Effect of Electric Pulse Parameters on Releasing Metallic Particles From Stainless Steel Electrodes During PEF Processing of Milk

Abstract

The acceptability of pulsed electric field (PEF) processing as an alternative method for liquid food preservation requires the elimination, or at least the reduction, of all the effects accompanying the flow of electric current. Metallic particles might be released from the electrode material as a result of electrically-driven electrochemical reactions. The presence of such metallic particles can affect the quality and the safety of PEF processed food. This study investigates the effect of varying the parameters of applied electric pulses on the amount of released metals aiming to reach the optimum conditions. It is expected that reducing the rate of releasing metals from the electrodes will extend their life time and reduce the running cost of the PEF process.

Migration of electrode material during food processing by high-field pulses

“…The difference between the two plots in Fig. 5(b) at high energy levels can be attributed to the iron released from the inner electrode due to the physical contact with circulating milk [3,4,10].…”

“…Blank samples are pipetted out before turning on the pulse generator. The sample preparation procedure and the analytical equipment are briefly described in [10]. Fig.…”

“…Electrode material migration can be also reduced by controlling the parameters of electrical pulses. Morren et al [9], and Gad and Jayaram [10] have showed preference of shorter-duration pulses to relatively longer ones. Roodenburg et al [3,4] found that the negative part of the current pulse reverses some of the electrochemical reactions.…”

Pulsed electric field technology in the manufacturing processes of wine, beer, and rice wine: A review

“…As reported in previous studies, PEF treatments induced electrochemical reactions then caused a release of metal ions from the electrode. Several authors also proposed that the release of these metallic particles from the electrode material is unavoidable when typical conditions of PEF processing were applied (Gad & Jayaram, 2014a). Nevertheless, another report suggested that the dissolution of metal likely occurred without PEF treatment, but the extent was minimal.…”

Performance of Electrode Materials During Food Processing by Pulsed Electric Fields

“…Attempts to eliminate, or at least reduce, the release of metallic ions during PEF processing include: 1) delivering zero net charges to the electrodes [7], [8]; 2) applying relatively short pulses [9], [10]; 3) generating oscillatory pulse shapes [5], [6]; 4) coating with conductive-plastic films [11]; and 5) utilizing ceramic-coated electrodes [12]. The PEF systems commonly use stainless steel electrodes [5]- [10].…”