Use of ohmic heating assisted evaporation in sumac syrup production: Effects on quality parameters and process conditions

This study aims to investigate the effects of ohmic heating assisted evaporation on the production of sumac syrup. To achieve this, both conventional evaporation and ohmic heating assisted evaporation methods were employed. Two different voltage gradients – 20 V/cm (188 V) and 25 V/cm (235 V) – were applied during the ohmic assisted evaporation process. The experimental design included the analysis of physicochemical parameters, HMF (5-hydroxymethylfurfural) content, antioxidant properties, rheological characteristics, energy consumption and other process conditions. There were no significantly differences in the antioxidant properties or HMF levels between the samples produced with ohmic heating assisted and conventional evaporation methods. However, in terms of energy efficiency, the energy consumption during the ohmic heating assisted evaporation (121.93±5.98 and 95.00±3.08 kj for 20 and 25 V/cm) process was approximately eleven times lower than that of the conventional method (1331,00±101,82 kj). Furthermore, the results demonstrated that ohmic heating assisted evaporation preserved the quality attributes of sumac syrups, while significantly reducing energy consumption, CO₂ emissions, and key process parameters.