Bacterially Clarified Milk (Bactofugation) - Use of separators in dairies
Bacteria, yeast and molds can contaminate milk products to a considerable extent. This may not only impair shelf-life, but also lead to product spoilage, making reliable bacterial clarification of milk all the more important. Bacteria removing centrifuges or bactofuges support a wide variety of dairy processes. Applications range from single-stage bacterial clarification through the 2-stage process to the special bacterial clarification of drinking milk, and variable bacterial clarification of cheese milk, treatment of whey concentrate and pre-treatment of milk powder. After the first successful bacterial clarification of cheese milk by centrifugal force in the 1980s, the new generation of bacteria removing centrifuges / bactofuges now pursues a wide variety of objectives. In milk processing, for example, spore-forming molds can cause serious problems. Nowadays these centrifuges are also used to extend the shelf life of milk (both for skimmed milk and for whole milk).
In drinking milk manufacture, aerobic spore-formers such as Bacillus cereus impair the shelflife of the product by sweet coagulation. In milk powder manufacture, especially with “low heat” products, anaerobic and aerobic spore formers can even cause product spoilage. All these are reduced to an absolute minimum by bacterial clarification. Bacterial clarification is recommended before processing into cheese, because this allows the addition of nitrate to prevent so-called blowing to be significantly reduced or even dispensed with. In whey processing, bacterial clarification is particularly meaningful when serum proteins in concentrated form (WPC = whey protein concentrate) are to be obtained from clarified and skimmed whey by ultrafiltration. This is because the long dwell times of the product in the system at sometimes ideal incubation temperatures mean that vigorous growth of bacteria can be expected.