Pressing techniques reshape the fungal community and characteristic metabolites of Fu tea

Fungal community succession critically determines the flavor and quality of Fu tea, yet the mechanism by which variable pressing intensity regulates microbial succession and metabolic remodeling remains unclear.

Using the same batch of raw dark tea, we systematically explored the effects of progressively increasing pressing intensity on fungal community dynamics and metabolite profiles. Increasing pressing intensity drove a pronounced shift from Aspergillus-dominated community (57.0%) to Eurotium-dominated community (93.6-99.2%). This succession was accompanied by significant depletion of free amino acids (FAA) and total flavonoids (FLA), with Eurotium abundance showing strong negative correlations with FAA (ρ = -0.914) and FLA (ρ = -0.773). Differential metabolites were predominantly enriched in FLA biosynthesis and degradation, phenylpropanoid biosynthesis, and arginine and proline metabolism. Integrative network analysis linked pressing intensity, fungal succession, extracellular enzyme secretion, and metabolic pathway activation, revealing that pressure-driven community remodeling redirects metabolic flux through coordinated enzymatic cascades.

These findings provide mechanistic insights into how pressing intensity governs microbial succession and quality formation during Fu tea manufacturing, offering a framework for process optimization and precise quality control. © 2026 Society of Chemical Industry.