Frequency of contamination of raw cow's milk by aflatoxin M1 in cooling tanks in Boyacá, Colombia

Abstract

The consumption, by animals, of fermented foods contaminated with mycotoxin-producing molds, mainly of the genus Aspergillus, allows the presence of aflatoxins in raw milk, generating a public health problem. The objective of the present work was to detect the concentrations and frequency of aflatoxin M1 in samples of raw milk from cows, stored in cooling tanks in four municipalities of the department of Boyacá for one year, determining the variations according to the season. The proposed study was longitudinal, descriptive and quantitative. Four cooling tanks were selected at convenience in four different municipalities of the department and were sampled twice a month for a whole year. An ANOVA was performed to determine the statistical differences between aflatoxin M1 concentrations for each period. Statistical differences were determined between each of the quarters of the study, 135 positive results were found from a total of 384 samples collected throughout the study. The maximum concentration of the toxin was found in the dry season with a value of 2.4 µg/kg, while the maximum value in the rainy season was 1.4 µg/kg. The concentrations and seasonal variations of aflatoxin M1 in samples from milk cooling tanks were determined for the first time in the department of Boyacá, finding the highest concentrations and number of positive cases of aflatoxin M1 in the dry season.