19th May, 2015
The casein glycomacropeptide (cGMP) in milk is a protein produced by enzymatic or bacterial induced degradation of the casein present in milk. This degradation takes place during the cheese manufacturing process, where specific proteases are added to act on the milk casein. Therefore its presence in milk is an indication of milk adulteration with whey. Other degradation processes (mostly related to the bacterial activity present in lactic products) are also capable of increasing the cGMP concentration but not as much as adulteration.
cGMP rapid test has been designed by OPERON for the detection of casein glycomacropeptide(cGMP) in milk. This molecule concentration may increase when milk has been adulterated with whey.
This immunochromatographic test is very sensitive, detecting even GMP levels that could indicate adulterations of the 4% of whey in milk. If the conditions of milk, conservation, transport and process are optimal, levels as low as 2% of whey in milk could be detected.