Biosynthesis of Edible Films to Control Food Born-Pathogens and Spoilage Microorganisms of Solanaceous Crops

Abstract

The present study aimed to evaluate the effect of Gum Arabic, gelatin and agar films with different component in the treatments of potato tubers, tomato and green bell pepper fruits as edible coatings and their effect on microbial load and physical characters at cold and ambient storage temperatures to extend the crops' shelf life for export and local markets. Fifteen groups of tested crops' samples (potato tubers, tomato and green bell pepper fruits) were collected from local market, Cairo, Egypt. The first group was left to spoil for isolating the spoiled microorganisms that affect these crops. The antimicrobial activity of EDTA, L. paracasei and Gum Arabic was detected. Mature crops' samples that are similar in shape, color, size and free of any defect were washed with tap water then dried at ambient air conditions before coating. These samples were divided into 14 groups; one group was uncoated as control samples, one coated with wax and the others coated with different edible films i.e., GA, gelatin and agar in addition to their treatments. Half of these groups stored at cold and the other stored at ambient temperature. During storage period, physical (pH, weight loss) and TSS for the best film) and microbial analysis (total bacterial, Enterobacteriaceae, mold and yeast count) were conducted at time intervals (3,5,7,10,15,20,25,30 and 35 days) of storage period. Scanning Electron Microscopy (SEM) and the Cytotoxicity test was conducted for the best film i.e., GA/EDTA/L. paracasei supernatant edible film. 1- The isolation of spoiled microorganisms revealed five gram negative (G-ve) bacterial isolates include, E. coli, Salmonella typhi, pseudomonas fluorescenc, Ralstonia solanacearum and Citrobacter