Ultrasonic pre-treatment to enhance drying of potentially probiotic guava (Psidium guajava): Impact on drying kinetics, Lacticaseibacillus rhamnosus GG viability, and functional quality

[Display omitted] •US pre-treatment improved the drying rate (up to 59%) of guava slices.•US pre-treatment reduced the drying time (up to 31%) of potentially probiotic guava.•US pre-treated dehydrated guavas showed higher L. rhamnosus GG viability.•US pre-treatment minimized thermal impact on the functional quality of dried guava.•US pre-treatment is a strategy to produce potentially probiotic dehydrated guava. This study aimed to evaluate the effects of ultrasound (US) on the drying acceleration of potentially probiotic guava, including its impact on drying kinetics, probiotic (Lacticaseibacillus rhamnosus GG) viability, and functional quality of the product during drying. To perform US pre-treatments, one group of samples were first pre-treated by US (38 W/L, 25 kHz) for 15 and 30 min and then immersed in the probiotic solution for 15 or 30 min, and another group of samples were submerged in the probiotic solution simultaneously applying US (US-assisted) for 15 and 30 min. After pre-treatments, the samples were convectively dried at 60 °C. Based on the results, all US pre-treatments improved the drying rate (up to 59%) and reduced the drying time (up to 31%) to reach 25% moisture compared to non-sonicated samples. The reduction in drying time (from ∼6 h to ∼4 h for US pre-treated samples) was crucial for maintaining the probiotic viability in the dehydrated guavas. These samples showed counts of 6.15 to 7.00 CFU∙g−1 after 4 h, while the control samples reached counts of 4.17 to 4.45 CFU∙g−1 after 6 h. US pre-treatment did not affect the color parameters of the samples before drying (p > 0.05). The functional compounds were reduced during drying (p