Essential oil-loaded starch/cellulose aerogel: Preparation, characterization and application in cheese packaging

Novel antimicrobial emitting aerogels based on starch/cellulose/Thymus daenensis Celak essential oil (SC-TDEO) were developed and optimized for antimicrobial packaging of Koopeh cheese. An aerogel formulation containing cellulose (1 %; extracted from sunflower stalks) and starch (5 %) in a 1:1 ratio was selected for in vitro antimicrobial assay and subsequent cheese application. The minimum inhibitory dose (MID) of TDEO in the vapor phase against Escherichia coli O157:H7 was determined by loading various concentrations of TDEO onto the aerogel, and an MID of 256 μL/L_headspace was recorded. Aerogels containing TDEO at 25 × MID and 50 × MID were then developed and used for cheese packaging. During a 21-day storage period, cheeses treated with SC-TDEO_{50 MID} aerogel exhibited a significant 3-log reduction in psychrophile counts and a 1-log reduction in yeast-mold counts. Moreover, significant changes in the population of E. coli O157:H7 were observed in cheese samples. After 7 and 14 days of storage with SC-TDEO_{25 MID} and SC-TDEO_{50 MID} aerogels, the initial bacterial count became undetectable, respectively. Sensory evaluations indicated that the samples treated with SC-TDEO_{25 MID} and SC-TDEO₅₀ aerogels received higher scores compared to the control group. These findings demonstrate the potential of the fabricated aerogel to develop antimicrobial packaging suitable for cheese applications.