Effect of thermosonication on the quality attributes of star fruit juice

The effect of pasteurization and thermosonication on the quality of star fruit (Averrhoa carambola) juice was reported in the present study. Freshly extracted star fruit juice was pasteurized and thermosonicated to compare the effect on physiochemical properties, antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC), ascorbic acid levels, microbial populations, and sensorial properties. The results were compared with the raw star fruit juice. The treatments did not show any significant (p < .05) variations in pH, total soluble solids, and titratable acidity. A significant (p < .05) increase in antioxidant activity, TPC, TFC, ascorbic acid content, cloud index, and browning index of thermosonicated juices was observed. Pasteurization and thermosonication treatments also displayed significant effect in the reduction of microbial populations. Thus, findings in this study revealed that thermosonication may be a viable option for fruit juice industry, especially, for star fruit processing. Ultrasound processing is an emerging nonthermal technique which can be utilized in the processing of liquid food products. In general, fruit juices are processed through thermal treatments to keep the safe microbial levels. However, thermal processing adversely affects the quality of food products. The present study demonstrated the application of thermosonication that effectively maintained the quality of star fruit juices. Furthermore, it can be added that, thermosonication may be employed as a suitable technique to improve the quality parameters of star fruit juice.