Large volume air plasma for fruit sterilization

Summary form only given. Large volume atmospheric pressure air plasmas [1,2] were generated by applying ~ 100 ns high voltage pulse between two parallel electrodes separated by 48 mm gap in air. The generated plasma frequencies can be varied from single pulse to 2000 Hz. A uniformly distributed stainless steel pens were welded to the high voltage electrode while the grounded electrode is a metallic flat disc. The pens have 32 mm length and 0.48 mm radius and separated by 8.7 mm to form a brush-shape. The pin tips are cut to form sharp ends to enhance the applied electric field and reduced the ignition voltage. The atmospheric pressure large volume glow discharges plasma ignite first at the outer pens forming luminousness circle then the internal pens ignited with the increase in the applied voltage. The glowed plasma expanded to cover the gap by increasing the applied voltage. Each pens form glow discharge with the ground electrode. The plasma intensity and homogeneity enhanced with increasing the applied voltage or the plasma frequency. The emission spectra investigations declared the main presence of nitrogen bands, second positive band and first negative band in the investigated range between 200 nm and 800 nm. The generated plasma was successfully proved as an efficacious tool for sterilizing a wide range of fruits from the naturally occurring bacterial and fungal contamination.