Milk Spoilage
Have you ever questioned why pasteurized milk sometimes spoils before the best before code whilst being stored in the fridge? At the same time, it is accompanied by a slight rancid odor as well.
Interestingly it is caused by the presence of a group of bacteria that loves living in the cold environment; these are called psychrotrophs or psychrotrophic bacteria. Pseudomonas is one of the most common within the group and interestingly this is the same bacterium that causes spoilage (slimy layer) in raw chicken during refrigerated storage.
Did you know that even if you keep the milk chilled within the recommended storage temperature, a single cell of pseudomonas can multiply to over a million cells in the space of just six days? Even one of this bacterium in a carton of milk can cause a spoilage problem.
So how do these bacteria enter the milk even though the milk is pasteurized! Easily, it’s due to poor hygiene by the manufacturers because if it is pasteurized and packaged hygienically there should not be any spoilage bacterium present at all, nada!
The only bacterium that can survive the heating process is heat resistant bacteria such as bacillus species and these types will not grow at the refrigeration temperature. Hence there is not premature spoilage.
