Influence of the type of dry-cured Italian PDO ham on Cathepsin B activity trend during processing. Cathepsin B activity was measured during processing in hams originating from the main Italian prosciutto PDOs: Parma, San Daniele and Toscano. Sixty-five heavy pig thighs, from 65 Italian Large white x Italian Landrace pigs bred and slaughtered in the same conditions, were considered. Five thighs represented the post-mortem control time. The other 60 were distributed in one plant per PDO, following a balanced plan. The thighs were sampled at Biceps femoris in groups of four per plant in the following ripening phases: salting, resting, drying, initial curing, end of curing. Cathepsin B activity (U/g protein) was determined by means of fluorescence measurements. The trend of cathepsin B activity during the ripening of the various PDOs was significantly different, particularly during the initial and mid curing stage. In this phase, San Daniele presented the lowest activity, while Parma showed the highest one, demonstrating that its processing procedure, characterized by a lower moisture loss, inactivated the proteolytic enzyme less noticeably than others PDO. The cumulative cathepsin B activity correlates with the proteolysis index through a PDO dependent pattern, suggesting that different percentages of the potential enzyme activity are effective on the muscle proteins during ripening, under the peculiar technological conditions of the three PDOs. At the end of seasoning, the lowest proteolysis index was observed in the saltier Toscano ham, also added of pepper and seasonings.
