# Construction of Color Prediction Model for Damaged Korla Pears during Storage Period
## 4 Prediction of Storage Quality of the Damaged Pears based on the ANFIS Model
### Model Verification  
To verify the general applicability of the optimal prediction model, a storage test of the damaged fragrant pears was carried out on 15 September 2022. The fragrant pears, which fell from the heights of 50 cm, 70 cm, and 90 cm (damaged areas of 306.54 mm\({}^{2}\), 628.43 mm\({}^{2}\), and 958.62 mm\({}^{2}\)), were chosen and stored for 0 d, 20 d, and 40 d to test the L*, a*, and b* values of the pericarp. The function trimf was applied for performing the linear fitting of the test and predicted values of the ANFIS model. The extracted results are shown in Figure 8. According to the verification, trimf showed a high prediction accuracy of the L*, a*, and b* values of the pericarp of fragrant pears (\(RMSE\) = 0.2303, \(R^{2}\) = 0.9685; \(RMSE\) = 0.7593, \(R^{2}\) = 0.9812; and \(RMSE\) = 0.5793, \(R^{2}\) = 0.9799). Hence, the L*, a*, and b* values of the pericarp of fragrant pears can be accurately predicted by inputting the degree of damages and storage time into the trained optimal model. \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Membership** & \(R^{2}\) & \(R^{2}\) & \(RMSE\) & \(RMSE\) \\
**Function** & **(Training Stage)** & **(Prediction Stage)** & **(Training Stage)** & **(Prediction Stage)** \\ \hline Tri & 0.9925 & 0.9853 & 0.3842 & 0.5894 \\ Trap & 0.9948 & 0.9750 & 0.3213 & 0.7456 \\ Gbell & 0.9951 & 0.9732 & 0.3096 & 0.7927 \\ Gauss & 0.9951 & 0.9729 & 0.3113 & 0.8036 \\ Gauss2 & 0.9949 & 0.9702 & 0.3155 & 0.8302 \\ Pi & 0.9946 & 0.9713 & 0.3251 & 0.8033 \\ Dsig & 0.9955 & 0.9790 & 0.2967 & 0.6855 \\ Psig & 0.9954 & 0.9831 & 0.3003 & 0.5980 \\ \hline \hline \end{tabular} \(R^{2}\): determination coefficient; \(RMSE\): root-mean-square error.  
\end{table} 
Table 3: \(RMSE\) and \(R^{2}\) of a* values predicted by different membership functions during the training and prediction stages. The above research results clearly proved the feasibility of the ANFIS model to predict the colors of fragment pears based on the degree of damage and storage time. However, the prediction effects among the eight membership functions were different. After performing optimal selection, trimf showed the best prediction effects of the L*, a*, and b* values of the pericarp of fragment pears. A storage test of the damaged fragment pears was also carried out in the second year to verify the optimal prediction model. According to the acquired results, the trained optimal prediction model could accurately predict the L*, a*, and b* values of the fragment pears. Based on the ANFIS model and the CIELab space color system, the variation laws of the colors of the damaged fragrant pears during the storage period were disclosed, and a method for scientific and effective color prediction was put forward. The appearance quality of fragrant pears can be assessed by the color, size, and shape. The \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Membership Function** & \(\mathbf{R^{2}}\) & \(\mathbf{R^{2}}\) & \(\mathbf{RMSE}\) & \(\mathbf{RMSE}\) \\
**(Training Stage)** & **(Prediction Stage)** & **(Training Stage)** & **(Prediction Stage)** \\ \hline Tri & 0.9951 & 0.9772 & 0.1092 & 0.2360 \\ Trap & 0.9964 & 0.9528 & 0.0929 & 0.3294 \\ Gbell & 0.9966 & 0.9727 & 0.0913 & 0.2597 \\ Gauss & 0.9961 & 0.9672 & 0.0970 & 0.2860 \\ Gauss2 & 0.9966 & 0.9627 & 0.0913 & 0.2947 \\ Pi & 0.9964 & 0.9551 & 0.0931 & 0.0920 \\ Dsig & 0.9962 & 0.9526 & 0.0965 & 0.3311 \\ Psig & 0.9961 & 0.9520 & 0.0968 & 0.3331 \\ \hline \hline \end{tabular} \(R^{2}\): determination coefficient; _RMSE_: root-mean-square error.  
\end{table} 
Table 4: _RMSE_ and \(R^{2}\) of b* values predicted by different membership functions during the training and prediction stages. Figure 8: The ANFIS model of the membership function trimf predicts the scatter plot of the L*, a*, and b* values and the actual values of the fragrant pear. shape and size are basic indexes for grading fragrant pears and have explicit execution standards.