Differential Pressure Expansion Drying for Jujube Slices
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Solution Overview
Problem
The existing methods for processing fresh jujube slices face challenges such as uneven texture and color due to varying water content, ease of fermentation and rot, and difficulties in maintaining brittleness and integrity during drying, leading to suboptimal product quality and shelf life.
Innovation Solution
A method involving quick-freezing, differential pressure expansion, and color protection treatments, combined with supersonic assistance and the use of phytic acid in steam, followed by vacuum drying and superfine seasoning powder coating, to produce crispy, nutritious, and uniformly colored dried jujube slices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional hot air drying is used, then drying efficiency is improved, but product texture becomes wizened and hard
Solution Approach 1:
The patent uses freeze-drying technology where water in the jujube slices transitions from solid ice to water vapor through sublimation under vacuum conditions. This phase transition allows drying at low temperatures, preserving the original texture and appearance of the jujube while achieving efficient moisture removal, thus resolving the contradiction between drying efficiency and texture quality
Solution Approach 2:
The patent changes the drying parameters by conducting the process under vacuum conditions with controlled temperature gradients. By adjusting pressure and temperature parameters, the drying rate is optimized while preventing the formation of hard and wizened texture, thereby improving both productivity and product texture simultaneously
2Strength
If low temperature freezing drying is used, then product texture is preserved, but the texture becomes too soft and crisp but not brittle
Solution Approach 1:
The patent applies preliminary freezing treatment before drying, where the jujube slices are frozen to form a solid structure. This preliminary action creates a framework that maintains texture integrity during the subsequent vacuum drying process, preventing the texture from becoming too soft while still allowing efficient moisture removal
Solution Approach 2:
By controlling the phase transition of water from liquid to solid during freezing, then from solid to vapor during sublimation, the patent achieves optimal texture characteristics. The controlled phase changes create a porous structure that provides both texture preservation and adequate brittleness while maintaining drying efficiency
3Loss of time
If fresh jujube slices are dried directly, then processing time is reduced, but color and texture become uneven due to varying water content
Solution Approach 1:
The patent applies preliminary uniform freezing treatment to the fresh jujube slices before drying. This preliminary action equalizes the water distribution and temperature throughout the slices, ensuring uniform drying characteristics. As a result, both processing time is minimized and color and texture uniformity are achieved across all slices despite variations in initial water content
4Shape
If jujube is corded and sliced for processing, then product form is improved, but fermentation and rot occur more easily
Solution Approach 1:
The patent conducts the entire processing and drying operation in a vacuum environment, which creates an inert atmosphere with minimal oxygen. This inert environment prevents oxidative browning and inhibits the growth of aerobic microorganisms that cause fermentation and rot, allowing the jujube to be corded and sliced while maintaining product safety and quality
Solution Approach 2:
By rapidly freezing the sliced jujube and then sublimating the ice under vacuum, the patent creates a protective porous structure that reduces moisture availability to microorganisms. This phase transition-based preservation method maintains the desired sliced form while significantly reducing susceptibility to fermentation and rot
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 enhances the texture, color, and nutritional value of dried jujube slices, maintaining cell integrity, reducing energy consumption, and achieving consistent quality by controlling pressure and temperature, resulting in a crispy and flavorful product with improved shelf life.
Implementation Method 1
quick-freezing, differential pressure expansion
Implementation Method 2
differential pressure expansion
Implementation Method 3
vacuum drying
Implementation Method 4
supersonic assistance
Data Source
AI summary
A method for processing dried fresh jujube slices includes the following steps: preparing jujube slices, coring and removing stems, quick-freezing and retaining freshness of the jujube slices, thawing frozen jujube slices, protecting color treatment, expanding jujube slices under differential pressure, preparing superfine mixed seasoning powder, and coating of the superfine mixed seasoning powder. For one hand, this method solves problems that the dried fresh jujube slices will be deeply oxidized and brown when dried by the hot air at a high temperature of 90-110° C., the jujube slices with compacted cells will become harder and be difficult to chew because of 6-8 h rapid dehydration. On the other hand, it solves problems that exist in freeze drying at a vacuum degree of 1.3-13 Pa, and at a low temperature of −10-50° C., such as high energy consumption, long processing cycle, high equipment investment, small size of slices, and poor taste.