Thermoanalytical and Kinetic study of sweeteners using thermal analysis

In recent decades, obesity and overweight have reached epidemic proportions. The World Obesity Federation predicts that the continued rise in obesity will cost about USD 4 trillion by 2035 in terms of direct healthcare costs and indirectly through job loss and premature death. In this context, sweeteners have been used in the food industry as sugar substitutes in foods and beverages, providing intense sweetness at a low caloric content. When subjected to thermal variations, the characterization of these compounds becomes relevant to achieve the best use of sweeteners. Therefore, the present work aims to study the thermal decomposition process of sugar and sweetener samples (natural and artificial) to determine their kinetic parameters and their physicochemical characterizations. Thermal characterization by TG/DTG and DSC analysis was performed on SDT Q600 model, TA Instruments, with a heating rate of 5, 10, and 20 ˚C min−1 at a temperature range from 25 to 800 °C under nitrogen atmosphere and on DSC1, Mettler Toledo, at a heating rate of 10 ˚C/min, heated from 0 to 400 ºC. Two methods (ASTM 2041 and ASTM E698) were used in the kinetic study of all samples. Samples marketed based on glycosidic natural sweeteners have more similarities regarding their thermal profiles, indicating the presence of a high erythritol or xylitol content in their composition. The thermal stability of sweeteners based on erythritol and xylitol was 170 and 200°C, respectively. In contrast, in the case of samples of artificial sweeteners (aspartame, saccharin, and sucralose), besides their a high dextrose content, their decomposition started at 65°C for all three. The results indicated that polyols influenced the decomposition kinetics of natural sweetener samples. According to thermal profiles, artificial sweeteners exhibit less resistance to degradation when subjected to heat treatments, such as in food processing. ASTM E-698 was the best method in terms of adjusting the kinetic profile of the decomposition of all sweeteners.