Mycotoxins in South African foods: a case study on aflatoxin M1 in milk

Abstract

The contamination of cow's milk at the farm level with aflatoxin M1 was investigated in South Africa. Samples of feeds, forage, maize and milk were taken at nine dairy farms, and at the same time samples of the processed milk (retail milk) were collected from the respective dairies to which the farms delivered their milk. The feeds were analysed for aflatoxin B1 and the milk samples for aflatoxin M1 using high performance liquid chromatography (HPLC) and fluorescence detection. All milk samples from the dairy farms were positive for aflatoxin M1, ranging from 0.02 μg/l to 1.5 μg/l. Retail milk was also frequently contaminated with AFM1, at levels of 0.01-3.1 μg/l. High AFB1 levels in feed materials on the farms supplying the raw milk indicate that various sources account for this contamination frequency in milk.

Aflatoxin Contamination of the Milk Supply: A Pakistan Perspective

“…Seasonal differences in concentrations of AFM1 in milk samples have also been reported [50]. A recent study [51] has shown the maximum concentration of AFs in milk marketed from small-holder dairy farms in the monsoon season in Punjab Pakistan was 2.59 ppb, whereas the lowest concentration was observed in summer (1.93 ppb).…”

A Decade of Aflatoxin M1 Surveillance in Milk and Dairy Products in Developing Countries (2001-2011): A Review

“…It may be screening, confirmatory or both. The most reported methods conventionally used for AFM1 extraction and detection are liquid-liquid extraction, silica gel, SPE cartridges (C18) cartridges [50] or immunoaffinity column (IAC), [57]. The inconvenience of this method is excessive use of chlorinated solvent in liquid-liquid extraction [21].…”

“…This is simple, quick, and more stable than IAC [54] will probably be used for AFM1 in the future as there have been no reports on this. Reports have shown that the detection and quantification of AFM1 can be done by separation using thin-layer chromatography (TLC) or high-performance liquid chromatography (HPLC) coupled with fluorescence detector [6,[55][56][57]. The inconvenience of the TLC method is that it is challenging in the determination of mycotoxin concentrations with exactitude.…”

“…As a result, there would be considerable practical benefit from further work on sample preparation and methods for separation prior to MS. Patel et al [21] reported on AFM1 detection 1 in milk and milk powder using an LC-MS/MS method and this contrasted the clean-up efficiencies of IAC and MFC. Dutton et al [57] reported the use of IAC clean-up and HPLC coupled with a fluorometer detector coupled with a Coring cell (Kobra cell) for AFM1 detection. The advantage of this method is the avoidance the derivatization procedure which is labour cost and health risky for the technician and corrosive for the column.…”

“…Numerous epidemiological studies have shown in some areas a correlation between high aflatoxin exposure and high incidence of hepatho carcinoma in several countries in Africa [74]. Data in Table 1 show that only few African countries apart from South Africa [57], Egypt [75] and Morocco [76] and Nigeria [77] were involved in the survey for AFM1. However the following Middle East, Asian and Latin American countries are implementing controls of the toxin in both dairy and human milk Iran [78] and Kuwait [79] and Pakistan [80][81][82][83] India, Argentina [84] and Brazil [18,[85][86][87] Data obtained clearly show that ELISA immunoassay technique has been the most used analytical method in the past decade to measure AFM1.…”