Figure 5.

Concentration of total saponins in fermentation extracts by 12 uniform design protocols. N1–N12 protocols containing the six mixing levels (potato concentration, glucose concentration, inoculation volume, fermentation broth pH, incubation temperature, and incubation) in the uniform design experiment were designed using DPS software version 9.0. The concentration of total saponins by N1–N12 protocols was determined by the ultraviolet spectrophotometry method. Data are expressed as mean ± SD (n = 3). * p < 0.05, *** p < 0.001.