High performance carbohydrate-based films incorporated with thyme essential oils/zinc-based metal-organic frameworks for cheese preservation.

This study addresses the preparation and characterization of high performance multifunctional carboxymethyl cellulose (CMC) films loaded with zinc-based metal-organic frameworks (Zn-MOFs) and thyme essential oil (TEO). The effects of introducing Zn-MOFs and TEO on the morphological, mechanical, thermal, water barrier, optical, antioxidant, and antimicrobial properties of the films were systematically investigated. SEM results showed a uniform distribution of Zn-MOFs in the polymer matrix, which improved the tensile strength, water barrier, thermal stability, UV shielding, antimicrobial and antioxidant properties of films. The incorporation of 1, 2, and 3 % Zn-MOFs and 500 mL TEO into CMC-based films resulted in a significant increase in antioxidant activity by 38, 43, and 56 %, respectively. CMC-based films loaded with Zn-MOFs and TEO showed excellent antifungal activity against Penicillium digitatum and Aspergillus niger. These superior antioxidant and antimicrobial properties can be attributed to the high absorption effect of Zn-MOFs due to their high porosity and maintaining a high content of bioactive compounds in the film matrix. The films produced were proven to play a crucial role in controlling microbial growth, reducing weight loss and lowering the pH of soft cheese and ultimately extending its shelf life.