Effect of UV-C Irradiation on Phenolic Composition of ‘Rishbaba’ Table Grape (Vitis vinifera cv. Rishbaba)

The effect of postharvest UV-C irradiation on phenolic compounds accumulation was investigated in berries of ‘Rishbaba’ table grape (Vitis vinifera cv. Rishbaba). Grape clusters were harvested at mature stage and irradiated with UV-C using fluorescent germicidal lamp (30 W, 90 cm) with a peak emission at 254 nm for 0 (control), 5 and 10 min. UV-C treatment had significant effect on individual phenolic compounds. Catechin, epicatechin, procyanidin B2, quercetin 3-galactoside, quercetin 3-rhamnoside, chlorogenic acid and total polyphenols increased with UV-C dosage, but procyanidin B1 and cyanidin 3-galactoside decreased. Positive correlation was observed between UV-C treatment and individual phenolics except procyanidin B1 and cyanidin 3-galactoside. In conclusion, UV-C irradiation increased phenolic compounds of ‘Rishbaba’ table grape and its nutritional value.