色谱分离分光光度法测定饲料中的叶黄素

用色谱法分离和分光光度法测定饲料产品中的叶黄素含量。以硅胶为固定相,分别洗脱胡萝卜素和叶黄素,叶黄素的测定波长为474nm,该测定方法的相对标准偏差为0.023%,测量不确定度为1%~2%。     

A Two-Stage Culture Strategy for Scenedesmus sp. FSP3 for CO2 Fixation and the Simultaneous Production of Lutein under Light and Salt Stress

In this study, Scenedesmus sp. FSP3 was cultured using a two-stage culture strategy for CO₂ fixation and lutein production. During the first stage, propylene carbonate was added to the medium, with 5% CO₂ introduced to promote the rapid growth and CO₂ fixation of the microalgae. During the second stage of cultivation, a NaCl concentration of 156 mmol L⁻¹ and a light intensity of 160 μmol m⁻² s⁻¹ were used to stimulate the accumulation of lutein in the microalgal cells. By using this culture method, high lutein production and CO₂ fixation were simultaneously achieved. The biomass productivity and carbon fixation rate of Scenedesmus sp. FSP3 reached 0.58 g L⁻¹ d⁻¹ and 1.09 g L⁻¹ d⁻¹, with a lutein content and yield as high as 6.45 mg g⁻¹ and 2.30 mg L⁻¹ d⁻¹, respectively. The results reveal a commercially feasible way to integrate microalgal lutein production with CO₂ fixation processes.     

An improved method of simultaneous determination of lutein and zeaxanthin in food

Based on an official standard method of lutein analysis, an improved high performance liquid chromatography (HPLC) method for simultaneously detecting lutein and zeaxanthin was developed as focusing on the sample preparation protocol. The optimal pretreatment conditions included a saponification in a water bath for 15?min at a constant temperature of 50?°C, using a 10?mL 60% (w/v) potassium hydroxide solution, followed by extraction using 100?mL mixture of n-hexane, ethyl ether and cyclohexane (40: 40: 20, v/v/v). A mixture of dichloromethane, acetonitrile and methanol (20: 30: 50, v/v/v) was validated to elute lutein and zeaxanthin on a C₃₀ column (4.6?×?250?mm, 5?µm). The resolution between lutein and zeaxanthin is ≥2.5. A millet sample was used for methodological verification and the results showed that the linear relations for lutein and zeaxanthin were good in ranges of 0.23–9.37?μg/mL and 0.30–12.02?μg/mL, respectively. The relative standard deviations of lutein and zeaxanthin were 1.40% and 5.09%, respectively, and their spiked recoveries were between 86.60% and 98.75%. The lutein and zeaxanthin results from this modified HPLC method are superior to those from the Chinese official method and ultrasonic extraction method.     

叶黄素的几类降解反应研究

类胡萝卜素是一大级一泛存在于动植物体内的四储类化合物,它们不仅颜色鲜艳,也是一类重要香味物质的前体。在Ｍ的烟０－Ｉ中已有１８种类型的胡萝卜素被分离和日表征。其中卜胡萝卜素和叶黄素是主要成分ｌ‘］。烟叶采收后,类胡萝卜素经生物降解,会生成一系列有挥发性芳香化合物,它什对卷烟的吸味、品质有很大的影响Ｉ２］。本文设计了四种化学方法,对叶黄素进行氧化降解,产物用ＧＣ／ＭＳ进行检测。结果表明,在适当条件下对叶黄素进行化学法氧化降解,可以得到如：氢化异佛尔酮、环氧紫萝兰酮、二氢弥猴桃内＠纺ｏ茶香螺酮等有重要…     

超高效液相色谱法测定婴幼儿配方奶粉中的叶黄素

建立了采用超高效液相色谱测定婴幼儿配方奶粉中叶黄素的检测方法。样品经丙酮溶液提取,离心分层,冷冻离心去脂,YMC Carotenoid C30色谱柱（150 mm×4.6 mm,3 μm）分离。以甲醇-甲基叔丁基醚（70：30,v/v）为流动相等度洗脱,流速为0.5 mL/min,进样量5 μL,柱温25 ℃,二极管阵列检测器检测,检测波长445 nm。方法在20~500 μg/L范围内线性关系良好;相关系数为0.999 9;定量限为20 μg/L。添加量在50、250、2000 μg/kg时,叶黄素的回收率为97.9%~104.4%。本方法操作简便,结果准确,灵敏度高,适用于婴幼儿奶粉中叶黄素的测定。     

叶黄素改善老龄大鼠抗氧化功能的研究

用D-半乳糖注射Wister雄性大鼠5个月,建立衰老模型.对模型组、药物组血清MDA含量、肝脏匀浆MDA含量和血液SOD、GSH-Px酶活性进行测定及比较.实验结果表明药物组血清MDA含量和肝脏匀浆MDA含量均比模型组有显著降低(P<0.01),而血液SOD、GSH-Px酶活性比模型组有显著升高(P<0.01).因此摄入适量叶黄素可以有效地增强大鼠机体抗氧化能力,从而延缓D-半乳糖诱发的大鼠衰老.     

Quantification of astaxanthin in salmons by chemiluminescence and absorption after TLC separation

Astaxanthin is a keto-carotenoid, belongs to the chemical class of terpenes and is a yellow lipid soluble compound. The compound is present in marine animals like salmons and crustacean. Its colour is due to conjugated double bonds and these double bonds are responsible for its antioxidant effect. Its antioxidant activity is ten times stronger than other carotenoids and nearly 500 fold stronger than vitamin-E. We present a new thin layer chromatography (TLC) method to measure astaxanthin on TLC-plates (Merck, 1.05554) in the visible absorption range as well as by using chemiluminescence. For separation a solvent mixture of cyclohexane and acetone (10?+?2.4, v/v) was used. The RF-value of astaxanthin is 0.14.The limit of detection in vis-absorption is 64?ng / band and the limit of quantification is 92?ng/band. In chemiluminescence the values are 90?ng / band and 115?ng/band. The method offers two independently working measurement modes on a single plate which increase the accuracy of the quantification.     

玉米黄色素的提取和分析

使用超临界CO2法从水解玉米蛋白粉中提取玉米黄色素.通过单因素实验和正交实验优化了超临界CO2萃取玉米黄色素的工艺条件,并通过HPLC检测提取物中玉米黄素和叶黄素的含量.结果表明:超临界CO2提取玉米黄色素的最佳条件为:萃取时间2 h,CO2流速35 kg/h,萃取压力30 MPa,萃取温度45℃,夹带剂15%无水乙醇,此时玉米黄色素产量为210.97 μg/g.     

Study of Electrochemical Behaviour of Carotenoids in Aqueous Media

Focus of this research was electrochemical study of β‐carotene, astaxanthin and lutein in aqueous media. Compounds were investigated on paraffin impregnated graphite electrode (PIGE) in 0.1 M HClO₄ aqueous electrolyte using square‐wave voltammetry (SWV) with pulse amplitude of 50 mV and step potential of 2 mV. Voltammetry of immobilized microparticles (VIM) allowed determination of β‐carotene and astaxanthin as solids immersed in aqueous electrolyte. Results obtained with SWV revealed oxidation peaks at 0.88 V and 1.09 V versus Ag/AgCl for β‐carotene and astaxanthin, respectively. To obtain additional information about their behaviour, stripping voltammetry microprobe (SPV) was employed. With this technique the responses of astaxanthin, β‐carotene and lutein exhibit three peaks (?0.345 V, 0.47 V and 0.65 V), two peaks (0.477 V and 0.725 V) and a single peak at 0.687 V, respectively. Based on these results, antioxidant activity of these carotenoids is in order: astaxanthin > β‐carotene > lutein. Good dose‐response relationship between carotenoid concentrations precipitated on PIGE and net peak current was obtained, but in rather narrow concentration range for each compound.