The effects of biofilms formed on whey reverse osmosis membranes on the microbial quality of the concentrated product

The study investigated the development of bacterial biofilms on spiral wound reverse osmosis (RO) whey concentration membranes and their influence on the microbial quality and safety of concentrated whey (retentate). Used RO membranes, obtained from a commercial whey processing plant, were evaluated at intervals of 2 months for a total duration of 14 months using standard techniques. Results confirmed the presence of multi‐species bacterial biofilms on whey RO membranes. Considerable variations were noticed in the distribution pattern of biofilms constitutive microflora as the membranes aged. A greater increase in retentate counts as compared to feed suggested the possibilities of cross‐contamination from the membrane biofilms.