This study was carried out to investigate the effect of sonication on physicochemical parameters and microorganisms of pear juice. Ultrasound processing of fresh pear juice was done at fixed amplitude [70% (500 W) and frequency (25 kHz) for 0, 15, 30, 45 and 60 min at 25 °C. Total soluble solids, pH, titratable acidity and Ca and Mn remained stable, while the cloud value, ascorbic acid, total phenols, total flavonoids, total antioxidant capacity, sugar contents and Na, K, Fe and Mg showed a significant increase. Decreases in microbial population and P and Cu were also observed. It may be inferred that ultrasound processing for 60 min exhibited optimum results in terms of physicochemical and microbial quality.
The present study was conducted with the aim of evaluating the effects of ultrasound processing on selected quality parameters of pear juice. The ultrasound treated juice samples exhibited best quality at treatment time of 60 min. It was observed that the ultrasound processing resulted in enhanced microbial safety with significant increase in mineral elements, sugar contents, ascorbic acid, bioactive compounds and antioxidant capacity of pear juice. Results of the present study suggest that sonication may be employed for commercial production of pear juice with improved quality and safety.