Optimization of Formula of Lepista sordida and Yam Fungal Substance Beverage and Its Antioxidant Activity

Fungal substance derived from bio-fermentation technology of Lepista sordida with yam in order to develop a beverage with health benefits, the quality of the fungal substance was studied through fourier transform infrared spectroscopy (FTIR), which was used as raw material, the beverage formulation was optimized by Box-Benhnken response surface experimental design on the basis of single factor experiment, the content of functional ingredients and antioxidant activity for the beverage were detected. The results showed that the obtained fungal substance not only had the basic components of yam, but also produced new functional components; the optimal formula was: 4.00% fungal substance, 4.11% xylitol, 0.75% citric acid, 0.24% carboxymethyl cellulose sodium (CMC-Na), the beverage was bright brown, sweet and sour, clear and transparent, with the unique aroma of the fungal substance, the sensory score was 88.7±0.40 points. The total flavonoids and phenolics were 58.43±0.94 and 45.77±0.43 mg/L. The maximum scavenging rates of the beverage to DPPH and hydroxyl radicals were 73.46% and 79.26%, which indicated that the beverage had certain antioxidant activity.