ANTIOXIDANT ACTIVITY TEST OF ETANOL EXTRACT OF ALGA (Halimeda opuntia) TAKEN FROM THE SHORE OF POOPOH VILLAGE, MINAHASA DISTRICT

Antioxidants are compounds that can protect body cells from damage caused by free radicals. Free radicals are unstable molecules that can damage body cells and cause oxidative stress. Antioxidants work by neutralizing free radicals to protect cells from damage and help maintain overall health. This study aims to test the antioxidant potential of ethanol extract of Halimeda opuntia algae taken from the southern coast of Minahasa Regency, North Sulawesi. Antioxidant activity was tested using DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The decrease in absorbance value observed directly illustrates the decrease in the number of DPPH radicals remaining after the reaction between the extract and DPPH. The test results showed antioxidant levels that occurred at concentrations of 25 ppm (52.925%), 50 ppm (61.659%), 75 ppm (65.304%), and 100 ppm (70.112%). The test results show that the higher the concentration of ethanol extract of Halimeda opuntia algae, the stronger its ability to inhibit DPPH radicals. Therefore, it can be concluded that the highest antioxidant content is found at a concentration of 100 ppm with an average percent inhibition of 70.112%.