Optimization of Dendrobium offcinale Fondant Formulation and Its Antioxidant Activity Determination by Response Surface Methodology

Dendrobium offcinale was used as the main raw material, and erythritol, citric acid and gelatin were used as auxiliary ingredients to make Dendrobium offcinale fondant. Using sensory evaluation as the index, single-factor experiments and response surface experiments were used to study the optimal production process and formulation of Dendrobium offcinale fondant. Then, the in vitro antioxidant activity of the fondant was illustrated by the determination of the scavenging of DPPH radicals and superoxide anion radicals and their reducing ability of the optimal Dendrobium offcinale fondant, meanwhile, the textural properties of Dendrobium offcinale fondant were determined. The results showed that the addition of 92.90% of Dendrobium offcinale, 18.30% of gelatin, 0.14% of citric acid and 29.20% of erythritol was the best, and the sensory score was 83.50 at that time. The reducing sugar and polyphenol contents of Dendrobium offcinale fondant made according to the optimal formulation were analyzed as 30.03 g/100 g and 0.85 mg/g. Respectively, the results of in vitro antioxidant analysis showed that the in vitro antioxidant activity of Dendrobium offcinale fondant was similar to that of V_C, and the half effective concentration (IC₅₀) of Dendrobium offcinale fondant against 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical was 0.50 mg/mL and the IC₅₀ value for the scavenging superoxide anion radicals was 0.13 mg/mL, which could prove that Dendrobium offcinale fondant had good antioxidant ability. The results of texture analysis concluded that the hardness of Dendrobium offcinale fondant ranged from 4600 to 4800 g, with suitable softness and hardness, the chewiness of Dendrobium offcinale fondant ranged from 4200 to 4300 g, and the acceptability was higher.