Analysis of Flavonoid Content of Red Seaweed (Gelidium amansii J.V.F. Lamouroux) growing in Krakal Beach, Gunung Kidul, Yogyakarta with a comparison of extraction

Abstract

Red seaweed (Gelidium amansii J.V.F. Lamouroux) is a plant found on the Krakal coast of Gunung Kidul, Yogyakarta. This seaweed is known to contain flavonoids and has antioxidant activity. The extraction method used can affect the levels of bioactive compounds produced. Therefore, a comparison between maceration and soxhlet extraction methods is necessary to determine the effectiveness of each method in extracting flavonoids from Gelidium amansii J.V.F. Lamouroux. The purpose of this study was to determine which method is more optimal in extracting flavonoid compounds. Methods: This study used two extraction methods: maceration (soaking at room temperature) and soxhlet (repeated heating with a soxhlet apparatus), using 96% ethanol as the solvent. Flavonoid content was quantitatively determined using UV-Vis spectrophotometry. Data were analyzed using the Shapiro-Wilk test for normality, homogeneity test, and the Mann-Whitney test to determine differences between methods. Results: The flavonoid content of the maceration method was 4.77% ± 0.033%, while that of the soxhletation method was 3.75% ± 0.02%. The normality test showed that the data were not normally distributed (p = 0.00), but were homogeneous (p = 0.06). The Mann-Whitney test showed a significance value of 0.043 (p > 0.05), indicating a significant difference between the two methods. Conclusion: The maceration method produced numerically higher flavonoid levels than soxhletation, resulting in a statistically significant difference. Therefore, both methods can be used depending on efficiency and the nature of the extracted compounds.