Submitted to: Coatings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2018
Publication Date: 1/20/2018
Citation: Li, R., Jin, Z.T., Liu, Z., Liu, L.S. 2018. Antimicrobial double-layer coating prepared from pure or doped-titanium dioxide and binders. Coatings. 8(1):41-51.
Interpretive Summary: As the consumption of fresh fruits and raw vegetables increases in many countries, the risk of foodborne illnesses also increases. Containers used for the collection and storage of fruits and vegetables can be contaminated by decayed fruits and vegetables and in turn, the microbe- carrying containers could transmit their microflora and pathogens, if any, to healthy fruits and vegetable, as well as to consumers. Titanium dioxide is a substance that can kill bacteria. In this study, ARS researchers developed a formulation of zein, a protein from corn, and titanium dioxide that can be coated on the surfaces of containers, such as cardboard, that can come into contact with fruits and vegetables. Experiments showed that the growth of E coli on the formulation was suppressed, suggesting the zein and titanium dioxide formulation can reduce the risk of contamination and the chance of foodborne diseases.
Technical Abstract: Fruit and vegetable containers with microbe-free surfaces can be made by coating them with titanium dioxide incorporated in substances such as zein, paint, or other wear resistant polymers. The comparison of E. coli cultured on TiO2/zein films with bilayered zein and TiO2/zein films indicates that the antibacterial activity of the films is determined by the amount of titanium dioxide nanoparticles on the surfaces of coatings. In addition, nonmetal (C, N, B, F) doped-TiO2 powders possess higher visible light-responsive antibacterial effects than non-modified titanium dioxide nanoparticles. Containers with microbe-free surfaces may prevent cross-contamination from infected workers or spoiled/decayed/contaminated fruits or vegetable and thus are expected to be able to reduce the risk from microbiological contamination of fruits and vegetables during harvest, postharvest storage or transportation.