Corn processing by pulsed electric fields with respect to microbial inactivation and improvement of seed vigour

Abstract

Abstract Pulsed electric field (PEF) treatment of corn grains as an alternative to improve seed vigour and inactivation of endogenous microflora by energies ranging from 1.20 to 28.8 J were applied to determine effectiveness of applied energies on germination rate (GR), normal seedling rate (NSR), electrical conductivity (EC), ability to germinate under salt (100- and 200 mM salt) and cold (at 10 C for 7 days and at 25C for 5 days) stresses in addition to inactivation of total aerobic mesophilic bacteria (TAMB), total mold and yeast (TMY), and inactivation rate (%) of Aspergillus parasiticus. Increased energy provided 11.10% increase in GR, 21.22% increase in NSR, 95.50% increase in germination at 10 °C for 7 days, 32.53% increase in germination at 24 °C for 5 days, 68.35% increase under 100 mM- and 76% increase under 200 mM NaCI salt stresses. EC of the corn grains significantly affected by the measurement time rather than PEF treatment. Inactivation on the mean initial TAMB and TMY were approximately 9.25 and 7.93 log, respectively, with 63.33 ± 0.22% reduction in A. parasiticus culture. Optimization studies revealed 300 Hz, 28.80 J, and 19.78 sec as the most optimal processing parameters. PEF treated corn seedlings had stronger and taller body formation with stronger roots. PEF treatment carries a high potential to improve corn vigour with inactivation of surface microflora.