Optimization of fermentation conditions for enhancing the antioxidant activity of medicine and food homologous materials using Lactobacillus plantarum.

This article focuses on optimizing the fermentation of a mixture of medicine and food homologous (MFH) materials—Codonopsis radix, Astragalus membranaceus, Platycodon grandiflorus, and Tiger milk mushroom—using Lactobacillus plantarum to enhance their antioxidant activity and bioavailability. Key fermentation parameters, including material-to-water ratio, sucrose concentration, and inoculum size, were identified and optimized through single-factor experiments, Pareto analysis, response surface methodology (RSM), and artificial neural networks (ANN), with ANN providing superior predictive accuracy. Under optimized conditions, fermentation significantly increased the levels of bioactive compounds such as polysaccharides, polyphenols, flavonoids, and saponins, resulting in enhanced antioxidant capacities measured by DPPH, ABTS, and ferric ion reducing assays. Fourier-transform infrared (FTIR) analysis confirmed structural changes in active compounds post-fermentation, supporting improved bioactivity. This study offers a methodological framework for developing MFH-based probiotic fermented functional foods with potential applications in dietary supplements and nutrition.