To examine extrusion temperature effects on oil stability, corn meal/ starch with soybean oil was extruded, frozen immediately in liquid nitrogen, freeze‐dried and ground. The conjugable oxidation products (COP), oxodiene values (OV), peroxide values (PV) and conjugated dienes were determined during storage. There was an increase in COP, OV, PV, and conjugated dienes with an increase in extrusion temperature. An increase in transition metal content, particularly iron, occurred with an increase in extrusion temperature. Starch and soybean oil were extruded with 50 ppm ferrous acetate (dry weight) and 50 ppm butylated hydroxyanisole (BHA) (oil weight). Ferrous acetate reduced the oxidation relative to the control, which contained neither antioxidant nor iron, and relative to the sample containing BHA.

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