Antioxidant and antimicrobial activities of extract and essential oil of korarima (Aframomum corrorima (Braun) P.C.M. Jansen)

Abstract

The antioxidant potential of extracts and essential oils of korarima (Aframomum corrorima (Braun) P.C.M. Jansen) were investigated, as well as total phenolics, total ascorbic acid (TAA), condensed tannins (CT) and antifungal potential. Antioxidant capacities of seeds and pods as assayed in methanol extracts, and of essential oils were at moderate levels.The antioxidant activity of seeds (29.59 imol/g dry weight (DW)) was significantly higher than that of pods (14.23 imol/g DW) by FRAP (Ferric Reducing Ability of Plasma) assay. Also the antiradical power of seeds (9.26 imol/g DW) was higher than of pods (3.08 imol/g DW) in the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. Similarly, the antioxidant activity of seeds was higher than of pods in the
-carotene bleaching test. A lower 50% effective concentration (EC50) was achieved with seeds (42.10 mg/mL) as compared to pods (120.50 mg/mL), while EC50 of pod oils (11.9 mg/mL) was lower than seed oils (59.2 mg/mL). The total phenolic content in seeds (3.98 mg/g DW) was significantly higher than in pods (1.32 mg/g DW), while TAA content was significantly lower in seeds (3.49 mg/100 g DW) than in pods (6.25 mg/100 g DW). Differences in CT were non-significant. Antifungal tests exhibited that the extracts from seed were more effective than the control. Based on the present study the consumption of korarima as a spice may be used as source of antioxidants.