Effect of the use of three different lamb paste rennets on lipolysis of the PDO Pecorino Romano Cheese

Two rennet pastes were prepared from lambs on different diets, and then, together with a commercial lamb rennet paste, were used to produce protected designation of origin (PDO) Pecorino Romano cheeses. Chymosin activity and lipolytic activity were higher in the prepared rennets than in the commercial rennet. Lipolysis was greatest in cheese produced with one of the prepared rennets. Both quantitative and qualitative differences in free fatty acids were found in the cheeses. The taste of cheeses made with the prepared rennets was preferred by an expert sensory panel and also considered more piquant than that of cheese made with commercial rennet. The results indicate that both the diet of the lambs and slaughtering conditions should be regulated to produce rennet that preserves the traditional characteristics of PDO Pecorino Romano cheese. Both lipolytic and proteolytic properties of rennet pastes should be standardised for the preparation of such cheeses.