Extraction Optimization of Arctium lappa L. Polysaccharides by Box–Behnken Response Surface Design and Their Antioxidant Capacity

Abstract Arctium lappa L is a good source of polysaccharides in addition to its nutrient content and health benefits. In this study, a Box–Behnken response surface design is used to optimize the extraction conditions of A. lappa L. polysaccharides (ALP) in hot water. The influence of different degreasing methods on polysaccharide yield is investigated for the first time and their antioxidant activity compared. The effects of liquid‐to‐solid ratio (10:1 to 30:1), extraction temperature (60–100°C) and extraction time (1–3 h) on the ALP yield are analyzed. Under the optimal extraction conditions (extraction temperature 71.12°C, extraction time 2.51 h, liquid‐to‐solid ratio 16.20:1), Derringer's desirability prediction tool obtains the highest extraction yield of polysaccharides (9.73%), which is confirmed through validation experiments. In addition, the 2,2‐diphenyl‐1‐picrylhydrazyl, 2,2‐azinobis (3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt), andoxygen radical antioxidant capacity values of the optimized ALP are 232.23 ± 4.19, 407.84 ± 1.48, and 2932.54 ± 145.29 µmol Trolox g –1 , respectively, indicating that ALP has potential antioxidant capacity. Therefore, ALP can be used as a functional food ingredient or nutraceutical.