Researchers from UFMG and Embrapa used near-infrared (NIR) images to identify two Fusarium fungi. The fungi F. verticillioides and F. graminearum are responsible for the main toxins that attack corn. New method is cheaper and quicker than conventional ones. Moreover, it is not destructive and does not require chemicals. HSI-NIR technique showed 100% de precisão, sensibilidade e especificidade na diferenciação de espécies de fungos do gênero Fusarium. Research developed by Embrapa in partnership with Federal University of Minas Gerais (UFMG) was able to identify Fusarium fungi that populate corn grains through an innovative method. The scientists combined hyperspectral near-infrared (NIR) images with pattern recognition methods and successfully identified the species F. verticillioides and F. graminearum, the fungi that most afflict corn grains and that are responsible for produzing the main mycotoxins that are known to inflict the crop. The first one is the top producer of the mycotoxin fumonisin and F. graminearum is associated with zearalenone. Mycotoxins are toxic metabolites that are produced by different fungal species that are present in grains. The mycotoxins' toxicity to animals and humans causes the incidence of several diseases. Meanwhile, detecting the fungi that produce them currently involves expensive and complex processes, which hinders their application. Hence there is a demand from specialists and large industries for a fast and precise identification method to prevent contamination by Fusarium species. “With the aim to obtain a non-destructive, chemical-free method that would be quicker to execute, we associated near infrared hyperspectral imaging (HSI NIR) with multivariate image analysis. This method was developed to allow por faster sample readings and more precision in the identification of pathogens”, reports the researcher Maria Lúcia Ferreira Simeone, from Embrapa Maize and Sorghum. Scientific publication The findings were published on the periodical Food Chemistry, in the paper Application of near-infrared hyperspectral (NIR) images combined with multivariate image analysis in the differentiation of two mycotoxicogenic Fusarium species associated with maize. She points out that the identification of such pathogenic fungi is an important initial stage in corn disease control; however, the more traditional methods of species differentiation require a high level of knowledge, complex laboratory techniques and a lot of time. Simeone adds that these pathogens are difficult to identify and control. “Therefore, the search for alternative methods is of great relevance for the entire corn production chain”, the scientist states. Stages of the PLS-DA classification model: a) RGB image of F. verticillioides and F. graminearum fungi used in the species classification model; b) Contour 2D image of PCA model before background is removed; c) Contour 2D of PCA model after background removal and with pre-treatments (dados centrados na média + SNV); d) e e) Imagem do modelo PLS-DA ilustrando os conjuntos de calibração e validação Obtaining such method was the goal of a PhD thesis developed at UFMG in partnership with Embrapa Cotton and Embrapa Maize and Sorghum. “In this work, we implemented the use of near infrared hyperspectral images (HSI-NIR) combined with pattern recognition analysis, partial-least-squares discriminant analysis (PLS-DA) of images, to develop a rapid method for identification of F. verticillioides and F.graminearum”, Simeone reports. The work was presented to UFMG's Institute of Biological Sciences Postgraduate Program in Microbiology by then PhD candidate Renata Regina Pereira da Conceição. The student was advised by professor Maria Aparecida de Resende Stoianoff and co-advised by Embrapa Maize and Sorghum researchers Maria Lúcia Simeone and Valéria Aparecida Vieira Queiroz. According to Renata Conceição, the PLS-DA model applied to F. verticillioides e F. graminearum ashowed a significant separation between the two species with 100% accuracy, sensitivity, and specificity, , demonstrating the effectiveness of the HSI-NIR to differentiate fungi in the Fusarium genus. “The results we obtained revealed that hyperspectral near-infrared imaging (HSI-NIR) is a useful tool to categorize two important agricultural Fusarium species. The research proved that the cost-effectiveness of the HSI-NIR technique offers a bigger advantage over the standard techniques to identify fungi because it is easier and faster to perform, as well as less expensive. And it has a non-destructive approach to the samples, dispensing with the use of chemical products in the process”, Conceição stresses. A problem in the corn chain Corn (Zea mays L.) is one of the most present foods in human and animal diets and it has major economic and social importance. Some of the evidences of such high socioeconomic importance include the expansion in cultivated area and its extensive use in several feed and food products, biofuel production and as raw materials for different industries. According to an estimate from the tenth Brazilian harvest survey (2020/2021 crop year), in the world ranking of corn production Brazil is the third-largest producer (around 109 million tons) second only to the US (360.3 million tons) and China (260.7 million tons). Brazil is the fourth largest consumer of the cereal with 70 million annual tons. Annually, mycotoxins affect 25% of the world’s corn production, according to the Food and Agriculture Organization (FAO), conforme publicação dos autores Mari Eskola e equipe, na pesquisa Worldwide contamination of food crops with mycotoxins: validity of the widely cited ‘FAO estimate’ of 25%, revista Food Science and Nutrition, em 2020. The Embrapa researcher Dagma Dionísia da Silva, coordinator of the project “Technologies to identify, quantify and mitigate toxigenic fungi and mycotoxins in corn grains” stresses that “corn is a crop that is highly susceptible to infection by pathogenic fungi”. “This infection can occur either before or after the harvest, and thus directly and indirectly compromise the quality of corn grains and their byproducts by reducing their sanitary and physical quality, interfering with their commercial classification and making the grains unsuitable for consumption”, Silva explains. “The contamination of corn and byproducts with microbiological pathogens can cause severe consequences for consumers, and it is a cause of major concern around the globe. That is why, in recent years, the search for alternatives to ensure food security has been the focus of international action", adds the Embrapa researcher Valéria Queiroz. Photos: Renata Silva (corn plantation) and Dagma Silva (corn with fungal rot symptoms)