Occurrence of aflatoxins M₁ and M₂ in milk commercialized in Ribeirão Preto-SP, Brazil

Abstract

Aflatoxins are toxic metabolites found in foods and feeds. When ruminants eat foodstuffs containing aflatoxins B₁ and B₂, these toxins are metabolized and excreted as aflatoxin M₁ and M₂ in milk. The aim was to determine the incidence of these aflatoxins in commercial milk collected from supermarkets in Ribeirão Preto-SP, Brazil, and consisting of 60 ultrahigh temperature (UHT) milk samples and 79 pasteurized milk samples. The milk samples were analysed according to method 986.16 of AOAC International. None of the milk samples analysed were contaminated with aflatoxin M₂, and aflatoxin M₁ was detected in 29 (20.9%) of samples in the range 50–240 ng l⁻¹. The results show that despite a high occurrence of aflatoxin M₁ in commercial pasteurized and UHT milk sold in Ribeirão Preto in 1999 and 2000, the contamination level of these toxins could not be considered a serious public health problem according to MERCOSUR Technical Regulations. However, levels in 20.9% of the milk samples exceeded the concentration of 50 ng l⁻¹ permitted by the European Union. Although it is not necessary to continue monitoring the incidence and levels of aflatoxins M₁ and M₂ in milk samples, surveillance could be appropriate.

Keywords:

• Aflatoxin M 1
• Aflatoxin M 2
• Milk
• Occurrence