Effect of thermosonication and probiotic fermentation on bioactive compounds and microbial activity of Elaeocarpus floribundus (jalpai) juice

This study investigated the impact of pasteurization (PS) and thermosonication (TS) on the quality of Jalpai ( Elaeocarpus floribundus ) juice. TS was applied at 30 °C, 40 °C, and 50 °C for 30–60 min using 40 % and 50 % amplitude. Compared to raw juice, TS enhanced total phenolic content (34.07 mg GAE/mL), flavonoids (17.99 mg QE/mL), vitamin C (15.28 mg/100 mL), and antioxidant activity (1.22 mg Trolox/mL), while reducing microbial loads. Complete inactivation of TVC and YMC was achieved at 50 % amplitude under optimum conditions. A probiotic beverage was developed using Lactobacillus plantarum and Lactobacillus paracasei . Fermentation led to reduced pH, TSS, and TPC, with increased titratable acidity, flavonoids, and antioxidant activity. TS retained heat-sensitive nutrients and supported probiotic growth. During storage at 4 °C, vitamin C declined slightly, but other nutrients remained stable. The synergistic effect of TS and fermentation improved juice quality, suggesting a commercially viable method for probiotic beverage production.