a. Hams At the end of the salting stage, the Aw of the internal fractions is still very high (>0.96) (5,14), and hams cannot yet be submitted to the temperature conditions that would facilitate the enzymatic processes responsible for the formation of their fundamental sensory properties.
The hams are thus placed in good drying conditions at refrigeration temperatures; this stage, normally referred to as resting, has the purpose of preventing the growth of and/or inactivating the harmful microorganisms present on the surface, and of progressively reducing the internal Aw to values that allow for the transfer of the product to rooms at a higher temperature.
At this stage (adopted in many technologies) the hams are placed in suitable locations (resting cells) so as to facilitate the exchange of matter (the evaporation of water) with the environment.
The thermohygrometric conditions differ greatly according to the characteristics of the product; in all cases, at first a rapid drying of the surface must be achieved (low relative humidity values and adequate ventilation) in refrigeration conditions (temperature similar to that of the salting stage) for a sufficient number of days (7-14); the drying conditions are subsequently slowed down so as not to cause damage to the external fractions (drying rim).
The duration of the resting stage depends on numerous parameters, in particular those which influence the diminution of the internal Aw, which, not being measurable directly, must be estimated by evaluating the quantity of salt and water in the more internal fractions.
The resting period is longer the greater the weight of the ham and the lower the quantities of salt absorbed, and ranges from a few weeks, for small-sized hams containing higher quantities of salt, to several months for sweeter products (e.g., 2-3 months for the bigger-sized Parma hams). For very small and salty products, this stage can be omitted.
b. Other Products What has been said regarding hams also applies to other products. The thermohygrometric conditions must be chosen according to the same rules;
in particular, the greater the dimensions, the lower the quantities of salt required, the lower the temperatures of the environment, and the longer the overall period of the stage.
The introduction of the resting phase for certain products prepared with limited quantities of salt and additives and of a certain dimension (coppa, dried meat from the Grisons, Bauernspeck etc.) reduces the incidence of microbiological contamination and improves some sensory properties (uniformity of color, greater proteolysis control, etc.).
The resting times at this stage are generally modest (1 to 3 weeks), although there are numerous exceptions, in particular for anatomic fractions isolated from pork legs.
If the product contains nitrates, the thermohygrometric conditions must be such as to facilitate a certain transformation of this additive, and thus it is preferable to adopt higher temperatures than those indicated for the salting stages (e.g., 3-6°C rather than 1-4°C). If the Aw at the end of the salting phase is very high, the resting period can be subdivided into two stages, the first at lower temperatures (1-4°C) and the second at higher ones.
Hams are normally hung on special supports (e.g., frames) with string or a similar material tied to the end part of the leg; for other products, differing solutions are available: some products are placed in individual containers of varying material and shape (including natural and artificial casing), in order to obtain a desired shape.
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