Assessment of Milk Quality by Analyzing Aflatoxin M1 in Branded and Non Branded Milk Samples Collected from Different Shops/Areas in Lahore, Pakistan

The non-branded samples were collected from retail milk shops of city Lahore, Pakistan. Forty samples of raw milk (500 ml each) were collected randomly from different markets of Samanabad Town, Iqbal Town, Shalimar Town and Gulberg Town during October, 2016 to March, 2017. 10 samples from each town were collected. Similarly, branded samples were also collected from different shops in Lahore. The milk samples were transported in sterilized polythene bags in ice-packed cooler to the aflatoxin laboratory at PCSIR Laboratories Complex, Lahore, where samples were kept at -20°C until analyzed for AFM1 detection (Muhammad et al., 2010). Samples were prepared by using Romer Labs Method #: PI-000047-1. Fresh milk sample (5 ml) was taken into test tubes and incubated at 4°C for 30 min. The samples were centrifuged at 3000 g for at least 10 min. Milk serum (0.4 ml) below fat layer was taken and mixed with 0.1mL of 100% methanol i.e. in the ratio is 4:1. ELISA kit (Romer Labs, Singapore), was used for the examination of M1 in milk samples (Kamkar et al., 2011).

Aflatoxin M1 was determined by ELISA method in branded and non-branded milk samples supplied in Lahore city of Pakistan. The percent maximum absorbance at 450 nm was observed for aflatoxin M1.

In present study it was determined that 58% of branded samples collected from Lahore shops were infected with aflatoxin M1, respectively. In a similar studies the occurrence of AFM1 contamination in the raw milk (non branded) samples collected from Gulberg Town, Ravi Town, Gunjbaksh Town and Shalimar Town was 71%, 86%, 81% and 86%, respectively (Muhammad et al., 2010). The results of aflatoxin M1 detection in different 40 branded milk samples are given in Table I.

*ND, not detected; MQ (ppt) ± SD, mean quantity ± standard deviation.

The branded sample (B29) was found with maximum concentration (605.90 ppt) of aflatoxin M1 beyond EU permissible limits i.e. 50 ppt. It was observed that all 40 raw milk (non-branded) samples collected from different shops of selected Towns were contaminated with aflatoxin M1. 100% contamination of milk samples show miserable conditions of supplied milk at Lahore shops. The results of aflatoxin M1 analysis in non-branded milk samples are given in Table II.

The sample with maximum concentration 2735.08 ppt (exceeding permissible limits set by EU) of aflatoxin M1 was also collected from Shalimar Town. In comparison with present study of aflatoxin M1 in non-branded milk samples range between 17.34-2735.08 ppt, the analysis of randomly selected raw cow milk samples in North African countries (Elgerbi et al., 2004), were contaminated with AFM1 (range between 30 and 3130 ppt). These results are in accordance with Elgerbi et al. (2004) and El-Sayed et al. (2000) who reported high levels of AFM1 in bovine raw milk samples. The percentage analysis of non-branded milk samples regarding aflatoxin M1 contamination showed that all the samples were highly infected with aflatoxin M1 among which 95% of the samples had aflatoxin M1 levels beyond permissible limits i.e. 50 ppt.

MQ (ppt) ± SD, mean quantity ± standard deviation.

The percentage analysis of branded milk samples showed that 42% samples were not contaminated and found no aflatoxin M1 while 58% samples were aflatoxin M1 contaminated. Among these contaminated samples all the samples contained aflatoxin M1 levels beyond permissible limits.

In a study conducted on buffalo and cow milk samples collected from dairy farms of Faisalabad, Pakistan. 84% buffalo milk samples and 72% cow milk samples were exceeded the European Commission MRL of 50 ppt (Sajid et al., 2015). Fungal metabolite AFM1 is carcinogenic, hepatotoxic and immunosuppressive and is accountable for injurious effects on human as well as animal’s health (Williams et al., 2004). This adverse scenario has dragged the international trepidation over AFM1 contamination in milk supplied.

In current study the analysis depicts that 58% of branded samples while 100% of non-branded milk samples were found contaminated with Aflatoxin M1, respectively. HACCP system and analytical inspection are highly recommended to limit aflatoxin M1 contamination in order to fearless consumption of milk in Pakistan.

The authors declare no conflict of interest.