Moreschi Silvânia R M, Petenate Ademir J, Meireles M Angela A
LASEFI-DEA/FEA (College of Food Engineering), UNICAMP (State University of Campinas), Caixa Postal 6121, 13083-970 Campinas, SP, Brazil.
J Agric Food Chem. 2004 Mar 24;52(6):1753-8. doi: 10.1021/jf035347a.
Ginger bagasse from supercritical extraction was hydrolyzed using subcritical water and CO(2) to produce reducing sugars and other low molecular mass substances. Response surface methodology was used to find the best hydrolysis conditions; the degree of hydrolysis and the yield were the two response variables selected for maximization. The kinetic studies of the hydrolysis were performed at 150 bar and temperatures of 176, 188, and 200 degrees C. The higher degree of hydrolysis (97.1% after 15 min of reaction) and higher reducing sugars yield (18.1% after 11 min of reaction) were established for the higher process temperature (200 degrees C). Different mixtures of oligosaccharides with different molecular mass distributions were obtained, depending on the temperature and on the reaction time. The ginger bagasse hydrolysis was treated as a heterogeneous reaction with a first-order global chemical kinetic, in relation to the starch concentration, which resulted in an activation energy of 180.2 kJ/mol and a preexponential factor of 5.79 x 10(17)/s.
采用亚临界水和二氧化碳对超临界萃取得到的姜渣进行水解，以生产还原糖和其他低分子量物质。利用响应面法寻找最佳水解条件；水解度和产率是选择用于最大化的两个响应变量。水解动力学研究在150巴压力以及176、188和200℃的温度下进行。对于较高的工艺温度（200℃），确定了较高的水解度（反应15分钟后为97.1%）和较高的还原糖产率（反应11分钟后为18.1%）。根据温度和反应时间，获得了具有不同分子量分布的低聚糖不同混合物。就淀粉浓度而言，姜渣水解被视为具有一级整体化学动力学的非均相反应，其活化能为180.2 kJ/mol，指前因子为5.79×10¹⁷/s。
