High-Pressure Shellfish Processing with Controlled Depressurization
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Solution Overview
Problem
Current methods for processing seafood, such as high hydrostatic pressure techniques, alter the texture, appearance, and flavor of shellfish, are time-consuming, costly, and do not preserve the organoleptic qualities, making them unsuitable for market, especially under European regulations.
Innovation Solution
Applying a controlled hydrostatic pressure of 2000-4000 bars with a controlled depressurization speed and pre-conditioning steps like thermal or osmotic stress to accelerate shell opening without altering the quality of the seafood, using a system with a horizontal press and liquid recycling for efficient processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If high hydrostatic pressure greater than 2000 bars is applied to open shellfish shells, then shell opening is achieved, but the texture, appearance, smell, color and flavor of the shellfish are altered
Solution Approach 1:
The shellfish are pre-cooled to a temperature between -100°C and -196°C before high-pressure treatment. This preliminary freezing action modifies the physical state of the shellfish, making the shell more susceptible to opening while preserving the flesh quality during subsequent depressurization
Solution Approach 2:
The invention utilizes phase transition of water in the shellfish by freezing it before high-pressure treatment. The frozen state changes the mechanical properties of the shell and tissues, enabling shell opening at lower pressures that preserve organoleptic qualities
2Ease of operation
If shellfish are exposed to high hydrostatic pressure for sufficient time for shell opening, then shell opening is achieved, but the processing time increases and quantity treated is limited
Solution Approach 1:
Freezing the shellfish before high-pressure treatment prepares the shell structure in advance, reducing the time required for shell opening during the high-pressure phase
Solution Approach 2:
The phase transition to frozen state modifies the shell's mechanical properties, enabling faster and more efficient shell opening during high-pressure treatment, thereby increasing throughput
3Productivity
If rapid depressurization is used to reduce processing time, then productivity increases, but the texture and appearance of the seafood are altered
Solution Approach 1:
The preliminary freezing step fundamentally changes the response of the shellfish tissues to pressure changes. When frozen, the tissues can withstand rapid depressurization without quality degradation, enabling both high productivity and quality preservation
4Productivity
If shellfish are packaged in bulk in a bag with liquid solution, then processing efficiency increases, but the composition and salinity of the water in the shell are modified
Solution Approach 1:
Freezing the shellfish before high-pressure treatment in bulk packaging prevents liquid exchange between the packaging solution and the shellfish. The frozen state locks the composition, preventing salinity changes while allowing efficient batch processing
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method preserves the quality and appearance of seafood, reduces processing time, and increases the volume processed, making it cost-effective and safe for consumption, while ensuring compliance with food safety regulations.
Implementation Method 1
expose shellfish, and for example oysters, to hydrostatic pressures greater than 2000 bars to cause their shells to open
Implementation Method 2
a controlled depressurization step in which the times for reducing the pressure applied to 50% and 20% of said predetermined hydrostatic pressure are at least 20 seconds, respectively at least 40 seconds
Implementation Method 3
exposing said crustacean or shellfish to at least one thermal and/or osmotic stress, so as to obtain a preconditioned crustacean or shellfish
Implementation Method 4
exposing said crustacean or shellfish to at least one thermal and/or osmotic stress
Data Source
Figure 1A
Figure 1B~1C
Figure 1D
AI summary
The method of processing Crustacean or shellfish by applying (11A) predetermined hydrostatic pressure of 2700 bars to obtain a shelled crustacean or shellfish having a significantly open shell, comprises performing (12A) a controlled depressurization for 65-120 seconds to reduce applied pressure from 50% to 20% of the predetermined hydrostatic pressure, exposing the crustacean or shellfish to heat and/or osmotic stress to obtain a pre-packed crustacean or shellfish, and applying the pre-packed crustacean or shellfish to predetermined pressure of 2700 bars for 35-45 seconds. The method of processing Crustacean or shellfish by applying (11A) predetermined hydrostatic pressure of 2700 bars to obtain a shelled crustacean or shellfish having a significantly open shell, comprises performing (12A) a controlled depressurization for 65-120 seconds to reduce applied pressure from 50% to 20% of the predetermined hydrostatic pressure, exposing the crustacean or shellfish to heat and/or osmotic stress to obtain a pre-packed crustacean or shellfish, and applying the pre-packed crustacean or shellfish to predetermined pressure of 2700 bars for 35-45 seconds to obtain a shelled crustacean or shellfish having an open shell. The depressurization step is released instantly when it reaches a predefined threshold of 300-700 bars. The step of exposure comprises a step of heating the shellfish at a preconditioning temperature of 12[deg] C and immersing the crustacean or shellfish in brine bath having a temperature lower than the preconditioning temperature and a salt concentration of greater than 38 g/l to produce osmotic stress. The pre-packed crustacean or shellfish is introduced, in bulk, in a bag containing micro-filtered seawater before applying the predetermined pressure.