effects are analyzed,and the existing problems and research prospects of the above techniques are explored. The research could provide reference for restoring farmland soil contaminated by Cd in China,recovering its production function and enhancing food safety standards.

The Total Diet Study: Changes in Food Safety Since the First TDS

This article discusses what we know about some of the main food safety risks in China. The focus is on role of the China Total Diet Study（TDS） as a tool for food safety risk assessment and the selection of priorities for monitoring. We compare the strengths and weaknesses of the TDS with those of two other major sources of information about food safety and nutrition： the National Food Safety Contamination Monitoring Network（FSCN） and the China Health and Nutrition Survey（CHNS）, showing how the different methods they use produce different but complementary information. We then use an analysis of lead, cadmium and pesticide residues to demonstrate that, despite its shortcomings, the TDS provides the most reliable source of information about the actual dietary intake of harmful substances.

Fish from a polluted lake(Lake Chivero,Zimbabwe):a food safety issue of concern

Objectives:A study to determine food safety hazard status of fish products from Lake Chivero was conducted in selected high density suburbs of Harare.Lake water and fish were tested for E.coli O157:H7,total bacterial,fungal counts,mercury(Hg)and aflatoxin B1(AFB1)to determine contamination levels and assessing human health hazard exposure.Materials and Methods:Membrane filtration method was used to determine E.coli O157:H7 viable counts using CHROM agar.Plate count and Potato dextrose agar were used for determination of total viable bacterial and fungal counts.Concentrations of Hg and AFB1 in fish and water were determined by Atomic Absorption Spectrophotometer and High Performance Liquid Chromatography-Mass Spectrometry.A questionnaire survey was conducted on 136 adult fish consumers to determine the fish consumption patterns to assess hazard exposure against international standards.Results:Significant levels of microbial contamination above international standards in both fish and water were recorded.Mean E.coli O157:H7 counts were 106±10(cfu/cm^(2))in fish and 52±14(cfu/100ml)in water.Mean Log10 TBC were 8.98±0.26(cfu/cm^(2))in fish and 9.05±0.05(cfu/ml)in water.Mean Log10 TFC were 4.83±0.02(cfu/cm^(2))in fish and 4.56±0.03(cfu/ml)in water.Hg and AFB1 were 0.018(μg/kg)and 0.025(μg/kg)in fish and 0.008(μg/kg)and 0.005(μg/kg)in water,both with a hazard quotient(HQ)<1 using CODEX STAN 193-1995 of 2015.Conclusion:Fish and water are contaminated with E.coli O157:H7,contain bacterial and fungal loads above international food safety guidance levels.Fish were caught already contaminated with pathogens together with toxigenic Hg and carcinogenic AFB1 although their concentration levels are within international food safety toxicological levels.Levels of Hg and AFB1 in water were almost double that of fish,implying bio-accumulation occurred in fish.Thus,fish consumers are exposed to food safety hazards and are at risk of contracting foodborne illnesses from consuming contaminated fish.

N-acetyl cysteine alters the genotoxic and estrogenic properties of Alternaria toxins in naturally occurring mixtures

It is unclear if complex mycotoxin mixtures produced by Alternaria spp.act estrogenic and/or genotoxic under physiological conditions,particularly considering the co-occurrence with antioxidants in food.Thus,this study focused on enlightening the impact of N-acetyl cysteine(NAC),as a representative antioxidative SH-donor,on the mentioned toxicological endpoints of the signature Alternaria toxins alternariol(AOH),altertoxin-II(ATX-II)and a complex extract(CE)of an Alternaria alternata culture.Using Ishikawa cells as an in vitro model,we monitored alterations in toxin concentrations by LC-MS/MS,estrogenicity by alkaline phosphatase assays,cytotoxicity by sulforhodamine B assays,genotoxicity by single-cell gel electrophoresis and the transcription of selected genes of interest by quantitative realtime PCR.The results indicate that the strong genotoxic effects of epoxide-carrying perylene quinones such as ATX-II are erased in the presence of NAC.The cellular effects of ATX-II/AOH mixtures are dominated by the genotoxicity of the perylene chinone.In this mixture,AOH regained its estrogenicity when coincubated with NAC.In contrast,NAC treatment of an AOH/CE mixture did not result in a recovery of estrogenicity,but in potentiated anti-estrogenic effects.These findings were in line with gene transcription data,that indicated the aryl hydrocarbon receptor(AhR)to be a prime mediator of Alternaria toxin e induced antagonistic effects towards estrogen receptor signaling.Taken together,further studies on potential endocrine-disruptive properties of non-genotoxic perylene quinones should be a future research priority in the field of these emerging contaminants.

Rice:Reducing arsenic content by controlling water irrigation

Arsenic has long been recognized as a poison.Arsenic in water supplies that are used for both drinking and crop irrigation can expose many people chronically to elevated levels of arsenic.

Assessing global fungal threats to humans

Fungi are an integral part of the earth's biosphere.They are broadly distributed in all continents and ecosystems and play a diversity of roles.Here,I review our current understanding of fungal threats to humans and describe the major factors that contribute to various threats.Among the 140,000 or so known species out of the estimated six million fungal species on Earth,about 10%directly or indirectly threaten human health and welfare.Major threats include mushroom poisoning,fungal allergies,infections of crop plants,food contamination by mycotoxins,and mycoses in humans.A growing number of factors have been identified to impact various fungal threats,including human demographics,crop distributions,anthropogenic activities,pathogen dispersals,global climate change,and/or the applications of antifungal drugs and agricultural fungicides.However,while models have been developed for analyzing various processes of individual threats and threat managements,current data are primarily descriptive and incomplete,and there are significant obstacles to integration of the diverse factors into accurate quantitative assessments of fungal threats.With increasing technological advances and concerted efforts to track the spatial and temporal data on climate and environmental variables;mycotoxins in the feed and food supply chains;fungal population dynamics in crop fields,human and animal populations,and the environment;human population demographics;and the prevalence and severities of fungal allergies and diseases,our ability to accurately assess fungal threats will improve.Such improvements should help us develop holistic strategies to manage fungal threats in the future.

The onset of surface-enhanced Raman scattering for single-particle detection of submicroplastics

Microplastics represent an emerging environmental problem worldwide, raising ecological and food safety concerns. Compared to microplastics, there is growing evidence of an even higher abundance of submicro-and nanoplastics in the environment, but a reliable monitoring method for detecting these smaller-sized plastics is lacking. Herein we presented the application of surface-enhanced Raman scattering(SERS) for this purpose. Particles of polystyrene(PS;600 nm) were used as the probe analyte. Gold nanourchins(Au NU;50 nm),i.e. urchin-shaped nanoparticles with irregular spikes around the core, were used as the SERS-active substrate. The effectiveness of SERS on PS was evaluated at a single-particle level with different numbers of Au NU in order to determine the minimum conditions required for the onset of the SERS effect. Our findings suggest that SERS of a single particle of PS can be induced by as few as 1–5 particles of Au NU, and that the use of excitation wavelength at 785 nm is appropriate to meet the red-shifted surface plasmon resonance of Au NU upon aggregation. These specifications provide additional information for the development of SERS-based tools for detecting plastic particles < 1 μm in food and environmental samples.

Benefits and risks associated with consumption of Great Lakes fish containing omega-3 fatty acids and polychlorinated biphenyls(PCBs)

Introduction Assessment of environmental health effects arising from exposure to multiple substances is often very challenging.This is particularly true when humans are exposed to a mixture that contains both beneficial and harmful substances.A good example relates to the risk and benefits of fish consumption.