A continuous high voltage electrostatic field system for thawing food materials

Abstract

A laboratory continuous HVEF thawing system was designed and constructed in accordance with standards for food machinery. Corona discharge in wire-plate electrodes was considered for the system and a stainless-steel sheet was utilized as the conveyor belt. Corona flow was created by applying high voltages of 15, 20, and 25 kV and electrode gaps of 6, 8, and 10 cm. To evaluate the system, frozen tylose MH4000 gel with a moisture content of 77% w.b. as a meat analog was thawed from −10 to 0°C. The thawing duration which was mostly devoted to increase the temperature of control sample (no electrostatic field), considerably decreased when thawing the gel in the presence of the high voltage. High voltage and EG indicated significant effect on both thawing duration and specific energy consumption (p˂0.0001). The thawing duration decreased significantly by decreasing the electrode gap and increasing the applied voltage. In terms of energy consumption, the best condition (minimum specific energy consumption of 10.33 kJ kg-1) was obtained for the voltage of 15 kV, and the electrode gap of 10 cm.

Keywords

• Continuous thawing
• corona flow
• electrostatics
• Tylose gel
• wire-plate arrangement.