Proteases for Acceleration of Ripening and Flavor Development
This objective is based on addition of microbial proteinases/peptidases to cheese milk in order to enhance secondary proteolysis. Addition of proteinase from Ps. Fluorescens in free form prior Cheddar cheese making was one of the first application patented (Haard and Patel, 1987); use of a carboxypeptidase from A. niger has been recently patented by Van Dijk et al. (2014). Currently, most effective procedures have been developed by which enzymes are entrapped for controlled release during ripening. Direct encapsulation using food gums (Kailasapathy et al., 1998) or liposomes (Weiner at al., 1995; Walde & Ichikawa, 2001) is one of the two entrapping methods available; the second method is encapsulation of cell-free extract from bacteria or whole bacterial cells in milk-fat capsules (El Soda, 1997; Wilkinson & Kilcawley, 2005).
The principal application of exogenous lipases in the dairy industry is enhancing cheese flavor and acceleration of cheese ripening throughout controlled hydrolysis of triglycerides. Animal lipases that are isolated from the epiglottis (throat) of calves, sheep, or goats, greatly contribute to release short-chain fatty acids responsible of sharp and piquant flavors. Instead, microbial lipases that are isolated from fungi such as Rhizomucor miehei contribute to lipolytic profiles rich in medium-chain fatty acids, which tend to impart a soapy taste (Hasan et al., 2006). At the commercial level the use of lipases in cheese manufacture is currently limited to certain Italian cheeses (Provolone and Caciocavallo) or for enzyme modified cheese production (Hernandez et al., 2005). Besides enhancing cheese flavor, other uses of lipases have been proposed, such as addition of fungal phospholipase A1 to milk for increasing cheese yield in manufacture of part-skim Mozzarella. The result is due to improved fat and moisture retention in cheese caused by the increased emulsifying property, that is, reduction of fat losses in whey and cooking water (Lilbsk et al., 2006). A further recent application is enhancing flavor and structure in butter and dairy cream (Kurtovic et al., 2011).