Optimization and Evaluation of Atrina Pectinata Polysaccharides Recovered by Subcritical Water Extraction: A Promising Path to Natural Products.

In this study, the recovery of Atrina pectinata posterior adductor polysaccharides (APP-PS) using subcritical water extraction (SWE) was optimized by response surface methodology (RSM) and the physicochemical and biological properties of the recovered APP-PS were evaluated. The optimal extraction conditions, which resulted in a maximum yield of 55.58 +/- 1.12 %, were temperature, 152.08 degrees C; extraction time, 10 min; solid-liquid ratio, 30 g/600 mL. The obtained APP-PS was found to be 88.05 +/- 0.17 % total sugar. Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (NMR) analyses confirmed the presence of the alpha-coordination of D-glucan in the polymer sample. The analysis of monosaccharide composition, along with thermogravimetric analysis, revealed the typical structure of the sample, composed of glucose alone. Total phenolic contents of APP-PS were measured as 5.47 +/- 0.01 mg Gallic acid/g of dry sample and total flavonoids contents were determined to be 0.78 +/- 0.06 mg Quercetin/g of dry sample. For biological activities, ABTS(+), DPPH and FRAP antioxidant activities were measured to be 20.00 +/- 0.71, 2.35 +/- 0.05 and 4.02 +/- 0.07 mu g Trolox equivalent/100 g of dry sample, respectively. Additionally ACE inhibitory was confirmed to be 87.02 +/- 0.47 %. These results showed that SWE is an effective method to recover biofunctional materials from marine organisms.