Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 2
To recover fat from meat residues, wet melting or dry melting is used. In the wet melting
process, the raw material is heated in a process kettle by direct steam injection to a temperature
of about 90 °C. This results in a watery phase and a fat containing phase. The phases are
separated by decantation and centrifugation. In the dry melting process, the raw material is
indirectly heated in the processing kettle (a kettle with a steam jacket). All the water which
evaporates is removed from the kettle under vacuum. The liquid phase or molten fat and the dry
phase or fat-free meat residue are separated by decantation.
The meat sector is very diverse in terms of its products due to specific local tastes and
traditions. However, three processes commonly used are canned meat, cooked ham, and cured
ham production.
2.2.1.1 Canned meat (beef muscle in gelatine)
Different raw materials, such as cooked or uncooked, chilled or frozen meat may be used to
produce canned meat. A general flow sheet is presented in Figure 2.3.
Cans
H1
Alternative 1
Frozen cooked meats
Thawing
Cutting
Meat dosing
Weight control
Cooking (de-aeration)
Sealing
Can washing
Thermal treatment
Cooling
Storage finished
products
Figure 2.3: Canned meat production
[91, Italian contribution, 2001]
2.2.1.1.1 Thawing (A.5)
Alternative 2
Frozen uncooked meats
Meat
Thawing
Trimming
Pre-cooking
Cutting
Canned meat
Gelatine preparation
Mixing
Cooking
Frozen meat is generally transported in plastic bags inside a cardboard secondary packaging.
Meat is stored at a temperature below -18 ºC. Thawing can be achieved with air at a controlled
temperature, or by an intermittent shower, or by immersion into running water. The two first
methods allow a reduction in water consumption, but require longer times and larger surface
areas. Moreover, the meat surface may be dried and its unsaturated fats, e.g. in pork, may be
oxidised. When thawing in a water bath, the unpacked meat is put in iron crates and completely
immersed in water at 15 to 18 ºC. The water consumption is about 3 – 5 m 3 /t.
62 January 2006 RHC/EIPPCB/FDM_BREF_FINAL
Soup
Tank
Filling