Ostojić Sanja, Micić Darko, Dukić Josipa, Sabljak Iva, Akyüz Ayça, Ersus Seda, Režek Jambrak Anet
Institute of General and Physical Chemistry, Studentski Trg 12/V, 11000 Belgrade, Serbia.
Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierotti Street 6, 10000 Zagreb, Croatia.
Foods. 2025 Jan 17;14(2):307. doi: 10.3390/foods14020307.
Thermal characteristics of dried sugar beet pulp, leaves and leaf fractions obtained after extraction: fibrous leaf pulp and fibre rich leaf fraction, were investigated by differential scanning calorimetry and thermogravimetry. The sugar beet samples showed a similar thermal behaviour associated with a similar composition. Two endotherms are found on the differential scanning calorimetry curves. First one in the temperature range 31-153 °C and the second from 150-160 °C. Thermal degradation kinetics was studied by thermogravimetric analysis. Four degradation stages were observed within the temperature range 25-700 °C. The kinetic parameters of the degradation, obtained by Ortega and Friedman non-isothermal isoconversional methods did not significantly differ between models: Ea-activation energy at a conversion degree 0.1-0.9 ranged 50-200 kJ/mol; lnA- the natural logarithm of the pre-exponential factor 8-48; kp-thermal degradation rate constant at a conversion extent of 0.5 ranged of 0.19-2.55 min. Constant rate of degradation is highest for the sugar beet leaves kp (2.58-2.55 min), and kp (70.1-70.4 min). The results obtained are valuable for sugar beet leaf industrial processing. A positive environmental impact is achieved by transforming the waste into high-value food additives.
对提取后得到的干甜菜 pulp、叶子及叶子组分（纤维状叶 pulp 和富含纤维的叶组分）的热特性进行了差示扫描量热法和热重分析法研究。甜菜样品表现出与相似组成相关的相似热行为。在差示扫描量热曲线中发现两个吸热峰。第一个在 31 - 153℃温度范围内，第二个在 150 - 160℃。通过热重分析研究了热降解动力学。在 25 - 700℃温度范围内观察到四个降解阶段。通过奥尔特加和弗里德曼非等温等转化率方法获得的降解动力学参数在模型之间没有显著差异：在转化率 0.1 - 0.9 时的活化能 Ea 范围为 50 - 200 kJ/mol；指前因子的自然对数 lnA 为 8 - 48；在转化率为 0.5 时的热降解速率常数 kp 范围为 0.19 - 2.55 min。甜菜叶的降解恒定速率最高，kp 为（2.58 - 2.55 min），以及 kp 为（70.1 - 70.4 min）。所得结果对甜菜叶的工业加工具有重要价值。通过将废物转化为高价值食品添加剂实现了积极的环境影响。
