Instituto Politécnico Nacional CIIDIR Oaxaca, Hornos 1003 Sta. Cruz Xoxocotlán, Oaxaca 71230, Mexico.
Instituto Politécnico Nacional CIIDIR Oaxaca, Hornos 1003 Sta. Cruz Xoxocotlán, Oaxaca 71230, Mexico.
Food Chem. 2017 Sep 1;230:174-181. doi: 10.1016/j.foodchem.2017.03.010. Epub 2017 Mar 8.
The thermal drying effects on strawberries were investigated in terms of the kinetics of antioxidant activity (AA), anthocyanins (A) and total phenolic compound content (TPC), as well as the final colour. The evaluated drying temperatures were 50 and 60°C with an air rate of 1.5m/s. The 2,2-diphenyl-2-picryl-hydrazyl, pH differential and Folin-Ciocalteu methods were used to assess the antioxidant properties. The kinetics of TPC and AA showed an initial and final period of degradation attributed to inhibition of enzymes. A plateau between these two periods suggests that under certain conditions of temperature and water content, no degradation reactions occurred. Final losses of up to 74, 45 and 78% were found for AA, A and TPC, respectively. The total colour change (ΔE) was lesser degree at 60 than 50°C. Thermal degradation of the antioxidant compounds followed a first-order reaction kinetics and the degradation rate constants (k) were calculated.
研究了草莓在热干燥过程中抗氧化活性（AA）、花色苷（A）和总酚含量（TPC）的变化动力学以及最终颜色。评估的干燥温度分别为 50°C 和 60°C，空气流速为 1.5m/s。采用 2,2-二苯基-2-苦肼基、pH 差和 Folin-Ciocalteu 法评估抗氧化性能。TPC 和 AA 的动力学表现出初始和最终的降解期，归因于酶的抑制。在这两个时期之间存在一个平台，表明在一定的温度和水分条件下，没有降解反应发生。AA、A 和 TPC 的最终损失分别达到了 74%、45%和 78%。在 60°C 时，总色差（ΔE）的变化程度小于 50°C。抗氧化化合物的热降解遵循一级反应动力学，计算了降解速率常数（k）。
