AFLATOXIN CONTAMINATION IN CORN SAMPLES DUE TO ENVIRONMENTAL-CONDITIONS, AFLATOXIN-PRODUCING STRAINS, AND NUTRIENTS IN GRAIN GROWN IN COSTA-RICA

Aflatoxins are considered a potential hazard to public health, due to their toxicity and carcinogenicity. Under favorable environmental cond itions, insect attack, and substrate, aflatoxin-producing fungal speci es can grow in certain foods and feeds. The total aflatoxin distributi on due to environmental conditions (temperature, relative humidity, an d rainfall), collection phase (early, middle, and late), microbiologic al analysis of aflatoxin-producing strains, and nutrients (minerals, m oisture, and carbohydrates) was evaluated in samples of corn grown in Costa Rica. A multiple regression analysis design determined that tota l aflatoxin levels were significantly correlated (p less than or equal to 0.05) with the presence of Aspergillus flavus in the grain and tem perature conditions. Levels of aflatoxin were highly correlated (p les s than or equal to 0.01) among minerals (Mg2+, Zn2+, and Ca2+) and the polynomial effect of their interactions. Collection phase had a signi ficant effect on aflatoxin levels (p less than or equal to 0.05) due t o differences in harvest and storage conditions, as well as agricultur al practices in each region. Also, the effect of xylose, fructose, and glucose/mannose content in corn grain on the level of aflatoxin was n ot significant (p less than or equal to 0.05). However, glucose/mannos e had an effect of multicollinearity.