Red beetroot juice fermented by water kefir grains: physicochemical, antioxidant profile and anticancer activity

This study determined the effects of red beetroot juice fermentation by water kefir grains on antioxidant and anticancer activities. The fermented red beetroot juice showed increased viable bacterial counts and titratable acidity, decreased pH, and reducing sugar. The colors of the fermented juice were purplish red and brighter than fresh juice. The capacity to scavenge free radicals of center dot OH, center dot O-2(-), ABTS(center dot)(+), and DPPH center dot increased significantly the same as anti-proliferative activity against human hepatoma cell HepG2 by inducing apoptosis when fermented 24 h. Fourteen betalains in red beetroot juice fermented by water kefir grains at different fermentation times were identified by high-performance liquid chromatography. Pearson's correlation analysis revealed that the increases in antioxidant and anticancer activities were positively correlated with the contents of 17-decarboxy-betanidin, betanidin, neobetain, and 6'-O-feruloyl-betanin following the fermentation.