# Late Shelf Life Saturation of Golden Delicious Apple Parameters: TSS, Weight, and Colorimetry
## 4 Discussion  
The regression equations and their corresponding coefficients of determination that perfectly represented the weight loss, color values L*, a*, b*, \(\Delta\)E, C*, and TSS are given in Table 2.  
During the storage period, apples become less acceptable with time from the aspect of consumer evaluation because of color change. The increasing tendency of a* and b* coordinates results in a color shift toward brown and yellow tones on the surface of the examined Golden Delicious specimens. [PERSON] et al., [PERSON] et al., and [PERSON] et al. have also observed similar variations in the values of L*, a*, and b* in the case of Golden Delicious apples and different varieties; however, they used image processing methodologies and other storage conditions [30,47,48]. As a novel and important finding, we can connect the significant changes in TSS in the fifth and sixth weeks, where L* and b* (yellowness) and C* values were nearing saturation. During the six weeks, the 90% saturation level is defined as the last consumption stage before the total degradation of stored fruits. Table 3 shows the percentage of examined fruits exceeding this quality level each week. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Regression Equations** & **Coefficient of Determination (R2)** & **A-Limit Parameter** & **Consumption Limit (90\% Saturation Level)** \\ \hline L* = \(-7.64\) e\({}^{-0.64\text{w}}-70.97\) & 0.840 & 70.97 (decay) & 71.35 \\ a* = \(-26.19\) e\({}^{-0.34\text{w}}+12.77\) & 0.999 & 12.77 (association) & 10.92 \\ b* = \(-26.85\) e\({}^{-1.08\text{w}}+56.34\) & 0.981 & 56.34 (association) & 55.42 \\ C* = \(-21.7\) e\({}^{-0.82\text{w}}+57.29\) & 0.970 & 57.29 (association) & 56.32 \\ \(\Delta\)E = 3.16 w + 6.44 & 0.991 & - & - \\ \hline \multicolumn{4}{c}{**Weight Loss**} \\ \hline
**Regression Equations** & **Coefficient of Determination (R2)** & **A-Limit Parameter** & **Consumption Limit (90\% Saturation Level)** \\ \hline \(\Delta\)m = 4.44 w & 0.985 & - & - \\ \hline \multicolumn{4}{c}{**Total Soluble Solids (TSS)**} \\ \hline
**Regression Equations** & **Coefficient of Determination (R2)** & **A-Limit Parameter** & **Consumption Limit (90\% Saturation Level)** \\ \hline TSS = 0.24 w + 13.44 & 0.961 & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Regression equations regarding the storage period with their corresponding coefficient of determination (R2) for measured quality parameters. By investigating the time constant (\(\tau\)) of the a* and b* values (4.216 and 2.012 weeks, respectively), it must be noted that the b* constant reaches this value significantly earlier, rendering it the dominant part of the visual degradation based on CIELAB color space. It must be pointed out that all asymptotic curves present their \(\tau\) in the investigated time region (Figure 9). Apples have a short shelf life because they are perishable foods with a rapid metabolism and respiration rate. Because losses during post-harvest handling might reach 25-28% [49], improvements in the post-harvest handling of fresh fruit are crucial for boosting food supply [50]. Apples contain a variety of nutritional benefits; however, they are destroyed during processing after harvest. Both internal and external circumstances influence losses that happen during storage. The most significant effects on apple storage effectiveness, fruit quality traits, and shelf life are caused by temperature and relative humidity during post-harvest handling activities [51]. For instance, they impact the fruit's firmness, weight loss, color, and total soluble solids. Fruit's shelf life is affected by the pectin degradation process that occurs during ripening and plays a significant part in breaking the fruit's cell walls [52]. Proper post-harvest treatment requires changing the product's natural environment to extend the product's post-harvest life. A new approach must be developed to increase the shelf life of fruit stored at room temperature and to prevent softening and senescence [53].