Detection of bovine milk adulterated with cheese whey by western blot immunoassay

Milk processor industries and distributors have problems of milk adulteration with cheese whey. The most frequently used method to detect cheese whey is the identification of a glycomacropeptide (GMP) which is present only in cheese whey but not in milk. At present, methods to detect GMP require major work and time, presenting problems of sensitivity and accuracy at low concentrations. We developed a novel western blot analysis for GMP detection, using anti-GMP polyclonal antibodies. This assay is easy, rapid, sensitive and specific and can detect 0.001% (w/v) GMP, 0.5% (v/v) liquid cheese whey and 0.001% w/v dehydrated cheese whey. Furthermore, it can be used successfully to detect GMP in various food matrices containing cheese whey.