The main challenges arise in pasteurization on an industrial scale. The most common method for pasteurization of eggs today is by heat treatment with a temperature of up to 67 degrees Celsius and a retention time of approximately 3.5 minutes, parameters that our machines offer. Our pasteurizers can operate at temperatures of 50 to 120 degrees Celsius to meet the processing requirements of various products, such as milk (up to 72) and juices (up to 98). Factors such as the heat resistance of pathogenic and perishable microorganisms, viscosity and the presence of solid particles in liquids all have an impact on the required retention time and pasteurization temperature. In addition, different countries have different minimum requirements for the heat treatment of each of the liquids. Depending on whether you are interested in pasteurizing eggs, milk or juice, we use different heat exchangers to meet these regulations and maintain the quality of the final product. They are not only some of the most compact and affordable on the market, but are also designed to reduce costs such as electricity, cleaning, water, labor and maintenance.
Heating and cooling the liquid requires a lot of energy and is the largest operating cost that modern pasteurizers have. In addition, prolonged heating of eggs, milk and juices has a negative impact on nutritional value and taste. That is why our machines are designed to optimize thermal processes in order to have a high quality pasteurized product and to minimize operating costs.
The way our machines work, is clear and easy to understand. Essentially, the material enters the pasteurizer, goes through several stages of heat treatment (first heated gradually and then gradually cooled) and exits the machine. When the liquid first enters the pasteurizer it goes into the receiving tank. Our pumps provide a pressure between 2-4 bar, which leads to a continuous flow in the pasteurizer. In the first stage of heat treatment in the pasteurizer, the liquid flows into the recuperator to heat up. There he uses residual heat from a previously pasteurized liquid. By transferring heat with plate heat exchangers, the cold liquid is heated to 55 degrees Celsius and the hot liquid is cooled to 25. In the next stage, the rotor heater additionally heats it until the desired temperature of 67 degrees is reached. It also prevents the release of fat from the other substances in the egg. In the third stage, the liquid flows through the holding tubes, where it maintains its temperature. The flow rate and length of the tubes are calculated so that the liquid takes 3.5 minutes (the desired retention time) to pass through them. The fourth stage consists of the material passing through the recuperator to cool, but in a different way than the previous one. It lowers its temperature by transferring its waste heat to the unpasteurized liquid. It then exits the recuperator and immediately enters the cooling section, where the same heat exchange process takes place, but this time with a refrigerant. This coolant is a liquid that has a temperature of -2 degrees Celsius. It circulates continuously between the cooling section and another machine called a chiller, which is located outside the pasteurizer. Finally, after cooling to 4 degrees, the liquid is ready for packaging.
Many pasteurizers require water or steam boilers as the main source of heat and homogenizers that distribute the fat globules evenly in the liquid. Our machines instead use a rotary heater that precisely heats the liquid to the desired temperature. This type of heat treatment is called “shock heating”. The rotary heater also ensures careful homogenization of the liquid, which prevents the separation of the liquid and does not damage the protein molecules. As a result, the quality of the final product is also maintained. We have a more detailed explanation of how this rotor works here.
Both the homogenizer and the boilers are expensive equipment that is difficult to integrate into a processing line. They also require regular cleaning and are not energy efficient, which will increase operating costs for production. Our rotor allows continuous processing for 9 hours without cleaning, unlike conventional pasteurizers. In addition, we design our machines to optimize the production process as much as possible. That’s why we also offer pasteurizers that are fully automated, with integrated filling machines, cleaning systems (CIP) and reliable and easy-to-use electronics.
Other commonly used pasteurization methods are UHT (ultra-heat treatment) and HTST (high temperature, short time). However, UHT and HTST are not applicable to eggs and are mainly used in other products such as milk and juices. They can usually be seen in stores in Tetra Pack containers. The liquid is heated to a higher temperature than standard pasteurization. However, this method requires more expensive machines. It is also difficult to clean and you need to do it more often. There is less demand for the resulting product due to changes in taste and loss of nutrients from this more aggressive heat treatment.
Our fully automated machines are designed for continuous pasteurization of one type of liquid. In addition, like an assembly line, all stages of pasteurization can operate simultaneously. This is the most cost-effective way of production. It is very energy efficient and requires less specialized work.
There is an alternative method called batch pasteurization. It is designed to produce a fully defined amount of pasteurized liquid for a given time before processing the next unpasteurized batch. Usually this type of production is performed by companies that want to produce several types of products with one production line, for example, pasteurize 300 liters of egg white and then – 300 liters of milk. Although batch pasteurization requires less capital investment for machinery, operating costs become much higher. Not only is the production process very inefficient, but it also requires more specialized labor, prolonged cleaning between batches and the quality of the final product is poor.