Extraction and identification of antioxidants from the spice Aframomum danielli

Successive extractions with diethyl ether and methanol of the whole seeds of the spice Aframomum danielli yielded diethyl ether extract (ADEE), 13.9%, and methanol extract (ADM), 3.4%, respectively. Similarly, reextraction of the defatted seeds of A. danielli successively with diethyl ether and methanol yielded extracts DFADEE (7.9%) and DFADM (6.7%), respectively. When these extracts were added to refined peanut oil (PNO) at 200 ppm, they showed good antioxidative effects. The percentage antioxidant effectiveness (AE) values were as follows: DFADM (87.3) > ADM (85.3) > ADEE (83.4)=tert-butyl hydroquinone (83.4) on day 20 of storage in an oven maintained at 65±1°C. Generally, antioxidant extracts prepared from A. danielli were also more effective than butylated hydroxytoluene and α-tocopherol in stabilizing refined PNO. Antioxidant components of A. danielli were tentatively identified as phenolic compounds of the trihydroxy type with reducing properties. All extracts prepared from A. danielli showed strong ultraviolet-absorbing characteristics, and methanol was a good extracting solvent.