A functional radish tea beverage was developed using pressure roasted radish pieces, barley, and cassia seeds. Stevia, short-chain fructooligosaccharides (scFOS), and inverted sugar syrup were used as sugar substitutes. The formula developed for mass production was, pressure roasted radish pieces, barley, and cassia seed teas prepared separately, then mixed (3:1:1, v/v/v). Inverted sugar syrup (54.4 g/L), stevia (0.73 g/L), scFOS (17 g/L), citric acid (0.01%), and vitamin C (0.05%) were added. Sweetness and caloric contents of the roasted radish tea beverage were 6.5°Bx and 19.35 Kcal/100 mL, respectively. Based on consumer acceptance testing (=60 persons), overall acceptance, taste, and sweetness scores of the roasted radish tea beverage were higher than for a commercially available H tea beverage. Caloric contents were reduced by approximately 23.5% using sugar substitutes. The IC value for the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of hot water extracts of dried radish increased 2.5-fold after pressure roasting.

The antioxidant and anti-inflammatory effects of roasted dried radish (RDR) against renal oxidative stress were examined in high-fat diet (HFD)-fed mice. The HFD was prepared by adding lard to chow diet to provide 50% of the calories from fat. Hot water extracts of dried radish (DR) or RDR were administered orally to mice at 237 mg/kg bw/day, whereas distilled water was administered as a vehicle for 12 weeks. Compared to the control group, renal reactive oxygen species, peroxynitrite, and thiobarbituric acid reactive substance level in the DR or RDR group were significantly decreased, whereas the glutathione level was increased (p<0.05). Protein expressions of antioxidant factors such as nuclear factor erythroid 2-related factor-2, heme oxygenase-1, glutathione S-transferase, superoxide dismutase, catalase, and glutathione peroxidase were significantly increased in the DR and RDR groups; however, nuclear factor-kappa B expression was suppressed (p<0.05). These antioxidant and anti-inflammatory effects of RDR were found to be significantly greater than those of DR.