Quantification of Mycotoxins in Animal Milk from India (FS14-04-19)

Abstract

ObjectivesAnimal milk can be contaminated with mycotoxins (secondary metabolites of fungi) through poor quality feed and may be a source of human exposure. Our objective was to develop and optimize a method to detect biologically relevant concentrations of 8 mycotoxins (Aflatoxins B1, B2, G1, G2, M1, M2; Ochratoxins A, B) in animal milk. MethodsWe used ultra-high performance liquid chromatography/tandem mass spectrometry using selected reaction monitoring (UHPLC/MS-SRM) to quantify mycotoxins in animal milk samples (total N = 38; n = 10 each from cow and commercial milk and n = 9 from buffalo and goat) from the southern Indian states of Karnataka and Tamil Nadu.Method development was conducted and stable isotope dilution employed, using AFB1-D3 for aflatoxins and OTA-D5 for ochratoxins. We validated the method and examined matrix effects, freeze-thaw and auto-sampler stability. Our dynamic ranges from quantification were between 7.8–5000 pg/mL. ResultsAmong samples collected from Southern India, 8 of 10 cow [median 103.35 pg/mL; n = 3 > 500 pg/mL]; 0 of 9 buffalo and 10 of 10 commercial [median: 151.5 pg/mL], milk samples were above the LOQ. AFM2 was also seen in samples from both regions, but in lower quantities when compared to AFM1 [median (north): 25.8 pg/mL; median (south): 70.95 pg/mL].All except 3 samples were below the LOQ (31.3 pg/mL) for OTA, however we detected a sodium adduct of OTA above LOQ, across samples. We found [Na-OTA] in goat milk [median: 5.9 ng/mL] > buffalo [median: 2.2 ng/mL] > commercial [median: 2.04 ng/mL] > cow [median: 0.8 ng/mL]. Other mycotoxins were seen in concentrations close to or below LOQ. We did not identify significant stability issues. ConclusionsWe developed a highly sensitive method with biologically relevant dynamic ranges for detection of mycotoxins in milk samples. We found AFM1, AFM2, and Na-OTA in milk samples from Southern India. Further studies with larger sample sizes are warranted to establish the extent of mycotoxin contamination in milk. Funding SourcesFunded by University Research Committee, Emory University and International Society for Research in Human Milk and Lactation.