556 Chapter 31
sugar addition, fermentation conditions) are
adjusted correctly.Raw Dry Hams
Fraqueza et al. (2007) , L ü cke (2007) , and
Toldr á et al. (2007) have compiled data on
the safe manufacture of high - quality, raw dry
ham. Table 31.8 gives an example for a
product common in Germany.
For raw hams, it is even more important
to specify the origin and the quality of the
raw material. For premium quality, the pigs ’
feeding regime, breed, and age at slaughter
are important and must be specifi ed and con-
trolled. This is only possible within a supply
chain with fair cooperation between all part-
ners. At delivery, cuts must be inspected
carefully for integrity and absence of any
signs of spoilage and fat deterioration. High
pH meat has a high water - binding capacity
and needs very long salting times; hence, the
pH of the ham before salting should gener-
ally not exceed 5.8. Only in certain pork
muscles, may pH values up to 6.0 be
tolerated.
The presence of spoilage or food - poison-
ing bacteria (including nonproteolytic strains
of Clostridium botulinum ) in the interior of
the ham can be minimized by appropriatemix. Filling is also critical for product quality,
because any holes remaining may be starting
points for rancidity, discolorations, and
growth of undesired microorganisms.
The microbiological quality and safety
depends very much on the correct fermenta-
tion and drying/aging conditions (tempera-
ture, relative humidity, air velocity), which
should be clearly specifi ed and monitored.
To protect the surface from undesired oxida-
tive or microbiological changes, most sau-
sages are either smoked after fermentation
or surface inoculated with selected mold
(sometimes also yeast) strains. To obtain the
desired aroma and to minimize the levels of
toxic residues, the smoking process should
be well controlled by specifying and record-
ing the type of the wood (or liquid - smoke
preparations), the charring temperature, and
the time and temperature during smoking.
Mold starters should be able to rapidly colo-
nize the surface after completion of lactic
fermentation.
Process records should include, among
other items, weighing protocols, and the time
course for temperature, relative humidity,
and weight loss. Continuous measurement of
pH during fermentation is diffi cult, but it
should be done at regular intervals, to verify
that process parameters (activity of starters,
Table 31.8. Examples for critical values for the manufacture of a typical German raw dry ham
(modifi ed from L ü cke, 2007 ; Lautenschl ä ger 2007 )
Process step Critical values
Selection of lean meat pH value (lean meat) between 5.6 and 6.2; fatty tissue white, fi rm, less than 15%
polyunsaturated fatty acids; temperature below 2 ° C; defi ned size, geometry
and integrity of the cut
Weighing of ingredients – Salt 40 – 50 g/kg meat- Curing agents, input level suffi ciently low to comply with maximum levels for
nitrite and nitrate as specifi ed by law
Dry salting Temperature below 5 ° C, relative humidity above 80%, until water activity in
Salt equilibration core below 0.96
Preparation for smoking Temperature below 18 ° C, no longer than 1 day
Smoking Temperature below 22 ° C; charring temperature below 700 ° C
Aging Temperature 12 – 15 ° C, 70 – 80% relative humidity, until water activity below 0.93
Storage below 15 ° C