Impact of climate change effects on contamination of cereal grains with deoxynivalenol

Changing climate, shifting mycotoxins: A comprehensive review of climate change impact on mycotoxin contamination

Climate change (CC) is a complex phenomenon that has the potential to significantly alter marine, terrestrial, and freshwater ecosystems worldwide. Global warming of 2°C is expected to be exceeded during the 21st century, and the frequency of extreme weather events, including floods, storms, droughts, extreme temperatures, and wildfires, has intensified globally over recent decades, differently affecting areas of the world. How CC may impact multiple food safety hazards is increasingly evident, with mycotoxin contamination in particular gaining in prominence. Research focusing on CC effects on mycotoxin contamination in edible crops has developed considerably throughout the years. Therefore, we conducted a comprehensive literature search to collect available studies in the scientific literature published between 2000 and 2023. The selected papers highlighted how warmer temperatures are enabling the migration, introduction, and mounting abundance of thermophilic and thermotolerant fungal species, including those producing mycotoxins. Certain mycotoxigenic fungal species, such as Aspergillus flavus and Fusarium graminearum, are expected to readily acclimatize to new conditions and could become more aggressive pathogens. Furthermore, abiotic stress factors resulting from CC are expected to weaken the resistance of host crops, rendering them more vulnerable to fungal disease outbreaks. Changed interactions of mycotoxigenic fungi are likewise expected, with the effect of influencing the prevalence and co-occurrence of mycotoxins in the future. Looking ahead, future research should focus on improving predictive modeling, expanding research into different pathosystems, and facilitating the application of effective strategies to mitigate the impact of CC.

Climate Change and Food Allergy

The role of environmental factors including climate change and consequent influences of air pollution on food allergy remains less explored compared with impacts on allergic rhinitis and asthma. In this review, we discuss the epithelial barrier hypothesis as a proposed mechanism of food allergy development that may be relevant in this context. We also discuss existing studies that provide insight into the intricate relationship between food allergy and climate-related environmental factors.

Distribution, toxicity, interactive effects, and detection of ochratoxin and deoxynivalenol in food: A review

Mycotoxins are secondary metabolites of fungi that cause severe damage to agricultural products and food in the food supply chain. These detrimental pollutants have been directly linked with poor socioeconomic patterns and human health issues. Among the natural micropollutants, ochratoxin A (OTA) and deoxynivalenol (DON) are widely distributed in food materials. The primary occurrence of these mycotoxins is reported in almost all cereal grains and fresh agro-products. Both mycotoxins have shown harmful effects, such as nephrotoxic, hepatotoxic, and genotoxic effects, in humans due to their complex structural formation during the degradation/acetylation reaction. In addition, improper preharvest, harvest, and postharvest handling tend to lead to the formation of OTA and DON in various food commodities, which allows different harmful fungicides in practice. Therefore, this review provides more insight into the distribution and toxicity of OTA/DON in the food matrix and human health. Furthermore, the interactive effects of OTA/DON with co-contaminated organic and inorganic compounds are discussed. Finally, international regulation and mitigation strategies for detoxication are critically evaluated to meet food safety and good agriculture practices.

Review: Future consequences of climate change for European Union pig production

Climate change is already a reality for livestock production. In contrast to the ruminant species, little is known about the impacts and the vulnerability of pig European Union (EU) sector to climate warming. This review deals with the potential and the already measurable effects of climate change in pig production. Based on evidences published in the literature, climate change may reduce EU pig productivity by indirectly reducing the availability of crops usually used in pig feeding, spreading the vector or pathogen to new locations and increasing the risk of exposure to cereals contaminated with mycotoxins; and directly mainly by inducing heat stress and increasing the animal's susceptibility to various diseases. Provision of realistic projections of possible impacts of future climate changes on EU pig sector is a prerequisite to evaluate its vulnerability and propose effective adaptation strategies. Simulation modelling approach is the most commonly used approach for exploring the effects of medium or long-term climate change/variability in pig production. One of the main challenges for this modelling approach is to account for both direct and indirect possible effects but also to uncertainties in parameter values that substantially increase the uncertainty estimates for model projections. The last part of the paper focus on the main issues that still need to be overcome for developing a decision support tools for simulating the direct and indirect effect of climate change in pig farms.

Climate change will influence disease resistance breeding in wheat in Northwestern Europe

Wheat productivity is threatened by global climate change. In several parts of NW Europe it will get warmer and dryer during the main crop growing period. The resulting likely lower realized on-farm crop yields must be kept by breeding for resistance against already existing and emerging diseases among other measures. Multi-disease resistance will get especially crucial. In this review, we focus on disease resistance breeding approaches in wheat, especially related to rust diseases and Fusarium head blight, because simulation studies of potential future disease risk have shown that these diseases will be increasingly relevant in the future. The long-term changes in disease occurrence must inevitably lead to adjustments of future resistance breeding strategies, whereby stability and durability of disease resistance under heat and water stress will be important in the future. In general, it would be important to focus on non-temperature sensitive resistance genes/QTLs. To conclude, research on the effects of heat and drought stress on disease resistance reactions must be given special attention in the future.

Effects of Durum Wheat Cultivars with Different Degrees of FHB Susceptibility Grown under Different Meteorological Conditions on the Contamination of Regulated, Modified and Emerging Mycotoxins

The enhancement of Fusarium head blight (FHB) resistance is one of the best options to reduce mycotoxin contamination in wheat. This study has aimed to verify that the genotypes with high tolerance to deoxynivalenol could guarantee an overall minimization of the sanitary risk, by evaluating the contamination of regulated, modified and emerging mycotoxins on durum wheat cvs with different degrees of FHB susceptibility, grown under different meteorological conditions, in 8 growing seasons in North-West Italy. The years which were characterized by frequent and heavy rainfall in spring were also those with the highest contamination of deoxynivalenol, zearalenone, moniliformin, and enniatins. The most FHB resistant genotypes resulted in the lowest contamination of all the mycotoxins but showed the highest deoxynivalenol-3-glucoside/deoxynivalenol ratio and moniliformin/deoxynivalenol ratio. An inverse relationship between the amount of deoxynivalenol and the deoxynivalenol-3-glucoside/deoxynivalenol ratio was recorded for all the cvs and all the years. Conversely, the enniatins/deoxynivalenol ratio had a less intense relationship with cv tolerance to FHB. In conclusion, even though the more tolerant cvs, showed higher relative relationships between modified/emerging mycotoxins and native/target mycotoxins than the susceptible ones, they showed lower absolute levels of contamination of both emerging and modified mycotoxins.

Risk assessment and spatial analysis of deoxynivalenol exposure in Chinese population

Deoxynivalenol (DON) is one of the most commonly found mycotoxins across the world, and it mainly contaminates staple food crops. This study aims to evaluate the dietary exposure of DON and to provide a geographical profile of DON exposure in China. The concentrations of DON and its acetylated derivatives in 15,004 cereal samples (10,192 wheat flour, 1750 maize meal, 892 oat flakes, and 2170 polished rice) were collected from 30 provinces, autonomous regions, or municipalities across China during 2010-2017, through a national food safety risk surveillance system. The consumption data for cereals were obtained from China National Nutrition and Health Survey in 2002, and 67,923 respondents from the same 30 regions were included in the analysis. Among all the cereals considered, the concentration was the highest in wheat flour, with the mean concentration of 250.8 μg/kg. Applying a worst-case scenario, some individuals were possibly at risk, but the probability of acute effects was low. The mean and median exposure for the entire population was 0.61 and 0.36 μg/kg bw/day, respectively, below the (PM) TDI, indicating an acceptable overall health risk in Chinese population. Wheat contributed to 86% of the total DON exposure. Significant discrepancy was observed between the exposure and the contamination of DON. The high-exposure cluster area was in northern China, whilst the most seriously contaminated regions were all located in the southeast, which formed a seriously contaminated area.

Mycotoxins in maize harvested in Serbia in the period 2012-2015. Part 2: Non-regulated mycotoxins and other fungal metabolites

The main objective of this study was to screen, for the first time, the natural occurrence of non-regulated fungal metabolites in 204 maize samples harvested in Serbia in maize growing seasons with extreme drought (2012), extreme precipitation and flood (2014) and moderate drought conditions (2013 and 2015). In total, 109 non-regulated fungal metabolites were detected in examined samples, whereby each sample was contaminated between 13 and 55 non-regulated fungal metabolites. Moniliformin and beauvericin occurred in all samples collected from each year. In samples from year 2012, oxaline, questiomycin A, cyclo (l-Pro-l-Val), cyclo (l-Pro-l-Tyr), bikaverin, kojic acid and 3-nitropropionic acid were the most predominant (98.0-100%). All samples from 2014 were contaminated with 7-hydroxypestalotin, 15-hydroxyculmorin, culmorin, butenolid and aurofusarin. Bikaverin and oxaline were quantified in 100% samples from 2013 and 2015, while 3-nitropropionic acid additionally occurred in 100% samples from 2015.

Contaminants in Grain-A Major Risk for Whole Grain Safety?

Grains are the main energy and carbohydrate sources for human nutrition globally. Governmental and non-governmental authorities recommend whole grains as a healthy food choice. The role of contaminants in (whole) grains and how to mitigate any potential risk following their consumption has not been reported. With this narrative review, we shed light on the potential human health risk from contaminants in whole grains and elaborate strategies to mitigate such risk. We found that grains represent a significant source of food-borne contaminants, the main ones being; mycotoxins including (A) aflatoxin B1; (B) ochratoxin A; (C) fumonisin B1; (D) deoxynivalenol; (E) zearalenone; toxic metals like arsenic, cadmium and lead; as well as process contaminants such as acrylamide. Whole grains usually contain more contaminants than refined products. However, whole grains also provide more nutrients that may reduce the impact of these contaminants. Strict regulatory thresholds aim to minimize the risk of contaminants to public health. The consumer can further impact on the mitigation of any risk by eating a healthy diet filled with nutrient-dense foods such as whole grains and probiotics. The risk posed by contaminants from whole grains do not outweigh the known nutritional benefits of whole grain consumption.

Predominant mycotoxins, mycotoxigenic fungi and climate change related to wine

Wine is a significant contributor to the economies of many countries. However, the commodity can become contaminated with mycotoxins produced by certain fungi. Most information on mycotoxins in wine is from Spain, Italy and France. Grapes can be infected by mycotoxigenic fungi, of which Aspergillus carbonarius producing ochratoxin A (OTA) is of highest concern. Climate is the most important factor in determining contamination once the fungi are established, with high temperatures being a major factor for OTA contamination: OTA in wine is at higher concentrations in warmer southern Europe than northern. Contamination by fumonisins is a particular concern, related to Aspergillus niger producing these compounds and the fungus being isolated frequently from grapes. Aflatoxins can be present in wine, but patulin is seldom detected. Alternaria mycotoxins (e.g. alternariol) have been frequently observed. There are indications that T-2 toxin may be common. Also, the combined effects of mycotoxins in wine require consideration. No other mycotoxins are currently of concern. Accurate fungal identifications and mycotoxin detection from the fungi are important and a consideration of practical methods are required. There is a diversity of wines that can be contaminated (e.g. red, white, sweet, dry and fortified). The occurrence of OTA is higher in red and sweet than white wines. Steps to control mycotoxins in wine involve good agriculture practices. The effect of climate change on vines and mycotoxins in wine needs urgent consideration by well-constructed modelling studies and expert interpretation of existing data. Reliable models of the effect of climate change on vines is a priority: the health of vines affects mycotoxin contamination. A modelling study of OTA in grapes at higher temperatures over 100years is required. Progress has been made in reducing OTA in wine. The other mycotoxins require consideration and the effects of climate change will become crucial.

Worldwide Mycotoxins Exposure in Pig and Poultry Feed Formulations

The purpose of this review is to present information about raw materials that can be used in pig and poultry diets and the factors responsible for variations in their mycotoxin contents. The levels of mycotoxins in pig and poultry feeds are calculated based on mycotoxin contamination levels of the raw materials with different diet formulations, to highlight the important role the stage of production and the raw materials used can have on mycotoxins levels in diets. Our analysis focuses on mycotoxins for which maximum tolerated levels or regulatory guidelines exist, and for which sufficient contamination data are available. Raw materials used in feed formulation vary considerably depending on the species of animal, and the stage of production. Mycotoxins are secondary fungal metabolites whose frequency and levels also vary considerably depending on the raw materials used and on the geographic location where they were produced. Although several reviews of existing data and of the literature on worldwide mycotoxin contamination of food and feed are available, the impact of the different raw materials used on feed formulation has not been widely studied.

How climate change and regulations can affect the economics of mycotoxins

In the decades to come, the one factor that will likely have the greatest effect on the economics of the mycotoxin problem is climate change. This article reviews the current state of known science on how the global climate has been changing in recent decades, as well as likely climate change trends in the near future. The article focuses in depth on how climatic variables affect fungal infection and production of specific mycotoxins in food crops, and how near-future climatic changes will shape the prevalence of these mycotoxins in crops in different parts of the world. Because of regulatory limits set on maximum allowable levels of mycotoxins in food and feed, growers will experience economic losses if climatic factors cause certain mycotoxins to become more prevalent. A case study is presented of how maize growers in the United States will experience increased economic losses due to slightly higher aflatoxin levels in maize, even if those levels may still be below regulatory limits. We discuss the overall expected economic impacts of climate change-induced mycotoxin contamination worldwide – not just market-related losses, but also losses to human and animal health and risks to food security. Aflatoxin is the mycotoxin that is most likely to increase under near-future climate scenarios; and thus is likely to pose the greatest amount of economic risk of all the mycotoxins.

Modelling climate change impacts on mycotoxin contamination

Projected climate change effects will influence primary agricultural systems and thus food security, directly via impacts on yields, and indirectly via impacts on its safety, with mycotoxins considered as crucial hazards. Mycotoxins are produced by a wide variety of fungal species, each having their own characteristics and requirements. The geographic distribution of toxigenic fungi reflects their ecological needs, with thermophilic fungi prevalent at lower latitudes and psychrophiles at the higher latitudes. A resulting gradient of mycotoxin contamination has been repeatedly stressed. Changes in climatic conditions will lead to shifts in the fungal population and the mycotoxin patterns. In general, climate change is expected to increase mycotoxin contamination of crops, but due to the complexity of mycoflora associated to each crop and its interaction with the environment, it appears rash to draw conclusions without specific studies. Very recently first quantitative estimations of impacts of climate change on mycotoxin occurrence have been made. Two studies each applied models of different disciplines including climate projection, crop phenology and fungal/mycotoxin prediction to cereals cultivated in Europe. They were followed by a case study on climate change effects on Alternaria moulds and their mycotoxins in tomato. Results showed that DON contamination of wheat grown in Europe was, in general, expected to increase. However, variation was large, and in some years and some regions a decrease in DON contamination was expected. Regarding aflatoxin contamination of maize grown in Europe, an increase was estimated, mainly in the +2 °C scenario. Two main research gaps were identified related to the (limited) number of existing quantitative models taking into account climate change and their validation in limited areas. Efforts are therefore mandatory to be prepared for future changes and challenges on model validation and limited mycotoxin-crop combinations.