Technological tools to include whey proteins in cheese : current status and perspectives

Background: Cheese manufacturing consists of a dehydration process by which most of the whey is drained off. Whey proteins (WP) represent a nutritionally valuable fraction largely lost in the whey stream. The increasing consumer demand for food with novel texture and functionality prompted the dairy industry to exploit the valorization of WP. Scope and approach: Cheese milk is considered a vehicle for the inclusion of WP. In this review, technological tools to fortify cheese with WP are discussed. Focus is addressed on both the pioneer approaches (the heat treatment of cheese milk, membrane separation technologies and the direct addition of milk- or whey-based derivatives) and on more recent techniques such as high hydrostatic pressure, ultra-high pressure homogenization, transglutaminase treatment of cheese milk and direct addition of buttermilk. Key findings and conclusions: Milk fortification with WP influences the yield and overall properties of resulting cheeses. Processing conditions need to be adapted to successfully manufacture WP-fortified conventional cheeses as well as novel varieties (such as low-fat cheeses). Up to now, only some technological tools to include WP in cheese are exploited at industrial scale. The combination of different techniques is a strategy to overcome the impairment of cheese properties.