S8: Whey Processing

A by product of dairy processing is whey. Whey is separated from curd when producing cheese. Most cheese whey is ca. 0.5% protein and 5% lactose. Traditionally, whey was simply disposed or used as a low-end consumable for anumal feed and fertilizers. More recently, whey has been used as a source of protein for human consumption. This type of whey not only requires a more refined and controlled separation process, but also has tighter specifications, including microbial content. In order to comply with these specs, the whey is not only pasteurized, but also processed through a variety of filters. Although pasteurization reduces microbial counts, the ultrafiltration membranes still foul resulting in costly cleaning interventions. Chemical control of microbial counts has been difficult due to limited food contact additives and high chemical demand of the actives by the whey. Peracetic acid has been found to be an excellent alternative to current practice due to its broad antimicrobial spectrum, low demand, low persistence in whey, food contact approvals and low cost to use.