不同采收期枸杞干燥过程中主要类胡萝卜素的变化

 【目的】通过分析了枸杞功能成分玉米黄素、β－胡萝卜素和主要酯化类胡萝卜素在干制加工中生物合成和降解规律，为改善加工条件，最大限度保存枸杞中类胡萝卜素，提高枸杞感观品质提供理论依据。【方法】采用反相高效液相色谱法、外标法定量测定不同采收期枸杞在干燥过程中主要类胡萝卜素的变化。【结果】干制起始阶段，玉米黄素、β-胡萝卜素含量大幅增加，是鲜果含量的2～22倍；干制中期，均有不同程度的降解，其中秋果的降解幅度较大；干制后期，两种色素含量有小幅增加并达到平衡状态。玉米黄素双棕榈酸酯在干制起始阶段全面降解，降幅达到40%以上；干制中期有小幅增加并最终达到稳定状态。夏果中的类胡萝卜素总量明显比秋果高。【结论】玉米黄素、β-胡萝卜素在枸杞干制后含量增加而酯化类胡萝卜素如玉米黄素双棕榈酸酯含量下降，从而对枸杞感观色泽产生影响。

Changes of the Main Carotenoids Pigment Contents During the Drying Processes at Different Harvest Stage in Lycium barbarum L. Fruits

Objective ] The test analysed the regularity of biosynthesis and degradation of the main functional components, such as zeaxanthin, beta-carotene and esterified carotenoids in the fruit of Lycium barbarum L. in order to provide theories reference for improvement of processing condition, appearance quality and preservation carotenoids. Method] RP-HPLC was adapted to assay the content changes of the main carotenoids of different harvested stage fruits during the drying processing quantification was realized using external standard with gradient elution. Result] Zeaxanthin and beta-carotene contents in fruits increased dramatically, 2-22 times of that in fresh fruits at the beginning of drying period. In middle of drying period, degradation occurred to some extent and autumn fruit degraded to a large extent. At the end of drying period, zeaxanthin and beta-carotene contents increased in small extent until to balance. Zeaxanthin dipalmitate content had a whole degradation at the beginning, reached to 40 percent or higher, while it had increased a little then reached to balance. The total carotenoid content analysis showed that summer fruit had higher carotenoid content than that of autumn fruit. Conclusion] Zeaxanthin and beta-carotene contents in fruits increased and zeaxanthin dipalmitate degradated during the drying process, which effected the production appearance.