Retention and stability of bioactive compounds in functional peach beverage using pasteurization, microwave and ultrasound technologies

The peach functional beverages pasteurized for 10 min at 90 °C, microwaved for 1.5 min at 850 W of power and sonicated for 90 min at 20 kHz of frequency were selected to keep in storage for up to 30 days in refrigerator to examine the changes happened to their physicochemical characteristics and functional components. It was observed that the pH and the cloud values of all processed juice samples reduces with the storage time, whereas, the total soluble solids almost remain consistent particularly in microwave and ultrasound treated samples. While storage period causes the decrement in total phenolic content (TPC) and total flavonoid content of treated beverage samples, but ultrasound processing showed greater retention of TPC value up to 5.7% more than other techniques during storage. The similar trend was observed for antioxidant activity where the ultrasound treatment showed improved free radicals (2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activities except ferric ion reducing antioxidant power after 30 days of storage.