Ye-Seul Park1, Jin-Seok Park1, Ji-Min Han1, Yu-Na Shin1, Ye-Ryeon Shin1, Sin-Won Park1 , Byung-Soo Chun1 and Hee-Jeong Lee2
1Department of Food Science and Technology, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 48513, Korea
2Department of Food and Nutrition, Kyungsung University,309 Suyeong-ro, Nam-gu, Busan 48434, Republic of Korea
Recently, functional foods have gained much attention from the public owing to improving the healthy life and reducing the risk of diseases. Ecklonia stolonifera, a brown seaweed, has been recognized as a potential source of polyphenols for manufacturing functional foods because of its excellent anti-diabetic, anti-arteriosclerosis and outstanding liver protection capability from toxins. E. stolonifera was treated with subcritical water extraction (SWE) at five extraction temperatures (120°C to 220°C) and the pressure of 30 bar for 30 min. 50 mg/mL of dried powder sample was taken as a solid to liquid ratio. Methanol extraction was used as a standard to compare to the SWE method. Physicochemical properties of SWE were analyzed to get total phenolic, total flavonoid, total sugar and reducing sugar contents. Subcritical water extracts of E. stolonifera exhibit excellent antioxidant activity from various tests such as DPPH, ABTS+ and FRAP. The highest amounts of antioxidant activity for ABTS+ (35.98±0.18 mg TE/g), DPPH radical scavenging (38.18±0.59 mg TE/g) and FRAP (25.29±0.37 mg TE/g) were recorded at 195 °C. The maximum amounts were observed at 195°C for phenolics (26.02±0.06 mg TA/g) and flavonoids (8.40±0.21 mg catechin/g). The highest total sugar (102.04 ± 0.92 mg glucose/g) was reported at 120 °C, and the highest reducing sugar (61.82±1.41 mg glucose/g) reported at 170 °C, followed by 61.54 ± 2.10 mg glucose/g at 195℃. Based on this study, E. stolonifera treated with SWE method demonstrates promising properties for new healthy functional foods.