RESPONSE SURFACE OPTIMIZATION OF MICROWAVE-ASSISTED SULFATED POLYSACCHARIDE EXTRACTION FROM PORPHYRA DENTATE

An experiment was performed by adjusting the pH value (4-10) of a 10%-to-90% ethanol solution (v/v) and using it as an extraction solvent and, subsequently, using microwave-assisted extraction (MAE) to extract Porphyra denate solutions. The sulfated polysaccharides (mu g/mL) of these extraction solutions were evaluated. The optimal treatments of P. denate extracts obtained using MAE were studied using response surface methodology. The study was performed using a three-level, four-factor design and aimed to determine the optimal combinations of the ethanol concentration (10%-90%, v/v, X-1), pH value of an ethanol solution (4-10, X-2), microwave power level (200-400W, X-3), and heating time of a microwave field (1-5 mm, X-4) that optimized the sulfated polysaccharide effect of a P. denate extract solution. The response variable of the sulfated polysaccharide effect was considerably affected by the ethanol concentration, and the pH value of the ethanol solution was at a 0.1% significant level. The optimal treatments were established by adjusting the pH value between 8 and 9 and the ethanol concentration between 30% and 50% and, subsequently, using a 1-min heating time in a 200-W microwave field.