Comparison of UV-radiation and pasteurization on chemical and microbial properties of cherry juice

Non-thermal processes such as ultraviolet radiation can be used for maintaining the beneficial and nutritious compounds of juices. This study was investigated the effect of pasteurization (LTLT) and UV-C radiation at doses of 8, 15 and 30 W on ascorbic acid, anthocyanins, total phenol and antioxidant capacity changes of cherry juice immediately after processing, and some chemical ( pH, acidity and color) and microbial properties for 120 days at room temperature (25 °C). Based on the results, irradiation at 10 minutes caused a significant increase in pH value. The titratable acidity level increased during the storage period and confirmed the pH results. Cherry juice treated with UV-C radiation had higher content of ascorbic acid, anthocyanin, total phenol and antioxidant activity compared to pasteurized samples. Increasing the dose and time irradiation had a positive effect on increasing the ascorbic acid, anthocyanins, total phenol and antioxidant activity. The brightness (L*) and redness (a*) indexes in irradiated samples were significantly higher than the pasteurized samples. Among the different treatments, irradiated samples at a dose of 30 W for 6 and 10 minutes were superior to other treatments in terms of qualitative and microbial properties. At the end of the storage period, the lowest count of mold and yeasts was obtained in the irradiated sample at a dose of 30 W for 10 minutes. Overall, it can be concluded that UV-C radiation is suggested as a suitable alternative to the pasteurization process (LTLT) of cherry juice.