Particle size distribution of nano-mist in a spinach-storage atmosphere and its effect on respiration and qualities Original Research Article

The aims of this research were (a) to characterize the particle size distribution of mist particles in a spinach-storage atmosphere influenced by the nano-mist application, and (b) to investigate the influence of the nano-mist on the respiration and qualities (leaves color and moisture content) of spinach. The particle size distribution of the mist was determined at 95% RH and 20 °C in a small-scale storage chamber and its influence on respiration rate, and qualities of spinach were investigated over six days of storage by comparing it with the control (without the nano-mist application). The nano-mist was found to alter the particle size distribution of the mist in a spinach-storage chamber by decreasing the total concentration and increasing the geometric mean diameter. The results suggested that the geometric mean diameter of nano-mist was larger than the water vapor appeared in air and that evaporated from the surface of spinach leaves through transpiration; and the transpiration could minimize the influence of nano-mist in modification of particle size distribution. The respiration rate was slightly lower in the first three days, but thereafter non-significant differences on respiration rate and leaves color were observed over the storage period, mainly because the spinach was stored at 20 °C. However, based on the obtained results, it could be expected that the use of nano-mist has an advantage over the conventional mist humidification that always contribute to the deterioration from the microbial growth because of the large particle size deposition onto the produce surface.