Aflatoxins and ochratoxin A in export quality raisins collected from different areas of Pakistan

Aflatoxins and Ochratoxin A in dried fruits from Morocco: Monitoring, regulatory aspects, and exposure assessment

The present study aims to investigate the presence of Aflatoxins (AF) in 180 samples dried fruits and Ochratoxin A (OTA) in 210 samples dried fruits and grape juices collected in Morocco. Mycotoxins were analyzed by high performance liquid chromatography (HPLC) coupled to fluorescence detection and immunoaffinity columns (IAC) cleanup. Contamination levels were compared with the maximum regulatory limits (MRL) recently adopted in the country, and mycotoxin exposure of adult consumers was assessed. Results showed that 13.8% of samples were contaminated with AF, with incidences of 23.3, 23.3, 20, 13.8, and 3.3%, in raisins, figs, nuts, peanuts and pistachio, respectively. There were 12 samples (6.6%) that exceeded the MRL of 2-12 ng/g set for aflatoxin B1 (AFB1). While OTA was detected in 17.1% of samples, with incidences of 3.3, 3.3, 30, 30, and 53.3% in walnuts, pistachios, peanuts, raisins and figs, respectively, and a maximum value of 99.1 in dried raisins, that exceeded the MRL (10 ng/g) set for OTA. The co-occurrence of OTA and AF was observed in 4.7% of total samples. Dietary intake showed that the OTA exposure level was lower than safety guidelines set by The Joint FAO/WHO Expert Committee on Food Additives (JECFA) at 100 ng/kg b.w./week.

Natural co-occurrence of aflatoxins and ochratoxin A in liquorice roots

The natural co-occurrence of aflatoxins (AFs) and ochratoxin A (OTA) in liquorice roots obtained from different herbal outlets of Karachi, Pakistan, was evaluated. A total of 60 samples were obtained during 2019‒2021 and analysed using HPLC with fluorescence detection. The method was validated according to the European Union (EU) regulation. The incidence of AFs was 52 in all tested samples (87%), with a contamination range of 1.2‒6.4 µg kg-1 and an average of 2.1 ± 0.3 µg kg-1. In all samples, the AFs contamination was below the maximum limit (ML) of 10 µg kg-1 for total AFs as set by the EU. The OTA contamination in all samples ranged 1.5‒60.3 µg kg-1, with a mean of 18.9 ± 0.8 µg kg-1. In 36 samples (60%) the OTA contamination was below the ML of 20 µg kg-1 as set by the EU. These results led to the recommendation to test liquorice root on mycotoxins, as it comes to food quality standards.

Aflatoxins posing threat to food safety and security in Pakistan: Call for a one health approach

Aflatoxins are among the most important mycotoxins due to their widespread occurrence and adverse impacts on humans and animals. These toxins and/or their metabolites cannot be destroyed with cooking or boiling methods. Therefore, consumption of aflatoxin-contaminated food may lead to impaired growth, compromised immunity, stomach and liver cancer, and acute toxicity. These adverse effects along with food wastage might have detrimental consequences on a country's economy. Several studies from Pakistan reported a high prevalence of aflatoxins in food and feed commodities (Range; milk = 0.6-99.4%, cereals, and grains = 0.38-41%, animal feed = 31-100%). Notably, Pakistan reported very high figures of impaired child growth-stunted 40.2%, wasted 17.7% and underweight 28.9%-that could be associated with the higher aflatoxin prevalence in food items. Importantly, high aflatoxins prevalence, i.e. 100%, 69% and 60.5%, in children has been reported in Pakistan. Food and feed are more prone to aflatoxin contamination due to Pakistan's hot and humid climate; however, limited awareness, inadequate policy framework, and weak implementation mechanisms are the major obstacles to effective control. This review will discuss aflatoxins prevalence, associated risk factors, adverse health effects, required regulatory regime, and effective control strategies adopting the One Health approach to ensure food safety and security.

A high-performance method for quantitation of aflatoxins B1, B2, G1, G2: Full validation for raisin, peanut matrices, and survey of related products at Ho Chi Minh City

Optimization and validation for simultaneous quantitation of four aflatoxins B1, B2, G1, and G2 in peanuts and raisins were performed on ultra-performance liquid chromatography in a combination of fluorescence detector, without derivatization. The advantages were short analysis time, simple sample handling, and reduced solvent consumption. Instrument detection limits of AFB1, AFB2, AFG1, and AFG2 were 0.07, 0.01, 0.1, and 0.008 μg/kg, respectively, lower than those obtained by LCMSMS and HPLC-FLD with derivatization. Two solvent mixtures were chosen for two different matrices whose matrix effect was not negligible (2.81%-8.04% for peanuts and 5.63%-11.43% for raisins). The linear ranges were from 0.2 to 20 μg/L for AFB1 and AFG1 and from 0.05 to 5 μg/L for AFB2 and AFG2. The limits of detection and quantification were 0.025-0.1 and 0.075-0.3 μg/kg for peanuts and raisins, respectively. Recoveries at three other concentrations from 0.75 to 125 μg/kg of total aflatoxins were obtained between 76.5% and 99.8% (with RSD < 6%) following the SANTE 11312/2021. Validation parameters complied with the requirements of ISO/IEC 17025:2017. The extracts and the sample could be stabilized at 4°C and 20°C for 24 h and at -20°C for up to 21 days, respectively. Thus, the study can be used as a standard method for the analysis of Aflatoxins (AFs) in peanut and raisin matrices. Investigation of 350 peanut samples collected at Markets in the central districts of HCM city showed that 28.6% were contaminated with AFB1 from 0.31 up to 554 μg/kg; 13.4% contained AFB2, and 5.7% of AFG1 in the range of 0.4-53 μg/kg and 0.4-9.57 μg/kg, respectively; AFG2 (about 0.6%) was detected from 0.45 to 0.75 μg/kg. Meanwhile, 12.8% exceeded the total aflatoxins limit, and 13.4% exceeded the AFB1 limit. AFs were almost not found in the 350 raisin samples.

Occurrence of Mycotoxins in Dried Fruits Worldwide, with a Focus on Aflatoxins and Ochratoxin A: A Review

Dried fruits are popular and nutritious snacks consumed worldwide due to their long shelf life and concentrated nutrient content. However, fruits can be contaminated with various toxigenic fungal species during different stages, including cultivation, harvesting, processing, drying, and storage. Consequently, these products may contain high levels of mycotoxins. This risk is particularly pronounced in developed countries due to the impact of climate change. Several factors contribute to mycotoxin production, including the type of fruit, geographical location, climate conditions, harvest treatments, and storage management practices. The main mycotoxins in dried fruits are aflatoxins (AFs) and ochratoxin A (OTA), which can induce human health problems and economic losses. Mycotoxin contamination can vary significantly depending on the geographic origin of dried fruits (vine fruits, figs, dates, apricots, prunes, and mulberries). The aim of this review was to fill the knowledge gap by consolidating data from various regions to understand the global picture and identify regions with higher contamination risks. By consolidating research from various origins and stages of the supply chain, the review intends to shed light on potential contamination events during pre-harvest, drying, storage, and trading, while also highlighting the effects of storage conditions and climate change on mycotoxin contamination.

Super-Sensitive LC-MS Analyses of Exposure Biomarkers for Multiple Mycotoxins in a Rural Pakistan Population

High levels of mycotoxin contamination have been reported in various food commodities in Pakistan, however, there has been no exposure assessment study using multiple mycotoxins’ biomarkers. This study aimed to simultaneously assess the exposure to the five major mycotoxins: aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), ochratoxin A (OTA) and zearalenone (ZEN) in a Pakistani population using an integrated approach of human biomonitoring. Human urine samples (n = 292) were analyzed by a super-sensitive liquid-chromatography tandem mass spectrometry (LC-MS/MS) method. Rice and wheat were also collected and analyzed for mycotoxins by the LC-MS/MS method. Food consumption data were collected using a 24 h recall method. A high prevalence of urinary AFM1 (66%, mean ± SD 20.8 ± 41.3 pg/mL) and OTA (99%, 134.7 ± 312.0 pg/mL) were found, whilst urinary DON, FB1 and ZEN levels were low. The probable daily intake (PDI) derived from the urinary biomarkers revealed that 89% of the participants had exposure to OTA exceeding the established tolerable daily intake (TDI = 17 ng/kg bw/day). The average PDI of AFB1 for the studied population was 43 ng/kg bw/day, with rice as the main source of AFB1 exposure. In summary, exposure to AFB1 and OTA are of health concern and require further management.

Genetic Diversity, Ochratoxin A and Fumonisin Profiles of Strains of Aspergillus Section Nigri Isolated from Dried Vine Fruits

We investigated ochratoxin A (OTA) contamination in raisin samples purchased from Slovak markets and determined the diversity of black-spored aspergilli as potential OTA and fumonisin (FB1 and FB2) producers. The taxonomic identification was performed using sequences of the nuclear ITS1-5.8s-ITS2 region, the calmodulin and beta-tubulin genes. We obtained 239 isolates from eight fungal genera, of which 197 belonged to Aspergillus (82%) and 42 strains (18%) to other fungal genera. OTA contamination was evidenced in 75% of the samples and its level ranged from 0.8 to 10.6 µg/kg. The combination of all three markers used enabled unambiguous identification of A. carbonarius, A. luchuensis, A. niger, A. tubingensis and A. welwitschiae. The dominant coloniser, simultaneously having the highest within-species diversity isolated from our raisin samples, was A. tubingensis. Out of all analysed strains, only A. carbonarius was found to produce OTA, but in relatively high quantity (2477–4382 µg/kg). The production of FB1 and FB2 was evidenced in A. niger strains only.

A preliminary assessment of dietary exposure of ochratoxin A in Central Anatolia Region, Turkey

The aim of this study was to determine dietary exposure to ochratoxin A (OTA) in Turkish adults. In this study, 500 food samples (50 rice, 50 wheat bread, 50 pasta, 50 raisins, 50 dried figs, 50 pistachios, 50 hazelnuts, 50 almonds, 50 chilli, 25 coffee, and 25 cocoa) collected from Turkey were analysed with a high-performance liquid chromatography (HPLC) method. Moreover, a total of 370 analytical results (110 cereal-based snacks, 95 wine, 35 beer, and 130 chocolate) collected from our previous observations were also used in the evaluation of exposure estimates. OTA was found in 52% of cocoa, 42% of raisins, 40% of coffee, 34% of chilli, 14% of dried figs, 10% of pasta, 8% of pistachios, 6% of wheat bread, 4% of rice, and 4% of hazelnuts. The chronic dietary exposure to OTA for Turkish adults, using lower bound (LB) and upper bound (UB) concentrations, varied from 0.683 to 4.487 ng/kg body weight (b.w.) per week for mean estimate and from 3.976 to 5.760 ng/kg b.w. per week for the 95th percentile (P95) estimate. Cereals and cereal-based products made the largest contribution (75.3-85.7%) to OTA exposure. Both mean and P95 chronic exposure to OTA were greatly below the tolerable weekly intake of 120 ng/kg b.w. per week and thus not a health concern for Turkish adults.