Vacuum Drying Food Products Using Humidity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing food drying methods, including solar drying, hot room drying, and vacuum drying, often result in significant crop yield loss and quality degradation due to uneven moisture content, high temperatures, and sensitivity to heat, leading to burning or charring of food products.
Innovation Solution
A system and method using a vacuum chamber to control moisture content by adjusting temperature and relative humidity, allowing for efficient drying without compromising food quality, by iteratively measuring and adjusting the humidity to achieve a target moisture level, and using eductors to manage water vapor, while ultrasonically vibrating the food for enhanced moisture removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperature drying is used to remove moisture efficiently, then drying speed is improved, but food product quality deteriorates due to burning or charring
Solution Approach 1:
The patent applies parameter changes by modifying the physical conditions of drying from atmospheric pressure to vacuum pressure. This changes the boiling point of water from 212°F to 113°F at 27 in-Hg vacuum, enabling moisture removal at lower temperatures that prevent burning while maintaining efficient drying rates through enhanced vaporization under vacuum conditions.
Solution Approach 2:
The patent utilizes phase transitions by controlling the vaporization of water from liquid to gas phase under vacuum conditions. The controlled phase change occurs at lower temperatures (113°F at 27 in-Hg) compared to atmospheric pressure, allowing moisture removal without subjecting the food to damaging high temperatures that cause burning or charring.
2Object-affected harmful factors
If vacuum drying is used to lower drying temperature, then food quality is preserved, but moisture removal efficiency decreases leading to prolonged drying time
Solution Approach 1:
The patent exploits phase transitions by creating a vacuum environment that lowers the boiling point of water to 113°F at 27 in-Hg. This enables rapid vaporization of moisture at low temperatures, combining the benefits of gentle drying that preserves food quality with efficient moisture removal through enhanced evaporation rates under vacuum conditions.
Solution Approach 2:
The patent applies parameter changes by modifying pressure conditions from atmospheric to vacuum (27 in-Hg), which fundamentally changes the vaporization characteristics of water. This parameter change enables simultaneous achievement of low temperature processing (preserving food quality) and high vaporization rate (maintaining productivity).
3Use of energy by stationary object
If sun drying is used to free of cost, then energy cost is reduced, but crop yield loss increases due to exposure to elements
Solution Approach 1:
The patent applies the inert atmosphere principle by using a controlled vacuum environment that isolates the food from harmful external elements such as humidity, rain, and wind. This controlled environment prevents the 60%+ crop yield losses associated with traditional sun drying while maintaining energy efficiency through the vacuum-assisted vaporization process.
4Device complexity
If traditional drying methods are used to handle high moisture content food, then processing is simpler, but product quality deteriorates due to uneven drying
Solution Approach 1:
The patent applies parameter changes by using vacuum pressure (27 in-Hg) to uniformly accelerate vaporization throughout the food product. This creates consistent drying conditions that prevent the uneven moisture distribution problem of traditional methods, ensuring all portions of the food dry at similar rates and achieve uniform final moisture content.
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 approach normalizes food products by adjusting moisture levels, reducing labor and energy costs, and maintaining the quality of food products by preventing burning, thereby improving product efficiency and reducing post-harvest losses.
Implementation Method 1
At 27 in-Hg of vacuum, water will vaporize at 113° F. (45° C.). Therefore, an atmospheric drop of 27 in-Hg increases the vaporization rate without a modification of temperature.
Implementation Method 2
At 27 in-Hg of vacuum, water will vaporize at 113° F. (45° C.). Therefore, an atmospheric drop of 27 in-Hg increases the vaporization rate without a modification of temperature.
Implementation Method 3
Heat is removed by the water vapor and provides evaporative cooling of the product.
Implementation Method 4
ultrasonically vibrating the food for enhanced moisture removal
Data Source
AI summary
A method of acclimatizing dates includes placing a plurality of dates into a vacuum chamber, heating the dates to a first temperature, and increasing a vacuum pressure of the vacuum chamber with the dates in the vacuum chamber. The first temperature is below a boiling point of water at an initial pressure within the vacuum chamber and the increase in vacuum pressure modifies the boiling point to below the first temperature. The method includes adjusting a relative humidity of the vacuum chamber towards a target relative humidity until the plurality of dates reach an equilibrium relative humidity, the target relative humidity corresponding to a target moisture content of the dates on an isotherm of the dates at the first temperature. The method includes cooling the dates to a second temperature to stop transpiration of water within the plurality of dates and decreasing the vacuum pressure of the vacuum chamber.