Fig. 4.

(A) Correlation analysis between VOCs and the main non-volatile metabolites during SSF with B. subtilis. (B) The correlation between the antioxidant activity of dark teas fermented by B. subtilis and the content of catechins, total phenols and total flavonoids. Note: the detail names of the VOCs are shown in Table 1. GA, gallic acid; CG, catechin gallate; C, catechin; EC, epicatechin; EGC, epigallocatechin; GCG, gallocatechin gallate; ECG, epicatechin gallate; EGCG, epigallocatechin gallate; GC, gallocatechin; TCs, total catechins; TPC, total polyphenols; TFC, total flavonoids. DPPH, DPPH radical scavenging activity; ABTS, ABTS radical cation scavenging activity; RP, reducing power; CHA, chelating ability.