Pulsed Electric Field Processing as an Effective Tomato Peeling Method

Abstract

Electrophysical technologies are a global trend of sustainable agriculture and food industry. Peeling is an energy-intensive procedure of fruit and vegetable processing. The research featured the effect of pulsed electric field (PEF) treatment on tomato peeling effectiveness. The assessment included such factors as specific effort, energy costs, and product losses in comparison with thermal and electrophysical methods. Tomatoes of Aurora variety underwent a PEF treatment at 1 kV/cm. The expended specific energy was 1, 5, and 10 kJ/kg. The tomatoes were visually evaluated with optical microscopy before and after processing. The peeling effectiveness and mass loss were measured with a texture analyzer and digital scales. The PEF treatment decreased the specific force of mechanical peel removal by 10%. The mass loss decreased by 4% at 1 kJ/kg. The PEF method resulted in cell electroporation, which activated the internal mass transfer of moisture from the endocarp region between the mesocarp and the integumentary tissue. The hydrostatic pressure produced a layer of liquid, which facilitated the peeling. In comparison with thermal treatment (blanching), ohmic heating, and ultrasonic processing, the PEF technology had the lowest production losses and energy costs. The research proves the prospects of the PEF treatment in commercial tomato processing.

Keywords

• peeling
• pulsed electric field
• tomato
• texture
• electroporation