Efficiency assessment of water reclamation processes in milk protein concentrate manufacturing plants: A predictive analysis

Abstract

Milk protein concentrates (MPC) are increasingly used as protein fortifiers in food formulations, as a means to increase cheese yield, and in the manufacture of Greek-style yogurt. However, manufacturing of MPC requires significant volumes of input water and generates polluting by-products such as permeates and/or diafiltrates. Reverse osmosis was suggested to reduce the impact of both issues by reclaiming water from dairy fluids, thereby reducing the volumes of by-products to be treated. Filtration performance data was obtained from the reverse osmosis of dairy fluids, namely skim milk and ultrafiltration permeate, and from the polishing process of their respective permeates. It allowed the comparison of various water reclamation scenarios through a predictive analysis, which revealed that, without increasing operational costs, preconcentrating the skim milk prior the MPC manufacture would reduce the use of water and electricity by 35% and 10%, respectively, compared to a traditional process that consists in the concentration of skim milk by ultrafiltration, followed by the concentration of the resulting retentate by reverse osmosis.