Effect of freezing under electrostatic field on selected properties of an agar gel

- The effect of electrostatic freezing on agar gel was investigated.
- Electrostatic freezing had no significant effect on the syneresis and the gel strength of agar gel.
- The size of ice crystals was decreased by 27% between control and higher field level.
- Freezing damage to the agar gel is independent to the ice crystal size.

The objective of this study was to investigate the effects of electrostatic freezing on the quality attributes of freeze-thaw agar gel. Agar gels were frozen under static electric field 0-5.8 × 104 V m− 1 at − 20 °C. Freezing rate and energy consumption were monitored during the freezing process and microstructures of the formed ice crystals were also analyzed by light microscopy techniques. Agar gel quality changes (syneresis and texture) were evaluated after thawing the frozen samples at + 4 °C. Results showed that the energy used by a DC high voltage generator was negligibly small as compared to the energy consumption by a freezer, and the freezing rate was not significantly influenced by electrostatic freezing (ESF). ESF also reduced the size of ice crystals but did not cause obvious changes in syneresis and texture of the samples.Industrial relevanceThe effects of electrostatic field freezing on the quality attributes of agar gel have been investigated. The results showed that the electrostatic freezing can be used as a potential tool to improve the microstructure of foodstuffs during freezing.