Abstract: A plant and method of treating low-fat milk, such as skim milk, so as to obtain with a low content of spores and bacteria, wherein the milk is subject to a first microfiltration causing a separation into a first permeate, the first permeate being subjected to an additional microfiltration. This double microfiltration ensures that the acceptable limits for bacterial counts in milk products are not exceeded in case of a membrane breakdown.

Abstract: A dispersion having an aqueous phase is filtered by a purality of membranes connected to pass the retentate or a portion of the retentate from one membrane step is used for feeding the one or more succeeding steps, and the permeate resulting from the plurality of membranes is subjected to a concentration step to produce a concentrate containing an increase concentration of dry matter, which is returned as a portion of the feeding dispersion to one or more of the plurality of membranes. The system provided with the membranes and concentration units and recirculation conduits is also disclosed.

Abstract: A plant and a method of treating milk so as to obtain milk with a low content of spores and bacteria. In a centrifugation unit (4) the milk is separated into a cream fraction (CR) and a skim-milk fraction. The skim-milk fraction is separated in a microfiltration unit (8) into a spore and bacteria-containing retentate (R) and a permeate (P) with a low content of spores and bacteria. The cream fraction (CR) is sterilized in a sterilizing unit (16), and the sterilized cream (STCR) or a portion thereof is mixed with the permeate (P) into standardized milk. The retentate is recirculated to the centrifugation unit (4) which is of the type separating the material into the cream fraction (CR), the skim-milk fraction (SM), and furthermore a sludge fraction (SL). The plant and the method ensure a high microfiltration capacity and the cheese formation properties of the milk is maintained.