College of Food Science and Engineering, Northwest A&F 1University, Yangling 712100, China.
College of Food Science and Engineering, Northwest A&F 1University, Yangling 712100, China.
Food Chem. 2020 Aug 30;322:126753. doi: 10.1016/j.foodchem.2020.126753. Epub 2020 Apr 6.
This paper investigated the effects of radio-frequency (RF) energy and conventional hot-water blanching (95 °C for 2 min) on the peroxidase (POD) activity, physiochemical properties, and changes in the cellular morphology of stem lettuce. The relative residual POD activity significantly decreased (P < 0.05) from 66.03% to 6.46% with increased RF heating temperature (65 °C-85 °C). The weight loss (3.06%-7.64%), color, texture, relative electrolyte leakage (23.45%-67.90%), and residual vitamin C content (72.22%-16.67%) significantly changed (P < 0.05) with increased RF heating temperature (65 °C-85 °C). Micrographs indicated that the changes in physiochemical property can be attributed to the destruction of cell membranes, loss of cell turgor, reduced rigidity of cell walls, and loose adhesion between adjacent cells. Samples treated by RF heating at 75 °C showed lesser cell damage and better nutrient retention than those treated by hot-water blanching at a similar level of POD inactivation.
本文研究了射频（RF）能量和传统热水烫漂（95°C，2min）对茎生菜过氧化物酶（POD）活性、理化性质和细胞形态变化的影响。相对残留 POD 活性随 RF 加热温度（65°C-85°C）的升高而显著降低（P<0.05），从 66.03%降至 6.46%。随着 RF 加热温度（65°C-85°C）的升高，重量损失（3.06%-7.64%）、颜色、质地、相对电解质渗出率（23.45%-67.90%）和残留维生素 C 含量（72.22%-16.67%）均显著变化（P<0.05）。显微照片表明，理化性质的变化可归因于细胞膜的破坏、细胞膨压的丧失、细胞壁刚性的降低以及相邻细胞之间的附着力降低。与在相似 POD 失活水平下用热水烫漂处理的样品相比，在 75°C 下用 RF 加热处理的样品显示出较小的细胞损伤和更好的营养保留。
