L. plantarum ITM21B was grown in media DM, M1, M2 or
M3 for 72 h at 30 °C to obtain the fermentation products DM-FP,
M1-FP, M2-FP or M3-FP. After growth, cells were harvested by
centrifugation at 10,000 ×g for 10 min at 4 °C, and the cell-free
culture supernatant (CFCS) was sterilized by filtration through
0.45 μm filter. Each FP was produced in triplicate.