Cell Membrane Damage by Vacuum Treatment at Different Pressure Reduction Rates

To investigate the damage of cell membrane induced by vacuum treatment at different pressure reduction rates, the onion epidermis was subjected to three different pressure reduction rates in a miniaturized, visual and vernier regulation experimental setup. The results of physical tests agreed well with the result of optical microscopy, which showed that treatment at the medium pressure reduction rate resulted in minimum changes in the spaces between the cell membrane and cell wall, water loss, relative electrical conductivity, color and micromechanical properties. Experimental results showed that the pressure reduction rate had obvious effects on the cell membrane integrity of vacuum‐treated onion epidermis. PRACTICAL APPLICATIONS This work tested the effect extent of different pressure rates on the cell membrane integrity during vacuum treatment, which has been demonstrated to provide many benefits to the food processing industry. This research could help the users to choose the appropriate operating parameters, to predict the characteristics of vacuum cooled products, to understand the mechanism of vacuum treatment and to learn the design of vacuum cooling equipment.