IDENTIFIKASI NANOPARTIKEL PERAK DAN KANDUNGAN TOTAL FENOL PADA EKSTRAKSI BERBANTU GELOMBANG ULTRASONIK RUMPUT LAUT (GRACILIRIA VERRUCOSA) DARI PANTAI ANYER

Gracilaria verrucosa is a type of red algae (Rhodophyta) found on the coast of Banten. Gracilaria verrucosa is helpful as an ingredient for making agar and contains active antioxidant compounds and silver and gold nanoparticles. Gracilaria verrucosa is widely found on the coast of Banten but has not been used widely and has not become a cultivar. The extraction method is essential to extract the desired active component. Ultrasonic wave-assisted extraction (UAE) requires less time and the amount of solvent than conventional extraction, so it is expected to have better effectiveness than conventional methods. This study aimed to identify the silver nanoparticles content of Gracilaria verrucosa from Anyer Beach and determine the effect of UAE and maceration extraction on the total phenol content. The sonication extraction time ranges from 15, 20, and 25 minutes. The results showed the presence of silver nanoparticles as indicated by the color change of the extract to dark brown. The ultrasonic wave-assisted total phenolic content was 896.0722 mg GAE/g extract; for the maceration method, it was 834.2133 mg GAE/g extract. Ultrasonic wave-assisted extraction has better effectiveness compared to the maceration method.