Near-infrared spectroscopy to assess mycotoxins contamination and nutritional composition of maize marketed in South America, years 2020-2021

Abstract

Mycotoxicological and nutritional analyses were conducted in maize from Argentina, Bolivia, Brazil (stratified by region), Colombia and Peru through near-infrared spectroscopy (NIRS) in 2020 and 2021. Concentrations of aflatoxin B1 (AFB1), fumonisins B1 + B2 (FBs), zearalenone (ZEN) and deoxynivalenol, in addition to water activity, crude protein (CP), ether extract (EE), starch and apparent metabolizable energy (AME) in poultry, were determined in 18,363 spectra (totalling 195,486 analyses). FBs were the most prevalent metabolites in South American maize, being detected in 91.6 and 91.9% of the samples; ZEN had the second highest positivity, 15.4 and 26.8%, followed by AFB1, 15.3 and 14.6% (2020 and 2021, respectively). FBs also had the highest incidence in Brazilian maize, 92.6 and 92.1%, followed by AFB1, 15.2 and 13.5%, and ZEN, 14.7 and 27.7% (2020 and 2021, respectively). Contamination with at least one mycotoxin was detected in 93.5% of the samples. The mycotoxins found co-contaminating the maize belong to the genera Fusarium and Aspergillus; FBs, followed by ZEN and AFB1, were the most prevalent toxins in the associations. Levels of water activity were below 0.70. Regarding chemical composition, CP presented the largest oscillation in relation to the mean in South American maize (both years). As for the Brazilian samples, the Southeast region showed the greatest positive variability in relation to the means for all evaluated parameters, followed by the Northeast region (excepting CP) in 2020; in 2021, the Central-West and Northeast regions had the highest levels of EE and AME. In both years, the South region presented lower levels in relation to the mean for most parameters. Data on prevalence, mycotoxicological contamination, storage conditions and nutritional quality of maize assist the decision-making process of raw material use. In this setting, NIRS suits the needs of the industry for providing information on multiple parameters in real time.