Editorial: Fungal toxic secondary metabolites in foods and feeds: recent sustainable analytical techniques and innovative preventative and remediation strategies for their formation and toxicity

Abstract

The Sustainable Development Goal to "End hunger, achieve food security and improved nutrition and promote sustainable agriculture" (SDG2) continues to be threatened by many factors, such as population increase, rising inflation, currency depreciation, disruptions in the supply chain and climate change which impacts of agricultural sustainability (The World Bank, 2023). Amongst these factors, it is also vitalessential to recognize the role food safety plays in delaying efforts to meet SDG 2 as reflected by increasing food commodity losses from contamination and increasing rate of outbreaks of foodborne diseases in many countries, especially in developing countries.World health Organization (WHO), for example, reports that an estimated 600 million people fall ill after eating contaminated food and 420 000 die every year, resulting in the loss of 33 million healthy life years (WHO, 2015). To reduce this burden of foodborne illnesses, multidisciplinary, urgent and concerted efforts must be directed towards food safety.Among food safety threats are mycotoxins, which are secondary metabolites produced by toxigenic fungi such as Aspergillus, Penicillium and Fusarium species (Mogopodi et al., 2022).These species produce a variety of mycotoxins that have been the subject of much research, such as aflatoxins, fumonisin, patulin, ochratoxin A (OTA), deoxynivalenol (DON), trichothenes: T-2 toxin, tremorgenic toxins, ergot alkaloids, and zearalenone (ZON) (Martínez-Culebras et al 2021, Nji et al., 2022d, Fashola et al 2023) due to their detrimental effects on human and animal health even at deficient concentrations and their economic impact. Mycotoxins are highly toxic even at very low concentrations and continue to be a major food safety problem, especially in developing countries where regulatory limits do not exist or are not adequately enforced.Mycotoxins exhibit four basic kinds of toxicity: acute, chronic, mutagenic, and teratogenic (Pitt, John. (2000). Acute mycotoxin poisoning is most usually associated with liver or renal dysfunction, which can, in severe situations, be fatal. (D'Mello and Macdonald, 2009). Some of the major concerns for their chronic impact is their ability to induce cancer with symptoms such as haemorrhage, acute liver damage, edema, digestion problems and even death in some instances (Sarma et al, 2017) in animals and humans. Another concern is that certain mycotoxins alter immune systems which enhances the susceptibility of humans and animals to infectious diseases,.Other mycotoxins mainly function by disrupting the synthesis of proteins, leading to a variety of consequences such as severe immunodeficiency and skin sensitivity or necrosis. (Pitt and John 2000). Studies carried out in Tanzania on the association of mycotoxins exposure and childhood growth, showed that exposure to fumonisins from maize-based foods was associated with impairment of growth (Mollay et al, 2020). Fumonisins and aflatoxins are recognized as significant contributing causes to stunting in children of African descent. Since exposure to aflatoxins occurs throughout pregnancy through the transplacental passage and during breastfeeding, it is especially important for young children (Pickova et al, 2021).Generally, according to Vieira (2003) all animal species can be affected by mycotoxins. However, sensitivity varies with numerous factors including among others the animal's sex, age, breed, physiological status and nutritional standing, the kind(s) of mycotoxin(s) consumed, intake level, duration of exposure, farm management (hygiene, temperature, air conditioning, humidity, production density, etc.) and possible infections (D'Mello and Macdonald, 2009). Among the most sensitive animals as well as all reproductive and young animals of all species. High producing cows and calves are demonstrably affected affected by mycotoxins. Mycotoxins can have a very pervasive, yet sub clinical effect on both performance and health in most animals that can easily go unnoticed.The broad impacts of these toxins require integrated solutions and strategies across disciplines with a focus on sensitive and selective cost-effective methods for sampling, analysis, and detection as well as innovative preventive, control and remediation strategies to ensure consumer safety and compliance with regulatory standards, as well as focus on the development of models that predict environmental factors that trigger the production of mycotoxins. This research topic focuses on three key areas: i) occurrence and biological control of mycotoxins for the reduction of their impact on crops, ii) environmental impact on mycotoxins as well as iii) method development and validation for analysis of mycotoxins essential for effective regulation and control of contaminants.Mycotoxins can contaminate various grain and oil crops, including maize, wheat, rice, rapeseed, soybeans, sorghum, and peanuts. Although publications are indicating that 25% of crops worldwide are mycotoxin-contaminated, dating as far back as 1988, a recent study by Eskola et al. (2020) points out that this is likely an underestimate, with 60-80% of crops likely mycotoxincontaminated to some degree and 20% or more exceeding permissible food safety levels. The authors reached these estimations of mycotoxin occurrences were estimated by reviewing literature and data of approximately 500,000 analyses from the European Food Safety Authority and large global survey for various mycotoxins in cereals and nuts using different thresholds (Eskola et al 2020). These staggering percentages are worrisome as crop contamination with mycotoxins cuts across the value chain, affecting farmers, traders, markets, and consumers (Smith et al., 2016). The proliferation of mycotoxins threatens global food stocks which would otherwise play a critical role in maintaining food security. It is important to come up with sustainable and green strategies to control the occurrence of various fungi and their metabolites in crops. Omotayo and Babalola (2023) review the use of environmentally safe rhizosphere-associated biocontrol agents such as Bacillus spp., Pseudomonas, Enterobacter, and Microbacterium oleivorans in order to prevent and control Fusarium verticillioides-a toxicogenic fungus that produces fumonisin. The mechanism of these microorganisms such as Bacillus amyloliquefaciens and Bacillus subtilis to reduce the level of occurrence of this fungus in the maize rhizosphere and hence promoting crop yield are also discussed (Omotayo and Babalola, 2023).Environmental conditions such as high temperature and humidity favour the growth of fungal spores, resulting in the production of mycotoxins, which are aggravated by climate change (Zingales et al, 2022;Nji et al., 2022 b). These environmental impacts are also corroborated by the numerous outbreaks of acute aflatoxin exposure that have been documented in warm tropical regions, including a sizable portion of Sub-Sahara as well as Kenya and Tanzania where people fatality from aflatoxicosis have been reported (Probst et al., 2007, Kimanya et al., 2021). At elevated temperatures, mycotoxigenic fungal species like Aspergillus species have been shown to observe an overall increase (Nji et al., 2022c). The study of Chinganda et al.(2021) demonstrates that aflatoxin-producing fungi species with differing in sclerotial morphology, specifically L-type and S-type species of Aspergillus section Flavi, were affected differently by aflatoxins, with Stype species highly competitive during host colonization compared to L-type species. Further, the total aflatoxins produced by these species increased at higher temperatures, with warmer temperatures favouring the growth of S-type species.The challenge of mycotoxin contamination has led to continued research growth on novel and systematic analytical techniques. Analytical method development and validation are crucial prerequisites for achieving reliable analytical data that is required to support mycotoxin research. These methods must be simple, effective, sensitive and applicable to various food matrices and possibly be optimized for analysis of multiple mycotoxins to cater for the co-occurence of mycotoxins. Accordingly, Mbisana et al.(2024) developed and validated a quick, easy, cheap, effective, rugged, and safe liquid chromatography-tandem mass spectrometry (QuEChERS-LC-MS/MS) and sensitive mycotoxin analysis method encompassing the total workflow from sample preparation to quantitative analysis for the simultaneous identification and quantification of ten mycotoxins. Within this work, the following performance characteristics of maize and sorghum were evaluated: selectivity, sensitivity, precision, and matrix effect. This method satisfied the requirements of Commission Implementing Regulation (EU) 2021/808, Commission Regulation It is not only critical to develop strategies for analysis of mycotoxins but also to develop remediation strategies with the aim of promoting food safety. Thus, the redevelopment of green and stable adsorption materials that can remove mycotoxin is an interesting area of research.Additionally, techniques such as nanotechnology can be explored to develop such materials. It is also essential to develop affordable, non-instrumental low cost and convenient methods for mycotoxin analysis suitable for routine on-site screening with ease of use even for untrained personnel, which can also be to farmers.