Search

Influence of pulsed electric field (PEF) on the drying rate of foods during the hot air drying process is investigated. Nine kinds of fruits and vegetables and two kinds of marine products are used as the samples, and changes in the weight of these samples during the process are evaluated. PEF is applied to the samples using parallel plate electrodes. The applied voltage ranges from 0.4 to 3 kV, and the input energy of the sample ranges from 1.5 to 115.5 J/g. The samples are dehydrated using a hot air dryer after the PEF treatment. The drying rate of leafy vegetables, apples, and wakame seaweed is accelerated by PEF. The results show that the moisture permeability of membrane can be improved by destroying the cell membrane by PEF. On the other hand, there is no effect on root vegetables because their hard tissues are hard to destroy. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

This study aimed to compare the impact of a pulsed electric field (PEF) with that of hot water (HW) and control (CONT) on subsequent drying rate, shrinkage, and quality parameters (degradation of l -ascorbic acid (L-AsA) and color) of spinach during hot air drying. PEF pre-treatment was conducted in 2.8 kV/cm of the electric field strength and 27.1 kJ/kg of the specific input energy. We found that the drying rate for PEF sample was increased compared with CONT and HW samples due to the inhibition of shrinkage during drying. Further, degradation of L-AsA and the surface color in PEF sample were significantly inhibited compared with HW sample, therefore we confirmed that PEF treatment could resolve the elution of water-soluble components caused by HW treatment. These findings showed that pre-treatment with PEF is suitable for reducing drying time and producing high-quality dried spinach. • Pulsed electric field was applied to drying of spinach as a pre-treatment. • The drying rate of treated samples increased in an early stage of drying. • Quality changes were inhibited compared with hot water pre-treatment. • The pulsed electric field treatment would contribute to produce high quality dried products. [ABSTRACT FROM AUTHOR]