No abstract

In recent years, thermosonication (TS) has been considered as a substitute to conventional heat treatments as it improves the quality characteristics of fruit juices. In the present research work, the impact of pasteurization (90 ± 2 C for 1 min) and TS on the quality of tangor fruit juice was examined and findings of the work were compared with freshly prepared juice. The quality characteristics, such as bioactive compounds, microbial counts and physicochemical properties were checked for all samples. After TS, the levels of total phenolic content (TPC) (683.25-747.84 μg gallic acid equivalents [GAE0/ml]), total flavonoid content (TFC) (61.76-71.51 μg quercetin equivalents [QE]/ml) and anti-oxidant activity (AOA) (73.27-83.63%) of tangor juices were improved as compared to fresh (TPC À 584.84 μg GAE/ml, TFC À 34.65 μg QE/ml and AOA À 49.71%) and pasteurized juices (TPC -471.74 μg GAE/ml, TFC -26.64 μg QE/ml and AOA -38.19%). But, a slight decrement in ascorbic acid content was perceived in thermosonicated juices (24.48-27.26 mg/100 ml) as compared to fresh tangor juice (45.55 mg/100 ml) but higher than pasteurized juice (22.55 mg/100 ml). TS also reduced the microbial populations in tangor juices with minor changes in the physicochemical properties as compared to fresh juices. Therefore, TS may be used effectively for the treatment of tangor juices to produce a product with better levels of bioactive compounds.