Caseins in Equid's Milk: The Hard Cheesemaking Process with Milk Produced by Non-Ruminants Herbivores

Milk proteins content varies between mammalian species reflecting the newborn growth rate. Equid species take 30-60 days to double their birth weight, showing a low level of protein in their milk. Caseins are the predominant class (80%) of proteins in bovine milk, while equid milk contains less caseins and more whey proteins. Caseins are precipitated by gastric acid and enzymes, forming a clot in the stomach that entraps fat. The hardness of this clot depends on milk casein content; high casein-containing milks will produce firm clots. Mammalian species that nurse frequently their neonate (i.e., equids and humans) produce diluted milk in which less than 60% of total proteins is casein, while animals that nurse infrequently, i.e. bovine, produce milk that is high in fat and caseins. In this work the attention was focused on equid caseins, evaluating the reasons that make hard cheesemaking using equid milk.