Green Tea Extract Preparation Reducing Bitterness

Solution Overview

Problem

Existing methods for preparing green tea extracts with high non-polymer catechin content result in increased bitterness and astringency, making them unsuitable for long-term consumption as beverages.

Innovation Solution

The process involves enzyme-inactivation of raw tea leaves followed by CTC processing, drying to a low water content, and extraction with a solvent-to-tea ratio of 30 or less, using a closed column extractor, to achieve a high concentration of non-polymer catechins with reduced bitterness and astringency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a large amount of catechins is extracted from green tea leaves to achieve high concentration, then the non-polymer catechin content increases, but the bitterness and astringency become stronger

Engineering Contradiction:

Improvenon-polymer catechin concentrationVSAvoidbitterness and astringency

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by inactivating enzymes in tea leaves before extraction through heating treatment. This prevents enzymatic degradation of catechins during subsequent processing, ensuring high non-polymer catechin concentration is maintained while reducing the formation of bitter and astringent compounds that would otherwise develop during prolonged processing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by controlling extraction temperature, solvent-to-tea ratio, and extraction time to optimize catechin extraction. By carefully adjusting these parameters, the process achieves high non-polymer catechin concentration while minimizing the extraction of compounds responsible for bitterness and astringency

Inventive Principle:

Principle #35Parameter changes

2Productivity

If conventional extraction methods are used to obtain high catechin content, then extraction efficiency improves, but the extract is not satisfactory for long-term beverage consumption

Engineering Contradiction:

Improvecatechin extraction efficiencyVSAvoidsuitability for long-term beverage consumption

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by inactivating enzymes in tea leaves before extraction through heating treatment. This prevents enzymatic degradation of catechins during subsequent processing, ensuring high non-polymer catechin concentration is maintained while reducing the formation of bitter and astringent compounds that would otherwise develop during prolonged processing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by controlling extraction temperature, solvent-to-tea ratio, and extraction time to optimize catechin extraction. By carefully adjusting these parameters, the process achieves high non-polymer catechin concentration while minimizing the extraction of compounds responsible for bitterness and astringency

Inventive Principle:

Principle #35Parameter changes

3Productivity

If tea leaves are pulverized to improve extraction efficiency, then catechin extraction increases, but bitterness and astringency are enhanced

Engineering Contradiction:

Improveextraction efficiencyVSAvoidbitterness and astringency

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent utilizes parameter changes by controlling extraction temperature, solvent-to-tea ratio, and extraction time to optimize catechin extraction. By carefully adjusting these parameters, the process achieves high non-polymer catechin concentration while minimizing the extraction of compounds responsible for bitterness and astringency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs an intermediary approach by using a specific extraction solvent system that selectively extracts non-polymer catechins while leaving behind compounds responsible for bitterness and astringency. The solvent acts as a mediator that facilitates selective extraction based on solubility differences

Inventive Principle:

Principle #24Intermediary (Mediator)

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 yields a green tea extract with 20-40 wt.% non-polymer catechins and 40-60 wt.% gallate content, providing a high catechin extraction ratio and reduced bitterness and astringency, suitable for use in packaged beverages.

Implementation Method 1

extracting the resulting tea leaves under the condition that the weight ratio of an extraction solvent to the tea leaves to be extracted is 30 or less

Methodology Applied

Scientific EffectDissolution: Solvation

Implementation Method 2

drying them until their water content becomes 20 wt. % or less

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS7910147B2Preparation process of green tea extract

Publication Date: 2011.03.22 KAO CORP

AI summary

An object is to provide a preparation process of a green tea extract having a high non-polymer catechin concentration and tasting good with less bitterness and less astringency. The present invention relates to a preparation process of a green tea extract, which comprises subjecting an enzyme-inactivated raw tea leaves to CTC processing, drying the tea leaves until the water content thereof becomes 20 wt. % or less, and extracting the tea leaves while setting the weight ratio of an extraction solvent to the tea leaves to be extracted to 30 or less.