Bacteria death curve is proportional to organism acidity percentage and the applied temperature. Degrading Enzymes’ breakedown occured in some vegetables at high temperatures. Therefore, the applied heat starts from 60°C until degrading enzyme broken down and some specific food bacteria die or become inactive. The temperature in center of the food to be considered as the base temprature. Products shelf life is from one week to one year, depending on nutritional strength. It is appropriate to store pasteurized foods at refrigerator conditions (5-7°C) and offer them for sale. Foods to be consumed in a longer span and not freshed to be pasteurized, to extend their shelf life. Milk heated up to 63°C, Pickles to 82°C, Tomato juice to 94°C, for bacteria neutralization. Halfway through the pasteurization period, the material must be cooled by water to 40°C, otherwise color and quality losses’ occured.
Meat and broths cannot be pasteurized; even if they were, the benefits would be very short-lived. Milk is one of the foods, through which this method is commonly applied. This method is also used for beverages such as fruit juices, beer & wine, and some solid foods. Sterilization is another heat treatment method to be applied at 101 degrees and/or above. It is usually applied for foods containing carbohydrates such as high-protein meat, legumes and flour. MIT pasteurizers and food equipment designed by our expert engineers, to operate & perform these processes in the best possible ways.
Plate pasteurizers consist of a series of plates. High temperature resistant gaskets applied between plates. These seals prevent the liquid mixture passing through the plates. The plates are of 95-125 mm thickness and made out of stainless steel. The grooves on the plates provide turbulent filling and increase the heat-transfering surface and extend the liquid heat-contacting time.
Pasteurizer Working Principle
1- Start
The milk enters the balance tank, to ensure supplying milk faces no interruption in the line. In another word, the milk transfer via the pipeline to be steadily stable from the Balance Tank.
2- First Regeneration
The milk pumps into the 1st regeneration section of the pasteurizer. This milk entering volume at the 1st regeneration section encounters the milk that has been previously pasteurized and reached to high temperature. In this encounter, direct contact does not occur because there are plates in between. The temperature of cold milk reaches to 55°C while exposed to pasteurized one. The milk that reaches to this temperature passes through the 1st regeneration and discharged to the separator.
3- Separator
At this stage, Milk reaches the optimum temperature for Cream separation. The cream of the milk thoroughly separated. (The desired fat ratio is obtained and standardized.)
4- Second Regeneration
Milk with standardized fat content enters to 2nd regeneration pjase. The entering milk encounters the milk coming from the holding tube. (holding tube will be explained at later stages.) At this stage, the milk temperature reaches to 60-70°C.
5- Heater
At the next stage, the milk reaches to the heating section and, hot water heating process started. Milk temperature gradually increased to reach exactly at the pasteurization temperature.
6- Holding Tube
The Milk, which has been reached to pasteurization temperature directed toward the Holding Tube, noted in Article 2. At this stage, Milk harmful microorganisms killed
The Milk, which has been reached to pasteurization temperature directed toward the Holding Tube, noted in Article 2. At this stage, Milk harmful microorganisms killed The Milk, which has been reached to pasteurization temperature directed toward the Holding Tube, noted in Article 2. At this stage, Milk harmful microorganisms killed after waiting for a certain period of time, in the Tube. The heat retainer consists of a long zigzag pipe system. The purpose of this process is to ensure that milk remains at pasteurization temperature for a certain period of time. This time is 15 seconds in average. (The milk passing through the holding tube mentioned in Article 4) Thermometer and valve installed at the end of the holding tube. If the milk temperature is not at the appropriate level, the valve operates automatically and the milk directed to the beginning of the pasteurizer to be pasteurized again, and the system allowed to recirculate.
7- First and Second Regeneration
If there is no problem with the temperature, the milk coming out of the warm holder is delivered to the 1st and 2nd regeneration compartment. The entering pasteurized milk meets raw milk and the pasteurized milk get cooled. While the pasteurized milk cools, the raw milk that has just entered the system to be pasteurized, is also heated. In this way, a great energy recovery is achieved.
8- Cooler
The pasteurized milk finally passes to the refrigerating section where to be cooled by ice water.
Energy Recovery in Pasteurization
The most important point of the pasteurizing process is where the temperature of the newly arrived raw milk increased to 65°C by means of already pasteurized milk. After this stage, the milk that reaches to 65°C to be only heated by 35 degrees more, to reach to 90°C. Since 90°-pasteurized milk, which initially heated, used to bring the raw milk temprature from its initial temperature to 65 degrees, through which a great energy-saving process implemented.