## 3 Results and Discussion
### Physicochemical Parameters of Tomato Flesl During Storage
Furthermore, the TSS results fully confirm the results of ATR-FTIR spectroscopy. Tomato firmness is a crucial quality trait that affects consumer acceptance and is influenced by ripening at the harvest stage, storage temperature and duration, transpiration-induced moisture loss, and enzymatic changes [63]. At the fourteenth day, the firmness, which represents the greatest force needed to chew the tomato flesh, showed a substantial (\(p\) < 0.05) decrease before stabilizing until the end of storage. The degradation of polysaccharides in the fruit flesh and the rise in moisture content may be the causes of tomato fruit softening during storage [66]. Additionally, ethylene is a critical factor in the ripening and ageing of tomato, regulating enzyme activity and causing several physiological and biochemical changes, including aroma generation and softening [64, 67]. [PERSON] et al. (2010) claim that the increased sensitivity of the fruit during storage is caused by the metabolism of cell wall carbohydrates, which is responsible for the breakdown and weakening of the cell walls and the firmness decrease [68]. The color parameter h angle of the tomato flesh samples showed an increase (\(p\) < 0.05) from day 17 to 24. All the previous days, the changes that occurred were not statistically significant. Based on the results of our research team's previous study on cucumbers [35], it appears that variations in moisture content caused corresponding variations in hue angle values. Moreover, similarly to our findings, [PERSON] et al. (2015) pinpointed that, in comparison to fruits kept at chilling temperature (4 \({}^{\circ}\)C), those held at higher temperatures maintained their distinctive hue [45]. Many factors, including maturity stage, variety, seasonal conditions, agricultural practices, light, temperature, geographical origin, and post-harvest treatment, have a notable impact on total phenolic content [68, 69, 70]. The TPC, antioxidant, and antiradical activity of the extracts from the tomato flesh samples, as well as their changes during storage, are listed in Table 3. The total phenolic content results of this study are in line with those of other researchers [68, 71, 72]. The predominant phenolic compounds in tomatoes are flavonoids and hydroxycinnamic acids, especially caffeic and chlorogenic acids [5, 31, 73, 74]. On days 10 and 14, the TPC of tomato pulp increased gradually and significantly (\(p\) < 0.05), and from day 17 it decreased (\(p\) < 0.05) until the end of storage. On days 14 and 17, antiradical activity increased (\(p\) < 0.05) and then decreased on day 24. Until the tenth day,the antioxidant activity fluctuated negligibly. It then decreased (_p_ < 0.05) on day 14, and a relatively constant level was maintained until the end of the storage period. A strong positive correlation (R\({}^{2}\) = 0.8188, \(p\) < 0.001) was found among TPC and antiradical activity, while TPC and antioxidant activity and antiradical and antioxidant activity also showed high correlations (R\({}^{2}\) = 0.7355, \(p\) < 0.001 and R\({}^{2}\) = 0.7406, \(p\) < 0.001, respectively). The increase in total phenolic constituents during storage, namely on the 14 th day, is probably due to the hydrolysis of their glycosidic derivatives and the production of more active aglycon substances [35]. Moreover, the autoxidation reaction of phenolic compounds by oxygen may possibly be the cause of the reduction in phenolic compounds after a period of storage [44]. It has also been reported that the increase in TPC during storage might be attributed to the activation of their biosynthesis by enzymes, as well as the inhibition of their oxidation [75;76]. This is probably associated with variations in storage conditions, such as different temperature and moisture levels, post-harvest irradiation treatment, and the use of controlled or modified atmosphere packaging. To a further step, the tomato samples were grouped according to the different storage days using moisture content, brix, and TPC (mg/kg), achieving a discrimination accuracy of 93.0%.