The concentration of aflatoxin M1 in raw and pasteurized milk: A worldwide systematic review and meta-analysis

Prevalence and concentration of mycotoxins in bovine feed and feed components: A global systematic review and meta-analysis

Mycotoxins are secondary metabolites produced by fungi and identified as contaminants in animal feed. They have potentially harmful effects, including carcinogenicity, mutagenicity, and repro-toxicity in animals and humans. As a result of climate change, there is the potential for a change in the prevalence and concentration of mycotoxins in animal feed components. This necessitates an assessment of the present and emerging threats to the food supply chain from mycotoxins. This systematic review and meta-analysis study synthesised studies on mycotoxin contamination and prevalence in cattle feed components. The studies were collected from scientific databases Web of Knowledge, Scopus, and Embase between 2011 and 2022. The meta-analysis synthesised 97 studies on the prevalence and the concentration of aflatoxins, ochratoxin A, deoxynivalenol, zearalenone, fumonisin and T-2/HT-2 toxins in feed components. Aflatoxin was highly prevalent (59 %), with a concentration of 2.58-3.92 μg kg-1 in feed components. Ochratoxin A had a global prevalence of 31 % with a concentration of 5.56-12.41 μg kg-1. Deoxynivalenol had a global concentration of 233.17-327.73 μg kg-1 and a prevalence of 74 %. Zearalenone had a prevalence of 70 % and a concentration of 42.47-66.19 μg kg-1. The concentration and prevalence of fumonisins was 232.19-393.07 μg kg-1 and 65 %, respectively. The prevalence and concentration of T-2/HT-2 toxins were 45 % and 23.54-35.12 μg kg-1, respectively. The synthesised concentration of the mycotoxins in the overall feed components was lower than the regulated and guidance values set by the European Union. However, in a few cases, the 95th percentile exceeded these concentration values due to high levels of uncertainty attributed to lower sample size, and thus, need to be considered while conducting risk assessments. The study highlights climates and regions likely to be conducive to the emergence of mycotoxin risk, especially considering the potential influences of climate change.

The prevalence and concentration of aflatoxins in beers: a global systematic review and meta-analysis and probabilistic health risk assessment

Mycotoxins have been identified as considerable contaminants in beer. The current investigation's concentration and prevalence of aflatoxins (AFs) in beer were meta-analyzed. The health risk of consumers was estimated through MOEs in the Monte Carlo simulation (MCS) model. The rank order of AFs in beer based on pooled prevalence was AFB1 (26.00%) > AFG1 (14.93%) > AFB2 (7.69%) > AFG2 (7.52%), In addition, the rank order of AFs in beer based on their pooled concentration was AFG1 (0.505 µg/l) > AFB1 (0.469 µg/l) > AFB2 (0.134 µg/l) > AFG2 (0.071 µg/l). The prevalence and concentration of AFs in beer in Malawi were higher than in other countries. The health risk assessment shows consumers in all countries, especially Malawi, Brazil, and Cameroon, are exposed to unacceptably health risks (MOEs <10,000). It is recommended to monitor levels of AFs in beer efficiently and implement control plans in order to decrease health risk of exposed population.

Studies of Mycotoxins in Medicinal Plants Conducted Worldwide over the Last Decade: A Systematic Review, Meta-Analysis, and Exposure Risk Assessment

BACKGROUND

Mycotoxins have been reported to be present in medicinal plants. With the growing usage of medicinal plants, contamination of mycotoxins has emerged as one of the biggest threats to global food hygiene and ecological environment, posing a severe threat to human health.

PURPOSE

This study aimed to determine the mycotoxin prevalence and levels in medicinal plants and conduct a risk assessment by conducting a systematic review and meta-analysis.

METHODS

A thorough search on Web of Science and PubMed was conducted for the last decade, resulting in 54 studies (meeting the inclusion criteria) with 2829 data items that were included in the meta-analysis.

RESULTS

The combined prevalence of mycotoxins in medicinal plants was 1.7% (95% confidence interval, CI = 1.1% - 2.4%), with a mean mycotoxin concentration in medicinal plants of 3.551 µg/kg (95% CI = 3.461 - 3.641 µg/kg). Risk assessment results indicated that aflatoxins and ochratoxin A found in several medicinal plants posed a health risk to humans; additionally, emerging enniatins exhibited possible health risks.

CONCLUSION

Therefore, the study underlines the need for establishing stringent control measures to reduce the severity of mycotoxin contamination in medicinal plants.

Milk-derived exosome nanovesicles: recent progress and daunting hurdles

Raw milk is the foundation of quality and safety in the dairy industry, and improving milk source management is the fundamental guarantee. Milk-derived exosomes (MDEs) are nanoscale information transfer molecules secreted by mammary cells with unique content and high stability, which can be used not only as potential markers to analyze key traits of lactation, reproduction, nutrition and health of animals, but also help farm managers to take timely interventions to improve animal welfare, milk quality, and functional traits. Our review first outlines the latest advances in MDEs isolation and purification, compositional analysis and characterization tools. We then provide a comprehensive summary of recent applications of MDEs liquid biopsy in breed selection, disease prevention and control, and feeding management. Finally, we evaluate the impact of processing on the stability of MDEs to offer guidance for dairy production and storage. The limitations and challenges in the development and use of MDEs markers are also discussed. As a noninvasive marker with high sensitivity and specificity, the MDEs-mediated assay technology is expected to be a powerful tool for measuring cow health and raw milk quality, enabling dynamic and precise regulation of dairy cows and full traceability of raw milk.

Occurrence and risk characterization of aflatoxin M1 in milk samples from southeastern Iran using the margin of exposure approach

This study aimed to investigate Aflatoxin-M1 (AFM1) contamination in pasteurized and raw milk samples consumed in Kerman and Rafsanjan in southeastern Iran. In this cross-sectional study, a total of 100 samples of raw (n = 67) and pasteurized (n = 33) milk were randomly collected from retail stores, supermarkets, and milk transport tankers in the winter of 2020 and the summer of 2021. The level of AFM1 contamination in the collected samples was evaluated by high-performance liquid chromatography with fluorescence detection (HPLC-FD). AFM1 was detected in 95% of samples and its median concentration was 17.38 ng/L. The median concentration of AFM1 in the pasteurized milk samples (24.89 ng/L) was significantly higher than in the raw milk samples (13.54 ng/L). The AFM1 contamination level in 20% (raw = 13% and pasteurized = 7%) of the samples was higher than the maximum permitted level (MPL) recommended by the European Union (i.e., 50 ng/L), whilst 4% (raw = 3% and pasteurized = 1%) of the samples was higher than the Iranian maximum standard limit (i.e., 100 ng/L). The hazard index (HI) was higher than 1 in 16%, 18%, and 35% of total milk samples for men, women, and children, respectively. The AFM1 contamination level in the milk samples collected in southeastern Iran was worrying. The margin of exposure (MoE) values were lower than 10,000 for children. Because aflatoxins are among the most potent carcinogens known, prevention of milk contamination in all stages from the farm to the table can considerably reduce the community's exposure to AFM1 and its consequent health risks.

Biomarkers and biosensors for early cancer diagnosis, monitoring and prognosis

Cancers continue to be of major concern due to their serious global socioeconomic impact, apart from the continued increase in the incidence of various cancer types. A major challenge that this disease poses is due to the low "early detection" rates which limit the therapeutic outcomes for the affected individuals. Current research has highlighted the discovering biomarkers that help in early cancer detection and the development of technologies for the detection and quantification of such biomarkers. Biomarkers range from proteins to nucleic acids, and can be specific to a particular cancer type. Detection and quantification of such biomarkers at low levels from biological samples is being made possible by the advent of developing biosensors and by using biomedical engineering technologies such as tumor-on-a-chip models. Here, we present biomarkers that can be helpful for the early detection of breast, colorectal, esophageal, lung, liver, ovarian, and prostate cancer. In addition, we discuss the potential of circulating tumor cell DNA (ctDNA) as an early diagnostic marker. Finally, biosensors available for the detection of cancer biomarkers, which is a recent advancement in this area of research, are discussed.

Review, meta-analysis and carcinogenic risk assessment of aflatoxin M1 in different types of milks in Iran

REVIEWS

Despite in recent decades, several studies on the concentration of aflatoxins M1(AFM1) in various milks have been studied, as we know, no systematic review, meta-analysis and carcinogenic risk assessment study was conducted in Iran till now.

OBJECTIVES

In this study, a systematic review was conducted to collect, meta-analysis and carcinogenic risk assessment of the quantitative data regarding the prevalence and concentration of AFM1 in several types of milk produced in Iran.

CONTENT

In our study, the concentration and prevalence of AFM1 in different types of milk (Raw, pasteurized, and UHT) from 113 original articles in Iran using searching the Web of Science, PubMed, Scopus, Science Direct and Google Scholar (in Persian and English) databases from 2002 to august 2021 were collected. The concentration of AFM1 was meta-analyzed using the random effect model (REM) based on type of milk (raw, pasteurized and UHT) subgroups and Monte Carlo simulation (MCS) approach was used to assess safety risks and investigate carcinogenic effects of AFM1 using Crystal-Ball software (Version 11.1.3, Oracle, Inc., USA).

SUMMARY AND OUTLOOK

The 113 original article (In English and Persian) were included in this review. Meta-analysis indicated lower and upper of AFM1 in subgroups of raw, pasteurized and UHT milk in Iran was 9, 720, 2.7, 230.2, 19.23, and 221.6 ng/kg respectively. The Point estimate for carcinogenic risk of AFM1 showed as result of age increasing, the carcinogenic risk of Aflatoxin M 1 decreases and concentration of Aflatoxin M1 (ng/liter), plays the most effective role in carcinogenic risk of AFM1.

CONCLUSION

The presence of AFM1 in milk and its products due to its high toxicity and carcinogenic properties is a public health concern that the results show that the risk of carcinogenesis is higher at younger ages (less than 20 years). As a result, there is a strong association between consumption of raw milk, pasteurized milk and UHT and the risk of cancer in children and adults in Iran.

Prevalence and concentration of Aflatoxin M1 in human breast milk in sub-Saharan Africa: a systematic review and meta-analysis, and cancer risk assessment

This study aimed to assess the prevalence, concentration of AFM1 in human breast milk, and to determine the risk of cancer for infants in sub-Saharan Africa. A systematic literature search was performed using PubMed, CINAHL, Web of science, global health, Cochrane, and Google Scholar electronic databases. A random-effects model was used to estimate the pooled prevalence and concentration of AFM1 in breast milk. The meta-analysis of 8 articles containing 9 studies showed the pooled prevalence of AFM1 in breast milk to be 56.18% (95% CI: 29.65-82.71) and the pooled concentration to be 31.12 ng/L (95% CI: 25.97-36.25). The cancer risk assessment indicated for both male and female 1-month infants in Sierra Leone (HI > 1) is high, and all the rest of the infants are free of risk (HI < 1). The pooled prevalence and mean concentration of AFM1 in breast milk is high. Monitoring of AFB1 concentration of commonly used foods will be of high value in reducing the burden of AFM1.

Isolation, Identification, and Characterization of the Native Yeast Strains from Homemade Cheese to Assess their Eliminating Impact on the Aflatoxin B1 and M1 of the Simulated Gastrointestinal Fluid

Background

The occurrence of aflatoxins in food products is a silent threat to human health worldwide. A range of strategies has been introduced to address the bioavailability of aflatoxins, which are considered microbial tools to provide a low-cost and promising approach.

Objectives

The present study focused on the separation of yeast strains from the homemade cheese rind layer to investigate the ability of native yeasts to eliminate AB1 and AM1 from simulated gastrointestinal fluids.

Material and Methods

Homemade cheese samples were prepared from different locations in Tehran provinces and yeast strains were isolated and identified through the biochemical methods and molecular analysis of internal transcribed spacer and D1/D2 domain of 26S rDNA regions. Isolated strains were screened using simulated gastrointestinal fluids, and the ability of yeast strains to absorb aflatoxin was evaluated.

Results

Out of 13 strains, 7 yeast strains were not affected by 5 ppm AFM1 while 11 strains did not show any significant response to 5 mg.L^-1 (ppm) of AFB1. On the other hand, 5 strains were able to successfully tolerate 20 ppm AFB1. Candidate yeasts showed different abilities to remove aflatoxins B1 and M1. In addition, C. lusitaniae, G. geotrichum, G. candidum, and C. sanyaensis exhibited a significant ability to detoxify aflatoxins from the gastrointestinal fluid, respectively.

Conclusion

Our data suggest that yeast communities with essential effects on the quality of homemade cheese appear to be precise candidates for the potential elimination of aflatoxins from the gastrointestinal fluid.

Effects of chronic low-dose aflatoxin B1 exposure in lactating Florida dairy goats

In the past few years there has been a growing trend in the prevalence of aflatoxins, attributable to climate change, in substances destined for animal feeding, together with an increase in dairy product consumption. These facts have triggered great concern in the scientific community over milk pollution by aflatoxin M₁. Therefore, our study aimed to determine the transfer of aflatoxin B₁ from the diet into milk as AFM₁ in goats exposed to different concentrations of AFB₁, and its possible effect on the production and serological parameters of this species. For this purpose, 18 goats in late lactation were divided into 3 groups (n = 6) and exposed to different daily doses of aflatoxin B₁ (T1 = 120 µg; T2 = 60 µg, and control = 0 µg), during 31 d. Pure aflatoxin B₁ was administered 6 h before each milking in an artificially contaminated pellet. The milk samples were taken individually in sequential samples. Milk yield and feed intake were recorded daily, and a blood sample was extracted on the last day of exposure. No aflatoxin M₁ was detected, either in the samples taken before the first administration, or in the control group ones. The aflatoxin M₁ concentration detected in the milk (T1 = 0.075 µg/kg; T2 = 0.035 µg/kg) increased significantly on a par with the amount of aflatoxin B₁ ingested. The amount of aflatoxin B₁ ingested did not have any influence on aflatoxin M₁ carryover (T1 = 0.066% and T2 = 0.060%), these being considerably lower than those described in dairy goats. Thus, we concluded that the concentration of aflatoxin M₁ in milk follows a linear relationship with respect to the aflatoxin B₁ ingested, and that the aflatoxin M₁ carryover was not affected by the administration of different aflatoxin B₁ doses. Similarly, no significant changes in the production parameters after chronic exposure to aflatoxin B₁ were observed, revealing a certain resistance of the goat to the possible effects of that aflatoxin.

Pasteurized milk quality in Brazil: a cross-sectional study over five years

This research communication delineates the quality of pasteurized cow milk sold in Brazil from 2015 to 2020. A cross-sectional study was performed gathering 1749 samples, which were evaluated for microbiological and physicochemical parameters, including Salmonella spp., total and thermotolerant coliforms, freezing point, alkaline phosphatase and lactoperoxidase. The proportion of compliant and non-compliant samples was compared through the years and jurisdiction of the inspection services. Interactions between the design and response variables were assessed by log-linear analysis. Overall, a considerable non-conformity rate (12%) was found for at least one microbiological or physicochemical parameter. Post-pasteurization contamination by coliforms was the major challenge for dairy industries. Notably, the non-compliance rate for freezing point increased during the SARS-CoV-2 pandemic. In addition, the ability to comply was linked to the type of inspection service. Thus, it is suggested that the SARS-CoV-2 pandemic is affecting the dairy industries in Brazil, and we strengthen the need for more studies monitoring the quality of milk over the years, which could assist industries and regulatory agencies to ensure the compliance of pasteurized milk.

Lactic Acid Bacteria as Potential Agents for Biocontrol of Aflatoxigenic and Ochratoxigenic Fungi

Aflatoxins (AF) and ochratoxin A (OTA) are fungal metabolites that have carcinogenic, teratogenic, embryotoxic, genotoxic, neurotoxic, and immunosuppressive effects in humans and animals. The increased consumption of plant-based foods and environmental conditions associated with climate change have intensified the risk of mycotoxin intoxication. This study aimed to investigate the abilities of eleven selected LAB strains to reduce/inhibit the growth of Aspergillus flavus, Aspergillus parasiticus, Aspergillus carbonarius, Aspergillus niger, Aspergillus welwitschiae, Aspergillus steynii, Aspergillus westerdijkiae, and Penicillium verrucosum and AF and OTA production under different temperature regiments. Data were treated by ANOVA, and machine learning (ML) models able to predict the growth inhibition percentage were built, and their performance was compared. All factors LAB strain, fungal species, and temperature significantly affected fungal growth and mycotoxin production. The fungal growth inhibition range was 0-100%. Overall, the most sensitive fungi to LAB treatments were P. verrucosum and A. steynii, while the least sensitive were A. niger and A. welwitschiae. The LAB strains with the highest antifungal activity were Pediococcus pentosaceus (strains S11sMM and M9MM5b). The reduction range for AF was 19.0% (aflatoxin B1)-60.8% (aflatoxin B2) and for OTA, 7.3-100%, depending on the bacterial and fungal strains and temperatures. The LAB strains with the highest anti-AF activity were the three strains of P. pentosaceus and Leuconostoc mesenteroides ssp. dextranicum (T2MM3), and those with the highest anti-OTA activity were Leuconostoc paracasei ssp. paracasei (3T3R1) and L. mesenteroides ssp. dextranicum (T2MM3). The best ML methods in predicting fungal growth inhibition were multilayer perceptron neural networks, followed by random forest. Due to anti-fungal and anti-mycotoxin capacity, the LABs strains used in this study could be good candidates as biocontrol agents against aflatoxigenic and ochratoxigenic fungi and AFL and OTA accumulation.

Decrease in Aflatoxin M1 Concentration in Milk during Cholesterol Removal by Application of β-Cyclodextrin

Approximately one-third of humankind is chronically exposed to the carcinogenic aflatoxin M1 contained in milk. As β-cyclodextrin is frequently used in the food industry, its effect on aflatoxin M1 concentration was investigated during cholesterol removal from milk due to the similarity among the physicochemical properties of aflatoxin M1 and cholesterol. Moreover, the elimination of cholesterol using β-cyclodextrin has been successfully applied in many studies without any substantial effect on the quality of the treated milk. Therefore, milk samples were spiked with aflatoxin M1 within the range from 0.20 to 2.00 µg/kg, and cholesterol removal was carried out by 2.0% (w/w) β-cyclodextrin addition, as this concentration is enough for the sufficient removal of cholesterol. It was found that the mean cholesterol concentration decreased by 92.3%, while the aflatoxin M1 concentration decreased to 0.53 ± 0.04 µg/kg, i.e., by 39.1% after treatment (n = 2). This mitigation procedure itself is easy and inexpensive and thus is fully applicable with a high potential for complete decontamination of aflatoxin M1 milk. This method will therefore considerably improve the food safety issues associated with aflatoxin M1 presence in milk and dairy products.

Electrochemical Methods for the Analysis of Milk

The milk and dairy industries are some of the most profitable sectors in many countries. This business requires close control of product quality and continuous testing to ensure the safety of the consumers. The potential risk of contaminants or degradation products and undesirable chemicals necessitates the use of fast, reliable detection tools to make immediate production decisions. This review covers studies on the application of electrochemical methods to milk (i.e., voltammetric and amperometric) to quantify different analytes, as reported over the last 10 to 15 years. The review covers a wide range of analytes, including allergens, antioxidants, organic compounds, nitrogen- and aldehyde containing compounds, biochemicals, heavy metals, hydrogen peroxide, nitrite, and endocrine disruptors. The review also examines pretreatment procedures applied to milk samples and the use of novel sensor materials. Final perspectives are provided on the future of cost-effective and easy-to-use electrochemical sensors and their advantages over conventional methods.

S. M. Montenegro MC, Rodríguez-Díaz JM. Contaminants in the cow's milk we consume? Pasteurization and other technologies in the elimination of contaminants

Cow's milk is currently the most consumed product worldwide. However, due to various direct and indirect contamination sources, different chemical and microbiological contaminants have been found in cow's milk. This review details the main contaminants found in cow's milk, referring to the sources of contamination and their impact on human health. A comparative approach highlights the poor efficacy and effects of the pasteurization process with other methods used in the treatment of cow's milk. Despite pasteurization and related techniques being the most widely applied to date, they have not demonstrated efficacy in eliminating contaminants. New technologies have appeared as alternative treatments to pasteurization. However, in addition to causing physicochemical changes in the raw material, their efficacy is not total in eliminating chemical contaminants, suggesting the need for new research to find a solution that contributes to improving food safety.

Advances in the Total Synthesis of Aflatoxins

Aflatoxins, which are produced by Aspergillus flavus, Aspergillus nomius, and Aspergillus parasiticus, are a group of pentacyclic natural products with difuran and coumarin skeletons. They mainly include aflatoxin B1, B2, G1, G2, M1, and M2. Biologically, aflatoxins are of concern to human health as they can be present as contaminants in food products. The unique skeletons of aflatoxins and their risk to human health have led to the publication of nine remarkable total syntheses (including three asymmetric syntheses) and ten formal total syntheses (including four asymmetric formal syntheses) of aflatoxins in the past 55 years. To better understand the mechanism of the biological activity of aflatoxins and their presence in samples from the food industry, this review summarizes progress in the total synthesis of aflatoxins.