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About Us


We are situated in Rousse, Bulgaria. Our company DION Ltd. was founded in 1997 with activity producing of whole egg powder and pasteurized egg mélange. We are producing around 1500 tons pasteurized liquid mélange and 1000 tons whole egg powder per year.

Our daughter company DION ENGINEERING Ltd. was founded as engineering company with activity designs, manufactures, supplies, installs, and launches into operation processing equipment for pasteurizing and drying of eggs, milk, juice etc. in the food industry. The equipment we offering is used for many years with success.

Our big advantage is that the client can come to our production plant and see how the equipment is working and we can share with you some details of the processing.

What is Pasteurization?


Pasteurization is a process, which relies on thermal processing of products, such as juices, eggs, milk and milk products, to kill microorganisms which carry diseases (pathogenic) and cause spoilage. Heat is lethal to microorganisms, but each species has its own particular heat tolerance. Therefore the time duration of the pasteurization process and the corresponding temperatures it has to be heated up and cooled down to varies with each product. The main purpose of this type of thermal processing is to kill all the pathogenic bacteria and leave an acceptable concentration of spoilage microorganisms, without reducing the quality of the end product.

History of Pasteurization?


Heat treatment processes were widely used for preservation purposes as early as the 12th century. However, it wasn’t until the early 19th century when more sophisticated and practical experimentation start. In 1810 a Parisian chef named Nicolas Appert created a simple and practical way of killing bacteria. He filled glass bottles with a variety of produce and would heat them up using boiled water for an extended period of time. Though the methodology managed to kill off most of the microorganisms which carry disease and cause spoilage, this also reduced the nutritional value and quality of the food.

A less aggressive method was developed in 1864 by the French chemist Louis Pasteur. He discovered that heating young wine and beer with a lower temperature and less time would kill the harmful bacteria without reducing the quality of the final product. In his honor this process is called pasteurization. Since then, pasteurization has been adapted and further developed to eliminate pathogenic microbes and prolong the shelf life of various products, such as juices, eggs, milk and milk products.

It took centuries for the discovery of pasteurization and the estimation of the correct temperature and time needed for each product. However, it is a very simple process which many people today unknowingly use by boiling fresh milk in their homes. Furthermore, many culinary professionals pasteurize raw eggs themselves. It is done by simply placing eggs in a saucepan with water heated to 61 degrees Celsius for 3 minutes.

Modern Pasteurization and Our Machines?


The main challenges arise when pasteurizing on an industrial scale. The most common method for pasteurization of eggs today is via thermal processing with temperature of up to 67 degrees Celsius and a holding time of approximately 3.5 minutes, parameters which our machines offer. Our pasteurizers can work with temperatures from 50 up to 120 degrees Celsius, to suit the requirements for processing different products, such as milk (up to 72) and juices (up to 98). Factors such as the thermal resistance of the pathogenic and spoilage microorganisms, the viscosity and presence of solid particles in liquids, all have an impact on the needed holding time and temperature for pasteurization. Furthermore, different countries have different minimum requirements for the thermal processing of each liquid. Depending on whether you’re interested in pasteurizing eggs, milk or juice, we use distinctive heat exchangers to satisfy those regulations and preserve the quality of the end product. They are not only some of the most compact and affordable on the market, but are also designed to decrease operating costs, such as electricity, process cleaning, water, labor and maintenance.

Heating up and cooling off the liquid requires a lot of energy and is the biggest operating cost modern pasteurizers have. Furthermore, prolonged heating of eggs, milk and juices have a negative effect on the nutrient value and taste. That is why our machines are designed to optimize the thermal processes in order to have a high quality pasteurized product and reduce operating costs as much as possible.

The way our machines function is straightforward and easy to understand. In essence, the material enters the pasteurizer, flows through several stages of thermal processing (it is first gradually heated and then gradually cooled down) and exits the machine. When the liquid first enters the pasteurizer it goes into a Reception tank. Our pumps provide pressure between 2-4 bars, which leads to a continuous flow in the pasteurizer. In the first stage of the thermal processing in the pasteurizer, the liquid flows into the recuperator to be heated up. There it makes use of the waste heat of the previously pasteurized liquid. Through heat transfer with plate heat exchangers, the cold liquid heats up to 55 degrees Celsius and the hot one cools down to 25. In the next stage the rotor spinning heater further heats it up to reach our desired temperature of 67 degrees. Furthermore, it prevents the separation of fat from the rest of the substances of the egg. In the third stage the liquid flows through the holding tubes, where it maintains its temperature. The flow rate and the length of the tubes are calculated so that the liquid takes 3.5 minutes (the desired holding time) to pass through them. The fourth stage consists of the material flowing into the recuperator to get cooled down, but through a different path than before. It lowers its temperature by transferring its waste heat to the inflowing unpasteurized liquid. Then it exits the recuperator and immediately enters the cooling section, where the same heat exchange process happens, but this time with a cooling agent. This cooling agent 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 externally from the pasteurizer. Finally, after being cooled down to 4 degrees, the liquid is pasteurized and ready to be packaged.

Many pasteurizers require water or steam boilers, as the main source of heat, and homogenizers, which distributes fat globules evenly in the liquid. Our machines instead use a rotor spinning heater, which accurately heats the liquid to the required temperature. This type of thermal processing is called shock heating. The rotor also provides a gentle homogenization to the liquid, which prevents the separation of the liquid and doesn’t damage the protein molecules. As a result, quality of the end 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, which can be hard to integrate into the processing line. They also require regular cleaning and are not energy efficient, which would increase the operating costs of the production. Our rotor allows constant processing for 9 hours without cleaning, unlike conventional pasteurizers. Furthermore, we design our machines to optimize the production process as much as possible. That is why we also offer pasteurizers which are fully automated, with integrated filling machines, cleaning-in-place (CIP) systems and reliable and easy to use electronics.

Other frequently used methods of pasteurization are UHT (ultra-heat-treating) and HTST (high-temperature, short-time). However, UHT and HTST are inapplicable 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 up to a higher temperature than standard pasteurization. However, this method requires more expensive machinery. In addition, it is complicated to clean and you have to do it more frequently. There is less demand for the resulting product as well, due to the changes in taste and loss of nutrient value from this more aggressive heat treatment.

Our fully automated machines are designed for a continuous pasteurization of a single type of liquid. Furthermore, similar to an assembly line, all the stages in the pasteurization can function simultaneously. This is the most financially efficient way of production. It is very energy efficient and requires less specialized labor.

There is an alternative method used, called batch production. It is designed to completely produce a specified amount of pasteurized liquid at a time, before starting the processing of the next unpasteurized batch. Typically this type of production is implemented by companies, which want to produce several types of products with a single production line, for example, pasteurize 300 liters of egg white and after that- 300 liters of milk. Although batch production requires lower capital investment for machinery, the operating costs become a lot higher. Not only is the production process very inefficient, but requires more specialized labor, extensive cleaning between batches and the quality of the end product is poor.

Why Us


Unlike our competitors, we have started out as a production company, producing whole egg powder and pasteurized egg mélange. We have been using the machines we are offering since 1997 and to this day we are the leaders in the Bulgarian market for egg products. When we founded DION ENGINEERING, we transferred all the core competencies we have obtained through years of experience. Whether you are an established or a new business, we have a variety of machines with different prices and production capacity to suit your needs.

We understand that constructing an egg processing line usually requires a costly investment. That is why we offer the best quality for your money. With our machines you are not required to purchase some of the costly equipment competing products require. In addition, we aim to provide the most energy efficient pasteurizers on the market and offer a 3 year guarantee.

In DION Ltd., DION ENGINEERING’s parent company, we have over 20 years’ worth of experience in production which we would happily share with you. At your discretion, we will give you a tour of our facilities, explain in detail how the machines work and answer any further questions you might have.