Effect of electric and electromagnetic fields on energy consumption, texture, and microstructure of dried black garlic

Abstract

Drying is one of the most energy-intensive food processing technologies and can contribute to greenhouse gas (GHG) emissions. Therefore, novel nonthermal pretreatment methods can be used to affect the plant tissue and decrease the drying time. A pulsed electric field (PEF), direct current electric field (DCEF), and electromagnetic field (EMF) were applied to black garlic cloves which were subsequently subjected to convective pre-drying followed by a vacuum-microwave finishing drying. The effect of these pretreatments on the physical properties, energy consumption, attributes of texture profile analysis (TPA), as well as microstructure determined by the use of X-ray computed tomography is presented. The application of pretreatments reduced the porosity of the material and resulted in an increased hardness compared to the unpretreated sample. Overall, nonthermal pretreatments proved beneficial in reducing the drying time and minimizing the energy consumption as well as greenhouse gas emissions during processing while maintaining a high quality of dried black garlic.