Laminarin (Beta-glucan) of Brown Algae <i>Sargassum mcclurei</i>: Extraction, Antioxidant Activity, Lipoxygenase Inhibition Activity, and Physicochemistry Properties
Đặng Xuân Cường
Abstract
Laminarin is a storage glucan found in almost brown algae and possesses value bioactive. The study focused on the effect of the input factors of the extraction such as the temperature (30, 50, 70, and 90°C), the time (01, 02, 03, and 04 hours), the aqueous to algae ratio (20/1, 30/1, 40/1, and 50/1 (v/w)), and solvent pH (2, 7, and 9) on the function targets (laminarin content, total antioxidant activity, reducing power activity, and lipoxygenase inhibition activity), and the physical chemistry characterization of highest laminarin content was analyzed. The results showed the temperature, the time, the aqueous to algae, solvent pH affected on laminarin content, total antioxidant activity, reducing power activity, and lipoxygenase inhibition activity that got the highest value of 11.98±0.49 mg laminarin equivalent/g DW, 19.66±0.47 mg ascorbic acid equivalent/g DW, 15.55±0.61 mg FeSO<sub>4</sub> equivalent/g DW, and 73.04±2.53 µM linoleic acid equivalent/g DW, respectively. The suitable condition of extraction was collected consisting of the temperature of 90°C for 2 hours with the solvent to algae ratio of 40/1 (v/w) in pH solvent of 7. The average molecular weight, viscosity, and sulfate content of laminarin was 505.18 kDa, 14,17±0.29 cPs, and 48.72%, respectively. FTIR spectrum exhibited function groups of laminarin composed of O-H, -CH2-, C=O, C-O, –C–H, -O-SO<sub>3</sub><sup>-</sup>, and -CH=CH-(cis).