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Cheese is one of the most susceptible dairy foods to accumulating aflatoxins due to their high affinity to caseins. The consumption of cheese contaminated with high levels of aflatoxin M1 (AFM1) can be highly harmful to humans. The present work, based on high-performance liquid chromatography (HPLC), highlights the frequency and levels of AFM1 in coalho and mozzarella cheese samples (n = 28) from the main cheese-processing plants in Araripe Sertão and Agreste in the state of Pernambuco, Brazil. Of the evaluated cheeses, 14 samples were artisanal cheeses and the remaining 14 were industrial (manufactured) cheeses. All samples (100%) had detectable levels of AFM1, with concentrations ranging from 0.026 to 0.132 µg/kg. Higher levels (p < 0.05) of AFM1 were observed in artisanal mozzarella cheeses, but none of the cheese samples exceed the maximum permissible limits (MPLs) of 2.5 µg/kg established for AFM1 in cheese in Brazil and 0.25 µg/kg in the European countries by the European Union (EU). The high incidence of low levels of AFM1 found in the evaluated cheeses underscores the need for stringent control measures to prevent this mycotoxin in milk used for cheese production in the study area, with the aim of protecting public health and reducing significant economic losses for producers. [ABSTRACT FROM AUTHOR]

The aim of this study was to conduct an up-to-date investigation on the occurrence levels of aflatoxin M1 (AFM1) in samples of raw milk (n = 40), pasteurized milk (n = 44), ultra-high temperature (UHT) milk (n = 27), Minas cheese (n = 57), and yogurt (n = 44) traded in São Paulo state, Brazil. AFM1 was extracted from fluid milks and dairy products using immunoaffinity columns and determined by high performance liquid chromatography. AFM1 was detected at the mean level of 0.080 ± 0.071 µg/L or kg in 72 samples (34.0%) evaluated in the study (n = 212). Detectable levels of AFM1 were observed in five samples of raw milk (12.5%), 16 samples of pasteurized milk (36.4%), 13 samples of UHT milk (48.1%), 27 samples of cheese (47.4%), and 11 samples of yogurt (25.0%), although none of them had concentrations above the maximum permitted levels (MPL) for AFM1 adopted in Brazil. However, 11.7% (n = 13) of samples of raw, pasteurized, and UHT milks would have AFM1 concentrations above the MPL of 0.05 μg/L adopted in the EU. The maximum level was detected in one cheese sample containing 0.695 µg/kg. Although none of the samples exceeded the Brazilian MPL, the high frequencies of AFM1 in Brazilian milk products warrant concern about their contribution to the human exposure to aflatoxins. Because aflatoxins are among the most potent carcinogens known, the results of this trial stress the need for stringent measures in the milk production system to avoid AFM1 in milk and derived products. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the in vitro ability of heat-killed (HK) and acid-killed (AK) cells from three commercial strains of lactic acid bacteria, alone or in combination with sorbitan monostearate (SM), to bind to aflatoxin M 1 (AFM 1) in skimmed milk at concentrations of 0.05, 0.2 and 0.5 ng mL−1. The stability of the AFM 1 -bacterial cell bonds and the cell wall and exopolysaccharides (EPS) contribution to AFM 1 decontamination were also investigated. Compared with HK cells, AK cells exhibited higher binding capacities in milk containing the highest AFM 1 level, with maximum removal of 81.4, 56.8, and 50.8% by Lactococcus lactis ssp. cremoris , Lacticaseibacillus rhamnosus (formerly Lactobacillus rhamnosus), and L. lactis ssp. lactis at 1010 cells mL−1, respectively. The combination of HK cells with SM increased the AFM 1 binding capacity, although no effect was found regarding AK cells. SM treatment also enhanced the stability of the AFM 1 bond formed with both HK and AK cells. Cell wall isolates and EPS were the major components involved in the AFM 1 binding process. Combining SM with HK cells is an interesting approach to reduce AFM 1 levels in milk, although further studies are needed to optimize the adsorbing process. [Display omitted] • Heat-killed (HK) and acid-killed (AK) LAB capacities to adsorb AFM 1 in skimmed milk. • Higher AFM 1 adsorption percentages (50.8–81.4%) by AK cells. • HK cells combined with sorbitan monoesterase (SM) had increased AFM 1 bind capacity. • SM increased the stability of the AFM 1 – bacterial cell complex. • Exopolysaccharides were the major components involved in the AFM 1 binding process. [ABSTRACT FROM AUTHOR]