INVESTIGATION ON INTERMITTENT MICROWAVE-ASSISTED EXTRACTION OF SULFATED POLYSACCHARIDES FROM PORPHYRA DENTATA

This study investigated the intermittent microwave-assisted extraction (MAE) of sulfated polysaccharides from Porphyra (P.) dentata Kjellman, 1897. The experiment consisted of adjusting 10% to 90% ethanol solutions (v/v) used as extraction solvents, and then applied intermittent MAE to extract dentata solutions. These different extract solutions were then further evaluated for their sulfated polysaccharides contents (ig/mL). The optimal conditions of the sulfated polysaccharides content using intermittent MAE with 3, 4, and 5 cycle treatment were studied using response surface methodology. This study was performed using a three-level, three-factor design and aimed to determine the optimal combination of ethanol concentration (10-90%, v/v, Xi), microwave power (200-400 W, X-2), and intermittency of the microwave field (0-1, X-3) for obtaining the optimal results in extracting sulfated polysaccharides from P dentata. The response variable of the sulfated polysaccharides content (p.g/mL) was significantly affected by the ethanol concentration (Xi), microwave power (X-2), and intermittency (X-3) at 5% level of significance. The optimal treatment was established by adjusting the ethanol concentration to 44.4%, followed by using a 200 W microwave with an intermittency of 0.75 at 4 cycles for this study. Verification tests indicated that the second order polynomial model generated was adequate. The optimal extraction condition was provided and the validation proved that the results were acceptable.