## 3 Results
### DSC Study of Cocoa Butter Extracted from Untroasted and Roasted Cocoa Beans Criollo and Forastero
Using the information presented in Table 3 and the Equations (2)-(4):  
\[\text{E}_{\text{a}}=-2.19\;\text{R}\;\frac{\text{d}\;\log\;\beta}{\text{d}(1/ \text{T})} \tag{2}\]  
\[Z=\frac{\beta\text{E}_{\text{a}}\;\frac{\text{E}_{\text{a}}}{\text{R}^{2}}}{ \text{R}^{2}} \tag{3}\]  
\[\text{k}=\text{Z}\;\text{exp}\;(-\;\text{E}_{\text{a}}/\text{RT}) \tag{4}\]  
where R is a gas constant, \(\beta\) is the heating rate (\({}^{\circ}\)C/min) and T is temperature (K), the kinetic parameters were calculated and the values were presented in Table 4.  
For the fat extracted from Criollo species, the values of activation energy reached 106.75 and 119.14 kJ mol\({}^{-1}\), for unroasted and roasted cocoa beans, respectively. For the fat extracted from Forastero species, the values of activation energy were significantly higher, 142.57 and 163.37 kJ mol\({}^{-1}\), for unroasted and roasted cocoa beans respectively. All the obtained values of activation energy are very high in comparison to other fats [18]. The thermal properties of fats are related to the fatty acid composition. The high values of E\({}_{\text{a}}\) for cocoa butter can be due to the dominant contribution of saturated fatty acids. A similar correlation was observed by [PERSON] et al. [39] who analysed edible oils with the use of UV-Vis and IR spectroscopy. The activation energy of the oxidation process for the fat from unroasted Criollo beans obtained in this article is comparable with the data in the literature [40]. However, the activation energy should not be used as the \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameter** & **Forastero Unroasted** & **Forastero Roasted** & **Criollo Unroasted** & **Criollo Roasted** \\ \hline a & 7023.8 & 6466.8 & 5863.6 & 6544.0 \\ b & 15.608 & 14.538 & 13.191 & 14.374 \\ R\({}^{2}\) & 0.994 & 0.994 & 0.996 & 0.988 \\ E\({}_{\text{a}}\)/kyl mol\({}^{-1}\) & 127.87 & 117.73 & 106.75 & 119.14 \\ log Z & 13.74 & 12.70 & 11.40 & 12.53 \\ Z/min\({}^{-1}\) & 5.45 \(\times\) 10\({}^{13}\) & 5.03 \(\times\) 10\({}^{12}\) & 2.50 \(\times\) 10\({}^{11}\) & 3.41 \(\times\) 10\({}^{12}\) \\ Melting point, T\({}_{1}\)/\({}^{\circ}\)C & 9.12 \(\pm\) 0.01 \({}^{\text{A}}\) & 15.90 \(\pm\) 0.03 \({}^{\text{B}}\) & 15.58 \(\pm\) 0.16 \({}^{\text{a}}\) & 15.92 \(\pm\) 0.09 \({}^{\text{a}}\) \\ Melting point, T\({}_{2}\)/\({}^{\circ}\)C & 18.84 \(\pm\) 0.06 \({}^{\text{C}}\) & 20.66 \(\pm\) 0.19 \({}^{\text{C}}\) & 20.66 \(\pm\) 0.01 \({}^{\text{b}}\) & 19.67 \(\pm\) 0.04 \({}^{\text{b}}\) \\ \hline \hline \end{tabular}  
* Values represent means \(\pm\) standard deviations. Means with equal superscripts in each group for the same column are not significantly different (\(p\) > 0.05) by [PERSON]’s test. The different lower-case letters (a–b) indicate significantly different values for Forastero beans (\(p\) < 0.05). The different capital letters (A–C) indicate significantly different values for Criollo beans (\(p\) < 0.05).  
\end{table} 
Table 4: Regression analysis of the DSC data, activation energies (E\({}_{\text{a}}\)), pre-exponential factors (Z) and melting points (\({}^{\circ}\)C). only parameter to assess the oxidation stability of different lipid systems. The values of activation energy of oxidation presented in Table 4 for roasted and unroasted cocoa beans of two species agreed with previously confirmed stability of fat from roasted Criollo species over unroasted ones and unroasted Forastero species over roasted ones. In both Forastero cocoa beans unroasted and roasted, saturated fatty acids are predominantly esterified in sn-1, 3 TAGs positions but in roasted Forastero beans, we can find a lower amount of C16:0 and C18:0 in external positions of TAGs in comparison to unroasted Forastero beans where the amounts of these acids were higher in external positions. That distribution of saturated fatty acids can influence physical properties of cocoa butter which is connected with melting characteristics.