Development of antimicrobial coating from tapioca starch incorporated with organic salt and acetic acid and its effect on cucumber quality

Abstract

The application of an antimicrobial coating is one of the alternative approaches for post-harvest treatment to extend the shelf-life of perishable vegetables and fruits. A coating was investigated developed from tapioca starch incorporated with organic salts (sodium lactate and potassium sorbate) and acetic acid for its effect on microbial inhibition on cucumbers. The results showed that the low pH of the developed coating containing acetic acid could increase the efficiency of microbial inhibition activity. The inhibition zones of each studied microorganism (Escherichia coli, Staphylococcus aureus and Aspergillus sp.) were significantly (p < 0.05) different. The antimicrobial coating of tapioca starch containing the mixture of sodium lactate potassium sorbate and acetic acid had the best antimicrobial activity as a result of synergy in the preservative combination. The surface application of the developed antimicrobial coating improved the quality of cucumber with little effect on color acceptance after storage for 3 d. Generally, the coated cucumbers received better sensory scores than control uncoated cucumbers. The coating of tapioca starch resulted in
a greater reduction in E. coli inoculation on cucumbers than for the other pathogens, indicating that this antimicrobial coating can be used for pathogen inhibition, specifically E. coli.