Determination of Regulated and Emerging Mycotoxins in Organic and Conventional Gluten-Free Flours by LC-MS/MS

Aptamer-modulated Pt/Au/MIL-100(Fe) nanozymatic activity for the colorimetric detection of deoxynivalenol in grains

In this study, Pt/Au nanoparticles functionalized metal-organic frameworks (Pt/Au/MIL-100(Fe)) nanocomposite was employed as a nanozyme and a colorimetric aptasensor based on aptamer-modulated nanozymatic activity was developed for deoxynivalenol (DON) detection. The catalytic activity of Pt/Au/MIL-100(Fe) was initially inhibited by aptamers due to the blocking of surface-active sites. However, the presence of DON detached the aptamer from Pt/Au/MIL-100(Fe) surface, restoring the enzyme-mimicking activity of the nanocomposites and producing a measurable colorimetric signal for DON quantitation. The nanozyme showed stable catalytic activities with a relative standard deviation within 3 % for storage at 4 °C for 21 days. Meanwhile, the developed aptasensor demonstrated a good linear range of 50-5000 ng/mL with a limit of detection of 44.14 ng/mL. The recovery rates for detecting DON in positive wheat and maize flour samples were 98.59 %-106.27 %. The developed method is cost-effective and easy to fabricate, providing a powerful tool for DON detection in food.

Aflatoxins in the rice production chain: A review on prevalence, detection, and decontamination strategies

Rice (Oryza sativa L.) is one of the most consumed cereals that along with several important nutritional constituents typically provide more than 21% of the caloric requirements of human beings. Aflatoxins (AFs) are toxic secondary metabolites of several Aspergillus species that are prevalent in cereals, including rice. This review provides a comprehensive overview on production factors, prevalence, regulations, detection methods, and decontamination strategies for AFs in the rice production chain. The prevalence of AFs in rice is more prominent in African and Asian than in European countries. Developed nations have more stringent regulations for AFs in rice than in the developing world. The contamination level of AFs in the rice varied at different stages of rice production chain and is affected by production practices, environmental conditions comprising temperature, humidity, moisture, and water activity as well as milling operations such as de-husking, parboiling, and polishing. A range of methods including chromatographic techniques, immunochemical methods, and spectrophotometric methods have been developed, and used for monitoring AFs in rice. Chromatographic methods are the most used methods of AFs detection followed by immunochemical techniques. AFs decontamination strategies adopted worldwide involve various physical, chemical, and biological strategies, and even using plant materials. In conclusion, adopting good agricultural practices, implementing efficient AFs detection methods, and developing innovative aflatoxin decontamination strategies are imperative to ensure the safety and quality of rice for consumers.

Simultaneous detection of mycotoxins and pesticides in human urine samples: A 24-h diet intervention study comparing conventional and organic diets in Spain

Pesticides and mycotoxins, prominent chemical hazards in the food chain, are commonly found in plant-based foods, contributing to their pervasive presence in the human body, as evidenced by biomonitoring programs. Despite this, there is limited knowledge about their co-occurrence patterns. While intervention studies have demonstrated that organic diets can significantly reduce pesticide levels, their impact on mycotoxin exposure has been overlooked. To address this gap, this study pursued two objectives: first, to characterize the simultaneous presence of mycotoxins and pesticides in human urine samples by means of the control of the biomarkers of exposure, and second, to investigate the influence of consuming organic foods on these co-exposure patterns. A pilot study involving 20 healthy volunteers was conducted, with participants consuming either exclusively organic or conventional foods during a 24-h diet intervention in autumn 2021 and spring 2022 to account for seasonal variability. Participants provided detailed 24-h dietary records, and their first-morning urine samples were collected, minimally treated and analysed using LC-Q-ToF-MS by means of a multitargeted method in order to detect the presence of these residues. Results indicated that among the 52 screened compounds, four mycotoxins and seven pesticides were detected in over 25% of the samples. Deoxynivalenol (DON) and the non-specific pesticide metabolite diethylphosphate (DEP) exhibited the highest frequency rates (100%) and concentration levels. Correlations were observed between urine levels of mycotoxins (DON, ochratoxin alpha [OTα], and enniatin B [ENNB]) and organophosphate pesticide metabolites DEP and 2-diethylamino-6-methyl-4-pyrimidinol (DEAMPY). The pilot intervention study suggested a reduction in ENNB and OTα levels and an increase in β-zearalenol levels in urine after a short-term replacement with organic food. However, caution is advised due to the study's small sample size and short duration, emphasizing the need for further research to enhance understanding of the human chemical exposome and refine chemical risk assessment.

Modified Mycotoxins and Multitoxin Contamination of Food and Feed as Major Analytical Challenges

Mycotoxins, as natural products of molds, are often unavoidable contaminants of food and feed, to which the increasingly evident climate changes contribute a large part. The consequences are more or less severe and range from economic losses to worrying health problems to a fatal outcome. One of the best preventive approaches is regular monitoring of food and feed for the presence of mycotoxins. However, even under conditions of frequent, comprehensive, and conscientious controls, the desired protection goal may not be achieved. In fact, it often happens that, despite favorable analytical results that do not indicate high mycotoxin contamination, symptoms of their presence occur in practice. The most common reasons for this are the simultaneous presence of several different mycotoxins whose individual content does not exceed the detectable or prescribed values and/or the alteration of the form of the mycotoxin, which renders it impossible to be analytically determined using routine methods. When such contaminated foods enter a living organism, toxic effects occur. This article aims to shed light on the above problems in order to pay more attention to them, work to reduce their impact, and, eventually, overcome them.

Natural Occurrence of Regulated and Emerging Mycotoxins in Wheat Grains and Assessment of the Risks from Dietary Mycotoxins Exposure in China

Wheat grains are susceptible to contamination with various natural mycotoxins including regulated and emerging mycotoxins. This study surveyed the natural presence of regulated mycotoxins, such as deoxynivalenol (DON) and zearalenone (ZEN), and emerging mycotoxins such as beauvericin (BEA), enniatins (ENNs such as ENA, ENA1, ENB, ENB1) and Alternaria mycotoxins (i.e., alternariol monomethyl ether (AME), alternariol (AOH), tenuazonic acid (TeA), tentoxin (TEN), and altenuene (ALT)) in wheat grains randomly collected from eight provinces across China in 2021. The results revealed that each wheat grain sample was detected with at least one type of mycotoxin. The detection rates of these mycotoxins ranged from 7.1% to 100%, with the average occurrence level ranging from 1.11 to 921.8 µg/kg. DON and TeA were the predominant mycotoxins with respect to both prevalence and concentration. Approximately 99.7% of samples were found to contain more than one toxin, and the co-occurrence of ten toxins (DON + ZEN + ENA + ENA1 + ENB + ENB1 + AME + AOH + TeA + TEN) was the most frequently detected combination. The dietary exposure to different mycotoxins among Chinese consumers aged 4-70 years was as follows: 0.592-0.992 µg/kg b.w./day for DON, 0.007-0.012 µg/kg b.w./day for ZEN, 0.0003-0.007 µg/kg b.w./day for BEA and ENNs, 0.223-0.373 µg/kg b.w./day for TeA, and 0.025-0.041 µg/kg b.w./day for TEN, which were lower than the health-based guidance values for each mycotoxin, with the corresponding hazard quotient (HQ) being far lower than 1, implying a tolerable health risk for Chinese consumers. However, the estimated dietary exposure to AME and AOH was in the range of 0.003-0.007 µg/kg b.w./day, exceeding the Threshold of Toxicological Concern (TTC) value of 0.0025 µg/kg b.w./day, demonstrating potential dietary risks for Chinese consumers. Therefore, developing practical control and management strategies is essential for controlling mycotoxins contamination in the agricultural systems, thereby ensuring public health.

Enniatin B1: Emerging Mycotoxin and Emerging Issues

Although over the last 10 years several studies have focused on the emerging mycotoxins known as enniatins (ENNs), there is still a lack of knowledge regarding their toxicological effects and the development of a correct risk assessment. This is especially true for enniatin B1 (ENN B1), considered the younger sister of the widely studied enniatin B (ENN B). ENN B1 has been found in several food commodities and, as with other mycotoxins, presents antibacterial and antifungal properties. On the other hand, ENN B1 has shown cytotoxic activity, impairment of the cell cycle, the induction of oxidative stress, and changes in mitochondrial membrane permeabilization, as well as negative genotoxic and estrogenic effects. Overall, considering the paucity of information available regarding ENN B1, further studies are necessary to perform a risk assessment. This review summarizes information on the biological characteristics and toxicological effects of ENN B1 as well as the future challenges that this mycotoxin could present.