Fresh-cut papaya is one of the perishable minimally processed product due to microbial decay rate. In this work, a novel nanocomposite coating was developed as a possible method for maintaining the quality attributes of the samples. Chitosan and ZnO nanoparticles (ZnONP) were selected to inhibit microbial growth on fresh-cut papaya. The aims of this work were to evaluate the antimicrobial activity and effect of nanocomposite coating made of chitosan combined with ZnONP on microbial growth of fresh-cut papaya stored for 12 days at 10°C. The preliminary work was conducted to select the best formulation exhibiting the greatest bacterial inhibition effect which was chitosan combined with 0.027% ZnONP (by weight of nanocomposite solution). The results revealed that the average diameter of ZnO was 611.30 nm with polydispersion index of 0.011 confirmed by particle size analyzer (PSA). All components were completely contained in nanocomposite analyzed by Fourier-Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) for its microstructure and presence of ZnONP in the film. Selected nanocomposite application on fresh-cut papaya could suppress microbial growth significantly in comparison with uncoated papaya during storage time. Our study suggests that nanocomposite treatment provides a desirable method to maintain and improve freshcut papaya postharvest life.

The objectives of this research were to characterize nanoemulsion from chitosan/nutmeg seed oil and to evaluate its coating on fresh strawberry which stored at 10oC for 5 days. The ultraturrax and high-pressure homogenizer were used to prepare 1.34±0.25 - 5.79±1.61 nm of nanoemulsion size which confirmed by particle size analyzer. The morphology observed by SEM that exhibited the oil globules were covered by chitosan. They were aggregated and rough droplets. Interactions among the materials were observed using FTIR which led to the presence of a new peak at 1736 cm-1 . The coated strawberry by high-pressure homogenizer-emulsion showed the best result suppressing microbial (2.41±0.01) and mould-yeast (2.78±0.10) growth at the end of storage compared to control which were 3.37±0.02 and 3.69±0.14 for microbial and mould-yeast count respectively.