Optimization of Clotting Donkey Milk Using an Aspartic Protease fromCynara Cardunculus Flowers

Donkey’s milk is an interesting commercial product, due to its high nutritional value, and can be considered as a suitable source of food for human consumption. For the first time, it was performed the optimization study of clotting process using donkey milk and a plant aspartic protease-cyprosin, obtained from Cynara cardunculus flowers. An experimental design was used for the preliminary factors selection such as: the clotting enzymes (cyprosin and microbial rennet), CaCl2 concentration (0.01%-0.1% (w/v)) and clotting temperature (32-35oC). The cyprosin and the 0.1% (w/v) CaCl2 concentration, as well as the relation between the CaCl2 concentration and the temperature, were the factors that showed a significant influence on the clotting activity. The 0.1% (w/v) CaCl2 concentration is an important factor because allows to obtain a more consistent curd, while the clotting activity of cyprosin was more efficient than microbial rennet. This preliminary study can give a new research base to obtain different types of cheeses using other milk origin as well as different clotting enzymes such as the cyprosin.