Phenolics and antioxidant activity in flax varieties with different productive attitude

Eighteen varieties of flax (Linum usitatissimum L.) with different productive attitude (oil, fiber and intermediate) were analyzed for total phenolic content (TPC) and antioxidant activity. The TPC ranged from 4.64 to 9.40 mg caffeic acid equivalents (CAE) g-1 dry weight of linseed. TPC were statistically different among productive attitude groups and increasing in this order: oil varieties → intermediate varieties → fiber varieties. The antioxidant activity ranged from 0.56 to 0.86 mmol trolox equivalents (TE) g-1 dry weight of linseed. The antioxidant activity was statistically lower in oil varieties than the other two groups although within each group a greater variability respect to TPC was observed. The antioxidant activity was significantly correlated to TPC (r = 0.549). The data presented show that the oil flax varieties are poorer in antioxidants. Consequently, if there is an industrial interest on the flour for their TPC, intermediate varieties would be recommended.