In the present study, shelf-life extension and maintaining quality of fresh strawberry using immersion method and electrospray was examined. Chitosan nanoparticles was produced by electrospraying as a new approach to coating agricultural products. In the first session, this study investigated how to produce chitosan nanoparticles by electrospraying with acceptable morphology and reach a suitable formula for polymer solution. Hence, the effects of various solution properties and processing parameters on particle formation were evaluated. Chitosan polymer solution consists of 2% (W/V %) chitosan, 30% glacial acetic acid (V/V %), 20% (V/V %) ethanol and 50% (V/V %) distilled water indicated high ability in producing nanoparticles with appropriate morphology. flow rate of 0.03 ml/h, 20 cm electrode–collector distance and 20 kV voltage showed the best performance in nanoparticles production. The average diameter of the chitosan particles and standard deviation were 62.74 nm and 28.32 nm, respectively. In the second session, effect of chitosan coatings on physical and chemical properties of strawberry samples such as weight loss, fungal decay incidence, total soluble solids (TSS), PH, titratable acidity, firmness and color changes was studied. In the electrospray process, because of deposition solid nanoparticles on the surface of fruit, surface roughness and surface energy cannot affect coating integration. Thus, maintaining more freshness and moisture content is possible. At the end of the fourth day, 93.33% of control samples showed fungal decay and data revealed significant difference between untreated fruits and coated fruits ( P 0.05). In addition, at the end of the storage time, nanoparticles coated samples indicated only 40% fungal decay and difference was significant compared to other treatments ( P 0.05). At the end of the storage period, the highest value of TSS belongs to electrosprayed samples. Application of integration nanoparticle coating led to lower enzymatic activity and respiration. At the end of the storage, there is no significant difference between PH value of 1.5% chitosan, 2% chitosan and electrospray treatments ( P 0.05). After week, electrosprayed samples showed highest citric acid (%). In the same time, chitosan 2% and nano coated samples maintained initial firmness properly. In seventh day, the lowest color changes was assessed for nanoparticles coated fruits ( P 0.05). Keywords: Chitosan nanoparticle, coating, electrospray, fungal infection, immersion, shelf-life
