Mycoflora and Fumonisin Contamination in Brazilian Corn from Sowing to Harvest

• Published in: Journal of agricultural and food chemistry 2002-06, Vol.50 (13), p.3877-3882
• Main Authors: Almeida, Adriana P, Fonseca, Homero, Fancelli, Antônio Luiz, Direito, Glória Maria, Ortega, Edwin M, Corrêa, Benedito
• Format: Article
• Language: English
• Subjects: Aspergillus flavus - growth & development; Aspergillus flavus - isolation & purification; Biological and medical sciences; Brazil; Carboxylic Acids - analysis; Food Contamination; Food industries; Food toxicology; Fumonisins; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fusarium - growth & development; Fusarium - isolation & purification; Mycotoxins - analysis; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Penicillium - growth & development; Penicillium - isolation & purification; Phytopathology. Animal pests. Plant and forest protection; Soil - analysis; Soil Microbiology; Zea mays - chemistry; Zea mays - microbiology
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf011531p

The present study aimed to analyze the mycoflora and potential mycotoxin contamination of soil and corn samples collected at different plant maturity stages in Capão Bonito and Ribeirão Preto, two regions of the State of São Paulo, Brazil. In addition, the data obtained were correlated with the occurrence of wind-dispersed fungi and the predominant climatic conditions of the two regions studied. Corn mycoflora profiles showed that Fusarium verticillioides prevailed in 35% of the samples from Capão Bonito and in 49% of the samples from Ribeirão Preto. Examination of wind-dispersed fungi also revealed a high incidence of F. verticillioides. Soil mycoflora analyses showed that Penicillium was the most prevalent genus, although F. verticillioides was present in 55.5% of Capão Bonito's samples and in 26.7% of Ribeirão Preto's samples. With respect to water activity, the corn kernels most contaminated with F. verticillioides had water activity levels of 0.70−0.80. HPLC analysis of fumonisins revealed that 88.5% of Capão Bonito's kernels were contaminated with fumonisin B1 (FB1) (0.09−10.87 μg/g) and 53.8% with fumonisin B2 (FB2) (0.05−0.52 μg/g); Ribeirão Preto's kernels presented contamination levels of 93.5% for FB1 (0.11−17.69 μg/g) and 61.3% for FB2 (0.05−5.24 μg/g). No aflatoxins were detected by thin-layer chromatography in corn grains of either region. The concomitant occurrence of F. verticillioides and fumonisins in most of the field corn assayed demonstrates the importance of an effective control of cultivation throughout the plant maturity stages. Keywords: Mycoflora; aflatoxin; fumonisin; corn