Processed cheese is produced through the processing of cheese at different stages of maturity. The cheese used should be suitable for general consumption. It is acceptable to use cheese with defects on the surface or structural defects. Cheese with any developed and unwanted micro-flora can also be used as this will be destroyed during heat treatment which is usually 75 to 95°С. It is unacceptable to use any cheese with unpleasant smell or taste as this will influence the quality of the finished product. Processed cheese is classified into three groups:
- cheese with a high moisture content - with a spreadable structure;
- cheese with a low moisture content - with a harder structure and suitable for cutting into slices;
- smoked processed cheese.
Additional ingredients including water, curd, cream, salt, emulsifiers and stabilizers are added during production. Different fillings can also be added such as: mushrooms, ham, spices etc. The use of a vacuum system during production improves the texture of the product and partly eliminates any unwanted odour. The end product is usually packaged at melting point. Cheese with a high moisture content (with a spreadable structure) should be cooled quickly after packaging and cheese with a lower moisture content (for cutting into slices) should be cooled slowly at room temperature. There is a large variety of packaging available dependent on the texture of the product.
Such lines are being used for making processed cheese, cheese and butter cream. They can be packaged later on according to beneficiary’s choice, either in thermoforming lid cups or in clipped roll-shaped films.
Production line structure:
A. CUTTER
- melting vat, with cover;
- blades entraining group;
- agitation mechanism;
- vacuum circuit;
- hot water circuit;
- valves;
- control panel;
- cradle.
B. PUMPS
C. HOMOGENIZER
D. PACKAGING MACHINE
- in casseroles;
- in films;
- packages of several shapes.
THE CUTTER is the basic piece of such lines and consists of:
a) Melting vat: is a double walled container made of stainless steel, with an overall capacity between 30 l ÷ 150 l. On the bottom vat axis there are rotating knives which perform the breaking and energetic mixing of the to-be-melt product, without a previous grinding of the raw matter. The heating of the rae material charge is made by hot water circulation in between the two vat walls.
The vat has a lid with a scraper agitator which removes the product off the walls during the melting process. In the lid there are fittings mounted for:
- vacuum pump
- air blowing
At the end of the working cycle the vat is emptied by air blowing into the vat above the product thus creating a pressure that evacuates the product through the drain outlet.
The thermal process is controlled by a thermally sensitive resistance element mounted on the pot wall sending signal to a thermo-regulator which displays product temperature value.
b) Blades entraining group: the two knives which ensures the grinding and homogenizing of the paste are driven by an electrical engine directly mounted on the blades. The entraining group allows two variants of blade rotation speed: - fixed 1500 rot/min, or variable.
c) Agitation mechanism: is placed on the vat lid and provides the entraining of the scraping shafts mounted inside the vat, aside from the main engine. The speed is 30 rot/min.
d) Vacuum circuit: comprises the following:
- vacuum pump - ensures the evacuation of the bad smelling volatile substances inside the vat;
- condensing container – is a stainless steel made reservoir with a capacity of 10 l, placed on the pump absorption circuit where much of the evacuated steam condense, and the collected liquid is periodically discharged;
- connecting hoses.
e) Hot water circuit or steam circuit
f) Valves: refers to all valves (electric or pneumatic ) mounted on the utility circuits which ensures unit operation.
g) Control panel: force and control electric circuit is mounted in a fixed panel nearby the unit.
h) Machine cradle is made of stainless steel.