Food Safety Assessment Research Articles

Assessment of Food Safety, Knowledge and Practices among Students and Staff at Zarqa University, Jordan

The food safety matter is an issue that is discussed widely, but cases of food poisoning in particular, are still ongoing. This may be associated with person’s level of knowledge and practices on food safety. This current study aimed to evaluate knowledge and practices levels related to food safety and to examine the relationship of some demographic characteristics with knowledge and practices levels related to food safety, as well as the relationship between food safety knowledge and practices among the students and staff members of Zarqa University, Jordan. The study was conducted via a Google form that was set up for this study. 406 subjectsparticipated in the study, where 37.7% were males and 62.3% of the participants were females. Results showed that 90.6% and 75.1% of the participants had a good knowledge and a high level of practices related to food safety, respectively. The findings also showed a significant relationship between age, marital status and the knowledge scores related to food safety, and a significant relationship (P˂ 0.05) between age, gender, marital status and practices related to food safety (P˂ 0.05). Further, a small significant positive relationship between food safety knowledge and food safety practices was found (P˂ 0.05). Overall, it was found that there is a good knowledge level related to food safety and high food safety practice level among the participants. As a result; to achieve an advanced level of knowledge continuing education programs, are required to increase understanding food safety.

Evaluating the food safety and risk assessment evidence-base of polyethylene terephthalate oligomers: A systematic evidence map

BackgroundThe presence of polyethylene terephthalate (PET) oligomers in food contact materials (FCMs) is well-documented. Consumers are exposed through their migration into foods and beverages; however, there is no specific guidance for their safety evaluation. ObjectivesThis systematic evidence map (SEM) aims to identify and organize existing knowledge and associated gaps in hazard and exposure information on 34 PET oligomers to support regulatory decision-making. MethodsThe methodology for this SEM was recently registered. A systematic search in bibliographic and gray literature sources was conducted and studies evaluated for inclusion according to the Populations, Exposures, Comparators, Outcomes, and Study type (PECOS) framework. Inclusion criteria were designed to record hazard and exposure information for all 34 PET oligomers and coded into the following evidence streams: human, animal, organism (non-animal), ex vivo, in vitro, in silico, migration, hydrolysis, and absorption, distribution, metabolism, excretion/toxicokinetics/pharmacokinetics (ADME/TK/PK) studies. Relevant information was extracted from eligible studies and synthesized according to the protocol. ResultsLiterature searches yielded 7445 unique records, of which 96 were included. Data comprised migration (560 entries), ADME/TK/PK-related (253 entries), health/bioactivity (98 entries) and very few hydrolysis studies (7 entries). Cyclic oligomers were studied more frequently than linear PET oligomers. In vitro results indicated that hydrolysis of cyclic oligomers generated a mixture of linear oligomers, but not monomers, potentially allowing their absorption in the gastrointestinal tract. Cyclic dimers, linear trimers and the respective smaller oligomers exhibit physico-chemical properties making oral absorption more likely. Information on health/bioactivity effects of oligomers was almost non-existent, except for limited data on mutagenicity. ConclusionsThis SEM revealed substantial deficiencies in the available evidence on ADME/TK/PK, hydrolysis, and health/bioactivity effects of PET oligomers, currently preventing appropriate risk assessment. It is essential to develop more systematic and tiered approaches to address the identified research needs and assess the risks of PET oligomers.

Taste sensations: the role of sensory analysis in controlling the quality of food products

The aim of the study was to investigate the factors that affect a persons subjective perception of food safety. Normative legal acts and documents regulating society as a whole and food products in particular were used during the study. It was proven that preserving and enhancing the specific sensory properties of a food product by changing its chemical composition using falsification methods, cheaper and less nutritious components, is a dangerous direction in the development of food technologies and the evolution of the food system. This approach can lead to a dissonance between the perception of the product as tasty and its nutritional value, which determines its health-preserving effect. The objective assessment of food safety is currently ensured (or should be ensured) by instrumental methods of quality control of food products, which are used in a system that includes both internal (production) control and external (state veterinary and state sanitary and epidemiological) supervision.

Determinants of Polish young adults' attitudes toward food safety

PurposeDetermine the elements of young adult consumers' attitudes toward food safety using a food safety attitude (FSA) questionnaire and identify the factors influencing them.Design/methodology/approachThis study adopts a descriptive and explanatory perspective to the research problem. Determination of students' attitudes was carried out by direct survey using a questionnaire. The ABC model of attitude was used to construct the statements in the questionnaire. The respondents' answers were analyzed using statistical methods.FindingsThe proposed questionnaire has proven to be a useful tool for assessing food safety attitudes and has identified important new elements in consumers' attitudes. Students' attitudes toward food safety are shaped by sociodemographic and psychosocial factors such as customer type, attitude toward risk, and how they make food purchasing decisions.Research limitations/implicationsInformation about students' attitudes was obtained only from surveys. The survey results provide valuable insights for business practice.Practical implicationsFindings can be used to increase the effectiveness of efforts by various organizations aimed at changing consumer attitudes and behavior and to help understand why consumers implement some food safety behaviors and not others.Social implicationsThe research results will help more effectively target efforts to change consumer attitudes, which could translate into a reduction in cases of illness caused by eating unsafe food or following proper practices when shopping and at the home preparation stage.Originality/valueDevelopment of a reliable tool for the study of attitudes. Identify the new elements of young adult consumers' attitudes and the factors that shape them.

CRISPR-Cas12a Biosensor Array for Ultrasensitive Detection of Unamplified DNA with Single-Nucleotide Polymorphic Discrimination

Quantitative polymerase chain reaction as a powerful tool for DNA detection has been pivotal to a vast range of applications, including disease screening, food safety assessment, environmental monitoring, and many others. However, the essential target amplification step in combination with fluorescence readout poses a significant challenge to rapid and streamlined analysis. The discovery and engineering of the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) technology have recently paved the way for a novel approach to nucleic acid detection, but the majority of current CRISPR-mediated DNA detection platforms are limited by insufficient sensitivity and still require target preamplification. Herein, we report a CRISPR-Cas12a-mediated graphene field-effect transistor (gFET) array, named CRISPR Cas12a-gFET, for amplification-free, ultrasensitive, and reliable detection of both single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) targets. CRISPR Cas12a-gFET leverages the multiturnover trans-cleavage activity of CRISPR Cas12a for intrinsic signal amplification and ultrasensitivity of gFET. As demonstrated, CRISPR Cas12a-gFET achieves a limit of detection of 1 aM for the ssDNA human papillomavirus 16 synthetic target and 10 aM for the dsDNA Escherichia coli plasmid target without target preamplification. In addition, an array of 48 sensors on a single 1.5 cm × 1.5 cm chip is employed to improve data reliability. Finally, Cas12a-gFET demonstrates the capability to discriminate single-nucleotide polymorphisms. Together, the CRISPR Cas12a-gFET biosensor array provides a detection tool for amplification-free, ultrasensitive, reliable, and highly specific DNA detections.

Assessment of food quality and safety among Nigerian school children

Abstract Nutrition is of vital importance in the physical, emotional, and intellectual development of children, for retarded academic performance is not the only risk of lack of good food; various health risks that may deform the body system or result in sickness or death are also, not unconnected to consumption of foods devoid of quality and safety. This article aims to assess the food quality and safety among Nigerian school children. A review of related online free-full articles written in the English language published from 2018 to 2022 was done. A consequent title and abstract review of articles published on food quality and safety, and over 1056 published studies identified, they were visualized, profiled, cleansed, prepared, analyzed, and summarized, of which 36 most relevant articles met the inclusion criteria and were utilized for the review. This study found that providing high-quality and safe foods to children is key to achieving sustainable development goals by 2030, and it is in this quest that tremendous educational and health benefits. We also found that the foods served or sold to children in schools are sometimes of low quality and unsafe to satisfy learners’ esthetic or nutritional needs, which have grave consequences for their physical growth, health status, and academic development. In conclusion, there is a need to train and monitor food handlers on food quality and safety in schools in Nigeria.

Sensitive and rapid sensing of dimetridazole in food and environmental samples using a water-stable luminescent zwitterionic Cd(Ⅱ) metal-organic framework

Dimetridazole (DTZ) is such a significant indicator in food safety assessment that a high priority should be given to it. In this work, a novel three-dimensional Metal-Organic Framework zwitterionic composite, {[CdL2]·Cl2·6H2O} (MOF 1), was synthesized by hydrothermal method and applied as a fluorescence probe for the detection of DTZ. Several crucial factors of the obtained MOF 1, such as structure stability, fluorescence properties, selectivity, sensitivity and reproducibility, were studied in detail. A series of sensing investigations demonstrate extremely specific and ultrafast detection of DTZ via a conspicuous fluorescence quenching (Ksv=8.1374 × 104M−1) from MOF 1 under the optimized conditions. The linear range for quantitative detection of DTZ was 0.0 µM∼40.0 µM with a low limit of detection of 0.012 µM. The fluorescence quenching mechanisms have been explained, being caused by a combination of both competitive absorption and photoinduced electron transfer. DTZ in milk, honey, tap and lake water were successfully determined by this fluorescence probe with quick response, and the recovery rates are 97.4%˜102.6%, which indicates MOF 1 having a tremendous application prospect in the detection of DTZ in food and environmental samples.

Using a value chain framework for food safety assessment of edible offals in Nairobi, Kenya

Edible offals comprise those parts of the animal considered fit for human consumption apart from the skeletal muscle, fat and attached skin. Edible offals form an important source of affordable animal protein and a delicacy for the larger Kenyan market. The offals are mainly traded in the informal markets which supplies at least 80% of the domestic market and where hygiene levels are low. The Meat Control Act Chapter 356, Laws of Kenya (Revised 2012) requires that offals be obtained from an officially declared food animal that has been slaughtered in a licensed slaughterhouse and declared fit for human consumption. According to the Meat Control Act, slaughterhouses in Kenya are classified as either export or local. The latter is subdivided into categories A, B, and C depending on their daily capacity, land size and the area they are authorized to supply meat and meat products. Each export slaughterhouse, category A and B slaughterhouses require a minimum of three meat inspectors to carry out inspection of carcasses and offals. The Directorate of Veterinary Services is the main regulator in Kenya on matters concerning safety of meat at the slaughterhouses. The Director of Veterinary Services appoints meat inspectors and veterinary officers who are responsible for ascertaining the safety of meat and meat products from the slaughterhouses. The meat inspectors also verify that slaughter facilities, staff, processes and equipment conform to food safety requirements. Offals, like carcass meat, should be handled under utmost hygiene conditions to minimize contamination or excessive growth of microorganisms. The current practices in slaughterhouses is that each set of edible offals is packaged separately in either polythene bags, plastic containers, meat transport containers or carriers and dispatched to the market. In some instances, stomachs and intestines are packaged for dispatch together with the lungs and hearts for transportation to distances over 50 km in either refrigerated or non-refrigerated containers or carriers. Some of these practices could compromise the safety of the offals. In this paper, we review the challenges faced in maintaining safety of edible offals especially at the slaughterhouses, distributors and retailers level from regulators' point of view.

Heavy metal concentrations in rice that meet safety standards can still pose a risk to human health

Long-term consumption of rice containing heavy metal(loid)s poses significant risks to public health, which can be scientifically evaluated through food safety assessment. However, spatial variability and uncertainty in exposure parameters are generally neglected in existing food safety assessment standards. This study focused on rice consumption in 32 provinces of China, and extracted 3376 data points of five heavy metal(loid)s (cadmium, arsenic, mercury, lead, and chromium) and two nutrient elements (copper and zinc) from 408 articles. Probability and fuzzy methods were integrated to cope with the spatial variability or uncertainty and more accurately evaluate the risk. The results demonstrated that long-term consumption of rice that meets the national food safety standards still can cause non-negligible health risks, particularly for children and toddlers with chronical exposure. Arsenic and Cd were found to be the most critical elements, which contribute to 64.57% and 22.38% of the overall human health risk, respectively. Fuzzy assessment indicated that the score in northern China is approximately eight folds of that in southern China, indicating that northern rice has lower risks and better nutrition. Our results demonstrate that the food safety standards need to be tailored according to local conditions with more specific receptor parameters and risk acceptance.

Antimicrobial-Resistant Listeria monocytogenes in Ready-to-Eat Foods: Implications for Food Safety and Risk Assessment.

Antimicrobial resistance is an existential threat to the health sector, with far-reaching consequences in managing microbial infections. In this study, one hundred and ninety-four Listeria monocytogenes isolates were profiled for susceptibility using disc diffusion techniques. Possible foodborne listeriosis risk associated with ready-to-eat (RTE) foods (RTEF) and the risk of empirical treatment (EMPT) of L. monocytogenes infections, using multiple antimicrobial resistance indices (MARI) and antimicrobial resistance indices (ARI), respectively, were investigated. Twelve European Committee on Antimicrobial Susceptibility Testing (EUCAST) prescribed/recommended antimicrobials (EPAS) for the treatment of listeriosis and ten non-prescribed antimicrobials (non-PAS)] were evaluated. Antimicrobial resistance > 50% against PAs including sulfamethoxazole (61.86%), trimethoprim (56.19%), amoxicillin (42.27%), penicillin (41.24%), and erythromycin (40.21%) was observed. Resistance > 50% against non-PAS, including oxytetracycline (60.89%), cefotetan (59.28%), ceftriaxone (53.09%), and streptomycin (40.21%) was also observed. About 55.67% and 65.46% of the isolates had MARI scores ranging from 0.25-0.92 and 0.30-0.70 for EPAs and non-PAs, respectively. There was a significant difference (p < 0.01) between the MARI scores of the isolates for EPAs and non-PAs (means of 0.27 ± 0.21 and 0.31 ± 0.14, respectively). MARI/ARI scores above the Krumperman permissible threshold (>0.2) suggested a high risk/level of antimicrobial-resistant L. monocytogenes. The MARI risks of the non-success of empirical treatment (EMPT) attributed to EPAs and non-PAs were generally high (55.67% and 65.463%, respectively) due to the antimicrobial resistance of the isolates. MARI-based estimated success and non-success of EMPT if EUCAST-prescribed antimicrobials were administered for the treatment of listeriosis were 44.329% and 55.67%, respectively. The EMPT if non-prescribed antimicrobials were administered for the treatment of listeriosis was 34.53% and 65.46%, respectively. This indicates a potentially high risk with PAs and non-PAs for the treatment of L. monocytogenes infection. Furthermore, ARI scores ≤ 0.2 for EPAs were observed in polony, potato chips, muffins, and assorted sandwiches, whereas ARI scores for non-PAs were >0.2 across all the RTE food types. The ARI-based estimate identified potential risks associated with some RTE foods, including fried fish, red Vienna sausage, Russian sausage, fruit salad, bread, meat pies, fried chicken, cupcakes, and vetkoek. This investigation identified a high risk of EMPT due to the presence of antimicrobial-resistant L. monocytogenes in RTE foods, which could result in severe health consequences.

Novel risk assessment model of food quality and safety considering physical-chemical and pollutant indexes based on coefficient of variance integrating entropy weight

Food safety is important for sustainable social and economic development and people's health. The traditional single risk assessment model is one-sided to the weight distribution of food safety factors including physical-chemical and pollutant indexes, which cannot comprehensively assess food safety risks. Therefore, a novel food safety risk assessment model combining the coefficient of variation (CV) integrating the entropy weight (EWM) (CV-EWM) is proposed in this paper. The CV and the EWM are used to calculate the objective weight of each index with physical-chemical and pollutant indexes effecting food safety, respectively. Then, the weights determined by the EWM and the CV are coupled by the Lagrange multiplier method. The ratio of the square root of the product of two weights and the weighted sum of the square root of the product are regarded as the combined weight. Thus, the CV-EWM risk assessment model is constructed to comprehensively assess the food safety risk. Moreover, the Spearman rank correlation coefficient method is used to test the compatibility of the risk assessment model. Finally, the proposed risk assessment model is applied to evaluate the quality and safety risk of sterilized milk. By analyzing the attribute weight and comprehensive risk value of physical-chemical and pollutant indexes effecting the sterilized milk quality, the results show that this proposed model can scientifically obtain the weight of physical-chemical and pollutant indexes to objectively and reasonably evaluate the overall risk of food, which has certain practical value for discovering the influencing factors of risk occurrence to risk prevention and control of food quality and safety.

Food Safety Knowledge and Practices among Household Food Handlers in Mangweni Village of Mpumalanga Province in South Africa

The study aimed to assess food safety knowledge and practices among household food handlers in Mangweni village, South Africa. A quantitative cross-sectional study was conducted on 120 households selected using systematic random sampling. Women over 18 years of age who were responsible for preparing food in the selected households were eligible for inclusion in the study. A simple random sample was used to select 15 from the 120 food handlers to observe their food handling practices. SPSS version 27 was used to run the descriptive statistics. Food handlers were between 19 and 43 years of age, with a mean age of 29.9 ± 1.39. Most food handlers had high school (58.3%) or university or college (33.3%) educations. Levels of food safety knowledge were found to be poor (44.5%), good (53.9%), and excellent (1.6%). Our findings show the need for an intervention to improve food safety knowledge and practices among food handlers.

Checklist to assess food safety when handling home enteral nutrition.

Identifying food safety risks when handling enteral formulations at home is important to restore and maintain the health of patients. Therefore, this study developed and validated a food safety assessment checklist for handling home enteral nutrition (HEN). This methodological study developed a checklist based on a literature review and interviews with food safety professionals. The content validation, which was conducted by food safety and enteral feeding experts, assessed the relevance, clarity, and simplicity of the checklist using the content validity index of items (CVI-I), categories (CVI-C), and the entire instrument (CVI-EI). Each item was rated as either essential, necessary, or recommended according to the risk in relation to foodborne diseases. The Food Safety for Handling Home Enteral Nutrition checklist (FSHEN checklist) that was developed includes 40 items and the following eight categories: physical structure; cleaning of facilities, equipment, furniture, and utensils; pests and waste; water supply; food handlers; ingredients and packaging; handling of enteral formulations; and the bottling and storage of enteral formulations. The CVI-EI was above the recommendation (≥0.93) for the three assessed criteria, as was the CVI-C in terms of clarity (≥0.95), relevance (≥0.98), and simplicity (≥0.84). A total of 52.5% of the items were rated as essential, 32.5% as necessary, and 15% as recommended. The FSHEN checklist is relevant, clear, and easy to use. It can help health professionals and individuals working in the field to assess and prioritize items to improve food safety in the management of HEN.

Optimization and evaluation of a multiplex PCR assay for detection of Staphylococcus aureus and its major virulence genes for assessing food safety.

Staphylococcus aureus is a natural commensal microflora of humans which causes opportunistic infections due to its large arsenal of exotoxins, invasion, immune evasion, and antibiotic resistance mechanisms. The primary goal of this study is to develop a multiplex PCR (mPCR) assay for simultaneous detection of Staphylococcus aureus (nuc) and its virulence genes coding for prominent exotoxins namely alpha hemolysin (hla), enterotoxins A (sea), enterotoxin B (seb), toxic shock syndrome toxin (tsst-1), and the gene coding for methicillin resistance (mecA). A competitive internal amplification control (IAC) was included in the assay to exclude the false negative outcomes. Highly specific primer pairs were designed for the target genes using in silico resources. At the outset, monoplex PCRs were standardized using reference S. aureus strains. Primer specificity to the target genes was authenticated through restriction digestion analysis of amplified PCR products. Multiplex PCR was optimized in increments of one gene starting with nuc and IAC amplified simultaneously using one pair of primers (nuc) in a competitive manner. The mPCR assay was found to be highly sensitive with a detection limit of ~10 CFUs per reaction for pure cultures. Multiplex PCR assay was further evaluated on the retail and processed food samples to test the prevalence of S. aureus and study their exotoxin profiles. Of the 57 samples examined, 13 samples (22.80%) were found to be contaminated with S. aureus whose DNA was extracted after a 6-h enrichment period. Among these, a high percentage of hemolytic and enterotoxin A positive strains were encountered. The mPCR assay developed in this study would be a useful tool for rapid and reliable monitoring of S. aureus for food quality testing and from clinical infections.

Portable Smartphone Platform Based on Aggregation-Induced Enhanced Emission Carbon Dots for Ratiometric Quantitative Sensing of Fluoride Ions.

The development of an instrument-free, on-site, real-time, sensitive, and visualized fluoride-ion (F-) content rapid detection strategy is crucial to ensuring the health of the population. Smart microdevices that are portable, directly read, and easy to operate have recently attracted much attention. Herein, a ratiometric fluorescent probe (AA-CDs@[Ru(bpy)3]2+)-based smartphone sensing platform was developed for the detection of F-. The red fluorescent ruthenium bipyridine [Ru(bpy)3]2+ molecule was chosen as the reference signal, and the carbon dots (AA-CDs) with Al3+ aggregation-induced enhanced emission (AIE) were designed as the response signal. The ratiometric probe fluorescence changed continuously from red to cyan in response to different concentrations of F-, and the red-green-blue (RGB) channel values of the fluorescence image were extracted through the smartphone color recognition application (APP). There was a linear relationship between the blue-red (B/R) ratio and the F- concentration, with a limit of detection (LOD) of 1.53 μM, far below the allowable content of F- in drinking water prescribed by the World Health Organization. The F- content was rapidly detected on-site with satisfactory repeatability and relative standard deviation using several water and toothpaste samples as the real sample. The platform features low cost, portability, easy operation, and good stability, selectivity, and repeatability, which provides a powerful tool for the visual quantitative detection of smartphone-based microsensing platforms possibly in the fields of environmental protection, diagnosis, and food safety assessment.

Extracting Tissue Optical Properties and Detecting Bruised Tissue in Pears Quickly and Accurately Based on Spatial Frequency Domain Imaging and Machine Learning.

Recently, Spatial Frequency Domain Imaging (SFDI) has gradually become an alternative method to extract tissue optical properties (OPs), as it provides a wide-field, no-contact acquisition. SFDI extracts OPs by least-square fitting (LSF) based on the diffuse approximation equation, but there are shortcomings in the speed and accuracy of extracting OPs. This study proposed a Long Short-term Memory Regressor (LSTMR) solution to extract tissue OPs. This method allows for fast and accurate extraction of tissue OPs. Firstly, the imaging system was developed, which is more compact and portable than conventional SFDI systems. Next, numerical simulation was performed using the Monte Carlo forward model to obtain the dataset, and then the mapping model was established using the dataset. Finally, the model was applied to detect the bruised tissue of 'crown' pears. The results show that the mean absolute errors of the absorption coefficient and the reduced scattering coefficient are no more than 0.32% and 0.21%, and the bruised tissue of 'crown' pears can be highlighted by the change of OPs. Compared with the LSF, the speed of extracting tissue OPs is improved by two orders of magnitude, and the accuracy is greatly improved. The study contributes to the rapid and accurate extraction of tissue OPs based on SFDI and has great potential in food safety assessment.

The continuous on-line leaching method coupled to inductively coupled plasma mass spectrometry for risk assessment of food safety and for sourcing of elements: a tutorial review

The continuous on-line leaching method is comparable to batch methods for assessment of food safety but allows sourcing of elements.

Rats' liver morphological features under conditions of different supply with vitamins and minerals

The current practice of novel food safety assessment in the Russian Federation involves toxicological studies on the alimentary model of adaptation potential reduction of laboratory animals. Since vitamin and mineral deficiency can affect the size of structural elements of tissues, an objective estimation of the results obtained using this model is possible when determining the range of fluctuations of the studied morphometric parameters under conditions of different essential substances' supply, as well as under conditions of simulated toxic effects on the background of the corresponding supply. The purpose of the research was to investigate the morphological and morphometric features of the liver under the influence of reduced intake of vitamins and mineral elements in the combination with toxic effects of various nature, during growth and puberty of male Wistar rats. Material and methods. The article analyzed data of 4 model experiments on 140 animals that received semi-synthetic casein diet with different supply of vitamins B1, B2, B3, B6 and mineral elements Fe3+ and Mg2+, as well as data of 2 experiments on 180 animals with simulated toxic load of cadmium (Cd2+) salts and carbon tetrachloride. The animals were ~95 days old at the time of sampling, the duration of the experiments was ~65 days. For the analysis we used data on rats' body weight on the day of material sampling, absolute and relative liver weight, hepatocyte diameter, nucleus diameter and hepatocyte cytoplasm size in the central and peripheral zones of hepatic lobules. A total of 200 cells were analyzed in each group of animals. In accordance with the study design, all quantitative traits of the groups that received diets with an essential nutrient supply ranging from 75 to 2% were compared with the group that received a complete diet (100%). Results. Morphometric examination of hepatocytes revealed a linear decrease in the size of cell structural elements in the series of reducing the content of essential micronutrients in the diet. Under the conditions of 2-4% vitamin and mineral supply, cell and nucleus diameters as well as cytoplasm size were by ~16.8, 12.6 and 21.1% (p<0.05) lower respectively than in rats with optimal supply of these substances; under the conditions of 9-19% supply were by ~9.2, 9.7 and 8.7% lower (p<0.05); higher levels of supply caused reduction of hepatocyte, nucleus and cytoplasm sizes in a range not exceeding 5% (p>0.05). When comparing the size of hepatocytes of rats subjected to toxic load with the hepatocytes of rats referred to the reference standard, an increase in the size of hepatocytes under the action of carbon tetrachloride by 17.4% (p<0.05) on average and under the action of cadmium salts by 4.6% (p<0.05) was noted. Conclusion. Based on the analysis of liver morphological and morphometric studies' data, there were established sizes of hepatocytes structural elements in the rats kept on diets with decreasing supply with B group vitamins, iron and magnesium salts; the linear decrease in the sizes of structural elements of hepatocytes in the series of reduction of B group vitamins, iron and magnesium intake was revealed. Toxic exposures to carbon tetrachloride and cadmium salts against the background of a 19-30-75% supply with essential substances led to an increase in the hepatocytes size, the correlation between the degree of toxicant exposure and the supply level is not significant.

Sensitive microscale thermophoresis assay for rapid ochratoxin A detection with fluorescently labeled engineered aptamer.

Ochratoxin A (OTA) is a widespread mycotoxin that causes contamination in a variety of foodstuffs and environments, inducing great health risks to humans and animals. Rapid and sensitive detection of OTA is necessary for food safety, environmental health, and risk assessment. Herein, we report an aptamer microscale thermophoresis (MST) assay for OTA, with the unique merits of ratiometric analysis, rapid measurement, simple operation, high sensitivity, low sample consumption, and high throughput. A fluorescein (FAM)-labeled high-affinity DNA aptamer with a G-quadruplex and duplex structure was used as the recognition element for OTA, and MST, which measures the fluorescence responses of the sample solution inside capillaries to a mild temperature increase generated by infrared laser heating, was employed for signal generation. Upon OTA binding, the FAM-labeled aptamer probe underwent changes in conformation and stability, and the bound and unbound aptamer probes showed significant differences in their MST signals. To achieve sensitive detection of OTA with a large signal change, we systematically characterized aptamers with different stem lengths, which had large effects on the MST responses of the aptamer probes to OTA. We found that a 32-mer aptamer with FAM label at the 3' end gave a sensitive MST response to OTA, allowing OTA detection within seconds with a detection limit of 0.98 nM under optimal experimental conditions. This aptamer MST assay shows potential in real sample analysis and broad applications.

Red Amaranth (Amaranthus tricolor L.) Irrigated with Domestic Sewage Wastewater as a Source of Irrigation: Environmental Food Security and Safety Assessment Perspectives through Acute and Sub- Acute Toxicity Study

Water deficiency is one of the main factors for limiting sustainable agricultural development in most arid and semi-arid regions. There is a gradual decline in the availability of fresh water to be used for irrigation in developing countries like India. Sewage farming is quite common in all urban areas in India. The effect of its direct and long-term use for irrigation needs a thorough study. However, there is increasing concern about food safety and health risks, hence, a case study was undertaken to understand the long-term effect of domestic sewage wastewater irrigation on heavy metal concentrations in soil and plants. The study reveals the mineral and heavy metal composition of irrigated domestic sewage wastewater and it has been compared with the well water irrigated in the rural area, soil parameters and also the mineral and heavy metal composition of a cultivated plant, Amaranthus tricolor L. Transfer factor (TF) was calculated to understand the extent of risk and associated hazard due to wastewater irrigation and the consequence of heavy metals accumulation in the edible portion of experimented vegetables. The present study was carried out to assess the potential toxicity of acetone extract of A. tricolor with some essential parameters such as haematological and biochemical parameters, liver and kidney weight and their histopathological study. After conducting in vivo acute and subchronic toxicity experiments using the rat model, there was no toxicity or mortality observed between domestic sewage water and well water irrigated to red amaranth, A. tricolor.