|WU, YUNPENG - University Of Maryland|
|Luo, Yaguang - Sunny|
|ZHANG, BOCEN - Oak Ridge Institute For Science And Education (ORISE)|
|WANG, QIN - University Of Maryland|
Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2018
Publication Date: 11/7/2018
Citation: Wu, Y., Luo, Y., Zhang, B., Zhou, B., Wang, Q. 2018. Porous metal-organic framework (MOF) carrier for incorporation of volatile antimicrobial essential oil. Food Control. 98:174-178.
Interpretive Summary: Increased demand for foods that are safe, high quality, and have long shelf life has motivated strong interest in developing food preservatives from natural antimicrobials. Thymol, an essential oil found in thyme and oregano has been demonstrated to have antifungal, antibacterial, insecticidal and antioxidant properties. However, the application of thymol as a food preservative is limited by two factors: undesirable aroma and low solubility in water. Both of these limitations can be overcome by encapsulating thymol in porous material. Since metal organic frameworks (MOFs) can be produced under relatively mild conditions they are advantageous compared to other porous materials for this application. In this study a MOF was synthesized and loaded with thymol. The structure of the porous crystal MOF was confirmed using scanning electron microscopy and X-ray diffraction and antibacterial activity of the thymol loaded MOF against a food borne pathogen was assessed. The encapsulated thymol was demonstrated to have strong antibacterial activity with greater stability than free thymol suggesting that MOF could be used to improve food safety while maintaining quality. The research findings are beneficial to fresh produce industry.
Technical Abstract: Zinc metal-organic framework (Zn@MOF) in this study was synthesized with zinc nitrate hexahydrate and 2-aminoterephthalic acid in N, N-dimethylformamide (DMF). Thymol was then loaded into the Zn@MOF at a loading rate of 3.96% as measured by thermogravimetric analysis. The crystal structure of porous MOF was confirmed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Antibacterial activity of thymol loaded Zn@MOF against E. coli O157:H7 was assessed using two methods (i.e. broth microdilution and disk diffusion). An E. coli O157:H7 reduction of 4.4 log CFU/mL was achieved at a thymol to broth ratio of 0.04g/100g. An inhibition area of 223.73 mm2 was observed after 12 hours of inhibition. This research demonstrates that Zn@MOF loaded with the essential oil thymol is an effective antimicrobial and may have potential to improve food safety while maintaining quality.