# The Plasma Ozonizer System for Mangosteen Storage Container to Preserve the Quality of Mangosteen
## 3 Results
### Assessment of the Quality and Sensory Evaluation  
Results of the study from the previous topic indicate that 2 L/min was the optimal oxygen flow rate. Consequently, the term \"ozone\" in studies on the impact of ozone on prolonging mangosteen's shelf life refers to the fruits treated with ozone generated by this condition. Fruit color, firmness, weight loss percentage, and sensory evaluation were used as the criteria for quality assessment in post-treatment studies.  
Fruit color was measured as L*, a*, and b* values. These three coordinates represent the lightness of the color, its position between red/magenta and green, and its position between yellow and blue, respectively. The L*, a*, and b* values for all storage days of all treatments are shown in Figure 5a-c.  
Figure 5: This showed that the treatments affected the quality of the color, namely the value of L*, a* and b* of mangosteen fruit during storage, respectively.  
The color was light greenish yellow with 5-50% scattered pink spots when harvested at stage 1. The L* value in the control treatment at 15 \({}^{\circ}\)C quickly decreased after the fifth day of storage. The color turned dark purple after ten days. It was a dark purple by day 19, and the value had slightly changed. On the same storage day, the a* value demonstrates opposite characteristics, and the b* value will continuously decrease. Furthermore, Figure 5a-c demonstrates that these transformations happened more slowly in the treatment fruit.  
When the fruit color developed uniformly dark purple, the storage life ended. After the fruit color developed to uniformly dark purple was evaluated the quality in terms of their weight loss percentage, pericarp firmness, and sensory evaluation in terms of fruit pericarp color, flavor, and overall acceptability by ten trained panelists using a five-point scale from 5 (extreme liking) to 1 (extreme disliking), as shown in the following Table 1. Fruit that was harvested at stage 1 continued storage development to stage 6 under the control treatment in 19 days whereas fruit under the ozone treatment completed color development in 28 days.  
Fruits under the ozone treatment lost significantly less weight than fruits in the control treatment. By the end of the storage day for each treatment, the weight loss from the ozone treatment was 1.24%, significantly less and different (_p_ < 0.05) than the weight loss from the control treatment, which was 4.58%. While the pericarp firmness in the control fruit was approximately 17.45 N, significantly different (_p_ < 0.05) than the firmness value in the fruit that had received ozone treatment was about 28.63 N.  
Furthermore, Table 1 displays the results of the sensory tests. The sensory score of the fruit treated with ozone was higher and significantly different (_p_ < 0.05) from that of the control fruit. Fruit pericarp color, flavor, and overall acceptance were 3.64, 3.37, and 3.62 for the control treatment, and 4.72, 4.58, and 4.65 for the ozone treatment, respectively. At the end of storage, the appearance of control and ozone-treated mangosteen, the fruit peel color of both treatments developed to a uniform dark purple. Nevertheless, it was observed that the calyx of the control treatment set turned brown, but the ozone treatment preserved the freshness of the green calyx.