The effects of radio-frequency (RF)-assisted blanching and conventional hot water blanching (HWB) on the polyphenol oxidase (PPO), microstructure, physical characteristics, and starch granules in potato were investigated. The residual activity of PPO decreased from 60.47% to 1.35% with increased RF heating temperature (50–90 °C). Moreover, RF achieved a similar level of enzyme inactivation as HWB at lower temperature (70 °C), thereby maintaining the good physical characteristics. With increased temperature from 50 °C to 90 °C, weight loss (1.15%–6.23%) and relative electrolyte leakage (REL) (6.57%–96.96%) increased. Transmission electron micrographs revealed that the increase in REL was due to the gradual degradation of cell membranes and walls. Confocal laser scanning micrographs suggested that RF and HWB treatments changed the cell morphology and gelatinized the starch granules, leading to texture softening. Furthermore, differential scanning calorimetry thermograms showed that ΔH decreased from 2.80 J/g to 0 J/g with increased temperature. All these findings indicated that the change in physical characteristics of potato depended on its microstructure during RF blanching.

研究了射频（RF）辅助热烫和常规热水热烫（HWB）对马铃薯中多酚氧化酶（PPO），微观结构，物理特性和淀粉颗粒的影响。随着射频加热温度（50–90°C）的升高，PPO的残留活性从60.47％降低至1.35％。此外，RF在较低温度（70°C）下达到了与HWB相似的酶灭活水平，从而保持了良好的物理特性。随着温度从50°C升至90°C，重量减轻（1.15％–6.23％）和相对电解质泄漏（REL）（6.57％–96.96％）会增加。透射电子显微照片显示，REL的增加是由于细胞膜和壁的逐渐降解。共聚焦激光扫描显微照片表明，RF和HWB处理改变了细胞形态，并使淀粉颗粒糊化，从而导致质地软化。此外，差示扫描量热法热分析图显示Δ随着温度的升高，H从2.80 J / g降至0 J / g。所有这些发现表明，土豆的物理特性的变化取决于其在RF热烫过程中的微观结构。