Abstract:
This study sought to establish an optimized solid-state fermentation (SSF) conditions for extraction of chlorogenic
acid (CA) from heilong48 soybean (HS) variety using two-step process: Plackett–Burman Design (PBD) and
Box-Behnken Design (BBD) systematically. Both designs revealed the significant screened and optimum SSF
conditions as pH (5.02), incubation time (11.52 h), inoculation size (5.00 %) and liquid-solid ratio (0.67). CA
yield (8.80 ± 0.08 mg/g), fermentation efficiency (31.29 ± 0.28 %), and antioxidant activity (DPPH)
(77.45 ± 0.60 μmol AA eq/g dry sample) obtained were acceptable (desirability, 1.00). Both the relative errors
and the residual standard errors obtained for the predicted and experimental values were less than 5%. Higher
(p < 0.05) CA yield and DPPH were obtained for the Lactobacillus casei fermented HS variety (LCFHS) than that of
the unfermented HS variety (RHSF). The effectiveness of the optimized SSF conditions on the degradation of the
cell wall of HS variety was affirmed by Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and
Fourier transform infrared (FTIR) results. The optimized extraction process was feasible, and HS variety could be
used for CA extraction.
