Superheated Steam Drying for Food Packaging Stability
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Solution Overview
Problem
Conventional methods for producing packed food products require extensive drying to prevent microbial growth, but recent studies suggest that less extensive drying can achieve satisfactory storage stability without sterilization, while maintaining microbial kill-off.
Innovation Solution
A method involving cooking and drying food products in an atmosphere of superheated steam with less than 3% O2 at temperatures of at least 120°C, achieving an a w value of 0.70 to 0.92, followed by hermetic packaging within the steam atmosphere to prevent microbial growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If extensive drying is performed to reduce a w value to prevent microbial growth, then storage stability is improved, but energy consumption and processing time increase
Solution Approach 1:
The invention changes the drying parameters by using superheated steam at temperatures above 100°C (specifically at least 120°C) instead of conventional lower temperature drying. This parameter change allows achieving the same microbial kill-off effect with significantly reduced drying time and lower final a w requirements (0.70-0.92 vs. conventional 0.60-0.65), thus resolving the contradiction between storage stability and processing time
Solution Approach 2:
The invention creates a composite atmosphere during drying by combining superheated steam with controlled low oxygen content (less than 3% O2). This composite environment achieves both thermal killing of microorganisms and prevention of spore germination, allowing reduced drying extent while maintaining storage stability
2Reliability
If extensive drying is performed to reduce a w value to prevent microbial growth, then storage stability is improved, but energy consumption increases
Solution Approach 1:
The invention uses superheated steam at elevated temperatures (at least 120°C) which provides more effective microbial kill-off per unit of energy input. The combination of higher temperature and low oxygen atmosphere (less than 3% O2) creates a synergistic effect that reduces the total energy required compared to conventional prolonged low-temperature drying to achieve a w values of 0.60-0.65
Solution Approach 2:
The invention converts the typically harmful effect of high temperature (which would normally require extensive cooling and energy input) into a beneficial dual function: the superheated steam both kills vegetative microorganisms and creates a low moisture activity environment that prevents spore germination, thereby reducing total energy consumption while maintaining storage stability
3Productivity
If less extensive drying is performed to reduce processing time and energy, then productivity is improved, but microbial growth risk increases
Solution Approach 1:
The invention changes the drying parameters by using superheated steam at temperatures of at least 120°C with controlled oxygen content (less than 3% O2). This parameter combination achieves effective microbial kill-off and spore germination prevention at higher final a w values (0.70-0.92), enabling reduced processing time and energy while eliminating microbial growth risk in the finished product
Solution Approach 2:
The invention creates a composite atmosphere during drying by combining superheated steam with controlled low oxygen content (less than 3% O2). This composite environment achieves both thermal killing of microorganisms and prevention of spore germination, allowing reduced drying extent while maintaining storage stability
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 effectively kills vegetative microorganisms and prevents spore germination, ensuring long-term storage stability and safety of the food product without the need for subsequent sterilization.
Implementation Method 1
drying the product in the atmosphere of superheated steam to an a w value ranging from 0.70 to 0.92... having a temperature of at least 120° C
Implementation Method 2
an atmosphere of superheated steam or an atmosphere of superheated steam consisting of water vapour and residual air and containing less than 3 % oxygen
Implementation Method 3
packaging the product within the atmosphere of superheated steam... hermetically packaged while it is still in the atmosphere of superheated steam with an oxygen content of no more than 3 % by volume
Data Source
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AI summary
Method of producing a packed food product, comprising: cooking a food product at a cooking temperature of at least 100°C; introducing the cooked food product into an atmosphere of superheated steam, the atmosphere of superheated steam containing less than 3% of oxygen and having a temperature of at least 120°C; drying the food product to an aw-value in the range from 0,70 to 0,92; in the superheated steam atmosphere, packaging the food product in a packaging container, feeding a protective gas into the packaging container and hermetically sealing the packaging container, and food product packed in a packaging impermeable to O2, obtainable by a method of any of the preceding claims, wherein the food product has an aw-value in the range from 0,70 to 0,92 and the packaging contains a protective gas.