High Pressure Processing or High Hydrostatic Pressure Processing (HPP) is a method of processing fish and seafood products such as Salmon, Lobster, Crab, Oysters, Shrimp and other Ready-To-Eat products without using added heat. It has the potential to produce high-quality, fresh, pure, nutritious, safe-to-consume fish and seafood products without using chemical preservatives or artificial additives. 

2 HPP Fish and Seafood Processing Applications:

• Fish.
• Lobster, Crab, Shrimp/Prawns, Crayfish and other Crustaceans.
• Oysters, Clams, Mussels & Whelk.
• Eel.
• Ready-to-Eat seafood (e.g. Cooked Salmon or Hake Fillets, Shrimp with Vegetables, etc.).

2 HPP Fish and Seafood Processing: 

      When using High Pressure Processing Technology, fish and seafood products are sealed and placed into a stainless steel pressure chamber containing water, and intensifiers are used to create pressure. The intensifier-supplied hydrostatic pressure is applied uniformly to all surfaces of the end-product, leaving the shape and integrity of the packaging intact.

       Since hydrostatic pressure acts quickly and evenly, neither the size of a product's container nor its thickness plays a role in the effectiveness of high pressure food preservation. Certain Fish products might incur a slight change in the color, but HPP does not greatly affect nutritional value, taste, texture, or appearance. As a result, high pressure treatment of fish and seafood products is regarded as a " natural" pressure pasteurization method, as it does not use or rely on any added chemical preservatives

   

2 Advantages of HPP vs. Pasteurisation and UHT Processing:

        HPP treatment is capable of rendering fish and seafood products that possess safety characteristics similar to those undergoing pasteurization or UHT processing. However, processing temperature and storage conditions have a significant impact on the final quality of products. High temperature processing can deteriorate sensory (touch, taste, and smell) characteristics.

        Since HPP is a cold temperature process it enhances shelf life while retaining organoleptic and nutritional qualities, and some textures will even be improved for fish and seafood products.

2 Advantages of HPP

• Increased shelf-life (2 to 4 times longer than the same product without HPP, stored at the same temperature).
• Easier and higher yield shucking and meat extraction (20% – 50% more meat).
• Product freshness.
• No Impact on sensory, nutritional or functional properties.
• Effective elimination of spoilage and pathogenic micro-organisms.
• Greater tolerance to cold chain abuse.

         

2 Main body of HPP Machine

    A. Pressure vessel, framework, pressurizer

    B. Hydraulic system

    C. Fluid complementing system

    D. Control system

 

2 A typical processing cycle:

1. Packaged food items are placed in the pressure vessel.

2. Vessel is sealed and filled with water.

3. A pump (with intensifier) forces more water into the vessel, creating hydrostatic pressure. Pressure is 

    isostatically transmitted by the fluid medium. A small temperature increase (~ 3°C per 100 MPa applied) 

    may occur in the product, depending on the product composition.

4. Vessel pressure is maintained for a predetermined period of time (usually between 30 seconds and 15 

    minutes), during which time pathogens and spoilage bacteria are inactivated.

5. When the cycle is complete, the vessel is quickly depressurized, and temperatures return to the starting 

    temperature. Vessel is opened and product is removed.