Effect of thermal and thermosonication on anthocyanin stability in jamun (Eugenia jambolana) fruit juice

The purpose of this investigation is to study the influence of high intensity ultrasound, sterilization and pasteurization on the stability of anthocyanin in jamun fruit juice. Different ultrasound process parameters for the treatments are compared to the classical thermal treatment like pasteurization and sterilization. For ultrasound treatments, three parameters were varied: temperature (80°C and 90°C), amplitude (80% and 100%) and time (5 and 10 minutes). Sterilization was carried out at F0-3. It was found that anthocyanin content after sterilization was reduced by 51.35% compared to untreated juice. Pasteurization (80°C for 5 min) reduced anthocyanin by 34% when compared to untreated jamun fruit juice. It was found that anthocyanin degradation increases with increase in temperature and time of pasteurization. After ultrasonic treatment (80% amplitude for 5 min), the degradation of anthocyanin was 21.9% when compared to the untreated juices. After treatment with thermosonication (80°C-5 min and 80% amplitude-5 min) it was found that anthocyanin degatradation slightly higher than that of pasteurization (80°C-5 min) and degradation was 35.4%. From the results it can be concluded that anthocyanin retention was greater in sonicated fruit juice compared to pasteurized, sterilized or thermosonicated fruit juices. Thermosonication can replace conventional heat processing methods for maximum retention of total anthocyanin content.