Impact of membrane selectivity on the compositional characteristics and model cheese-making properties of liquid pre-cheese concentrates

Ultrafiltration (UF) is a commonly used membrane process in dairy industries, but little attention has been given to reverse osmosis (RO) and nanofiltration (NF) for cheese milk concentration. The objective of this work was to compare composition, rennet-induced coagulation kinetics and cheesemaking properties of UF, NF and RO concentrates. Rennet-induced coagulation kinetics, at a constant rennet concentration, were characterized by dynamic rheology and model cheeses were made to study cheesemaking properties. Rennet coagulation time (RCT) and time to reach maximal firming rate (MFR) were similar for UF concentrates and skim milk (SM). However, RO and NF concentrates had longer RCTs and MFRs. Model cheeses experiments showed that all concentrates had higher moisture adjusted curd yield. However, RO and NF curds had higher moisture than UF. This study has shown that RO and NF milks impaired cheesemaking properties, probably because of their higher salt content.