The risks associated with aflatoxins M1 occurrence in Lebanese dairy products

Assessment of mycotoxins in cornflakes marketed in Lebanon

Cornflakes are a popular and convenient breakfast cereal made from corn and widely consumed worldwide, including in Lebanon. However, they are susceptible to mycotoxin contamination, which can have harmful effects on human health. Our study evaluated the occurrence of five mycotoxins (AFB1, OTA, FUM, ZEA, DON) levels in packed cornflakes marketed in Lebanon. A market screening identified 35 different cornflake stock-keeping units (SKU) in the Lebanese market, originating from 10 different brands and having different tastes and shapes. SKUs were collected and tested for five mycotoxins in triplicates using enzyme-linked immunosorbent assay technique. The results showed the presence of the five mycotoxins in the samples. The average levels of AFB1, OTA, ZEA and FUM among positive samples (above limit of detection) were 1.58, 1.2, 15.1 and 774.1 μg/kg, respectively, and were below the EU limits. On the other hand, the average level of DON was 1206.7 μg/kg, exceeding the EU limit. Furthermore, out of the positive samples, 60%, 17%, 9%, 14%, and 6% exceeded the EU limits for DON, OTA, AFB1, FUM, and ZEA, respectively. Notably, SKUs made in Lebanon had significantly (p < 0.05) higher levels of AFB1 and FUM. The packing size of the cornflakes had no significant (p > 0.05) effect on the levels of the five mycotoxins detected in the samples. AFB1, FUM and ZEA levels differed significantly among SKUs (p > 0.05). Considering these findings, further studies should be conducted to assess the exposure to mycotoxins from the consumption of cornflakes in Lebanon, especially among children.

Aflatoxins and Ochratoxin A in Tea Sold in Lebanon: Effects of Type, Packaging, and Origin

Tea is among the oldest and most-known beverages around the world, and it has many flavors and types. Tea can be easily contaminated in any of its production steps, especially with mycotoxins that are produced particularly in humid and warm environments. This study aims to examine the level of ochratoxin A (OTA) and total aflatoxin (AF) contamination in black and green tea sold in Lebanon, evaluate its safety compared to international standards, and assess the effect of different variables on the levels of OTA and AFs. For this, the Lebanese market was screened and all tea brands (n = 37; 24 black and 13 green) were collected twice. The Enzyme-Linked Immunoassay (ELISA) method was used to determine OTA and AFs in the samples. AFs and OTA were detected in 28 (75.7%) and 31 (88.6%) samples, respectively. The average of AFs in the positive (above detection limit: 1.75 μg/kg) samples was 2.66 ± 0.15 μg/kg, while the average of OTA in the positive (above detection limit: 1.6 μg/kg) samples was 3.74 ± 0.72 μg/kg. The mean AFs in black and green tea were 2.65 ± 0.55 and 2.54 ± 0.40 μg/kg, respectively, while for OTA, the mean levels were 3.67 ± 0.96 and 3.46 ± 1.09 μg/kg in black and green tea samples, respectively. Four brands (10.8%) contained total aflatoxin levels above the EU limit (4 μg/kg). As for OTA, all samples had OTA levels below the Chinese limit (5 μg/kg). No significant association (p > 0.05) was found between OTA and tea type, level of packaging, country of origin, country of packing, and country of distribution. However, AF contamination was significantly (p < 0.05) higher in unpacked tea, and in brands where the country of origin, packing, and distributor was in Asia. The results showed that the tea brands in Lebanon are relatively safe in terms of AFs and OTA.

Occurrence of Aflatoxin M1 in Milk and Dairy Products Traded in São Paulo, Brazil: An Update

The aim of this study was to conduct an up-to-date investigation on the occurrence levels of aflatoxin M1 (AFM1) in samples of raw milk (n = 40), pasteurized milk (n = 44), ultra-high temperature (UHT) milk (n = 27), Minas cheese (n = 57), and yogurt (n = 44) traded in São Paulo state, Brazil. AFM1 was extracted from fluid milks and dairy products using immunoaffinity columns and determined by high performance liquid chromatography. AFM1 was detected at the mean level of 0.080 ± 0.071 µg/L or kg in 72 samples (34.0%) evaluated in the study (n = 212). Detectable levels of AFM1 were observed in five samples of raw milk (12.5%), 16 samples of pasteurized milk (36.4%), 13 samples of UHT milk (48.1%), 27 samples of cheese (47.4%), and 11 samples of yogurt (25.0%), although none of them had concentrations above the maximum permitted levels (MPL) for AFM1 adopted in Brazil. However, 11.7% (n = 13) of samples of raw, pasteurized, and UHT milks would have AFM1 concentrations above the MPL of 0.05 μg/L adopted in the EU. The maximum level was detected in one cheese sample containing 0.695 µg/kg. Although none of the samples exceeded the Brazilian MPL, the high frequencies of AFM1 in Brazilian milk products warrant concern about their contribution to the human exposure to aflatoxins. Because aflatoxins are among the most potent carcinogens known, the results of this trial stress the need for stringent measures in the milk production system to avoid AFM1 in milk and derived products.

Aflatoxin B1 in Rice: Effects of Storage Duration, Grain Type and Size, Production Site, and Season

ABSTRACT

Our study evaluated aflatoxin B1 (AFB1) levels in packed rice marketed in Lebanon and determined the exposure to this toxin from rice consumption. A total of 105 packed white, parboiled, and brown rice bags were collected. Enzyme-linked immunosorbent assay was used to measure AFB1. A comprehensive food frequency questionnaire was completed by 500 participants to determine patterns of rice consumption and, subsequently, the exposure levels to AFB1 from rice consumption in Lebanon. AFB1 was detected in all rice samples (100%). The average concentration ± standard deviation of AFB1 was 0.5 ± 0.3 μg/kg. Contamination ranged between 0.06 and 2.08 μg/kg. Moisture content in all rice samples was below the recommended percentage (14%). Only 1% of the samples had an AFB1 level above the European Union limit (2 μg/kg). Brown rice had a significantly higher AFB1 level than white and parboiled rice (P = 0.02), while a significant difference was found between both collections for the same brands (P = 0.016). Packing season, packing country, country of origin, presence of a food safety management certification, grain size, and time between packing and purchasing had no significant effect. Exposure to AFB1 from rice consumption in Lebanon was calculated as 0.1 to 2 ng/kg of body weight per day.

HIGHLIGHTS

The prevalence of aflatoxin M1 (AFM1) in conventional and industrial dairy products (yogurt, cheese, kashk and dough) of Iran: a systematic review and meta-analysis

Aflatoxin is a toxic metabolite produced mainly by Aspergillus spp. which may occur in dairy products because of biotransformation. In this work, a systematic and meta-analysis approach has been considered on the topic of aflatoxin M1 (AFM1) content in dairy Iranian products. Based on the literature review, AFM1 was the most common aflatoxin contamination in dairy product. Additionally, studies revealed that higher levels of AFM1 were produced during cold seasons includes winter and autumn. Although, immunochemical technique (ELISA) was the frequent and rapid test, thin-layer chromatography (TLC) and chromatographic methods (HPLC) were commonly used as confirmative techniques to determine the level of aflatoxin. Meta-analyzing of the results showed that AFM1 can be found in the dairy products with overall prevalence percentage of 63.53 (95% confidence interval [CI]: 56.28-70.78) and 54.05 (95% CI: 43.09-65.02) based on the sample type and production process, respectively. The higher prevalence percentage of AFM1 of 73.96 (95% CI: 60.27-87.66) and 69.91 (95% CI: 62.00-78.83) was found in yoghurt and industrial production type of samples, respectively. In general, 17.8% of cheese, 14% of yogurt, 12.63% of kashk, and 2.1% of doogh contained AFM1 in concentrations exceeding the permitted level of standards. Totally, results showed that 88.89% of dairy products were contaminated by AFM1 exceeding from standard limits.

Fate of aflatoxins M1 and B1 within the period of production and storage of Tarkhineh: A traditional Persian fermented food

The objective of the study was to assess the amount of aflatoxin M₁ (AFM₁) and aflatoxin B₁ (AFB₁) during fermentation, drying, and storage of Tarkhineh-a traditional Persian fermented food-over four months. Tarkhineh samples were produced based on a traditional method. Various concentrations of AFB₁ (2.5, 5, 7.5, and 10 µg/kg) and AFM₁, stood at 0.25, 0.5, 0.75, and 1 µg/kg, were added to Iranian yogurt drink, called doogh, samples. Tarkhineh samples were evaluated for AFB₁ and AFM₁ on days 0, 2, 6, and 8 and also after drying and four months of storage. In cases of repeatability, recovery, and reproducibility, the high-performance liquid chromatography through fluorescence detector (HPLC-FD) method was successfully done to demonstrate aflatoxins (AFs) in Tarkhineh samples. The fermentation process had a considerable consequence on the reduction in AFM₁ and AFB₁ as compared to the control group, evidenced by 65.10%-81.20% and 55.80%-74.10%, respectively, after eight days of fermentation (p < .05). The highest reduction in AFB₁ existed in samples containing 2.5 µg/kg toxin, followed by 5, 7.5, and 10 µg/kg, respectively. A similar trend was found for AFM₁, as the highest concentration was found in samples containing 0.25 µg/kg toxin, followed by 0.5, 0.75, and 1 µg/kg, respectively.

Development of a microarray lateral flow strip test using a luminescent organic compound for multiplex detection of five mycotoxins

While lateral flow immunoassay (LFIA) is a simple technique that offers a rapid, robust, user friendly, and point-of-care test, its capacity for multiplex detection is rather limited. This study therefore combined the multiplexity of microarray technique and the simple and rapid characteristics of LFIA to enable simultaneous and quantitative detection of five mycotoxins, namely aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FUMB1), T-2 toxin (T-2), and zearalenone (ZON). In addition, we have synthesized a novel extra-large Stokes shift and strong fluorescence organic compound to be used as a reporter molecule which can be detected under UV light without light filter requirement. Many parameters including microarray spotting buffer, blocking buffer, and concentrations of mycotoxin antibodies were optimized for the microarray LFIA (μLFIA) construction. With the optimal conditions, the μLFIA could accurately and quantitatively detect multiple mycotoxins at the same time. The limits of detection of AFB1, DON, FUMB1, T-2, and ZON were 1.3, 0.5, 0.4, 0.4, and 0.9 ppb, respectively. The recoveries of these five mycotoxins were 70.7%-119.5% and 80.4%-124.8% for intra-assay and inter-assay, respectively. Combining the advantages of the novel reporter molecule and the multiplex capability of μLFIA test, this system could simultaneously detect multiple mycotoxins in one sample with high specificity and high sensitivity. Moreover, this system presents a promising affordable point-of-care platform to detect other analytes as well.

A Recent Overview of Producers and Important Dietary Sources of Aflatoxins

Aflatoxins (AFs) are some of the most agriculturally important and harmful mycotoxins. At least 20 AFs have been identified to this date. Aflatoxin B1 (AFB1), the most potent fungal toxin, can cause toxicity in many species, including humans. AFs are produced by 22 species of Aspergillus section Flavi, 4 species of A. section Nidulantes, and 2 species of A. section Ochraceorosei. The most important and well-known AF-producing species of section Flavi are Aspergillus flavus, A. parasiticus, and A. nomius. AFs contaminate a wide range of crops (mainly groundnuts, pistachio nuts, dried figs, hazelnuts, spices, almonds, rice, melon seeds, Brazil nuts, and maize). Foods of animal origin (milk and animal tissues) are less likely contributors to human AF exposure. Despite the efforts to mitigate the AF concentrations in foods, and thus enhance food safety, AFs continue to be present, even at high levels. AFs thus remain a current and continuously pressing problem in the world.

An assessment of the occurrence and nutritional factors associated with aflatoxin M1, ochratoxin A, and zearalenone in the breast milk of nursing mothers in Hamadan, Iran

This research investigated the occurrence of aflatoxin M1 (AFM1), ochratoxin A (OTA), and zearalenone (ZEN) in human milk samples in the Hamadan city, Iran. The study was carried out using the milk of nursing mothers from ten governmental health care centers. Mycotoxin content of ninety milk samples measured using enzyme-linked immunosorbent assay (ELISA). All samples that tested positive for AFM1 with the ELISA test were subsequently analyzed by high-performance liquid chromatography (HPLC). The mean ± SD concentrations of AFM1, determined by ELISA and HPLC were 5.98 ± 1.47 and 4.36 ± 1.23 ng/L, respectively. OTA and ZEN levels were below the detection limit (<5 ng/L) in all samples. None of the contaminated samples exceeded the regulation limit set by the European Commission (25 ng/L) for AFM1 in infant formula. We found a significant correlation between the AFM1 concentration in breast milk and infant age and milk consumption by the nursing mother (p < 0.05). These findings revealed that infants are susceptible to AFM1 exposure from their mother's milk. The authors recommend that additional research be conducted on the analysis of foodstuff and biological fluids for various mycotoxins.

Prevalence and Exposure Assessment of Aflatoxins Through Black Tea Consumption in the Multan City of Pakistan and the Impact of Tea Making Process on Aflatoxins

Aflatoxins are the highly toxic secondary metabolites of certain fungi, being mainly produced by Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are classified as group 1 category carcinogens by the International Agency for Research on Cancer (IARC). A large number of food commodities are reported to be contaminated with aflatoxins. Tea is the world's second most consumed beverage and the consumption of tea is increasing day by day. Besides being a source of several health promoting substances, tea leaves are also reported to be contaminated with aflatoxins. However, not a single study is reported from Pakistan regarding the level of aflatoxins in commercially available black tea samples. The current study aimed to quantify the level of aflatoxins in commercially available branded and non-branded black tea samples. The estimated daily intake (EDI) of aflatoxins through branded and non-branded black tea consumption and the health risk assessment based on margin of exposure (MOE) approach was assessed. Furthermore, the impact of local tea making processes on the concentration of aflatoxins in tea beverage (filtrate) was also investigated.

Detection of aflatoxin M1 in milk and milk products in Turkey

This study examined the presence of Aflatoxin M₁ (AFM₁) in raw milk, cheese, and cheese halva samples collected from the Çanakkale province of Turkey. Raw milk, Ezine cheese, and cheese halva samples (n 120 for each group, total 360) were collected from bazaars, local manufacturers, and supermarkets in the Çanakkale province of Turkey during 2014 and 2015. ELISA was used to detect AFM₁ in these products. AFM₁ mean values were 5.14-78.69, 19.43-158.30, and 50.25-213.50 ng/kg in raw milk, Ezine cheese, and cheese halva samples, respectively. The levels of AFM1 in four raw milk samples (3.3%) were above the legal limits, whereas AFM₁ levels in Ezine cheese and cheese halva samples were within the legal limits according to the requirements of the Turkish Food Codex and the European Commission. Turkey has a wealth of cultures and local delicacies. Over previous decades, gastronomic tourism in Turkey has become popular owing to an increase in visitor demand, and traditional foods are being exported abroad. Our research investigated the presence of AFM₁ in these types of food products. Çanakkale is one of the best representative cities in the Marmara Region in Turkey as a source of these unique products.

Purification, characterization, and functional groups of an extracellular aflatoxin M1 -detoxifizyme from Bacillus pumilus E-1-1-1

The experiment was conducted to purify high activity extracellular enzymes, which were produced by a strain that we previously screened was able to degrade aflatoxin effectively, and speculate the functional groups of the enzyme associated with degradation. An extracellular aflatoxin-detoxifizyme (DAFE) from Bacillus pumilus E-1-1-1 was purified through a process including ammonium sulfate precipitation, ultrafiltration, Sephadex chromatography, and ion exchange chromatography. The molecular mass of the enzyme assessed by SDS-PAGE was found to be approximately 58 kDa. The optimum reaction temperature and pH for the purified enzyme were 45°C and pH 7, respectively. The enzyme showed temperature stability of up to 60°C. Ba²⁺ , Ca²⁺ Na⁺ , Mn²⁺ , EDTA, and β-mercaptoethanol showed inhibitory effects on the enzyme activity. Mg²⁺ , Fe³⁺ , Zn²⁺ and K⁺ were the activators of enzymes. This enzyme was composed of at least 15 kinds of amino acids. Lysine, tryptophan, and histidine residues were necessary and major functional groups to maintain enzyme activity, disulfide bonds were observed, serine residues had little effect on the enzyme activity, so it was not the necessary group to reflect the enzyme activity, and arginine had no effect on enzyme activity.

Quantum bead-based fluorescence-linked immunosorbent assay for ultrasensitive detection of aflatoxin M1 in pasteurized milk, yogurt, and milk powder

Herein, we reported a novel direct competitive fluorescence-linked immunosorbent assay (dcFLISA) for the ultrasensitive detection of aflatoxin M₁ (AFM₁) in pasteurized milk, yogurt, and milk powder using 150-nm quantum dot beads (QB) as the carrier of competing antigen. Large QB were applied to decrease the binding affinity of the competing antigen to antibody and enhance the fluorescent signal intensity. The aflatoxin B₁ molecule was used as the surrogate of AFM₁ to label with BSA on the surface of QB because of its 63% cross reaction to anti-AFM₁ mAb. The binding affinity of the competing antigen to mAb was tuned by changing the labeled molar ratios of aflatoxin B₁ to BSA. Through combining the advantages of QB as the carrier of the competing antigen, including low binding affinity to mAb and highly fluorescent signal output, the proposed dcFLISA exhibited an ultrahigh sensitivity for AFM₁ detection, with a half-maximal inhibitory concentration of 3.15 pg/mL in 0.01 M phosphate-buffered saline solution (pH 7.4), which is substantially lower than that of the traditional horseradish peroxidase-based ELISA. The proposed method also exhibited very low detection limitations of 0.5, 0.6, and 0.72 pg/mL for real pasteurized milk, yogurt, and milk powder, respectively. These values are considerably below the maximum permissible level of the European Commission standard for AFM₁ in dairy products. In summary, the proposed dcFLISA offers a novel strategy with an ultrahigh sensitivity for the routine monitoring of AFM₁ in various dairy products.

Pilot Study for The Presence of Fungal Metabolites in Sheep Milk from First Spring Milking

Introduction

A mini-study of 20 raw milk samples was conducted to examine the spectrum of fungal metabolites in sheep milk from the first spring milking.

Material and Methods

Samples were collected from randomly selected ewes in two animal flocks from the Bieszczady Mountains and analysed using liquid chromatography-tandem mass spectrometry.

Results

Out of ~700 bacterial, fungal, and plant metabolites tested for, only one mycotoxin – Enniatin B – was detected in sheep milk samples (18/20; 0.0055–0.0121 μg/kg; 0.0078 μg/kg average).

Conclusions

The results indicated that there was no high-level exposure to fungal metabolites via consumption of raw sheep milk during the sample collection period.

Assessment of Aflatoxin M1 and M2 exposure risk through Oaxaca cheese consumption in southeastern Mexico

The present study evaluated the exposure of Southeast Mexican population to Aflatoxin M1 (AFM1) and M2 (AFM2) through the consumption of Oaxaca cheese. The intake of Oaxaca cheese was assessed via a food 7-day dairy questionnaire (N = 1100, 2014 and 2015). Thirty Oaxaca cheeses were randomly sampled, and the origin of the samples was also investigated. AFM1 and AFM2 were quantified by HPLC-FD. The exposure was assessed through the combination of the Probabilistic Density Functions (probabilistic approach). The percentage of the population at risk was calculated through the population exceeding the toxicological reference values (TDI). The risk assessment revealed that the population at higher risk to AFM1 and AFM2 was the children, followed by the adolescents and adult women. To our knowledge, the present study is the first to assess the exposure risk of different age groups of a population to AFM1 and AFM2 through the consumption of cheese.

Analysis of Aflatoxin M1 in Breast Milk and Its Association with Nutritional and Socioeconomic Status of Lactating Mothers in Lebanon

Aflatoxin B₁ (AFB₁) is the most potent of the dietary aflatoxins, and its major metabolite, aflatoxin M₁ (AFM₁), is frequently found in the breast milk of lactating mothers. The aim of this study was to assess the occurrence and factors associated with AFM₁ contamination of breast milk collected from lactating mothers in Lebanon. A total of 111 breast milk samples were collected according to the guidelines set by the World Health Organization. Samples were analyzed with a competitive enzyme-linked immunosorbent assay between December 2015 and November 2016. A survey was used to determine the demographic and anthropometric characteristics of participating lactating mothers. Dietary habits were assessed using a semiquantitative food frequency questionnaire. Mean (±standard deviation) concentration of AFM₁ in the breast milk samples was 4.31 ± 1.8 ng/L, and 93.8% of samples contained AFM₁ at 0.2 to 7.9 ng/L. The mean concentration of AFM₁ was significantly lower (P < 0.05) in fall and winter (4.1 ± 1.9 ng/L) than in spring and summer (5.0 ± 1.7 ng/L). None of the samples exceeded the European Commission regulation limit (25 ng/L) for infant milk replacement formula. AFM₁ contamination was significantly associated (P < 0.05) with the daily consumption of white cheeses but not with the consumption of meat or cereal products. No significant association (P > 0.05) was observed between AFM₁ concentrations in breast milk and anthropometric sociodemographic factors (age and level of education) or the governorate of residence of the nursing mothers. The mean AFM₁ estimated daily intake was found to be 0.69 ng/day/kg of body weight. Although the incidence of AFM₁ contamination was low, our first-of-its-kind study highlights the importance of conducting investigations on mycotoxin contamination in breast milk and of developing protection strategies to tackle the exposure of infants to this potent chemical hazard.

Aflatoxin M1 in milk and milk products: a short review

Aflatoxin M1 (AFM1) is associated with carcinogenicity, genotoxicity, mutagenicity, and teratogenicity and as a result, represents a human health problem worldwide. This review will detail the toxicity, analytical methodology, occurrence, and prevention and control of AFM1 in milk and milk products. The probable daily intakes (PDI) per bodyweight (bw) worldwide ranged from 0.002 to 0.26 ng/kg bw/day for AFM1. Nevertheless, the high occurrence of AFM1 demonstrated in this review establishes the need for monitoring to reduce the risk of toxicity to humans. The recommended extraction method of AFM1 from milk is liquid-liquid with acetonitrile because of the acceptable recoveries (85-97%), compatibility with the environment, and cleanest extracts. The recommended analytical technique for the determination of AFM1 in milk is the high performance-liquid chromatography-fluorescence detector (HPLC-FLD), achieving a 0.001 µg/kg detection limit. The HPLC-FLD is the most common internationally recognised official method for the analysis of AFM1 in milk. The suggested extraction and analytical method for cheese is dichloromethane (81-108% recoveries) and ELISA, respectively. This review reports the projected worldwide occurrence of AFM1 in milk of 2010-2015. Of the 7,841 samples, 5,873 (75%) were positive for AFM1, 26% (2,042) exceeded the maximum residue levels (MRL) of 0.05 µg/kg defined by the European Union and 1.53% (120) exceeded the MRL of 0.5 µg/kg defined by the US Food and Drug Administration. The most effective way of preventing AFM1 occurrences is to reduce contamination of AFB1 in animal feed using biological control with atoxigenic strains of Aspergillus flavus, proper storage of crops, and the addition of binders to AFB1-contaminated feed. Controllable measures include the addition of binders and use of biological transforming agents such as lactic acid bacteria applied directly to milk. Though the one accepted method for the control of AFM1 in milk and milk products is the enforcement of governmental MRL.

Aflatoxin M1: Prevalence and decontamination strategies in milk and milk products

Aflatoxin M1 (AFM1) in milk is among the most carcinogenic compounds, relatively high levels being consumed, especially by the most vulnerable age groups, i.e. infants and the elderly. Reports on its prevalence are constantly being received from various parts of the world compelling nations to establish their own standard limits for AFM1. Global review of the literature indicates the existence of methods of partial decontamination of AFM1, however; evidence based studies do not suggest that any single strategy as a coherent and complete solution to the issue. Microbial decontamination of AFM1 has emerged as the most suitable method up to now but the stability of toxin-microbial cell complexes still remains questionable. This review discusses the chemical nature, established maximum permissible limits and prevalence of AFM1 in various countries from 2009 to 2014. Moreover, the possible mechanisms for AFM1 reduction mainly the microbial decontamination and the stability and bioaccessibility of microbial-AFM1 complexes are also discussed.