Abstract:

To improve the total antioxidant activity of fermented Morchella, single-factor experiments and response surface methodology were used to optimize the composition and culture conditions of the fermentation medium. In the single-factor experiments, the concentrations of sucrose, yeast powder,(NH₄)₂SO₄, KH₂PO₄, and MgSO₄·7H₂O, as well as pH value in the fermentation medium were changed, to screen for optimal conditions based on the total antioxidant value of the fermentation broth. Then, based on the results of the single-factor experiments, three main influencing factors were selected for the Box-Behnken response surface design, and variance analysis and regression analysis were carried out using Design-Expert software. The results showed that the optimal composition of the medium was: yeast extract 4.3 g/L, sucrose 32 g/L, MgSO₄·7H₂O 1.5 g/L, KH₂PO₄ 1.4 g/L, (NH₄)₂SO₄ 2.5 g/L, and a pH of 6. These conditions significantly enhanced the antioxidant activity of the fermentation broth and were cost-effective. The findings of this study provide theoretical and practical guidance for the Morchella fermentation industry, help to improve the quality and antioxidant performance of Morchella fermentation products, and further promote the applications of Morchella in health supplements, cosmetics, and other fields.

Key words: Morchella, antioxidant, response surface methodolgy, fermentation, medium optimization, single-factor experiment