Effect of Fermentation With and Without the Addition of Carrots on the Total Antioxidant Capacity of White and Red Cabbage

Cabbage is one of the most popular vegetables all over the world, with white cabbage generally being more popular than red cabbage. This study aimed at a comparison of the antioxidant properties of fresh and fermented white and red cabbage. Total phenolic content, the content of anthocyanins and carotenoids, and the Total Antioxidant Capacity (TAC) assayed by ABTS• scavenging, DPPH• scavenging, FRAP, and ORAC of fresh white and red cabbage, fermented white and red cabbage (sauerkraut), and sauerkraut juice were compared. The TAC of fresh and fermented red cabbage, and of red sauerkraut juice (110.3 ± 8.9, 47.4 ± 4.6 and 48.9 ± 5.7 mmol Trolox equivalents/kg, respectively) was significantly higher than the TAC of fresh and fermented white cabbage and white sauerkraut juice (5.1 ± 0.2, 7.9 ± 0.9 and 6.6 ± 0.9 mmol TE/kg, respectively, when assayed by ORAC). The TAC of white sauerkraut and white sauerkraut juice could be elevated by fermentation with 20% of black carrots (to 16.4 ± 1.2 and 10.5 ± 0.8 mmol TE/kg, respectively) but the TAC of red sauerkraut and red sauerkraut juice was diminished by a mixture of either orange or black carrots, which are of lower anthocyanin content than the red cabbage (41.8 ± 3.0 and 29.2 ± 3.1 mmol TE/kg, respectively). These results may justify the promotion of the broad consumption of red cabbage, both fresh and fermented, and encourage the usage of red cabbage as a promising material for functional foods.