Modelling the spoilage of pasteurized milk

Spoilage of pasteurized milk is almost always due to the growth of microorganisms. These are generally introduced after heat treatment and are referred to as post process contaminants (PPCs).

The shelf life of pasteurized milk is largely dependent on the number of PPCs and storage temperature (e.g. Muir, 1996). Muir (1996) has described a simple equation (equation 1) relating the number of number of PPCs and storage temperature to shelf life of pasteurised milk.

Equation 1. Shelf life (h)={0.00621*(T+273-(269.55-0.74))*(CFC15)-0.11 x ( CFC15) x 2} -2.

Where T = storage temperature in °K; CFC15, =log10 count after pre-incubation of pasteurized milk at 15°C for 24 hours enumeration on milk agar containing a selective supplement for pseudomonads called cetrimide-fucidincephaloridine (CFC).

Muir (1996) has explained that the equation can predict shelf life at storage temperatures between 6°C and 14°C to within 1 day for between 60 and 90% of samples. The accuracy of the equation has been reported to increase as the storage temperature of the pasteurized milk increases.

Go to Shelf Life of Pasteurized Milk Calculator .



Literature cited
Muir, D.D. (1996) The shelf-life of dairy products: 2. Raw milk and fresh products. Journal of the Society of Dairy Technology. 49, 44-48.


How to cite this article

Mullan, W.M.A. (2015). [On-line]. Available from: https://www.dairyscience.info/index.php/food-model/255-pasteurized-milk.html . Accessed: 28 March, 2024.