## 3 Results
### DSC Study of Cocoa Butter Extracted from Untroasted and Roasted Cocoa Beans Criollo and Forastero
Figure 6: TGA and DTG curves of fats extracted from cocoa beans Forastero (Ecuador), unroasted (**a**) in nitrogen (**a**’) in oxygen and roasted (**b**) in nitrogen and (**b**’) in oxygen. In Figure 4, the TGA and DTG curves of unroasted and roasted cocoa beans Forastero (Ecuador) in nitrogen (a, b) and oxygen (a', b') were presented. For unroasted and roasted cocoa beans Forastero, three main mass losses were detected in the nitrogen atmosphere. First mass loss of 21.89 and 20.59% at temperature range 120-325 \({}^{\circ}\)C for both (unroasted and roasted) cocoa beans Forastero was observed (Figure 4a,b). At this temperature decomposition of saccharides occurs. The saccharides are the components of cocoa beans Forastero and Criollo. The second mass loss of cocoa beans Forastero of 58.33 and 60.29% (unroasted and roasted) and the third mass change of 14.70 and 11.55% (unroasted and roasted) were at similar levels but the temperature range was different. The second mass loss for unroasted cocoa beans Forastero was observed in the temperature range from 325 to 475 \({}^{\circ}\)C, whereas in the case of roasted cocoa beans--325-525 \({}^{\circ}\)C. The maximum temperature of DTG curves for unroasted and roasted cocoa beans occurred at 390 and 397 \({}^{\circ}\)C, respectively. The third mass loss, at temperature range 475-625 \({}^{\circ}\)C (unroasted cocoa beans) and 525-625 \({}^{\circ}\)C (roasted cocoa beans) was an indication of inorganic residues in analysed cocoa beans. The courses of TGA and DTG curves indicated that cocoa bean samples of Criollo cocoa beans did not fully decompose. In Figure 4a',b', TGA/DTG diagrams for cocoa beans Forastero unroasted and roasted in oxygen were presented. Two main mass losses on TGA/DTG diagrams for unroasted and roasted cocoa beans Forastero were observed. The first and second mass loss indicated the decomposition of saccharides and oxidation of cocoa butter in the cocoa beans Forastero samples. The first stage ranged from 175 to 275 \({}^{\circ}\)C, second--from 275 to 450 \({}^{\circ}\)C and third from 450 to 700 \({}^{\circ}\)C (Figure 4a',b'). The maximum temperatures for unroasted Forastero cocoa beans were observed at 248 and 420 \({}^{\circ}\)C. The maximum peaks on DTG curves for roasted Forastero cocoa beans were obtained at 250 and 395 \({}^{\circ}\)C. The last mass loss finished with the total decomposition of cocoa beans in the oxygen atmosphere. The differences between the maximum temperature of second mass change stages for unroasted and roasted Forastero cocoa beans could have been caused by variation of distribution on sn-1 and sn-3 positions in triacylglycerols of palmitic and stearic fatty acids (Table 2). Saturated fatty acids are characterized by the high temperature of combustion and long induction time of oxidation [41] which can be an explanation of better stability of cocoa butter. Oxidation of lipids is affected by processing and storage conditions, the content of unsaturated fatty acids and their distribution in triacylglycerol molecule and the presence of antioxidants or prooxidants [42]. The thermogravimetric behaviours of the cocoa butter extracted from Criollo (Peru) and Forastero (Ecuador) species are shown in Figures 5 and 6 (TGA/DTG curves). The TGA/DTG curves of cocoa butter extracted from unroasted and roasted cocoa beans Criollo in nitrogen are characterized by one step of decomposition (Figure 5a,b). The maximum temperature on DTG curves for unroasted and roasted cocoa beans Criollo were obtained at 416 and 418 \({}^{\circ}\)C, respectively. The thermal decomposition of fat extracted from both types of Criollo cocoa beans was detected in the temperature range from 300 to 480 \({}^{\circ}\)C. There are no differences of values between mass loss for cocoa butter extracted from unroasted and roasted cocoa beans Criollo. The values of mass loss of 98.45 and 98.33% for unroasted and roasted cocoa beans Criollo, respectively, were obtained.