Antioxidant activities of rosemary, sage, and sumac extracts and their combinations on stability of natural peanut oil.

The antioxidant efficacy of rosemary (Rosmarinus officinalis L.), sage (Salvia fruticosa L.), and sumac (Rhus coriaria L.) extracts and combinations at 4% concentrations (wt/vol, extract/oil) were investigated. Methanolic extracts of rosemary, sage, sumac, and their combinations were applied to peanut oil stored at 80 degrees C for 24 h. The antioxidant effect was determined by measuring the peroxide value. All extracts showed antioxidant effects compared with control. But the antioxidant effect of all extracts was low compared with that of butylated hydroxytoluene. Rosemary extract (except for 3 and 4 h) exhibited the most antioxidant effect compared with other individual extracts. Of blends, the most effective ones were sage plus sumac combinations. Sumac extract is also promising as a source of natural antioxidants.