Field incidence of mycotoxins in commercial popcorn and potential environmental influences

Abstract

Popcorn ear damage by insects and mycotoxin levels in kernels were monitored in several commercial popcorn fields in central Illinois over a 4-year period. Aflatoxin was rare, but fumonisin and deoxynivalenol (DON) were commonly encountered each year, and occurred at mean levels in fields up to 1.7 mg/kg (sample max. 2.77 mg/kg) and 1.9 mg/kg (sample max. 2.66 mg/kg), respectively. Neither fumonisin nor DON levels were significantly correlated with the percent of ears with visibly moldy insect-damaged kernels. Significant correlations were noted for the percent of ears with early caterpillar damage and both fumonisin and DON levels overall for some years and at specific sites in other years. Fumonisin levels were generally more highly correlated with insect damage than DON levels. Insect damaged kernels had 100- to 500-fold or greater levels of fumonisin compared to noninsect-damaged kernels, while DON levels were closer to 10- to 30-fold higher in insect damaged versus nondamaged kernels. A high percentage of DON-contaminated kernels were not insect damaged in 2007 and 2008. In some cases, differing mycotoxin levels for the same hybrid and same year planted at different locations appeared to be due to the prior crop. Higher DON levels in 2008 than other years were most likely associated with higher levels of rainfall and cooler temperatures than average during ear fill. While kernel sorters are reported to remove mycotoxin-contaminated popcorn kernels to acceptible levels, consideration of environmental factors that promote mycotoxins in popcorn should result in more effective control measures in the field.

Isolation and characterization of Fusarium verticillioides from maize in eastern China

“…Dorn et al (2009Dorn et al ( , 2011 found that the distributions of Fusarium species could not be explained by temperature alone; it was suggested that temperature may not be critical and that other, yet unknown, factors more strongly influence Fusarium prevalence. Dowd and Johnson (2010) working in America, and Goertz et al (2010) in Germany, suggested that local field effects may influence both Fusarium outbreaks and maize mycotoxin levels more than do weather conditions. Additionally, Fusarium species competed when inoculated simultaneously into maize ears (Reid et al 1999) or kernels (Velluti et al 2000).…”

Fusarium species complex and mycotoxins in grain maize from maize hybrid trials and from grower’s fields

“…Other studies also suggest that local effects of the field site may be more important to explain Fusarium infection and mycotoxin concentrations in maize than weather conditions alone. For example, Dowd and Johnson (2010) in the United States and Goertz et al. (2010) in Germany conducted monitoring studies of maize under natural infection.…”

Mycotoxin Contamination of Maize in China

“…An investigation on mycotoxin contamination of maize samples collected in Shandong Province at various stages in 2013 and 2014 showed that the incidences and average contents of FBs (FB 1 , FB 2 , and FB 3 ), AF (AFB 1 , AFB 2 , and AFG 1 ), DON, and ZEN increased from harvest stage to storage period, and the authors deduced that the increase in mycotoxin content was caused by fungal growth and reproduction (Wang and others 2016). Investigations also revealed that 100-to 500-fold or greater levels of fumonisin had been detected in insect-damaged maize kernels in comparison with those which were not insect-damaged, while closer to 10-to 30-fold higher levels of DON were determined in insect-damaged versus noninsect-damaged maize kernels (Dowd and Johnson 2010). The cocontamination of foods/feeds with known or unknown mycotoxins is being reported at an increasingly high rate (Stoev and others 2010a, b).…”