Proofing of bread dough assisted by ohmic heating

•Proofing of bread dough assisted by ohmic heating allows the yeasts to quickly reach their temperature activity optimum.•Using higher heating rates than that of conventional proofing decreases the proofing time by decreasing the lag phase.•Using ohmic heating may lead to lower energy consumption and may be of interest for baking industry.•Proofing by ohmic heating leads to lower temperature gradients, meaning a potential increase of the dough quality.•Ohmic heating technology can be of interest in the case of proofing dough from low temperatures.

Proofing of bread dough was studied under ohmic heating for a target temperature of 35°C. An experimental device based on PLC monitoring was developed to study the effect of heating rates and voltages on the proofing process. Conventional and ohmic heating-assisted proofing were compared; the results showed that the process itself had no impact on the proofing when identical heating rates (0.065°C·min− 1) were used. However, increasing the heating rate could significantly reduce the time needed to reach an expansion ratio of 3 (from 122 min during conventional proofing to 65-70 min during ohmic heating in the range of 1-10°C·min− 1). This was due to the shortening of the lag phase at the beginning of proofing (from 58 min during conventional heating to 20 min at 10°C·min− 1 in ohmic heating). Results also showed that the voltage intensity had no significant effect on the proofing kinetics in the range of 50-150 V. The evolution of expansion ratios with proofing time could be fitted by a Gompertz model with a very high accuracy (R2 > 0.999)