Selective Caffeine Removal in Green Tea Extraction

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Solution Overview

Problem

Existing methods for extracting non-polymer catechins from tea leaves often result in reduced caffeine content but also diminish the taste and flavor of green tea, posing a challenge to selectively remove caffeine without impairing the tea's quality.

Innovation Solution

A production method involving bringing tea leaves into contact with an aqueous solution with a Brix of 0.2% to 1.0% at temperatures between 80° C. to 100° C., followed by extraction with water at 50° C. to 100° C., to selectively remove caffeine while preserving the taste and flavor of green tea.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If non-polymer catechins are extracted from tea leaves using conventional methods, then caffeine content is reduced, but taste and flavor of green tea are diminished

Engineering Contradiction:
Improvecaffeine contentVSAvoidtaste and flavor quality
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The invention changes the temperature parameter to a specific range of 80-100°C and controls the aqueous solution concentration (Brix) to 0.2-1.0%, which selectively removes caffeine while preserving taste and flavor compounds. This parameter optimization allows differential extraction based on solubility characteristics at controlled temperatures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a controlled aqueous solution with specific Brix (0.2-1.0%) as an intermediary medium that facilitates selective caffeine removal while protecting taste and flavor compounds. The controlled concentration acts as a mediator to achieve selective extraction without over-extraction of beneficial compounds.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If hot water treatment is performed at high temperature and pressure to reduce caffeine, then caffeine content decreases, but tea leaf quality and fermentation control are affected

Engineering Contradiction:
Improvecaffeine contentVSAvoidtea leaf quality and fermentation state
Core Design Contradiction:
Object-generated harmful factorsVSStability of the object's composition

Solution Approach 1:

The invention optimizes temperature to 80-100°C (avoiding excessive heat that causes deterioration) and controls aqueous solution concentration to Brix 0.2-1.0%, which selectively removes caffeine while maintaining tea leaf quality and preventing unwanted fermentation changes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies partial action by using a controlled, moderate aqueous solution concentration (Brix 0.2-1.0%) rather than excessive water or strong solutions, achieving sufficient caffeine removal while avoiding over-extraction and quality deterioration of tea leaves.

Inventive Principle:
Principle #16Partial or excessive action

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 efficiently produces a composition with reduced caffeine content and rich taste and flavor, maintaining the quality of green tea by suppressing fermentation and enhancing catechin extraction.

Implementation Method 1

a step of bringing tea leaves into contact with an aqueous solution having a Brix of from 0.2% to 1.0% at from 80° C. to 100° C.

Methodology Applied
Scientific EffectExtraction: Liquid-Liquid Extraction

Implementation Method 2

bringing tea leaves into contact with an aqueous solution... to selectively remove caffeine while preserving the taste and flavor of green tea

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

at from 80° C. to 100° C.

Methodology Applied
Scientific EffectThermal energy: Heating

Data Source

PatentUS11812759B2Production method for composition which contains non-polymer catechin
Publication Date: 2023.11.14 KAO CORP

AI summary

Provided is a production method for a composition containing non-polymer catechins, including the following step (A): (A) a step of bringing tea leaves into contact with an aqueous solution having a Brix of from 0.2% to 1.0% at from 80° C. to 100° C.