Green Tea Clarity via Microfiltration and Ultrafiltration
Solution Overview
Problem
Green tea products often exhibit excessive bitterness and astringency, which detract from their refreshing attributes and enjoyment, especially in functional beverages with high tea solids, due to the presence of catechins, flavonol-glycosides, saponins, caffeine, and amino acids, leading to a loss of refreshment and enjoyment.
Innovation Solution
The method involves microfiltration and ultrafiltration of green tea extracts using membranes with specific molecular weight cutoffs, followed by reduced temperature fractionation to selectively remove compounds contributing to bitterness and astringency without additives or chemicals, maintaining antioxidant and caffeine levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If green tea extract is used in functional beverages with high tea solids, then antioxidant content and nutritional advantages are maintained, but bitterness and astringency become excessive and noticeable
Solution Approach 1:
The patent applies selective extraction to remove specific compounds (flavonol-glycosides, saponins, and excess catechins) that contribute to bitterness and astringency while preserving beneficial antioxidants and caffeine. This is achieved through controlled extraction processes that separate undesirable compounds from the tea matrix, allowing high antioxidant content to be maintained without excessive bitterness.
Solution Approach 2:
The patent modifies the chemical composition parameters of green tea extract by adjusting the ratios of different polyphenolic compounds. Through controlled processing, the concentration of bitter and astringent compounds is reduced while maintaining or enhancing the concentration of antioxidants and caffeine, thereby changing the overall parameter profile to achieve a more palatable taste.
2Reliability
If conventional green tea processing is used, then characteristic tea flavor is maintained, but clarity and refreshing attributes are reduced due to excessive bitterness and astringency
Solution Approach 1:
The patent converts the harmful effect of polyphenolic compounds (which cause bitterness and astringency) into a benefit by selectively removing only the excessive portions that cause negative sensory attributes. The remaining polyphenolics continue to provide antioxidant benefits and characteristic tea flavor, while the harmful over-concentration is transformed into a balanced composition that enhances clarity and refreshment.
3Object-affected harmful factors
If additives or chemicals are used to reduce bitterness and astringency, then refreshing attributes improve, but natural composition and nutritional advantages are compromised
Solution Approach 1:
The patent employs self-service by using natural physical and chemical processes (selective extraction, filtration, and concentration) to remove bitter and astringent compounds without requiring external additives or chemical treatments. The green tea extract itself provides the means for its own purification through processes that leverage the inherent properties of its constituents, maintaining natural composition while reducing harmful sensory attributes.
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 process enhances the clarity and refreshing attributes of green tea while reducing bitterness and astringency, resulting in a product with a smoother flavor and higher sensory appeal, maintaining high antioxidant content and a bright color.
Implementation Method 1
performing microfiltration on green tea extract to form a microfiltration retentate and a microfiltration permeate
Implementation Method 2
performing ultrafiltration on the microfiltration permeate to form an ultrafiltration retentate and an ultrafiltration permeate; the ultrafiltration is performed with a membrane having a molecular weight cutoff (MWCO) of 5000 to 25000 Da
Implementation Method 3
performing reduced temperature fractionation on the ultrafiltration permeate to form a supernatant and a sediment
Data Source
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AI summary
Methods for modulating the bitterness and astringency of green tea, and nutritional products having a green tea with reduced bitterness and astringency, are provided. In a general embodiment, the methods comprise performing microfiltration on green tea extract to form a microfiltration retentate and a microfiltration permeate; performing at least one of ultrafiltration or reduced temperature fractionation on the microfiltration permeate; and using theultrafiltration permeate from the ultrafiltration or the supernatant from the reduced temperature fractionation to make a green tea product. The ultrafiltration permeate or the supernatant can be further concentrated, spray or freeze dried to form a powder, used as a concentrate, or diluted to form a ready-to-drink beverage. In an embodiment, the ultrafiltration is performed on the microfiltration permeate to form an ultrafiltration retentate and an ultrafiltration permeate and then the reduced temperature fractionation is performed on the ultrafiltration permeate to form a supernatant and a sediment.