## 3 Results and Discussion  
### Effect of Exogenous Melatonin on Sun-Dried Apricot Color  
Our study investigated the effects of exogenous melatonin application on the color parameters of sun-dried apricots and the results revealed significant changes in L* (lightness), a* (redness), and b* (yellowness) values across different melatonin concentrations. Melatonin treatments generally resulted in higher L* values compared to the control, with 100 uM-MT (28.74) and 1000 uM-MT (28.84) treatments showing statistically significant increases in lightness (\(p<0.05\)). All melatonin treatments increased the a* value, indicating enhanced redness, with the 100 uM-MT treatment yielding the highest a* value (6.67). Similarly, b* values were significantly higher in melatonin-treated samples, particularly at 100 uM-MT (11.33) and 1000 uM-MT (11.15) concentrations, suggesting enhanced yellowness (Table 1). These findings demonstrate that melatonin application has a protective effect against color darkening during the drying process. The increase in L* values align with the previous research by [PERSON] et al. (2018), who reported similar effects in fresh-cut products. However, our L* values were slightly lower than those reported for untreated sun-dried Hachhaliloglu apricots in previous studies, which may be attributed to variations in the drying conditions or the initial fruit characteristics. This discrepancy warrants further investigation to optimize the drying process for color retention. On the other hand, the observed increases in both a* and b* values suggest that melatonin not only prevents darkening but also enhances the vibrant colors of the apricots. This color preservation effect could be attributed to melatonin's antioxidant properties, potentially inhibiting the degradation of carotenoids and other pigments responsible for the characteristic color of apricots. Our results are consistent with [PERSON]'s [1] findings that decreased L* and b* values indicate color darkening, as evidenced by the lower values in our control group. Interestingly, our data suggest a concentration-dependent effect of melatonin on color parameters, with 100 \(\upmu\)M-MT generally showing the most pronounced effects. The lack of further improvements with the 1000 \(\upmu\)M-MT treatment indicates a possible saturation point in melatonin's protective effects. This finding has important implications for optimizing melatonin application in commercial drying processes, suggesting there is an optimal concentration that balances color preservation with treatment costs. While our study clearly demonstrates the positive effects of melatonin on color retention in sun-dried apricots, the underlying mechanisms warrant further investigation. Potential explanations for melatonin's effects include its antioxidant activity, enzyme inhibition in browning reactions, and membrane stabilization. Future studies should, in this regard, focus on elucidating these mechanisms through biochemical analyses and exploring the impact of these color changes on consumer perception through sensory evaluations. In general, our results indicate that exogenous melatonin application is a promising approach for preserving the desirable color characteristics of sun-dried apricots. The treatment not only prevents excessive darkening but also enhances the vibrant red and yellow hues that are attractive to consumers. These findings have significant implications for the dried fruit industry, potentially leading to improved product quality and consumer acceptance.