Three different plant materials (sage, thyme and rosemary) were extracted by refined rapeseed oil for 24 h at 30 °C and after separation of the plant material the oil was used for frying of French fries over a period of 32 h. Rapeseed oils treated with plant materials reached the limit of 12% oligomer triacylglycerides within 16 h of frying, while the formation of oligomer triacylglycerides in the control was significantly slower (P = 0.01). None of the oils exceeded the limit for free fatty acids of 2 g/100 g. The content of free fatty acids in the control was significantly lower after 32 h of frying. After 16 h of frying no tocopherols were detectable in untreated rapeseed oil, while in the treated oils tocopherols were still available after 28 h (thyme) and 32 h (sage and rosemary), respectively. In comparison to the control with an induction period of 4.7 h in the Rancimat test the treatment with thyme, rosemary and sage resulted in induction periods of 5.3, 9.3 and 11.0 h, respectively, corresponding to stabilization factors of 1.1, 2.0 and 2.4, respectively.