Aflatoxin M1 in Cow’s Milk: Method Validation for Milk Sampled in Northern Italy

Abstract

Aflatoxins (AFs) are mycotoxins produced by some species of Aspergillus. In dairy cows, ingested AFB1 is metabolized into carcinogenic AFM1 which is eliminated through milk, thus posing a risk for consumer health. Here we describe the set, validation, and application of screening (ELISA) and confirmatory (HPLC) tests carried out on milk samples collected through official control of mycotoxin levels in northern Italy over a three-year period (2012–2014). The limit of detection (LOD) was set at 5 ppt (ng/kg) and 2 ppt for ELISA and HPLC, respectively, and the limit of quantification (LOQ) was 10 ppt for confirmatory HPLC. A total of 1668 milk samples were analyzed: ELISA identified 36 (2.2%) positive milk samples that were subsequently confirmed by HPLC. The level of AFM1 in the positive samples ranged between 18 ± 2 and 208 ± 27 ppt. Of the total samples, only eight (0.5%) were found non-compliant with the EU regulatory limit (50 ppt; range 74 ± 10 to 208 ± 27 ppt). Use of ELISA and HPLC tests in series allows for high-volume analysis of samples, thus saving time and money while guaranteeing high analytical precision and accuracy.

Aflatoxin M1 in Nicaraguan and locally made hard white cheeses marketed in El Salvador

“…It has been described that prolonged events or conditions of shortage of rain or drought and high temperatures are associated with increases in AFM 1 contamination in dairy products or in their raw material [ 15 , [22] , [23] , [24] , 41 ]. The increases in temperature and the decrease in rainfall upsurge the conditions for the growth of aflatoxicogenic fungi in corn [ 3 , 4 , 42 , 43 ], the main raw ingredient of feedstuff for cattle [ 22 , 42 , 44 , 45 ], therefore, the consumption of contaminated feed will cause the temporary increase of AFM 1 in milk and its derivatives [ 13 , 15 , 23 ]. The previous framework would explain the increase in the prevalence of samples of Salvadoran and Nicaraguan cheeses, with levels of AFM 1 that exceed the limit of 0.050 μg/kg during the dry season months, precisely when the use of supplementary food is used more before the shortage of grass for all the cattle, especially the lactating ones.…”

“…Aflatoxin M 1 (AFM 1 ) is the main metabolite of Aflatoxin B 1 (AFB 1 ), which is one of the four most common variants of Aflatoxins (AFs) [ [1] , [2] , [3] , [4] , [5] , [6] ]. There is sufficient evidence for the carcinogenicity of AFM 1 alone or mixed with AFB 1 and Aflatoxin G 1 (AFG 1 ) [ 7 ], although of lower potency than AFB 1 [ 8 , 9 ].…”

“…There is sufficient evidence for the carcinogenicity of AFM 1 alone or mixed with AFB 1 and Aflatoxin G 1 (AFG 1 ) [ 7 ], although of lower potency than AFB 1 [ 8 , 9 ]. When cattle ingest food or feed contaminated by AFs, it is estimated that up to 6.2 % of the content of AFB 1 is transformed into AFM 1 and excreted in milk [ [2] , [3] , [4] , 10 , 11 ]. If milk contaminated by AFM 1 is used to formulate cheese or other dairy products, the toxin is transferred from the raw material to the final product [ [12] , [13] , [14] ], a process enhanced by the affinity that AFM 1 has for casein [ 13 , [15] , [16] , [17] , [18] ].…”

Incidence of aflatoxin M1 in fresh milk from small farms

“…Picinin et al (2013) It is known that aflatoxins are heat treatment stable (Assem et al, 2011;Prandini et al, 2009;Shundo et al, 2009). Studies carried out in Brazil (Scaglioni et al, 2014) and other countries (Farah Nadira et al, 2017;Armorini et al, 2016;Bellio et al, 2016;Zheng et al, 2013;Kabak & Özbey, 2012) prove that even in pasteurized or ultrapasteurized milk, aflatoxin M 1 is found at levels often higher than the allowed maximum limit established by national regulations (Becker-Algeri et al, 2016).…”

Fabrication of microfluidic device for Aflatoxin M1 detection in milk samples with specific aptamers

“…www.nature.com/scientificreports www.nature.com/scientificreports/ relevance in remote areas, and resource limited developing countries like India due to its stability, ease of production, and use 20 . To meet this requirement, aptamer (as a biorecognition element) based detection has recently increased in demand, due to its higher specificity and lesser cross reactivity as compared to antibodies, as well as ease of production 12,21 . Microfluidic devices are gaining importance as cheap, mass producible, and ecofriendly which can be used as an alternative technology for on-site detection of Afl M1 [22][23][24][25] .…”