Occurrence of Aflatoxin M1 in raw and processed milk consumed in Pakistan

Abstract

Aflatoxin M1 (AFM1) is a hydroxylated metabolite of Aflatoxin B1 (AFB1). It appears in milk, when lactating animals consume AFB1 contaminated feed. It is carcinogenic and teratogenic in nature. Present study was planned to determine levels of AFM1 in raw and processed milk. For this, a total of five hundred and seventy milk samples (raw =340 and processed = 230) were collected from Punjab (province of Pakistan). Processed milk included ultra-heat treated (UHT) (n=105), pasteurized (n=65), dried (n=40) and condensed milk (n=20). Concentration of AFM1 was quantified by direct competitive ELISA technique. Analysis revealed 100 percent incidence of AFM1 in UHT and pasteurized milk with a mean of 0.35±0.28ng/ml and 0.11+0.03ng/ml respectively. However, 86.66% raw milk samples were tainted with AFM1 with mean of 0.52±0.42ng/ml and 66.66% of dried milk samples with mean of 0.03+0.02ng/ml. However, none of the condensed milk sample was found positive. Data of raw milk contamination was further computed for seasonal variation. Highest prevalence (100%) was observed during autumn season followed by winter (81.81%), summer (80%) and spring season (62.06%) respectively. Furthermore, all mean values except raw milk were below the FDA legislation.Study results indicate the possible adverse effects on health of people of Pakistan. Good agriculture practices (GAP) and regular screening of raw materials of animal feed prior to supplying may help to control AFM1 levels in milk.