光照、加热对虾青素稳定性和抗氧化性的影响

Effect of light and heat on the stability and antioxidant activity of astaxanthin

目的考察光照、加热情况下虾青素的稳定性和抗氧化性的变化。方法配制一定浓度的虾青素溶液,分别经过阳光直射、紫外和加热处理,测定溶液中各虾青素异构体的浓度,并做1,1-二苯基-2-三硝基苯肼(DPPH)抗氧化性试验。结果在光照和加热条件下,减少的全反式虾青素转化为其顺式异构体,且主要转化为13-顺式异构体,对应的转化率分别为50%、100%。通过紫外照射试验发现,虾青素各异构体含量变化与光照相近,说明光照对虾青素的影响主要是由于其中的紫外光引起的。1,1-二苯基-2-三硝基苯肼清除试验表明,虾青素不止一种异构体有活性,且13-顺式异构体抗氧化性高于全反式。结论在光照和加热情况下虾青素容易发生降解以及异构体之间的转化。

Objective To investigate the stability and antioxidant activity of astaxanthin in different light and heat conditions.Methods After preparation of a certain concentration of astaxanthin solution,the concentration of astaxanthin isomer was measured by direct sunlight,ultraviolet ray and heat treatment respectively,and DPPH antioxidation test was performed.Results Under the conditions of light and heat,the reduction of all-trans-astaxanthinw as converted into its c i s-i-som ers,and the main conversion is the 1 3-c i s-i s o m e r,with the corresponding conversion rate of 5 0%,1 0 0%.The results showed that the changes in the contents of different isomers were similar to that of sunlight,indicating that the effects of sunlight on astaxanthin were mainly caused by ultraviolet light.The D PPH anti-oxidative test showed that there was more than one isomer of astaxanthin possesses antioxidant activity,and the anti-oxidability of the 1 3-c is isomers was higher than a l l-trans astaxanthin.Conclusion It was easy to degradation and conversion between isomersof astaxanthin.