直链淀粉-番茄红素复合物的氧稳定性及降解动力学研究

Oxygen stability and degradation kinetics of amylose-lycopene complexes

以直链淀粉-番茄红素复合物(ALCs)为研究对象,对其结构进行表征,研究了N_(2)和O_(2)处理条件下ALCs中番茄红素保留率和抗氧化活性的变化,并进一步构建番茄红素降解动力学模型。结果表明:直链淀粉包合番茄红素形成了V-型单螺旋结构,且番茄红素与直链淀粉发生的分子链缠绕使ALCs的双螺旋含量增加;N_(2)处理条件下,ALCs中番茄红素的质量浓度和抗氧化活性高于O_(2)处理条件,且降解较缓慢;N_(2)环境下处理24 h后,ALCs中番茄红素保留率和DPPH清除率分别为(85.17±0.42)%和(35.74±0.01)%,均显著高于对照组的(59.74±0.06)%和(17.20±0.01)%;O_(2)环境下处理24 h后,ALCs中番茄红素保留率和DPPH清除率分别为(77.09±0.90)%和(33.24±0.03)%,均显著高于对照组的(50.32±0.42)%和(16.32±0.09)%;N_(2)和O_(2)处理条件下,ALCs中番茄红素的降解均符合二级动力学模型,降解速率常数分别为6.0×10^(-4)μg/(mL·h)和8.0×10^(-4)μg/(mL·h),其半衰期(T_(1/2))分别为115.92 h和86.94 h、十分之一衰期(T_(9/10))分别为17.57 h和13.18 h,均显著优于对照组。因此,ALCs具有良好的氧稳定性,可较好保持番茄红素质量浓度和抗氧化活性,对番茄红素具有有效的保护作用。

The structure of amylose-lycopene complexes(ALCs)was characterized,and the changes of lycopene retention and antioxidant activity in ALCs treated with N_(2)or O_(2)were studied,and the kinetic model of lycopene degradation was further developed.Results showed that lycopene encapsulated by amylose formed a V-type helix structure,and the molecular chain winding of lycopene and amylose increased the double helix content of ALCs.The content and antioxidant activity of lycopene in ALCs treated with N_(2)were higher than those treated with O_(2),and the degradation was slower.After 24 h treatment in N_(2),the retention rate of lycopene and the clearance rate of DPPH in ALCs were(85.17±0.42)%and(35.74±0.01)%,respectively,which were significantly higher than those in the control group(59.74±0.06)%and(17.20±0.01)%(P<0.01).After 24 h treatment in O_(2),the retention rate of lycopene and the clearance rate of DPPH in ALCs were(77.09±0.90)%and(33.24±0.03)%,respectively,which were significantly higher than those of lycopene standard(50.32±0.42)%and(16.32±0.09)%in the control group.Under the condition of N_(2)and O_(2)treatment,the degradation of lycopene in ALCs conformed to the second-order kinetic model,the degradation rate constants were 6.0×10^(-4)μg/(mL·h)and 8.0×10^(-4)μg/(mL·h),respectively,and the lifetimes of T_(1/2)was 115.92 h and 86.94 h,respectively,and the T_(9/10)was 17.57 h and 13.18 h,respectively,which were significantly better than those in the control group.Therefore,the ALCs was effective in enhance lycopene stability,and better maintained the content and antioxidant activity of the lycopene.