Influence of ultrasound processing on the quality of guava juice

Ultrasound has been found to be a non-thermal method for inactivating microorganisms pertinent to fruit juices. The current research was planned with the goal of investigating the influence of sonication on the quality of guava juice when treated at a constant 40 kHz frequency, 200 W radiating power for different processing times of 2, 6, and 10 min in ultrasonic bath. After ultrasound treatment, the values of pH and titratable acidity varied non-significantly (p > 0.05), while 6 min of sonication showed significant decrement in total soluble solids. The cloud value, color attributes (a* and b*), hue angle, chroma, and antioxidant increased after ultrasound processing. On the other hand, non-enzymatic browning decreased significantly. Furthermore, ultrasound processing significantly (p < 0.05) enhanced the amount of ascorbic acid (2.45%-4.70%) and total phenolics (3.50%-4.35%) regardless of the processing time. The sonication also demonstrated significant effect to inactivate microbial load with maximum total plate count inactivation of 38.18% and highest yeast and mold count inactivation of 33.20% at 10 min of time. A sensory test showed that the sonicated samples of guava juice had a good acceptance similar to fresh juice of guava. Thus, result of this investigation showed that ultrasound processing at 40 kHz can be a practical choice for fruit juice processing at industry level, particularly for guava juice production. Practical Applications Increasing consumer preferences for healthier foods stimulate the growth of the global fruit juice market. The ultrasound is an emerging novel technology that is seen as a prospective substitute to traditional thermal treatments due to its capability to enhance stability and nutritional quality of juices. This research investigation displayed that the sonication treatment effectively retained the quality attributes of the guava juice. The improved phenolic and antioxidant stability achieved with a novel non-thermal approach is directly linked to the nutritive and economic benefits of industrial processing. This research work promotes a novel processing treatment of ultrasound which enhances the quality and stability of juices.