Natural occurrence of aflatoxin B1 in marketed foods and risk estimates of dietary exposure in Koreans

Automated Paper-Based Femtogram Sensing Device for Competitive Enzyme-Linked Immunosorbent Assay of Aflatoxin B1 Using Submicroliter Samples

Microfluidic paper-based analytical devices (μPADs) are promising biosensors that may be used in a variety of bioanalytical applications. A μPAD for automating the competitive enzyme-linked immunosorbent assay (ELISA) of small-sized target detection at the femtogram level using submicroliter samples is reported in this study. The proposed μPAD was integrated with a sucrose valve to automate the sequential delivery of reagents, providing simple control of reagent delivery time and simple operation. The use of a sample solution dropping location at the zones on the device that had been prepared with an antibody-conjugated enzyme before immersion in a running buffer allowed minimization of sample volume to 0.6 μL, while eliminating the possible loss of a target molecule by adsorption on the membrane, thus improving detection sensitivity. Furthermore, the proposed device was successfully applied to the automation of competitive ELISA for the detection of aflatoxin B₁ (AFB₁), a potent carcinogen that causes substantial health risks to humans worldwide, with a detection limit of 60 femtograms or 0.1 ng/mL. The method developed in this study provides high sensitivity, small sample volume, on-site and equipment-free measurements, low-cost operation, and user-friendliness. This approach could be used to analyze small-sized molecules in the fields of food safety and quality control, environmental monitoring, and clinical diagnostics.

Simple chromatographic determination of aflatoxins in Korean fermented soybean products doenjang, ganjang, and gochujang, with comparison of derivatization methods

Korean fermented soybean products doenjang, ganjang, and gochujang are vulnerable to contamination with aflatoxigenic fungi in the open fermentation environment. Therefore, simple and effective methods to determine aflatoxins (AFs) in these complex food matrices are needed. High-performance liquid chromatography with fluorescence detection using two derivatization methods for AF determination in three fermented soybean products was optimized and validated. Pre-column derivatization (preCD) of the AF extracts was performed using trifluoroacetic acid, and post-column derivatization (PCD) was performed in a photochemical reactor for enhanced detection. Both derivatization methods resulted in acceptable performances for linearity (R2 > 0.999), recovery (71-118%), and precision (< 10.6%) values. Recovery and precision with preCD and PCD were similar, but the limit of detection was superior with PCD. When these analytical methods were applied to commercially available fermented soybean products, the AF levels of all commercial products were ranged from not detected to 6.06 μg/kg.

Contamination characteristics and risk assessment of aflatoxins in homemade soybean paste, a traditional fermented soybean food, in South Korea

Soybean paste is manufactured through microbial fermentation and may become contaminated with aflatoxins. Herein, we conducted nationwide large-scale monitoring (n = 1436) over three years (2018-2020) to investigate aflatoxin levels according to geographic, demographic, manufacturing, quality factors, and risk characteristics of homemade soybean paste produced through fermentation. The mean level of total aflatoxins was 5.88 μg/kg (range, 0.01-281.92), with the most common contaminating type being the B type. Aflatoxin levels significantly differed according to the region, age of the manufacturer, type of starter used, and the amino-type nitrogen content and pH of the homemade soybean paste (p < 0.05). Aflatoxin levels was significantly higher when starters were manufactured using the traditional method (inoculation with a naturally occurring strain in the surrounding environment). The aflatoxin exposure level estimated through the average intake of homemade soybean paste in all age groups was 0.1012 ng/kg body weight/day. The risk assessment for the genotoxic and carcinogenic potential of aflatoxins using the margin of exposure approach revealed values of 3705-3954 for average intake of homemade soybean paste, indicating public health concern. These results suggest that follow-up studies and safety management strategies are needed to reduce aflatoxin levels in homemade soybean paste.

Gallbladder adenocarcinomas undergo subclonal diversification and selection from precancerous lesions to metastatic tumors

We aimed to elucidate the evolutionary trajectories of gallbladder adenocarcinoma (GBAC) using multi-regional and longitudinal tumor samples. Using whole-exome sequencing data, we constructed phylogenetic trees in each patient and analyzed mutational signatures. A total of 11 patients including 2 rapid autopsy cases were enrolled. The most frequently altered gene in primary tumors was ERBB2 and TP53 (54.5%), followed by FBXW7 (27.3%). Most mutations in frequently altered genes in primary tumors were detectable in concurrent precancerous lesions (biliary intraepithelial neoplasia [BilIN]), but a substantial proportion was subclonal. Subclonal diversity was common in BilIN (n=4). However, among subclones in BilIN, a certain subclone commonly shrank in concurrent primary tumors. In addition, selected subclones underwent linear and branching evolution, maintaining subclonal diversity. Combined analysis with metastatic tumors (n=11) identified branching evolution in nine patients (81.8%). Of these, eight patients (88.9%) had a total of 11 subclones expanded at least sevenfold during metastasis. These subclones harbored putative metastasis-driving mutations in cancer-related genes such as SMAD4, ROBO1, and DICER1. In mutational signature analysis, six mutational signatures were identified: 1, 3, 7, 13, 22, and 24 (cosine similarity >0.9). Signatures 1 (age) and 13 (APOBEC) decreased during metastasis while signatures 22 (aristolochic acid) and 24 (aflatoxin) were relatively highlighted. Subclonal diversity arose early in precancerous lesions and clonal selection was a common event during malignant transformation in GBAC. However, selected cancer clones continued to evolve and thus maintained subclonal diversity in metastatic tumors.

Spatial analysis of dietary exposure of aflatoxins in peanuts and peanut oil in different areas of China

Peanuts in China are heavily contaminated with aflatoxin, which pose a threaten to human health. To compare the dietary exposure risk of aflatoxins (AFT) in peanuts and peanut oil in different areas of China, the spatial distribution of AFT contamination levels in peanuts and peanut oil from different areas was analyzed. The dietary exposure was calculated by simple distributed risk assessment method before characterizing the health risk using both the margin of exposure (MOE) approach proposed by the European Food Safety Authority (EFSA) and the quantitative liver cancer risk approach proposed by the Joint Food and Agricultural Organization/World Health Organization (FAO/WHO) Expert Committee on Food Additives (JECFA). The results showed that the AFT content in peanuts and peanut oil was high with agglomeration in several provinces of East and South China under a subtropical temperate monsoon climate, and the AFT contamination in peanut oil was more substantial than peanuts. On average, the estimated dietary exposure to AFT from the total of peanuts and peanut oil for Chinese general population ranged from 1.776 to 1.940 ng/kg bw/day (LB-UB), from which the MOE values of 88-96 (UB-LB) and liver cancer risk of 0.055-0.060 cases/100,000 persons/year (LB-UB) were calculated. As for different areas in China, the mean AFT exposure ranged between 0.000 and 17.270 ng/kg bw/day. Moreover, the corresponding health risk was estimated at 10-868759 MOE values and 0.000-0.851 liver cancer cases/100,000 persons/year. Guangdong, Fujian and Jiangxi provinces were at a higher risk rank. The liver cancer risk of AFT exposure from peanuts and peanut oil was far below all-cause liver cancer incidence (18.0 cases/100,000 persons/year) in China, but several areas with relatively high risk should be of concern. Compared with other age groups, children aged 2-6 years should be paid more attention because they have the highest AFT exposure level.

Probabilistic risk assessment of dietary exposure to aflatoxin B1 in Guangzhou, China

Aflatoxin B1 (AFB1) contamination in foods is an important health challenge for low-and middle-income countries in subtropical regions. AFB1 has been detected in a variety of foodsin Guangzhou, while the risk of dietary exposure is unknown. This study aimed to assess the probabilistic risk of dietary exposure to AFB1 contamination in food stuffs in Guangzhou by using margin of exposure (MOE) and quantitative liver cancer risk approaches. A total of1854 AFB1-contaminated foodstuffs were sampled in supermarkets, agricultural markets, retail shops, and family workshops from 11 districts of Guangzhou, and AFB1 content was determined by HPLC-fluorescence detector. In total, 9.9% (184/1854) of the test samples had AFB1 concentrations above the limit of detection. Home-made peanut oil had the highest AFB1 concentration, with a mean value of 38.74 ± 47.45 μg kg-1. The average MOE levels of Guangzhou residents ranged from 100 to 1000. The risk of liver cancer was 0.0264 cancers (100,000 population year)-1. The health risks of suburban people were higher than those of urban people, and home-made peanut oil was the main contributorto dietary exposure to AFB1 among suburban residents in Guangzhou. The production of home-made peanut oil should be supervised to reduce the risk of AFB1 exposure.

Aspergillus section Flavi and Aflatoxins: Occurrence, Detection, and Identification in Raw Peanuts and Peanut-Based Products Along the Supply Chain

Aflatoxin contamination in foods is a global concern as they are carcinogenic, teratogenic and mutagenic compounds. The aflatoxin-producing fungi, mainly from the Aspergillus section Flavi, are ubiquitous in nature and readily contaminate various food commodities, thereby affecting human's health. The incidence of aflatoxigenic Aspergillus spp. and aflatoxins in various types of food, especially raw peanuts and peanut-based products along the supply chain has been a concern particularly in countries having tropical and sub-tropical climate, including Malaysia. These climatic conditions naturally support the growth of Aspergillus section Flavi, especially A. flavus, particularly when raw peanuts and peanut-based products are stored under inappropriate conditions. Peanut supply chain generally consists of several major stakeholders which include the producers, collectors, exporters, importers, manufacturers, retailers and finally, the consumers. A thorough examination of the processes along the supply chain reveals that Aspergillus section Flavi and aflatoxins could occur at any step along the chain, from farm to table. Thus, this review aims to give an overview on the prevalence of Aspergillus section Flavi and the occurrence of aflatoxins in raw peanuts and peanut-based products, the impact of aflatoxins on global trade, and aflatoxin management in peanuts with a special focus on peanut supply chain in Malaysia. Furthermore, aflatoxin detection and quantification methods as well as the identification of Aspergillus section Flavi are also reviewed herein. This review could help to shed light to the researchers, peanut stakeholders and consumers on the risk of aflatoxin contamination in peanuts along the supply chain.

Simultaneous Determination of Twenty Mycotoxins in the Korean Soybean Paste Doenjang by LC-MS/MS with Immunoaffinity Cleanup

Doenjang, a Korean fermented soybean paste, is vulnerable to contamination by mycotoxins because it is directly exposed to environmental microbiota during fermentation. A method that simultaneously determines 20 mycotoxins in doenjang, including aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEN), and fumonisins (FBs) with an immunoaffinity column cleanup was optimized and validated in doenjang using LC-MS/MS. The method showed good performance in the analysis of 20 mycotoxins in doenjang with good linearity (R2 > 0.999), intra- and inter-day precision (<16%), recovery (72-112%), matrix effect (87-104%), and measurement uncertainty (<42%). The validated method was applied to investigate mycotoxin contamination levels in commercial and homemade doenjang. The mycotoxins that frequently contaminated doenjang were AFs, OTA, ZEN, and FBs and the average contamination level and number of co-occurring mycotoxins in homemade doenjang were higher than those in commercially produced doenjang.

A sensitive biosensing method for detecting of ultra-trace amounts of AFB1 based on "Aptamer/reduced graphene oxide" nano-bio interaction

A simple, low-cost and sensitive label-free aptasensor assembled with assisting reduced graphene oxide nanosheets as the signal amplifier was fabricated and applied for detecting ultra-low levels of Aflatoxin B1(AFB1) through a nano-bio interaction system. The conditions of different modified glassy carbon electrodes as the base of aptasensor were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The performance of the fabricated aptasensor was evaluated by FESEM, HRTEM and AFM images. The proposed biosensor detected AFB1sensitively in a wide linear range (0.5 nM-4μM) by DPV with a considerable low limit of detection (LOD = 0.07 nM) and good repeatability (RSD = 2.9) and stability. Finally, the present aptasensor was applied successfully for monitoring AFB1 with appropriate recoveries in pasteurized cow milk and human blood plasma as real samples.

A Review of Current Methods for Analysis of Mycotoxins in Herbal Medicines

The presence of mycotoxins in herbal medicines is an established problem throughout the entire world. The sensitive and accurate analysis of mycotoxin in complicated matrices (e.g., herbs) typically involves challenging sample pretreatment procedures and an efficient detection instrument. However, although numerous reviews have been published regarding the occurrence of mycotoxins in herbal medicines, few of them provided a detailed summary of related analytical methods for mycotoxin determination. This review focuses on analytical techniques including sampling, extraction, cleanup, and detection for mycotoxin determination in herbal medicines established within the past ten years. Dedicated sections of this article address the significant developments in sample preparation, and highlight the importance of this procedure in the analytical technology. This review also summarizes conventional chromatographic techniques for mycotoxin qualification or quantitation, as well as recent studies regarding the development and application of screening assays such as enzyme-linked immunosorbent assays, lateral flow immunoassays, aptamer-based lateral flow assays, and cytometric bead arrays. The present work provides a good insight regarding the advanced research that has been done and closes with an indication of future demand for the emerging technologies.

Investigation of Non-Covalent Interactions of Aflatoxins (B1, B2, G1, G2, and M1) with Serum Albumin

Aflatoxins are widely spread mycotoxins produced mainly by Aspergillus species. Consumption of aflatoxin-contaminated foods and drinks causes serious health risks for people worldwide. It is well-known that the reactive epoxide metabolite of aflatoxin B1 (AFB1) forms covalent adducts with serum albumin. However, non-covalent interactions of aflatoxins with human serum albumin (HSA) are poorly characterized. Thus, in this study the complex formation of aflatoxins was examined with HSA applying spectroscopic and molecular modelling studies. Our results demonstrate that aflatoxins form stable complexes with HSA as reflected by binding constants between 2.1 × 10⁴ and 4.5 × 10⁴ dm³/mol. A binding free energy value of −26.90 kJ mol⁻¹ suggests a spontaneous binding process between AFB1 and HSA at room-temperature, while the positive entropy change of 55.1 JK⁻¹ mol⁻¹ indicates a partial decomposition of the solvation shells of the interacting molecules. Modeling studies and investigations with site markers suggest that Sudlow’s Site I of subdomain IIA is the high affinity binding site of aflatoxins on HSA. Interaction of AFB1 with bovine, porcine, and rat serum albumins was also investigated. Similar stabilities of the examined AFB1-albumin complexes were observed suggesting the low species differences of the albumin-binding of aflatoxins.

Mycotoxin monitoring for commercial foodstuffs in Taiwan

Mycotoxins are toxic food contaminants that are naturally produced by certain fungi. They induce negative effects on human health by making food unsafe for consumption. In this study, analyses were performed to determine the levels and incidence of aflatoxins (AFs) in peanut products, tree nuts, spices, and Coix seeds; ochratoxin A (OTA) in wheat and roasted coffee, as well as OTA and AFs in rice; and citrinin (CIT) in red yeast rice (RYR) products. A total of 712 samples from nine different food categories were collected between 2012 and 2013. The samples were analyzed over 2 years for AFs, OTA, and CIT by methods recommended by the Ministry of Health and Welfare. These official analytical methods were extensively validated in-house and through interlaboratory trials. The analytical values of suspected contaminated specimens were confirmed by liquid chromatography - tandem mass spectrometry analysis to identify the specific mycotoxin present in the sample. We show that 689 samples (96.8%) complied with the regulations set by the Ministry of Health and Welfare. AFs were found in four peanut-candy products, one peanut-flour product, one pistachio product, one Sichuan-pepper product, and one Coix seed product. All had exceeded the maximum levels of 15 parts per billion for peanut and 10 parts per billion for other food products. Furthermore, 14 RYR samples contained CIT above 5 parts per million, and one RYR tablet exceeded the maximum amount allowed. Instances of AFs in substandard Sichuan pepper and Coix seeds were first detected in Taiwan. Measures were taken by the relevant authorities to remove substandard products from the market in order to decrease consumer exposure to mycotoxin. Border control measures were applied to importing food commodities with a higher risk of mycotoxin contamination, such as peanut, Sichuan pepper, and RYR products. Declining trends were observed in the noncompliance rate of AFs in peanut products, as well as that of CIT in RYR raw materials monitored from 2010 to 2013.

Risk Assessment on Dietary Exposure to Aflatoxin B₁ in Post-Harvest Peanuts in the Yangtze River Ecological Region

Based on the 2983 peanut samples from 122 counties in six provinces of China's Yangtze River ecological region collected between 2009-2014, along with the dietary consumption data in Chinese resident nutrition and health survey reports from 2002 and 2004, dietary aflatoxin exposure and percentiles in the corresponding statistics were calculated by non-parametric probability assessment, Monte Carlo simulation and bootstrap sampling methods. Average climatic conditions in the Yangtze River ecological region were calculated based on the data from 118 weather stations via the Thiessen polygon method. The survey results found that the aflatoxin contamination of peanuts was significantly high in 2013. The determination coefficient (R²) of multiple regression reflected by the aflatoxin B₁ content with average precipitation and mean temperature in different periods showed that climatic conditions one month before harvest had the strongest impact on aflatoxin B₁ contamination, and that Hunan and Jiangxi provinces were greatly influenced. The simulated mean aflatoxin B₁ intake from peanuts at the mean peanut consumption level was 0.777-0.790 and 0.343-0.349 ng/(kg·d) for children aged 2-6 and standard adults respectively. Moreover, the evaluated cancer risks were 0.024 and 0.011/(100,000 persons·year) respectively, generally less than China's current liver cancer incidence of 24.6 cases/(100,000 persons·year). In general, the dietary risk caused by peanut production and harvest was low. Further studies would focus on the impacts of peanut circulation and storage on aflatoxin B₁ contamination risk assessment in order to protect peanut consumers' safety and boost international trade.

Dietary exposure and risk assessment for aflatoxins in New Zealand

Aflatoxin concentration data for a range of foods available in New Zealand (maize products, nuts and nut products, dried fruits and spices) were combined with dietary recall food consumption information from New Zealand national nutrition surveys to derive exposure estimates for a range of age-gender groups. Mean exposure estimates for total aflatoxins ranged from 0.09-0.11 ng/kg body weight/day for adult females, to 0.32-0.39 ng/kg body weight/ day for 5-10 year old children. Spices were the major contributors to dietary exposure for all population subgroups, followed by nuts and nut products. However, the contribution of spices to total dietary exposure could be traced to a single sample with a very high concentration. A life-time weighted average aflatoxin exposure was derived for New Zealand males and females and was combined with cancer potency estimates to give an assessment of risk. The mean risk equates to a potential for less than one excess cancer every 10 years.

Dietary aflatoxin B1 intake, genetic polymorphisms of CYP1A2, CYP2E1, EPHX1, GSTM1, and GSTT1, and gastric cancer risk in Korean

PURPOSE

We investigated the effects of aflatoxin B1 (AFB1) intake, genetic polymorphisms of AFB1 metabolic enzymes, and interactions between the polymorphisms and intake of AFB1 with regard to the risk of gastric cancer in Korean.

METHODS

The participants in the study included 477 gastric cancer patients and 477 age- and sex-matched control subjects. Direct interviews and a structured questionnaire were used to determine the level of exposure to AFB1, and the GoldenGate assay and multiplex polymerase chain reaction were used for genotypic analyses of the cytochrome P450 1A2 (CYP1A2), cytochrome P450 1E1, epoxide hydrolase 1, and glutathione S-transferase genes.

RESULTS

The probable daily intake of AFB1 was significantly higher among gastric cancer patients than among control subjects (cases vs. controls: 1.91 ± 0.87 vs. 1.65 ± 0.72 ng/kg bw/day, p < 0.0001), and increased AFB1 intake was significantly associated with an elevated risk of gastric cancer (odds ratio 1.94; 95 % confidence interval 1.43-2.63). However, genetic polymorphisms of AFB1 metabolic enzymes were not associated with gastric cancer, with the exception of CYP1A2. Moreover, there was no interaction between AFB1 intake and the genotypes of metabolic enzymes that affect gastric cancer risk.

CONCLUSIONS

Our results suggest that dietary AFB1 exposure might be associated with a risk of gastric cancer. However, the effect of AFB1 on gastric carcinogenesis may not be modulated by genetic polymorphisms of AFB1 metabolic enzymes.

RETRACTED ARTICLE: Assessment of aflatoxins in peanuts grown in the Pothohar area of Pakistan

A survey was carried out to assess the mycotoxin (aflatoxins) contamination in locally grown peanuts. A total of 72 samples of raw, roasted and salty peanuts were collected randomly from the Pothohar Plateau of Pakistan. The samples were dried, ground and extracted by adding acetonitrile:water (84:16; v/v%). The filtered extracts were cleaned with MycoSep-226 columns and analysed by high-performance liquid chromatography with a fluorescence detector. The limit of quantification for aflatoxin B₁ was 1 μg/kg with 70% recovery observed in spiked samples with a concentration range of 1-10 μg/kg. The results indicated that aflatoxins were present in almost 82% of the samples tested, with levels ranging from 14.3 to 98.8 μg/kg. This reflects that optimal conditions for fungal growth and mycotoxin contamination are frequent in peanut crop fields as well as in storehouses. Human exposure to such toxins can be controlled through appropriate measures, creating awareness and implementing regulations.

Dietary intake of aflatoxins in the adult Malaysian population - an assessment of risk

Exposure to aflatoxins in the adult Malaysian diet was estimated by analysing aflatoxins in 236 food composites prepared as "ready for consumption". Dietary exposure to aflatoxin B1 (AFB1) ranged from 24.3 to 34.00 ng/kg b.w./day (lower to upper bound), with peanuts being the main contributor. Estimated liver cancer risk from this exposure was 0.61-0.85 cancers/100,000 population/year, contributing 12.4%-17.3% of the liver cancer cases. Excluding AFB1 occurrence data higher than 15 µg/kg reduced exposure by 65%-91% to 2.27-11.99 ng/kg b.w./day, reducing the cancer risk to 0.06-0.30 cancers/100,000 population/year (contributing 1.2%-6.1% liver cancer cases). Reducing further the ML of AFB1 from 15 to 5 µg/kg yielded 3%-7% greater drop in the exposure to 0.47-10.26 ng/kg b.w./day with an estimated risk of 0.01-0.26 cancers/100,000 population/year (0.2%-5.1% liver cancer cases attributed to dietary AFB1). These findings indicate that current MLs are adequate in protecting Malaysians' health.

Aflatoxin species: their health effects and determination methods in different foodstuffs

Carcinogenic and mutagenic properties of aflatoxin species are known in literature. Their intake over a long time period might be health-dangerous for human even at trace levels. It is well known that different foodstuffs can be contaminated by aflatoxin species through growing and storage. Due to the serious health effects, sensitive determination of aflatoxin species in any matrices related with the human being is very crucial at trace levels. In literature, there are sensitive techniques to analyze the different samples for the contents of their aflatoxin species. Each technique has some advantages and disadvantages over the other techniques. This review aims to summarize the different health effects of aflatoxin species, development of analytical techniques and applications of developed techniques in a variety of matrices.

Global burden of aflatoxin-induced hepatocellular carcinoma: a risk assessment

BACKGROUND

Hepatocellular carcinoma (HCC), or liver cancer, is the third leading cause of cancer deaths worldwide, with prevalence 16-32 times higher in developing countries than in developed countries. Aflatoxin, a contaminant produced by the fungi Aspergillus flavus and Aspergillus parasiticus in maize and nuts, is a known human liver carcinogen.

OBJECTIVES

We sought to determine the global burden of HCC attributable to aflatoxin exposure.

METHODS

We conducted a quantitative cancer risk assessment, for which we collected global data on food-borne aflatoxin levels, consumption of aflatoxin-contaminated foods, and hepatitis B virus (HBV) prevalence. We calculated the cancer potency of aflatoxin for HBV-postive and HBV-negative individuals, as well as the uncertainty in all variables, to estimate the global burden of aflatoxin-related HCC.

RESULTS

Of the 550,000-600,000 new HCC cases worldwide each year, about 25,200-155,000 may be attributable to aflatoxin exposure. Most cases occur in sub-Saharan Africa, Southeast Asia, and China where populations suffer from both high HBV prevalence and largely uncontrolled aflatoxin exposure in food.

CONCLUSIONS

Aflatoxin may play a causative role in 4.6-28.2% of all global HCC cases.

Fumonisins B1 and B2 in agricultural products consumed in South Korea: an exposure assessment

To survey fumonisins B1 (FB1) and B2 (FB2) in agricultural products consumed in South Korea and provide an exposure assessment, ground samples were extracted (80% MeOH), filtered (0.2 microm), and cleaned up. After evaporation, dry residues were reconstituted in 50% MeOH, and a 50-micro1 aliquot of this sample was mixed with 200 micro1 of o-phthaldialdehyde for derivatization. The derivatives were analyzed with a high-performance liquid chromatography system equipped with a fluorescence detector. For validation of the detection procedure, linearity, accuracy, precision, detection limit, and quantification limit were determined. The validated detection method was then used to survey fumonisins in white rice, brown rice, barley, barley tea, beer, wheat flour, millet, dried corn, corn flour, corn tea, canned corn, popcorn, and breakfast cereal. Retention times for FB1 and FB2 standards were 7 and 18 min, respectively. Linearity (R2 = 0.99995 to 0.99998), accuracy (81.47 to 108.83%), precision (2.35 to 5.77), detection limit (25 ng/g or ng/ml), and quantification limit (37 ng/g or ng/ml) indicated that this procedure is capable of quantifying fumonisins in agricultural products. Only FB1-positive samples (5.12%, three dried corn samples and five corn flour samples) were found at 90.89 to 439.67 ng/g. According the survey results, an estimated daily intake of FB1 and FB2 in Korea was 0.087 ng/kg of body weight per day. These results indicate that continuous monitoring of these mycotoxins is necessary to establish appropriate risk assessment, and the maximum tolerable daily intake of fumonisins in Korea is lower than the 2 microg/kg set by the Joint Food and Agriculture Organization-World Health Organization Expert Committee.

Developments in mycotoxin analysis: an update for 2007-2008

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2007 and mid-2008. It covers the major mycotoxins: aflatoxins, Alternaria toxins, cyclopiazonic acid, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. Some aspects of natural occurrence, particularly if linked to novel aspects of analytical methods, are also included. The review demonstrates the rise of LC-MS methods, the continuing interest in developing alternative and rapid methods and the modification of well-established mycotoxin analytical methods by individual laboratories to meet their own requirements.

Determination of deoxynivalenol in cereal-based foods and estimation of dietary exposure

Deoxynivalenol (DON) is a trichothecene mycotoxin. DON contamination in agricultural food staples such as wheat, barley, and maize due to Fusarium colonization is an increasing problem. In order to provide risk managers with better guidance for regulatory measures, the concentration of DON in cereal-based foods (n = 689), collected from six cities between June 2005 and August 2008, was determined. Further, dietary exposure to DON was estimated by combining data on DON concentration in these foods with their consumption rates. Among 689 samples, 272 samples (39%) were contaminated with DON. Relatively high DON concentrations were found in dried corn, with a mean concentration of 109 microg/kg (n = 74). Daily intake of DON simulated by the @Risk program was estimated to between 0.066 and 0.142 microg/kg body weight (bw)/d for males and between 0.066 and 0.144 microg/kg bw/d for females. The major contributor to DON exposure in the 50th and 95th percentile intake groups was polished rice. For each age class, young children (3-6 yr) showed the highest relative intake, with a mean intake of 0.142 microg/kg bw/d for males and 0.144 microg/kg bw/d for females. However, the estimated daily DON intake did not exceed the provisional maximum tolerable daily intake (1 microg/kg bw/d) for any age group or gender. From our risk assessment, it was concluded that the current intake of DON in South Korea may not serve as a serious health hazard.