Extraction Temperature Affect on Methanolic Extract Antioxidant Activity of Eucheuma spinosum

Abstract

A red alga Eucheuma spinosum is widely cultivated and also one of the superior commodities because it has phenolic and flavonoid compounds that can act as antioxidants. Phenolic content and flavonoids in E. spinosum can be obtained through a maceration process with methanol as a solvent which is generally carried out at room temperature. The extraction process to obtain maximum yield can be accelerated by increasing the extraction temperature. This research aims to determine the antioxidant activity of E. spinosum extracted using methanol at temperatures of 55, 65, and 75 °C. Before extraction, the seaweed was washed and dried in an oven at 40 °C for 24 hours. Extraction was carried out with 80% methanol in a ratio of 1:10 (w/v). The parameters analyzed in this research were yield, phytochemical test, total phenolic content (TPC), total flavonoids, antioxidant activity including DPPH and FRAP. The data indicated that the extraction temperature affected total phenolic and antioxidant activity of both DPPH and FRAP, but did not affect the yield and total flavonoids. Extraction temperature of 55 °C resulted extract with higher antioxidant activity with an IC50 DPPH value was 362.52±7.10 ppm and FRAP value 70.3010.01 μM equivalent to Fe (II)/g.