Occurrence of Multiple Mycotoxins in Various Types of Rice and Barley Samples in Thailand

The occurrence and biological control of zearalenone in cereals and cereal-based feedstuffs: a review

Zearalenone, a prominent mycotoxin produced by Fusarium spp., ubiquitously contaminates cereal grains and animal feedstuffs. The thermal stability of zearalenone creates serious obstacles for traditional removal methods, which may introduce new safety issues, or reducing nutritional quality. In contrast, biological technologies provide appealing benefits such as easy to apply and effective, with low toxicity byproducts. Thus, this review aims to describe the occurrence of zearalenone in cereals and cereal-based feedstuffs in the recent 5 years, outline the rules and regulations regarding zearalenone in the major countries, and discuss the recent developments of biological methods for controlling zearalenone in cereals and cereal-based feedstuffs. In addition, this article also reviews the application and the development trend of biological strategies for removal zearalenone in cereals and cereal-based feedstuffs.

Review of the Terminology, Approaches, and Formulations Used in the Guidelines on Quantitative Risk Assessment of Chemical Hazards in Food

This paper reviews the published terminology, mathematical models, and the possible approaches used to characterise the risk of foodborne chemical hazards, particularly pesticides, metals, mycotoxins, acrylamide, and polycyclic aromatic hydrocarbons (PAHs). The results confirmed the wide variability of the nomenclature used, e.g., 28 different ways of referencing exposure, 13 of cancer risk, or 9 of slope factor. On the other hand, a total of 16 equations were identified to formulate all the risk characterisation parameters of interest. Therefore, the present study proposes a terminology and formulation for some risk characterisation parameters based on the guidelines of international organisations and the literature review. The mathematical model used for non-genotoxic hazards is a ratio in all cases. However, the authors used the probability of cancer or different ratios, such as the margin of exposure (MOE) for genotoxic hazards. For each effect studied per hazard, the non-genotoxic effect was mostly studied in pesticides (79.73%), the genotoxic effect was mostly studied in PAHs (71.15%), and both effects were mainly studied in metals (59.4%). The authors of the works reviewed generally opted for a deterministic approach, although most of those who assessed the risk for mycotoxins or the ratio and risk for acrylamide used the probabilistic approach.

Quantitative risk assessment of the presence of fumonisin in corn produced in different regions of Brazil: Influence of climatic conditions

In this study, the probability of occurrence of fumonisins in corn in the states of greatest production in Brazil was determined. The data were analyzed through quantitative risk analysis using the Monte Carlo simulation. The results indicated that there is a strong correlation between fumonisins contamination levels and the geographical region due to the influence of climatic characteristics, with temperature having the main influence. The Southern states presented higher risks of occurrence and concentration levels of fumonisins in corn due to the temperate climate with lower average temperature and higher relative humidity and precipitation indices. Cultivation in the best season indicates a significant reduction in the production of fumonisins when this period was evaluated, with average concentration levels up to 42% lower. The generated data are important for regulatory agencies and the agricultural sector, which needs to be aware that the chance of success in grain production depends on efficient planning of the growing season, mainly concerning the climatic conditions to which it is subject to minimize the risks.

Storage Fungi and Mycotoxins Associated with Rice Samples Commercialized in Thailand

The study focused on the examination of the different fungal species isolated from commercial rice samples, applying conventional culture techniques, as well as different molecular and phylogenic analyses to confirm phenotypic identification. Additionally, the mycotoxin production and contamination were analyzed using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS). In total, 40 rice samples were obtained covering rice berry, red jasmine rice, brown rice, germinated brown rice, and white rice. The blotting paper technique applied on the 5 different types of rice samples detected 4285 seed-borne fungal infections (26.8%) for 16,000 rice grains. Gross morphological data revealed that 19 fungal isolates belonged to the genera Penicillium/Talaromyces (18 of 90 isolates; 20%) and Aspergillus (72 of 90 isolates; 80%). To check their morphologies, molecular data (fungal sequence-based BLAST results and a phylogenetic tree of the combined ITS, BenA, CaM, and RPB2 datasets) confirmed the initial classification. The phylogenic analysis revealed that eight isolates belonged to P. citrinum and, additionally, one isolate each belonged to P. chermesinum, A. niger, A. fumigatus, and A. tubingensis. Furthermore, four isolates of T. pinophilus and one isolate of each taxon were identified as Talaromyces (T. radicus, T. purpureogenum, and T. islandicus). The results showed that A. niger and T. pinophilus were two commonly occurring fungal species in rice samples. After subculturing, ochratoxin A (OTA), generated by T. pinophilus code W3-04, was discovered using LC-MS/MS. In addition, the Fusarium toxin beauvericin was detected in one of the samples. Aflatoxin B1 or other mycotoxins, such as citrinin, trichothecenes, and fumonisins, were detected. These preliminary findings should provide valuable guidance for hazard analysis critical control point concepts used by commercial food suppliers, including the analysis of multiple mycotoxins. Based on the current findings, mycotoxin analyses should focus on A. niger toxins, including OTA and metabolites of T. pinophilus (recently considered a producer of emerging mycotoxins) to exclude health hazards related to the traditionally high consumption of rice by Thai people.

Determination of Mycotoxin Contamination Levels in Rice and Dietary Exposure Assessment

The contamination by aflatoxins, ochratoxin A, and zearalenone of samples of paddy and polished rice stored in silos located in Chiriquí, Panama, was evaluated. A total of 23 samples were extracted using immunoaffinity columns and analyzed by high-performance liquid chromatography (HPLC) with a fluorescence detector (FLD) and post-column photochemical derivatization. For the method used, the detection limits were lower than 0.25 μg/Kg for aflatoxins (AFB1, AFB2, AFG1, AFG2) and ochratoxin A and 9.35 μg/Kg for zearalenone; the limits of quantification were between 0.25 and 18.75 μg/Kg, respectively. Of the samples analyzed, all of the paddy rice samples were positive for at least one of the mycotoxins studied, zearalenone being the one found with the highest incidence (90.91%); for the polished rice samples, the mycotoxin with the highest incidence was zearalenone (50%), although in concentrations lower than those established in European legislation (100 μg/Kg). The estimate of the daily zearalenone intake according to the concentrations found was always less than 0.07 μg/Kg/bw. This is the first report on the determination of 6 mycotoxins in rice grains from Panama by the HPLC-FLD methodology. Considering the high incidence of mycotoxins in the analyzed rice samples, regular control in the production process is recommended to improve quality and ascertain its safety.

Determination of Multiple Mycotoxins and Their Natural Occurrence in Edible Vegetable Oils Using Liquid Chromatography-Tandem Mass Spectrometry

The prevalence of mycotoxins is often increased by the climatic conditions prevailing in tropical regions. Reports have revealed the contamination of mycotoxins in some types of vegetable oil. However, vegetable oil is one of the essential ingredients used in food preparation. Thus, this study determined the occurrence of multi-mycotoxins in six types of vegetable oils commercially available in Thailand to assess the consumer health risk. In total, 300 vegetable oil samples (olive oil, palm oil, soybean oil, corn oil, sunflower oil, and rice bran oil) collected from various markets in Thailand were analyzed for the presence of nine mycotoxins, namely, aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), beauvericin (BEA), ochratoxin A (OTA), zearalenone (ZEA), fumonisin B1 (FB1), and fumonisin B2 (FB2) using a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based procedure and a triple quadrupole mass spectrometer equipped with an electrospray ionization source. The incidences of mycotoxin contamination varied among the different types of oil samples. AFB1, AFB2, ZEA, FB1, and FB2 were most frequently found in contaminated samples. AFB2, BEA, ZEA, FB1, and FB2 contaminated olive oil samples, whereas AFB1, AFB2, AFG2, and OTA contaminated palm oil samples. AFB1, AFB2, and ZEA were found in soybean oils, whereas ZEA, FB1, and FB2 contaminated corn oil samples. AFB1 and AFG1 contaminated sunflower oil samples, whereas AFB1, AFB2, AFG1, and OTA were detected in rice bran oil samples. However, the contamination levels of the analyzed mycotoxins were below the regulatory limits.

Impact of Season, Region, and Traditional Agricultural Practices on Aflatoxins and Fumonisins Contamination in the Rice Chain in the Mekong Delta, Vietnam

The current study aimed to evaluate the impact of the crop season, cultivation region, and traditional pre- and post-harvest agricultural practices on mycotoxin contamination in the Mekong Delta rice chain of Vietnam. The results showed that aflatoxins (AFs) and fumonisins (FBs) were predominantly detected in both paddy (n = 91/184, 50%) and white rice (n = 9/46, 20%). Aflatoxin B1 (AFB1)-contaminated paddy samples (n = 3) exceeded the regulatory threshold (5 µg·kg-1). The contamination of paddy with AFs and FBs was not significantly different by growing seasons and cultivation localities. Evidently, in the winter-spring season, fumonisins frequently occurred in paddy planted in Can Tho, while AFs were found in paddy planted in regions Dong Thap and An Giang, and such toxins were absent in Can Tho. Furthermore, the selection of paddy varieties strongly impacted the occurrence of these toxins, especially AFs, for example, line DT8 and Jasmine were susceptible to AFs and FBs. In addition, poor pre- and post-harvest practices (such as crop residue-free fields, fertilizer application, unsanitary means of transport, delayed drying time) had an impact on the AFs and FBs contamination. Our findings can help to understand the dynamics of AFs and FBs in the rice chain in the Vietnamese Mekong Delta, leading to the mitigation of the contamination of AFs and FBs in rice.

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.