Response surface optimization of mucilage aqueous extraction from flixweed (Descurainia sophia) seeds

The effects of four factors of pH (4-8), temperature (50-95°C), weed-seed ratio (W/S, 15-45), and time (1-4 h) on the yield of mucilage extraction of Descurainia sophia seeds were investigated using response surface methodology-Box-Behnken design (RSM-BBD). Results showed that a second-order model for the studied response was adequately fitted with a coefficient of determination of 98.7% (p<0.0001). The optimum conditions to achieve the highest yield (10.45%) were extraction time of 2.9 h, extraction temperature of 94.32°C, pH of 7.55 and the W/S ratio of 44.2. The extracted mucilage at the optimal point effectively scavenged DPPH free radical, and more concentrations of this polysaccharide indicated potent antioxidant activity in a dose-dependent manner.