Principles And Mechanism Of The High Pressure Processing (HPP) Process



v  Principle of High Pressure Processing (HPP) Process.

The used of pressure will cause a physical and chemical changes. Applying pressure physically will resulted in a decrement of volume and an increment of temperature and energy. The logic in the use of HPP is in compliances with the three elements of physical and chemical principles which are the Le Chatelier’s principle, Principle of microscopic ordering and Isostatic principle.

a)      Le Chatelier’s principle
This principle resulted to equilibrium changes when pressure is applied. This principle states that any phenomenon that occur by a decrease in volume is intensify by pressure.

b)      Principle of microscopic ordering
At constant temperature, increase in pressure will increase the degree of ordering of molecules of a particular substances. Thus, the pressure and the temperature applied will opposed forces on the molecular structure and chemical reactions.

c)      Isostatic principle
This principle presumes that the steady application of pressure acts equally in all direction. A true hydrostatic conditions should be independent of time and space. The principle can be applied when pressure is transmitted through a fluid medium in food. In excessive pressure applications, the pressure and, more importantly, its outcomes are instantaneously and homogeneously distributed within the food item, regardless of food geometry and size. This unique characteristic has enabled the development of processes that have been successfully commercialized.
This theory helps provide an explanation for why nonporous foods with high-moisture content material are not damaged macroscopically with the aid of pressure treatment. Under pressure, air and water vary in its compressibility value. The structure and form of the foods containing air pockets can also be altered upon pressure treatment, until the foods is perfectly elastic and consists of closed-cell foam from which air cannot escape.


v  Mechanism of High Pressure Processing (HPP) Process


A high hydrostatic pressure system is an example of a typical HPP process. This system consists of a high pressure vessels with its closure, a pressure generation system, a temperature controller and last but not least the material handling system.

High Pressure Vessel
            Typically a cylinder vessel constructed by a low-alloy steel with high tensile strength. The thickness of the wall is determined by the maximum working pressure , the vessel diameter and the number of cycles which is designed for the vessel. The wall thickness of the wall can be reduced by using a multiplayer, wire-wound or other pre-stressed designs.

Pressure Transmitting Medium
            A medium of water mixed with a small quantity of soluble oil for lubrication and anticorrosion purposes. Other common medium can also be used such as food-grade glycol water solutions, silicone oil, sodium benzoate solutions, ethanol solutions, and castor oil.

Pressure Generation
When all air has been removed from the high pressure vessel, through the generation of direct compression or indirect compression, high pressure is generated. The direct compression can be generate by a piston type compressor. indirect compression can be generate by a pump type compressor. However, both of the compression type have its own advantages and disadvantages.
The pressure medium in the high pressure vessel by the direct piston compression is directly pressurized by the piston which allows a very fast compression. But this system can only be practically applied to a small-diameter pilot plant with high pressure system. Meanwhile, the desired pressure is achieved in indirect compression by using a high intensifier to pump the high pressure vessel. This method only required a static high pressure seals within the high pressure vessel.


v  How the process happen in the HPP process.


A typical processing type for the HPP process are as follows:

1.      A packaged food items are placed in a high pressure vessel which will then filled with water and tightly sealed.
2.      Then, more water is pumped into the vessel that will create a hydrostatic pressure. The pressure is isostatically transmitted by the fluid medium in the vessel.
3.      The vessel pressure is maintained for a predetermined length of time ususally between 30 seconds to 15 minutes where the pathogens and spoilage bacteria is activated.
4.      Immediately depressurized the vessel when the cycle is complete where the temperature will return to the initial temperature.

5.      The vessel is opened and the product is removed.

If you guys wish to further to understand how the HPP process happen, you may watch HPP process video at this link https://www.hiperbaric.com/en/hpp. This video by Hiperbaric explain how HPP process occur in a simple and concise manner. Hopefully this video will help you guys too!

Diagram of operation of HPP unit. 
(Sources: https://www.hiperbaric.com/en/high-pressure)



REFERENCES



HPP Technology: What is High Pressure. (2012). Retrieved from Hiperbaric: https://www.hiperbaric.com/en/high-pressure

Muntean, M. V., Marian, O., Barbieru, V., Catunescu, G. M., Ranta, O., Drocas, I., & Terhes, S. (2016). High Pressure Processing in Food Industry-Characteristics and Application. Procedia, 378-383.

Sai, M., Madhu, B., Srivinas, G., & Jain, S. K. (2018). High Pressure Processing of Foods: A Review. Agricultural Journal, 467-476.






REFERENCES
HPP Technology: What is High Pressure. (2012). Retrieved from Hiperbaric: https://www.hiperbaric.com/en/high-pressure

Muntean, M. V., Marian, O., Barbieru, V., Catunescu, G. M., Ranta, O., Drocas, I., & Terhes, S. (2016). High Pressure Processing in Food Industry-Characteristics and Application. Procedia, 378-383.

Sai, M., Madhu, B., Srivinas, G., & Jain, S. K. (2018). High Pressure Processing of Foods: A Review. Agricultural Journal, 467-476.




Comments

Post a Comment

Popular posts from this blog

Image
Application of High Pressure Processing in Food Industry The present techniques to manufacturing milk usually used thermal processing which are pasteurization and sterilization methods. High pressure processing is an alternate novel to the thermal processing technique such that it brings many benefits to the variety of food products produced (Naik, Sharma, Rajput, & Manju, 2013) . The application of high pressure processing (HPP) has been available since the era of 1990s. However, its application for commercial is still not wide and quite limited. The most common application of high pressure processing is in dairy products such as milk, yoghurt, cheese and cream (Datta & Deeth, 1999) . Others include processing of various fruits and vegetables based products such as carrot juices and apple juices (Gopal, Kalla, & Srikanth, 2017) . In this writing, we will shows selected example on the process of almond milk. Figure 1: Schematic of almond milk preparation, pr...
Read more
Assalamualaikum and Good Day to everyone! This blog purpose is to share information about High Pressure Processing (HPP) process. My friends and I would like to share with all the readers out there about information that we manage to gather. So, do read all of our post below and comment if you like. Thank you! =)
Read more
Image
Introduction to High Pressure Processing Process. Food processing is the transformation of raw animal or plant materials into products that can be consumed to stabilize the food products by preventing or reducing negative changes in quality. Without this food processing, the food cannot be stored for a long time. Thus, this will be a problem for the food that need to be transported for a long distance. Therefore, there are many food processing technologies that can be explored and implemented in order to provide safety, fresher-tasting and nutritive foods without using of heat or chemical preservatives   (E. Hogan, 2008) . One of the technologies is by using high pressure processing (HPP). High pressure processing (HPP) is a non-thermal technique of food preservation that inactivates the harmful pathogens and spoilage microorganisms by using pressure rather than heat to induce a pasteurization effect. This pressure treatment can be used to both liquid and solid foods with ...
Read more