Cellulose/Salep-based intelligent aerogel with red grape anthocyanins: Preparation, characterization and application in beef packaging.

The purpose of this study was to prepare a porous intelligent aerogel for food packaging applications, in particular for monitoring minced beef freshness, using cellulose extracted from grape stalk, Salep as a copolymer, and red grape anthocyanins as a pH-sensitive pigment. Aerogels based on cellulose 1% (w/v) and Salep 1% (w/v) at ratios of 1:3, 3:1, and 1:1 were prepared by lyophilization. Aerogel with high porosity, low density, and higher mean pore size was chosen for preparing intelligent colorimetric aerogel (ICA) with the addition of 0.44 mg/100 mL of anthocyanins. Based on the color parameters, the stability of ICA was satisfactory when exposed to both light and dark conditions, as well as when stored at either 4 or 25 °C. Additionally, X-ray diffraction and thermogravimetric analyses indicated that an amorphous aerogel was formed, with a thermal decomposition temperature of 320 °C. The color of the ICA changed from purple on the first and 3rd days of packaging to blue-gray on the 6th day. As the spoilage process continued, the color of the indicator became dark brown. Taken together, ICA showed a quick response to minced beef spoilage with the ability to differentiate between fresh and spoiled meat during storage at 4 °C.

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/Lheadspace 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-TDEO50 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-TDEO25 MID and SC-TDEO50 MID aerogels, the initial bacterial count became undetectable, respectively. Sensory evaluations indicated that the samples treated with SC-TDEO25 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.