Processed fluid milk (pH~6.5) is produced using heat treatments to reduce the initial microbiota of the raw milk. It may contain added ingredients such as flavors and vitamins, and can also be made from reconstituted dried milk.
Spoilage is usually due to the growth of spore-forming or thermoduric bacteria surviving after the pasteurization process or contaminating psychrotrophic microorganisms, in particular Pseudomonas spp. Spoilage is characterized by the development of off-tastes and off-odors and physical changes of the product (curdling or coagulation). Post-pasteurization contamination by pathogens (e.g. L. monocytogenes) from the processing environment and insufficiently cleaned processing lines can occur.
In such cases of the shelf life of these products can be extended to avoid consumer complaints by addition of Lysoch™ E4 / Lysoch™ G4.
*Processed fluid milk includes Whole milk, Low-fat milk, Skim milk, Flavored low-fat milks, Shelf-life stable milk