贡柑皮热风干燥动力学及抗氧化活性变化研究

Study on kinetics and antioxidant activity of hot air drying of Tribute orange peel

中文关键词:  贡柑皮  热风干燥  干燥动力学  活化能  抗氧化能力

英文关键词:Tribute orange peel  hot air drying  drying kinetics  activation energy  antioxidant capacity

中文摘要:

      目的 探究贡柑副产物果皮的热风干燥过程(50、60、70、80 ℃)中水分的干燥动力学变化规律及对应干燥温度下的抗氧化活性变化。方法 借助Fick定律和Arrhenius方程对贡柑皮干燥过程水分的扩散情况、干燥活化能进行研究, 解析了干燥过程贡柑皮的抗氧化活性变化。结果 随着干燥的进行, 贡柑皮的水分逐渐减少, 且干燥温度越高, 所需的干燥时间越短。贡柑皮水分干燥动力学规律遵循Page模型。水分扩散系数随温度的升高而增大, 贡柑皮干燥所需的活化能为18.0374 kJ/mol。贡柑皮的1,1-二苯基-2-三硝基苯肼(2,2-diphenyl-1-picrylhydrazyl, DPPH)自由基抑制率随干燥温度升高而逐步降低, 最优值在50 ℃, 为49.73%; 2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate), ABTS]阳离子自由基、超氧化物歧化酶(superoxide dismutase, SOD)抑制率以及总抗氧化能力(total antioxidant capacity, T-AOC)随干燥温度的升高先上升后降低, 均在60 ℃时最优, 分别为51.95%、61.99%和5.13 mmol/g, 但贡柑皮在4个热风干燥温度下羟自由基清除率并无显著性差异。结论 在恒定的风速下, 综合效能、干燥时间和抗氧化能力, 确定60 ℃为最佳的热风干燥温度, 为“岭南佳果”贡柑的高效利用和产业链持续发展提供了理论支持。

英文摘要:

      Objective To study the changes of drying kinetics of water and antioxidant activity at 50, 60, 70, 80 ℃ during hot air drying of the byproduct peel of Tribute orange. Methods Fick’s law and Arrhenius equation were used to study the water diffusion and activation energy of Tribute orange peel during drying, and the change of antioxidant activity of Tribute peel during drying was analyzed. Results With the drying process, the moisture in the peel decreased gradually, and the higher the drying temperature, the shorter the drying time. The water drying kinetics of Tribute orange peel followed Page model. The moisture diffusion coefficient increased with the increase of temperature, and the activation energy required for drying of Tribute orange peel was 18.0374 kJ/mol. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical inhibition rate decreased with increasing drying temperature, and the optimal value was 50 ℃, which was 49.73%. The inhibition rates of 2,2’-azino-bis(3-ethylbenzothiazoline-6- sulfonate) (ABTS) cationic radical, superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) first increased and then decreased with the increase of drying temperature, and the optimal values were 51.95%, 61.99% and 5.13 mmol/g at 60 ℃, respectively, however, there was no significant difference in the scavenging rate of hydroxyl radical at four hot air drying temperatures. Conclusion Under constant wind speed, 60 ℃ is the best hot air drying temperature for comprehensive efficiency, drying time and antioxidant capacity. This study provides theoretical support for the efficiency utilization and the sustainable development of Tribute orange which called “LingNan fruit”.