*3.4. Quality Analysis of Cherry Tomatoes*

3.4.1. Internal Atmosphere Composition

The gas permeability of the film is an important factor affecting the exchange of internal and external gases. The respiration of fruits and vegetable produces CO2 and consumes O2 in the microenvironment of package. On account of relative gas pressure differences between the inside and outside of the package, CO2 gets released to the atmosphere and O2 will enter the package. Thus, films with appropriate gas permeability to O2 and CO2 can significantly prolong the shelf life of fruit and vegetables. As shown in Figure 5a, the CO2 concentration inside the package maintained an equilibrium concentration of 4–7%, while the corresponding O2 concentration was 4–6% (Figure 5b). The difference in gas concentration in the final package was not obvious, although the loading of AGO was different, which may be caused by the originally low loading of AGO. However, the higher the loading of AGO, the lower the final equilibrium concentration of CO2 in the package. Accordingly, it was speculated herein that the modified atmosphere packaging with an AGO loading of 0.5–0.9% (*w/w*) is more suitable for preservation.

**Figure 5.** Internal atmosphere composition under AGO/SPEEK films packaging in the storage of cherry tomatoes. (**a**) CO2, (**b**) O2.

#### 3.4.2. Sensory Properties

The sensory properties such as color, hardness, and overall acceptability of cherry tomatoes packaged with AGO/SPEEK films were determined during storage, and their results are presented in Figure 6. In general, cherry tomatoes were ranked almost similar with respect to their sensory properties; however, packaged cherry tomatoes had better peel color when the AGO content in the package was higher. Interestingly, cherry tomatoes packaged with 0.9% (*w/w*) AGO/SPEEK films maintained acceptable sensory scores even after 30 days of storage, showing the potential of AGO/SPEEK film in extending the shelf life.

**Figure 6.** Sensory evaluation scores of AGO/SPEEK films in the storage of cherry tomatoes (a 5-point scale: 1 means unacceptable, 2 means barely accepted, 3 means general, 4 means good, and 5 means excellent).
