Dairy pilot plant
The department was supported and facilitated by the establishment of the existing pasteurization dairy pilot plant as a training plant for dairy processing and dairy technology students. It is intended to equip the graduates with the knowledge and technical know-how needed for good professional performance.
Also, it is intended to serve the community through practical training of college and technical institutes students, in addition to the education of public school students in their visits to the
Below are brief notes on the pasteurization plant and its usable equipments:-
The Pasteurizer and other Equipments
Pasteurization is a process of heating milk (all parts or components of it) to a certain degree of temperature, and for a definite time enough for killing all pathogenic microorganisms (microbes) as well as killing most or a high percentage of spoilage non-pathogenic ones, without affecting the physical, sensory and nutritional properties.
Most Important Benefits of Pasteurization
1- Destruction of all pathogenic microorganisms present in milk, thus insuring safety of milk and milk products consumers>
2- Destruction of most microorganisms (95-99% pathogenic or non-pathogenic) present in milk, thus insuring its good quality and long shelf life.
Most Important Methods of Pasteurization
Low Heat Long Time Method (HLT):-In this method milk is heated to 145-150oF (62-63o C) for 30 min., then immediately cooled to less than 45-50o F (4-5o C). This method depends on the heat exchange between milk, heating medium and/or cooling medium. The pasteurization is accomplished by the plate exchanger which is equipped with a double-face stainless steel plates fitted together in a controlled frame ; through which milk passes in a thin layer or membrane over one face , while on the other passes the heating medium (hot water or pasteurized milk) or the cooling medium(chilled water) .
Flow of Milk in the Pasteurizer
1- Milk is received at the reception platform of the processing dairy plant, afterwards a sample is taken for simple primary tests such as taste, flavor, temperature, acidity(which should not exceed 0.2 % lactic acid), fat%, sediments and specific weight. Then, milk is weighed and pumped to storage tanks at 40-50o C.
2- From the storage tank, milk is drawn or pumped to the balance tank, where its flow is organized by a float.
3- From the balance tank, milk is pushed to the heat exchanger where it exchanges heat with reduced temperature pasteurized milk (who's temp. is reduced to 65o C). As a result the temp. of this coming milk is in turn further reduced to 40-45 o C.
4- The primary heated milk is passed to the clarifier and then to the fat separator for clarification and fat separation, consequently.
5- Milk is then passed to the second heat exchange chamber where it exchanges heat with pasteurized milk (at 72-74 ° C) and where it acquires heat (up to 65° C). From here it is passed to the homogenizer for homogenization.
6- After homogenization, milk is pumped to the last heating chamber where it is heated to 72-74 ° C.
7- Afterwards milk is passed to the holding chamber of the pasteurizer where it should be held for 15 seconds before its passage through the check valve (which will divert improperly pasteurized milk (heated to les than 72-74° C) back to the balance tank. If it is well pasteurized, it will be directed to the heat exchanger automatically.
8- Post-passage of the pasteurized milk through the heat exchanger, it will be passed to the cooling chamber where it's temp. is reduced to 40-50 ° F, and from there it is pumped to the packaging machine.