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Thursday, December 20, 2018

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HPP is now on a growing scale commercially utilised in food industry in order to satisfy customers’ demand for minimal processed food. This is because the covalent bonds related to dietary and organoleptic properties cannot be broken down throughout HPP. The processed fruit or vegetable products freshness will be better retained. Furthermore, with microorganisms and endogenous enzymes inactivation, during shelf of life the microbial spoilage and high-quality deterioration can be minimised. This kind of method commonly used for frozen food to make sure any microorganism and bacteria remove in order to keep the frozen food long lasting.

1.      Type of process
In industrial production, there are three types of system of processing which are batch, continuous and semi continuous. Typically for HPP method use batch system to process their food. In batch system there are consists of pump, pressurization fluid, pressure vessel, and intensifier. This system can operates in liquid and solid products while semi continuous can only processing for liquid product (Elamin, Endan, Yosuf, Shamsudin, & Ahmedov, 2015). So that batch system has more advantages rather than semi continuous system. Alternatively, the pressure vessel can additionally be designed as a pressure intensifier. The pressure vessel is constructed to resist a certain amount of pressure and temperature, and incorporates the packaged food product and pressurization fluid. Pressure vessel sizes are described through the volume of fluid that the vessel can keep. The pressurization fluid is commonly water, and is delivered to the pressure vessel to get rid of air pockets between the packages of food.

2.      Effect of pressure
According to Ginsau, 2015 the suitable pressure for HPP method had been discovered by Hite in year 1899. He found that microorganism can be obstructed by using HPP and at the same time it can increase the period of realistic of usability. He tried if milk treated with different levels of pressure remained sweet for a more drawn out period than unpressurized milk did. It was appeared utilizing a pressure of over 463 MPa for one hour normally decelerates the souring of milk for not less than twenty four hours. Typical pressures applied to foods range from 300 – 800 MPa. Heat may also be applied, however, the majority of high pressure processes are conducted at refrigerated temperatures, relying mainly on pressure to process the food. It is important to note that some temperature increase does occur naturally during a typical HPP treatment due to adiabatic heating, which is dependent on the target pressure and food composition.

3.      Effect on protein and enzyme
The processing conditions are depended on the stimulation of the enzymatic activity. Protein have not been previously modified by other process for example drying or fermentation because proteins in HPP method are partially denatured in products. The electrostatic interactions and hydrophobic bond will affected by the pressures. At pressure more than 200 MPa denaturation commonly irreversible that caused pressure denaturation become complex.

4.      Food quality
In avoiding the excessive thermal treatments or chemical preservation, HPP method are applied to provide a means for retaining food quality. Storage temperatures and the barrier properties of the packaging rather than by the high pressure treatments to maintain the quality throughout shelf-life is influenced more by subsequent distribution (Yordanov, 2014). In keeping good nutrients and food quality HPP method played its role in food preservation in order to making food safer to eat by the consumer. During pressure treatment, due to physical compression and returns back to its initial value upon decompression the temperature of different food materials will increases quickly. This condition can be lead to higher compression of fatty foods heating due to their higher compressibility with long-chain unsaturated fatty acids.

5.      Applications
In the past 25 years, high pressure processing has stimulated from being a laboratory preservation method to become an economically useful technology. To enhance the efficiency of the process and expand new knowledge in this promising field high pressure processing of foods method has been used globally. For example, meat of application of HPP reduced the activity of calpain compared with the controlling (Zhang, 2018).

Generally HPP method are used for,

·         Spoilage control – HPP may be used to extend shelf-life by increasing the period over which the food can be marketed by reducing the foods microbial load.
·         Pathogen control – By elimination or reduction to safe levels pathogens of concern.
·         Product reformulation – The use of HPP for enhancing the characteristics of reformulated products.
·         Product forming – By subjecting food products such as reformed meats to the very high pressures used in HPP, the cohesion of many small pieces of meat into one larger piece will be become easier.

During HPP, pressure is uniformly applied around and throughout the food product. Pressure additionally gives a completely unique possibility to create and manage novel food textures in protein-based or starch-based foods. In a few instances, pressure can be used to form protein gels and increase viscosity without the use of heat. HPP machines are broadly utilized for the processing of meat, dairy, seafood, fruits and vegetable items, and different beverages.


High pressure processing at low and high temperatures in foods and beverages packaged in flexible packaging can likely bring about modifications within the useful properties of packaging, specifically in structures with organic coatings including metallization and structures laminated with aluminium foil that may be extensively affected by processing. Finding the right temperature and pressure combination is vital to using the equipment correctly but the most important is in maintaining the quality of the food is a concern. HPP has ability as a phyto sanitary remedy to control quarantine insect pests in fresh or minimum processed fruits and vegetables to increase their shelf-life

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UNIVERSITI TEKNOLOGI MARA SHAH ALAM FOOD PRESERVATION TECHNOLOGY (CBE 658) EH2205F Group Members; 1. Syarifah Rysmalia ...