The effect of different extraction methods on the total phenolic content and antioxidant activity in galam sawdust (Melaleuca leucadendron linn.)

Abstract

Sawdust is a waste that can be used as microcrystalline cellulose. Galam (Melaleuca leucadendron Linn.) is one of the woods that produce microcrystalline cellulose from its sawdust which is used for construction and furniture manufacturing purposes. Microcrystalline cellulose sawdust extraction can produce residual extracts that can be utilized for certain potential activities. This study aimed to determine the difference between reflux extraction and maceration method towards antioxidant activity and total phenolic content of Galam sawdust. Extraction of Galam sawdust was carried out using n-hexane: ethanol (1:2) consisting of two treatment groups: maceration and reflux extraction methods. Total phenolic contents were determined spectrophotometrically using Folin-Ciocalteu reagent with gallic acid as a standard. Measurement of antioxidant activity was done by DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging method. The total phenolic contents of the reflux extract (93.555 ± 0.872 mg GAE/g extract) were found significantly higher as compared to the macerated extract (40.735 ± 0.903 mg GAE/g extract). The reflux extract showed higher DPPH scavenging activity (IC50 = 259.431 ppm) than the macerated extract (IC50 = 389.698 ppm) but very weak antioxidant activity when compared with the positive control, Gallic acid (IC50 = 2.256 ppm). The results of the study showed that the reflux extract from Galam sawdust produces better antioxidant activity compared to the macerated extract, even though very weak antioxidant activity, the antioxidant result correlated with their phenolic contents.