Influence of ultrasound application and NaCl concentrations on brining kinetics and textural properties of Chinese cabbage

The effects of ultrasound application on the brining kinetics of Chinese cabbage leaves was evaluated at different NaCl concentrations (10, 15, and 20%) of the brine, and its influence on textural properties and salt distribution was also investigated. To identify the effects of these two factors on water and NaCl fluxes, the kinetics of transport was analyzed by taking the diffusion theory into account. The results showed that NaCl concentration and ultrasound application significantly affected moisture and NaCl transport. Based on Fick's equation, the NaCl effective diffusivities were enhanced upon ultrasound application during the brining process, increasing from 147.09 to 812.22%. With regard to the textural properties, a higher content of NaCl resulted in lower textural profile values. Moreover, ultrasound application significantly increased the cabbage hardness. Scanning electron microscopy and energy dispersive X-ray mapping images showed the intensification of NaCl transport brought about by ultrasound application and by the increase in NaCl content, which confirms the results of the modeling analysis. Therefore, ultrasound could be a potential technology for accelerating the brining process of cabbage. These results have direct implications for the quality management of kimchi products.