Effect of recombinant chymosin on ewes' milk coagulation and Manchego cheese characteristics

Abstract

SummaryEwes' milk coagulation was significantly influenced by the type of rennet when recombinant chymosin produced by Kluyveromyces lactis was compared with two commercial calf rennets with declared chymosin contents of 55 and 70%. Recombinant chymosin and calf rennet with 70% chymosin exhibited similar thrombelastographic characteristics, and coagulated milk more rapidly than calf rennet with 55% chymosin. The type of rennet had no effect on Manchego cheese dry matter, pH or recovery of dry matter in cheese. N soluble at pH 4·6 was the only N fraction influenced by the type of rennet, with slightly higher levels for cheese made with recombinant chymosin or with calf rennet containing 70% chymosin than for that made with rennet containing 55% chymosin. No significant differences in rheological or sensory characteristics between Manchego cheese made with recombinant chymosin and that made with the calf rennets were detected.