Changes in the metabolite composition and enzyme activity of fermented tea during processing

Area of Science:

• Food Science and Technology
• Microbiology
• Biochemistry

Background:

• Green tea possesses bioactive compounds with antihypertensive potential but limited health effects due to enzyme inactivation during processing.
• Eurotium cristatum (E. cristatum) is a key microorganism in Fuzhuan brick tea, known for biotransforming substrates and enhancing health benefits.
• Radix Puerariae (RP) is often used for its medicinal properties.

Purpose of the Study:

• To evaluate the impact of Eurotium cristatum (E. cristatum) during solid-state fermentation (SSF) of a green tea and Radix Puerariae (RP) mixture.
• To assess the changes in bioactive compounds and enzyme activity.
• To determine the antihypertensive potential of the novel fermented tea.

Main Methods:

• Solid-state fermentation (SSF) of a green tea and Radix Puerariae (RP) mixture using Eurotium cristatum (E. cristatum).
• Enzyme activity assays (polyphenol oxidase, α-amylase).
• Analysis of bioactive compound content.
• In vitro assessment of Angiotensin-converting enzyme (ACE) inhibition.

Main Results:

• Fermented samples showed secretion of enzymes like polyphenol oxidase and α-amylase.
• Significant alterations in the content of bioactive compounds were observed compared to unfermented controls.
• The fermented tea exhibited significantly higher in vitro Angiotensin-converting enzyme (ACE) inhibition, indicating enhanced antihypertensive potential.

Conclusions:

• Eurotium cristatum (E. cristatum) fermentation effectively biotransforms green tea and Radix Puerariae (RP).
• The fermentation process enhances bioactive compound profiles and enzyme activities.
• The novel fermented tea demonstrates significant potential for antihypertensive applications.