Progressive freeze concentration of cheese whey for protein and lactose recovery

Cheese whey (CW) is one of the main problematic waste streams in the dairy industry. CW and its protein and lactose content was concentrated through progressive freeze concentration (FC). The screening of different operating conditions was performed to set the agitation rate and cooling temperature resulting in optimal concentration efficiencies (600 rpm and-5 ?). In each screening assay 50% of the initial CW volume was frozen and the influence of the operating conditions on protein and lactose phase distri-bution (ice and concentrated liquid) and content. Additionally, a four-stage FC procedure was also per-formed under optimal conditions resulting in a concentration up to 20.52% (w/w) of total solids, with 13.93% of protein content in the concentrated fraction and 6.24% (w/w) of lactose in the ice fraction. The present study demonstrated the potential behind FC to concentrate and valorise waste streams such as cheese whey.