Distribution and stability of aflatoxin M1 during processing and storage of Minas Frescal cheese

Aflatoxin M1 (AFM1) is a hepatocarcinogen found in milk of animals that have consumed feeds with aflatoxin B1. The carry-over of AFM1 from milk to Minas Frescal cheese produced with or without starter cultures was determined. 40 L of milk were divided into 10 L each and assigned to the following treatments for cheese manufacture: 0.250 ng AFM1 mL−1, 0.500 ng AFM1 mL−1, 0.250 ng AFM1 mL−1 + starter, 0.500 ng AFM1 mL−1 + starter. Quantification of AFM1 was achieved by high performance liquid chromatography. The carry-over of AFM1 from milk to cheese ranged from 30.64% to 42.26%. There was no effect of storage time on AFM1. Milk with AFM1 in levels studied may concentrate the toxin in Minas Frescal cheese, but at concentrations below the Brazilian tolerance limit. The addition of starter cultures did not influence concentration or stability of the AFM1 in cheese over 30 days storage.