ANTIPOLYMERIZATION ACTIVITY OF OAT EXTRACT IN SOYBEAN AND COTTONSEED OILS UNDER FRYING CONDITIONS

A methanolic extract of Noble oat (Avena sativa L.) was tested for its antipolymerization activity in soybean and cottonseed oils heated to 180 degrees C for 10 h per day for 10 d and for its carry-through prop erties in fried bread cubes. The soybean and cottonseed oils containin g 0.005 or 0.007% oat extract (based on total phenolic content) formed significantly lesser amounts of polar compounds with high molecular w eight than did the oils containing 0.02% tertiary butyl hydroquinone ( TBHQ), 1 ppm dimethylpolysiloxane (DMS) and oils containing no additiv es (control) as measured by high-performance size-exclusion chromatogr aphy. Fatty acid composition, also monitored, showed that oils with ei ther level of oat extract maintained a significantly higher linoleic-t o-palmitic acid ratio (18:2/16:0) than did the other treatments. Oil e xtracted from bread cubes fried (180 degrees C) in oils containing TBH Q and oat extract and then stored at 60 degrees C in the dark for up t o 14 d had significantly lower (P less than or equal to 0.05) peroxide values and higher (P less than or equal to 0.05) 18:2/16:0 ratios tha n did oil extracted from cubes fried in oil containing DMS and in the control oil.