Compositional and physico-chemical modifications during the manufacture and ripening of Leon raw cow's milk cheese

摘要

The gross and mineral composition and the most relevant physico-chemical parameters were determined in five batches of Leon cow's milk cheese throughout ripening and in the milk used in their manufacture. The milk used in the manufacture of this cheese is characterized by having high values of fat and total solids; the mineral composition and the values of pH do not differ significantly from those observed in cow's milk from different origins. During ripening, Leon cow's milk cheese undergoes a very intense dehydration, due to this, the final values of moisture and A_w are among the lowest observed in cow's milk cheese. The fat contents in this cheese are placed in the higher extreme of the range of values observed in other cheeses. The presence of residual lactose in cheese after 90 days (end of ripening) is exceptional. During curdling a very intense acidification takes place as a consequence of which very low values of pH are reached in the curd (around 4.6) and remain during ripening with minimum variation, with the final values of pH being among the lowest found in cow's milk cheese. As a consequence of acidification during curdling, the minerals for the most part bound to the micelle of casein (Ca, P, Mg and Zn) underwent a solubilizationand were lost in significant amounts in the whey. The contents of these minerals and of total ash at the end of ripening are clearly lower than those observed in other similar cow's milk cheeses.