直链淀粉-番茄红素复合物的热稳定性及降解动力学变化

Changes in Thermal Stability and Degradation Kinetics of Amylose-lycopene Complexes

摘要:

为评价直链淀粉-番茄红素复合物（Amylose-Lycopene Complexes，ALCs）的热稳定性，以番茄红素标准品为对照，研究了ALCs在50、70、90、110和130 ℃系列环境温度下其番茄红素的含量、保留率和抗氧化活性变化规律；并进一步研究了其热降解动力学过程。研究发现：ALCs的热稳定性优于对照组，对其中的番茄红素具有保护作用。在50 ℃（4 h）和130 ℃（1 h）时，ALCs中的番茄红素含量分别为12.55 μg/mL和11.06 μg/mL，均显著高于标准品中的10.80 μg/mL和8.43 μg/mL（p<0.05）；随环境温度升高和处理时间的增加，ALCs中的番茄红素保留率和抗氧化活性逐渐降低，但显著优于番茄红素标准品对照组。在90 ℃下处理10 h后，ALCs中番茄红素保留率和抗氧化活性分别降至66.59%和23.83%，均显著优于对照组的44.19%和4.81%（p<0.05）。ALCs中番茄红素的热降解行为符合方程1/Ct-1/C0=kt+b，其降解速率常数k与温度呈正相关，半衰期和十分之一衰期与温度呈负相关。结果表明：直链淀粉-番茄红素复合物具有良好的热稳定性，可对其中的番茄红素起到有效的保护作用，其番茄红素热降解过程符合二级降解动力学模型。

Abstract:

To investigate the thermal stability of amylose-lycopene complexes (ALCs), the changes in the lycopene content, retention rate, and antioxidant activity of ALCs were investigated at 50 ℃, 70 ℃, 90 ℃, 110 ℃, and 130 ℃, respectively, with lycopene standard as the control, and the thermal degradation kinetics were further investigated. The results showed that the thermal stability of ALCs was better than that of the control group, and they protected the present lycopene. The contents of lycopene in ALCs with treatment conditions of 50 ℃ (4 h) and 130 ℃ (1 h) were 12.55 μg/mL and 11.06 μg/mL, respectively, which were significantly higher than 10.80 μg/mL and 8.43 μg/mL of lycopene standard (p<0.05). The lycopene retention, and antioxidant activity of ALCs decreased gradually with increasing ambient temperature and treatment duration, although they were significantly better than those of the lycopene standard control. After treatment at 90 ℃ for 10 h, the lycopene retention rate and antioxidant activity of ALCs decreased to 66.59% and 23.83%, respectively, which were significantly better than 44.19% and 4.81% in the control group (p<0.05). Furthermore, the thermal degradation behavior of lycopene in ALCs accorded with the equation 1/Ct-1/C0=kt+b. The degradation rate constant k showed a positive correlation with temperature, while degradation half-life and one-tenth-life showed a negative correlation with temperature. These results suggest that ALCs may effectively protect lycopene with excellent thermal stability. The thermal degradation process of lycopene in ALCs accords with the second-order degradation kinetic model.