Ultrasonication effects on the phytochemical, volatile and sensorial characteristics of lactic acid fermented mulberry juice

The effects of ultrasonication (US) on phytochemical, volatile profile and sensory qualities of lactic-acid-fermented mulberry juice were studied. The juice was sonicated at 5.0 °C, 60 W and at varying pulsed frequencies and times (22 kHz for 10 min, 22 kHz for 20 min, 24 kHz for 10 min and 24 kHz for 20 min). It was observed that US significantly (p < 0.05) improved the phytochemical, volatile profile, odor activity values and sensory attributes of the fermented juice. Sonication decreased the Hunter L* and b* values but increased a* and total color difference values of the fermented juice. Correlation analysis showed that the changes in chromatic parameters were closely correlated with the phytochemical properties of the samples. The study showed that sonication at 24 kHz, exposure time of 10 min and a constant power of 60 W gave the best results.