Effect of Coating Using Gelatin, Carboxy Methyl Cellulose and Nanoparticles on the Microbial Content of Apple Fruit Samples

Abstract

The study was conducted to evaluate the effectiveness of composite and edible coatings prepared from gelatin and carboxy methyl cellulose supported by nanoparticles of silver AgNPS and titanium TiO₂NPs in preserving apple fruit samples, conducting microbial examination for a period of 28 days and evaluating the effectiveness of nanoparticles of silver and titanium as anti-microbial agents. The results of the microbial examination for T3 and T4 treatments showed that there was no growth of bacteria and fungi during the storage period except in the fourth week, a little growth appeared. As for treatment T2, there was an escalating growth of bacteria and fungi in the second, third and fourth week, whereas the T1 Treatment showed that the growth of bacteria and fungi was appeared in the first week, and a significant increase in growth was observed as the storage period progressed until reaching the fourth week. The inhibitory activity of nanoparticles added to the composite coatings that coated with apple samples was evaluated. The results showed that the effectiveness of nanoparticles against Pseudomonas aeruginosa bacteria, as the diameter of inhibition area of silver nanoparticles was 9-26 mm while it was 11-17 mm for titanium nanoparticles. As for Escherichia coli bacteria, the results showed that the diameter of inhibition area of silver nanoparticles was 13-29 mm while it was 7-18 mm for titanium nanoparticles. Regarding of Bacillus pumilus bacteria, the results showed that the diameter of inhibition area of silver nanoparticles was 14-30 mm while it was 8-19 mm for titanium nanoparticles. It is noted from the results of the study that the nanoparticles proved to be effective against bacteria that infected apple fruit samples during the storage periods, and the silver nanoparticles were more effective compared with titanium nanoparticles.