Abstract:

Based on the results of single factor tests, the extraction conditions of fucoidan and alginc acid from Laminaria
japonica were optimized by response surface methodology (RSM) using the extraction rates of fucoidan and alginc acid (Y1
and Y2) as response values. Based on three dimensions and overlay contour plots, the optimal extraction conditions included
extraction temperature of 77 ℃, extraction time of 4.4 h, liquid-solid ratio of 52.0:1, digestion temperature of 48 ℃, alkali
liquor concentration of 2.2 g/100 mL, and digestion time of 4.3 h. Under the optimal conditions, the extraction rates of
fucoidan and alginc acid were 2.58% and 28.11%, respectively, which were in close agreement with the predicted values.
The RSM is practicable for optimizing extraction process. This method will improve the extraction conditions of fucoidan
and alginc acid from Laminaria japonica.

Key words: Laminaria japonica, fucoidan, alginc acid, extraction, response surface methodology, overlay contour plot