Preservatives in Milk

According to Dairy Farmers of America, milk sold for public consumption does not contain preservatives. Instead, pathogens and harmful bacteria are controlled by combination of heat treatment (pasteurization), refrigeration and protection from light. Additionally, most milk sold for public consumption is homogenized, which prevents the creme from separating. However, preservatives are used in dairy heard improvement milk samples when refrigeration is not practical. In fact, their use is required under these circumstances in most states. Some of these preservatives are toxic, and milk that contains these preservatives is not meant for human consumption.

Potassium Dichromate

• Potassium Dichromate is a low-cost preservative that has color to indicate its presence in the milk. It is easily dispersed throughout the milk sample. It is a toxic substance that tends to deteriorate the fat in samples, and also pollutes the sewer system.

Bronopol

• Bronopol is a low-cost preservative that is easily dispersed through milk samples. It has low toxicity levels. Bronopol must be stored under dry conditions, and does not prevent the growth of yeast in unrefrigerated samples.

Formaldehyde

• Formaldehyde is a low-cost preservative easily dispersed through milk samples. However, it was found unsuitable for test milk samples because it interfered with fat tests in electronic equipment.

Hydrogen Peroxide

• Hydrogen peroxide has a low toxicity level, is inexpensive, and is easily dispersed through milk. The disadvantages of hydrogen peroxide are that it has a short preservation time and adds no color to the samples.