Phytochemical Composition and Antioxidant Activity of Etlingera elatior Fruit: A Comparative Study of Methanol and Ethanol Extracts

Etlingera elatior fruit is widely used in culinary and traditional medicine and is recognized for its rich content of phenolic compounds and organic acids. However, the influence of extraction solvent on its phytochemical composition and antioxidant behavior has not been systematically evaluated. This study compared methanolic and ethanolic extracts of Etlingera elatior fruit concerning total phenolic content (TPC), condensed tannins, metabolite profiles, and antioxidant activity using multiple complementary assays. Dried fruit material was extracted with absolute methanol or ethanol. TPC (mg GAE/g extract), condensed tannins (mg CE/g extract), and antioxidant capacity were determined in triplicate using ABTS, DPPH, FRAP, and TBARS assays. Untargeted LC-HRMS was employed for putative metabolite annotation based on accurate mass and MS/MS matching. The ethanolic extract exhibited significantly higher TPC (۸۴.۴۹ ± ۰.۸۸ mg GAE/g) and condensed tannin content (۱۳۱.۳۴ ± ۰.۵۲ mg CE/g) than the methanolic extract (۶۲.۶۴ ± ۰.۹۰ mg GAE/g and ۳۱.۱۵ ± ۰.۴۳ mg CE/g, respectively). Antioxidant performance was strongly solvent-dependent. The methanolic extract showed superior ABTS radical scavenging (IC₅₀ = ۲۸۷.۲۵ vs. ۷۴۳.۶۲ µg/mL), ferric-reducing capacity (۹۰۳۰.۱۱ vs. ۲۴۰۶.۲۲ µmol Fe²⁺/g), and inhibition of lipid peroxidation (۳.۷۸ vs. ۱۲.۱۸ mg MDA/kg), while the ethanolic extract exhibited stronger DPPH scavenging activity (IC₅₀ = ۲۴.۹۰ vs. ۵۲.۱۳ µg/mL). LC-HRMS analysis revealed complementary metabolite profiles, with methanol preferentially enriching flavonoids and phenolic acids, and ethanol favoring organic acids and nitrogenous metabolites. Citric acid was the dominant compound in both extracts. Overall, methanol and ethanol yielded chemically distinct extracts with different antioxidant mechanisms. Methanol favored electron transfer activity and lipid protection, whereas ethanol enhanced hydrogen atom transfer and polyphenol recovery, including condensed tannins. These solvent-dependent characteristics provide a rational basis for selecting extraction conditions tailored to specific nutraceutical and functional food applications.

کلیدواژه ها:

Etlingera elatior ، kecombrang ، bunga kantan ، antioxidants ، torch ginger