The Effect of Storage Temperature on Antioxidant Activity of Sargassum hystrix Powder

The aim of this study was to determine the effect of storage temperature on the antioxidant activity of Sargassum hystrix. Samples were collected from Sepanjang Beach Gunung Kidul, Yogyakarta, and dried, pulverized, and then stored for two months at room temperature (17-33 °C), refrigerator (4 °C) and freezer (-18°C). Furthermore, the samples were tested every two weeks to determine their water content, total phenol, DPPH, and FIC. Also, Gas Chromatography-Mass Spectrometry (GC-MS) analysis was performed for two months before and after storage. The results showed that the water content increased after treatments, along with storage time which ranges from 8.55 to 14.27 %. Total phenol before storage was 175.73 mg GAE/g extract, and freezing has the highest total phenol levels after storage which was 22.07 mg GAE/g extract. Also, DPPH testing showed S. hystrix has an
IC50 value of 0.45 mg/mL, and refrigeration has the lowest IC50 value of 3.18 mg/mL. FIC test showed IC50 value of 1.44 mg/mL, and freezing has the lowest FIC IC50 value of 15.36 mg/mL. In addition, GC-MS sample analysis before storage detected 8 compounds with antioxidant activity of 86.96 %. After two months, they were detected at room temperature, refrigerator, and freezing which are 4, 3, and 8 compounds respectively.