2014-017 – Detection of Psychrotrophic Bacteria to Improve Shelf-Life of Dairy Products

Researchers at Kansas State University are developing a diagnostic assay to detect the presence of psychrotrophic bacteria in milk samples to improve the shelf-life of dairy products. The growth of (usually gram negative) psychrotrophic bacteria is not impeded under conditions where milk is stored (< 7oC). Commonly found psychrotrophic bacteria are species of Pseudomonas, Flavovacterium, Alcaligenes, and Acinetobacter, and others. Psychrotrophic bacteria in raw milk produce heat stable proteolytic and lipolytic enzymes, which are not deactivated by pasteurization. They contaminate milk because they can survive harsh conditions, making the sterilization of dairy equipment difficult. The main advantage of using Kansas State’s detection technology is that it is highly sensitive and allows detecting the presence of psychrotrophic bacteria before they are able to spoil the milk and/or drastically reduce the shelf life of pasteurized milk products. The activity of bacterial proteases indicates the presence of psychrotrophic bacteria in raw and pasteurized milk. Therefore, this technology can be used to assess milk quality and predetermine the shelf life of milk products For larger dairies, it may be advantageous to use the proposed psychrotrophic bacteria detection technology at the plate-reader level, which will provide even greater accuracy and prediction capability of the shelf life of dairy products. Caronda Moore caronda@ksu.edu 785-532-1366