« Nous vous tiendrons informés »
Moba egg grading, packaging, and processing equipment are packed with technology. Some designs are worth further investigation as they represent crucial customer value. In this series of articles, we will be zooming in on these "hidden gems". In this edition of Moba News, we share the many ways that Moba's pasteurization technology benefits the functional properties of the egg.
To preserve egg products for as long as possible it is important to eliminate microorganisms. The method to obtain a certain shelf life for a food product is called pasteurization. Unlike, fruit juice or milk, for example, egg products cannot be sterilized. Instead of heating the product to a high end temperature, the product is heated to a significantly lower temperature, but the product is then held at that specific level for a certain amount of time. The lower the pasteurization temperature, the longer the holding time will have to be. Then, the pasteurized product is cooled down quickly. Depending on the level of bacterial reduction, this will lead to a certain shelf life of the end product.
In the last few years, Moba has upgraded its pasteurization method to preserve the functional properties of the egg product as much as possible. This is very important since the functional properties of the products are specifically used to create all kinds of food products. To achieve this, the parameters that affect shelf life need to be optimally coordinated.
It is important to realize that the quality of the incoming eggs relates directly to the quality of the final product — the lower the bacterial load of the input product, the lower the impact required from pasteurization. Ideally, the pasteurization process is done in combination with the lowest possible time-temperature ratio. This guarantees a salmonella-free product and the highest quality end product.
For pasteurizing, heat exchange plays a key role. First, the raw product is cooled as quickly as possible after breaking, and must then be properly heated during pasteurization. Whether you are cooling the eggs or heating them, it is all about transferring heat from one medium to another. With eggs, the medium that is used is water by use of heat exchangers. You can use tubular heat exchangers or plate heat exchangers.
Tubular heat exchangers consist of two or more tubes that are mounted inside each other. The raw product is transferred through the inner tube, while the heated water is in the tube surrounding it. By making the hot water flow at a certain speed in the opposite direction, the product is heated evenly to the right temperature. This method of heat transfer is known as 'counter-current flow'.
Plate heat exchanger
Dual tubular heat exchanger
A plate heat exchanger consists of several corrugated plates but uses the same method. By placing different shaped gaskets between the plates, two different channels are created in the heat exchanger; one channel for the product and the other channel for hot water. Again, by making the hot water flow in the opposite direction of the product at a certain speed, the product is heated evenly to the right temperature.
For egg processing, normally plate heat exchangers are used in projects as in most situations they are the most efficient and economical solution. Also they allow efficient designs where the system can easily be switched between yolk products, whole egg products and whites products. In case of special customer requirements, Moba does implement tubular heat exchangers as well.
When heating egg product for pasteurizing, there is always a moment the product starts to coagulate inside the pasteurizer. If this happens too much, you have to clean the installation to be able to continue pasteurization, which is costly. This cleaning period can be postponed considerably by homogenizing the product at a molecular level. Homogenizing is required, also to make sure the pasteurized product does not segregate and remains homogenous during its shelf life. Homogenizing is typically performed using high pressure piston pumps, but the same result can also be obtained by controlled cavitation.
The Moba cavitator creates vacuum bubbles, which implode immediately, releasing energy, which is transferred into the liquid. This causes the liquid to homogenize in the best possible way. Also, this energy causes the liquid to heat up in a gentle and controlled way. The beauty of the system is that there is no direct contact from a heat transfer surface. This makes cavitation the ideal way to use for final heating of the liquid to the required pasteurizing temperature, reducing the risk of coagulation considerably and therefore allowing for longer production runs, up to 8 hours or more!
The Moba cavitator will not only create an improved product but will also save on cleaning time and cost!
Saving 80% in energy costs
Pasteurizing requires a lot of energy. Why? Because first, you need to heat the raw product quickly to a specific temperature and after pasteurizing you need to cool down the product as soon as possible to preserve the shelf life of the product. To make the pasteurizing process more efficient, our equipment reuses the energy utilized in the process. The first heating stage of the raw product can be performed using the heat from the pasteurized product. By doing so, the raw product is pre-heated, while the pasteurized product is pre-cooled during the same process. This heat-recovery method will reduce the amount of energy needed for both heating and cooling tremendously, making it a big money-saver. Compared to other indirect systems, Moba's method saves approximately 80% in energy costs!
Moba pasteurizing solutions suit every customer. From complete integrated solutions with Moba Ovolution, to fully customized modular solutions completely tailor-made to your specific operation. The software that controls the pasteurizer is very user-friendly and enables you to make the products you need in the most straightforward and hassle-free way.
If you want to know more, please contact your local sales representative.