The antioxidant, phenol, ascorbic acid, electrode corrosion and engineering factors of concentration process of kiwifruit juice by ohmic heating-vacuum conditions (OHVC) were evaluated and compared with ohmic heating under atmospheric conditions (OHAC). Results showed that the total phenol content was decreased with an increasing voltage gradient for both heating modes. The OHVC can better save the antioxidant capacity and ascorbic acid of concentrated samples than the OHAC. The processing time of OHVC was significantly higher than the OHAC at the same voltage gradient (P < 0.05). The electrode corrosion rate at the vacuum mode was 7- to 40-fold higher than the atmospheric mode. The energy efficiency at OHAC was lower than the OHVC. The energy consumption was found in the range of 3.37 to 3.75 MJ kg−1 water for OHAC and 4.08 to 11.09 MJ kg−1 water for OHVC. The electrical conductivity under the vacuum mode was lower than the atmospheric mode.
