THE EFFECTS OF UV-C AND HOT WATER TREATMENTS ON TOTAL PHENOLIC COMPOUNDS OF JUICE, PEEL AND SEED EXTRACTS OF POMEGRANATES (PUNICA GRANATUM L.)

In this research, the effects of UV-C and hot water treatments on total phenolic compounds of juice, peel and seed extracts of pomegranate fruits were investigated during the storage period. After harvest fruit were divided into four groups. The first group of pomegranates was dipped into hot water at 53°C for 3 min. The second group of fruit was exposed to UV-C light (254 nm) at 3.6 kJ m^-2. The third group of of fruit samples were treated with a combination of hot water and UV-C. The fourth group of pomegranates, untreated fruits, were used as control. After the treatments, pomegranates were stored at 6°C with 90-92% relative humidity for 6 months. During the storage period, changes in the total phenolic compounds were determined in juice, peel and seed extracts of the pomegranate fruits. The results showed that UV-C illumination and heat treatment increased the total phenolic concentration in different parts of pomegranates. The total phenolic content is closely related to antioxidant activity that may be improved by some physical treatments.