Characterization of Carboxymethyl Cellulose Films Incorporated with Chinese Fir Essential Oil and Their Application to Quality Improvement of Shine Muscat Grape

In this study, carboxymethyl cellulose (CMC) films containing 1%, 2%, and 3% Chinese fir essential oil (CFEO) were prepared. The mechanical, optical, physical, microstructural, thermal stability and antimicrobial properties of the films were studied. A traditional steam distillation method was applied for CFEO extraction, in which 35 volatile components were identified. The research results showed that the CMC film mixed with 1% CFEO had the highest tensile strength (TS) and elongation at break (EB), whereas the flexibility was decreased under higher concentrations of CFEO. However, the film’s degree of transparency under controlled humidity did not decrease with an increase in CFEO concentration; thus, the sensory evaluation was not adversely effect. Furthermore, the thickness and the water solubility (WS) of film increased after the addition of CFEO. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results indicated that the thermal stability of the CMC-CFEO films improved. Moreover, the composite films showed excellent inhibitory effects toward Gram-positive bacterias and Penicillium citrinum. The treatments of grapes with CMC + 1% CFEO resulted in the best properties during storage. CMC-CFEO film can be a candidate for food packaging due to its excellent performances.