Optimisation of ultrasound-assisted extraction conditions of fucoidan from brown seaweed Tubinaria decurrens

Fucoidan is a sulfated polysaccharide derived from brown seaweed, and it has been applied in pharmaceutical fields.Recently, the trend of applying advanced extraction techniques and optimizing extraction conditions has been particularly interested in order to achieve high extraction yield. In this study, response surface methodology (RSM) were employed to optimise the ultrasound-assisted extraction of fucoidan from brown seaweed Tubinaria decurrens. The impacts of three independent variables, including extraction temperatures (X1: 50-80°C), extraction time (X2: 30-60 min), and ultrasound power (X3: 40-100%) was investigated through Box-Behnken experimental design. The results showed that the optimised condition was at extraction temperatures of 70°C, extraction time of 53 min, and ultrasound power of 90%. Under this optimised condition, the extraction yield was 4.28% and close to the predicted yield of 4.34%.