Simultaneous multifrequency: A possible alternative to improve the efficacy of ultrasound treatment on cherry tomato during storage

The productiveness of ultrasound (US) is affected by its frequency, power, and time, which has been reported to be very effective during food treatment when combined with other techniques of treatments. The study was aimed to evaluate the effect of mono‐frequency (MFU), simultaneous dual‐frequency (SDFU), and simultaneous tri‐frequency US (STFU) at treatment times of 5–25 min on microbial inactivation and nutritional quality of cherry tomato. Results revealed that within 10 min of sonication, SDFU was most effective compared with MFU toward inhibiting the spoilage microorganisms, delaying ripening as well as maintaining firmness, total phenolic, flavonoid, and antioxidant of the fruit during 21 days of storage at 4°C. Although STFU caused a higher reduction in microbial load after treatment, it, however, showed several adverse effects on the fruit during storage. Overall, SDFU treatment had great potential in preserving shelf life and nutritional value of cherry tomato during storage. PRACTICAL APPLICATIONS: US treatment has been implemented toward improving the shelf life of fruit and vegetables. However, a high desirable result has been related to its combination with other physical or chemical methods. The remarkable inactivation of microorganisms obtained for the dual‐ and tri‐frequency treatments under this study would contribute to the application of a nonthermal technique in the reduction of contaminants on ready‐to‐eat fresh products including cherry tomato. Furthermore, the positive effect of this treatment on the quality of the cherry tomato during storage indicated that this technique could be used to replace the common practice of combining US with chemical treatment in food preservation industries. Nevertheless, further exploration is needed toward determining the synergistic effect of these treatments with heat (thermosonication).