Three Successive Infusions: Scientific Insights Into a Traditional Green Tea Drinking Custom.

Area of Science:

• Food Science
• Analytical Chemistry
• Nutraceuticals

Background:

• Traditional Asian tea brewing involves multiple infusions of the same tea leaves.
• Understanding the impact of repeated extraction on green tea composition and properties is crucial for quality assessment and consumer guidance.

Purpose of the Study:

• To investigate the scientific basis of multi-infusion green tea brewing.
• To evaluate changes in chemical composition, antioxidant activity, and sensory attributes across successive infusions.

Main Methods:

• Utilized Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS), Gas Chromatography-Ion Mobility Spectrometry (GC-IMS), and elemental profiling.
• Quantified key bioactive compounds, including flavonoids, polyphenols, polysaccharides, amino acids, gallic acid, and L-theanine.
• Assessed antioxidant capacity and sensory profiles (flavor, taste) of sequential infusions.

Main Results:

• Bioactive compounds like gallic acid and L-theanine decreased with successive infusions (GT1-GT3), correlating with reduced radical-scavenging activity.
• Volatile profiles and sensory evaluations showed distinct shifts in flavor and taste across infusions.
• Pearson correlation and Variable Importance in Projection (VIP) analysis identified specific compounds (e.g., L-lysine, epicatechin, L-theanine) influencing sensory perception.

Conclusions:

• Multiple green tea infusions diversify flavor profiles while modulating the concentration of bioactive compounds.
• Findings provide scientific insights into traditional brewing practices and inform product development for optimized green tea experiences.