# Mathematical Description of Changes of Dried Apple Characteristics during Their Rehydration
## 3 Results and Discussion  
The summary results of statistical analyses on the modelling of mass, volume, and dry matter changes during the rehydration of dried apples are given in Table 2. As can be concluded from the statistical analysis results, all considered models may be assumed to characterise mass gain during the rehydration of dried apples. The R\({}^{2}\) values varied between 0.9541 and 0.9981, and only the [PERSON] ([PERSON]) and Henderson and Pabis modelswere within 0.8840 to 0.9549. On the other hand, however, the SSE values for two mentioned models fell within the range of 0.0660 to 0.2210, and the RMSE ones varied between 0.0580 and 0.1064, whereas for the [PERSON], Pilosof-Bouquet-Batholomai, and Singh and Kulshrestha models, the discussed values were between 0.0488 and 0.6592 for SSE and 0.0570 and 0.1910 for RMSE. Taking into account, however, the values of all considered statistical test methods (SSE, R\({}^{2}\), adjusted R\({}^{2}\), and RMSE), it can be stated that the Page and the modified Page models can be considered to be the most appropriate. Their sum squared error varied between 0.0027 and 0.0843, the coefficient of determination ranged from 0.9541 to 0.9981, the adjusted coefficient of determination changed from 0.9520 to 0.9980, and the root mean square error fell within the range of 0.0143 to 0.0619. As for as the changes of dried apple volume during the rehydration, it was found that all models except the [PERSON] ([PERSON]) and Henderson and Pabis models described the volume increase quite satisfactorily. The R\({}^{2}\) values were between 0.8452 and 0.9983, and only two mentioned models varied between 0.8071 and 0.9538. Taking into account all considered statistical test methods, it can be assumed that the Page model and the modified Page model characterised the volume increase during dried apple rehydration in the most acceptable way. The values of the considered statistical test methods for both models were as follows: SSE = 0.0022-0.2092, R\({}^{2}\) = 0.8686-0.9983, adjusted R\({}^{2}\) = 0.8598-0.9982, RMSE = 0.0142-0.1130. It turned out from the statistical analysis results that all models except the [PERSON] (Newton) model fitted well to the experimental data of dry matter loss during the rehydration of dried apples. The values of determination coefficient fell within the range of 0.8590 to 0.9976 for models (1)-(3) and (5)-(7), whereas the [PERSON] (Newton) model varied between 0.8398 and 0.9672. Taking into consideration, however, all applied statistical test methods, the Peleg, Pilosof-Bouquet-Batholomai, and Singh and Kulshrestha models can be selected as the most suitable models to represent the dry matter loss during the rehydration of dried apples. The sum squared error for three mentioned models ranged from 0.0018 to 0.0385, the coefficient of determination varied between 0.9329 and 0.9976, the adjusted coefficient of determination changed from 0.92299 to 0.9974, and the root mean square error fell within the range of 0.016 to 0.0454. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Model No.