Studies On Separated And Determined Methods Of The Carotenoids Composition In Pepper Leaves

The study was conducted to investigate the extraction technology of carotenoidsand establish the method of component separation and determination content of lutein,zeaxanthin and β-carotene three carotenoids in pepper leaves (var. Longjiao No.3) bythe way of the selection of appropriate extraction solvent, saponification temperature,saponification time, the concentration of KOH-ethanol saponification solution, thevolume of KOH-ethanol saponification solution and the ratio of solid-liquid andsuitable chromatographic condition. The objective of the study was to research on therelationship between the composition of carotenoids in pepper leaves and resistancecapacity of low temperature and low light. It will provide the method for separatingand determining the composition and content of carotenoids in pepper leaves. Themain study results were as follows:1. The study had established the extraction technology of carotenoids in pepperleaves by the way of the selection of appropriate extraction solvent, saponificationtemperature, saponification time, the concentration of KOH-ethanol saponificationsolution, the volume of KOH-ethanol saponification solution and the ratio ofsolid-liquid.The key technology for separation and determination of carotenoids inpepper leaves was that petroleum ether was used as extraction solvent, thesaponification temperature was80℃, saponification time was40min, theconcentration of KOH-ethanol saponification solution was20%, the volume ofKOH-ethanol saponification solution was10ml and the ratio of solid-liquid was1:5.2. On the basis of studying the chromatographic condition of separation anddetermination of carotenoid in pepper leaves including mobile phase, flow rate,column temperature, detection wavelength and the selection of C30or C18column, areversed-phase high performance liquid chromatography was developed forseparation and determination the composition and content of three carotenoids oflutein, zeaxanthin and β-carotene in pepper leaves.The suitable chromatographicconditions were as follows: separation and determination was achieved by using aYMC C30column (250mm×4.6mm i.d.5μm); a mobile phase of acetonitrile-methanol (60:40，v/v)(A) and methyl tert-butyl ether (100%)(B) was eluted with the gradient;three kinds of carotenoids were resolved with the flow-rate at1.0ml/min, columntemperature at25℃and wavelength of detection at450nm.3. It was scientific and feasible method of separation and determination thecomposition and content three carotenoids of lutein, zeaxanthin and β-carotene inpepper leaves through the test of external standardmethod.There were good linearcorrelation betweenthe concentration of lutein, zeaxanthin and β-carotene and peakarea.The correlation coefficient were0.9961,0.9999and0.9961respectively. Theaverage recoveries of three carotenoids were between80%and98.9%.