超声波皂化法提取叶黄素的工艺研究

试验采用了超声波辅助KOH-碱溶液进行皂化工艺研究,以皂化碱液浓度、碱液加入量、皂化时间、皂化温度为自变量。通过响应面分析法,研究了各因素及其交互作用对万寿菊中叶黄素皂化反应的影响。结果表明:叶黄素皂化的最佳工艺条件为:KOH-碱溶液浓度11.35%、碱液加入量172.37mL、皂化温度51.55℃、皂化时间2.09h。叶黄素含量的预测值为15.53mg/g。当选取KOH-碱溶液浓度11%、碱液加入量170mL、皂化温度50℃、皂化时间2h的实际条件时,叶黄素的含量实际值达到15.64mg/g。     

游离态叶黄素和玉米黄素体外单线态氧淬灭率的比较研究

为比较玉米黄素和叶黄素单体的体外淬灭单线态氧能力,本实验分别萃取万寿菊与枸杞中的叶黄素与玉米黄素酯,经皂化和纯化后得到游离的叶黄素与玉米黄素组分。使用C30-HPLC-PDA 分别对制备组分进行定性和定量分析。用次氯酸钠-双氧水反应产生单线态氧,使用微弱发光测量仪测定制备组分对单线态氧的淬灭率。结果显示：游离叶黄素和玉米黄素均能减少次氯酸钠-双氧水反应体系产生的单线态氧数量,导致最大光子计数值下降。二者淬灭单线态氧的能力相似,最小作用剂量均为0.005～0.05 g/L。     

高纯度玉米黄素的制备

本文研究了氢氧化钾(KOH)与叶黄素的摩尔比例、KOH水溶液的摩尔浓度、反应温度、料液比四个因素对叶黄素转化为玉米黄素反应的影响。实验结果表明,当KOH和叶黄素的摩尔比为56:1,KOH水溶液摩尔浓度为12M,料液比为1:25,温度为90℃,反应时间为1h,叶黄素转化效率最高,经过重结晶,所得玉米黄素的含量可达90%以上,总收率在60%以上。     

高纯度玉米黄素的制备

本文研究了氢氧化钾(KOH)与叶黄素的摩尔比例、KOH水溶液的摩尔浓度、反应温度、料液比四个因素对叶黄素转化为玉米黄素反应的影响。实验结果表明,当KOH和叶黄素的摩尔比为56∶1,KOH水溶液摩尔浓度为12M,料液比为1∶25,温度为90℃,反应时间1h,叶黄素转化效率最高,经过重结晶,所得玉米黄素的含量可达90%以上,总收率在60%以上。     

玉米蛋白粉中叶黄素和玉米黄素对口腔癌细胞DNA的损伤作用

研究玉米蛋白粉中叶黄素和玉米黄素对人口腔癌KB细胞的作用机制。在人口腔癌KB细胞的细胞培养液中分别加入40μL/L、60μL/L叶黄素和30μL/L、40μL/L玉米黄素,分别培养48h、72h。用单细胞凝胶电泳(SCGE)检测叶黄素和玉米黄素对人口腔癌KB细胞DNA损伤程度。玉米蛋白粉中叶黄素和玉米黄素可引起KB细胞DNA链断裂,细胞尾长、尾DNA百分含量和尾矩显著高于对照组,差异有统计学意义(P<0.01)。叶黄素和玉米黄素能导致人口腔癌细胞KB的DNA损伤,抑制肿瘤细胞生长。     

类胡萝卜素之间的转化

类胡萝卜素是广泛存在与自然界中的一种天然色素,不同种类的类胡萝卜素具有不同的生理功能,本文描述了多种类胡萝卜素之间的转化,包括叶黄素酯向玉米黄素的转化,叶黄素向4-酮基叶黄素的转化,辣椒红色素向4-酮基辣椒红色素的转化,玉米黄素向虾青素的转化,β-胡萝卜素向斑蝥黄质的转化,以及叶黄素向隐黄质的转化。     

北京社区居民夏秋季节膳食叶黄素、玉米黄素摄入量分析

目的:测算北京社区居民夏秋季膳食叶黄素、玉米黄素摄入量。方法:采用高效液相色谱法(HPLC)对13种常见蔬菜、水果和蛋类中叶黄素、玉米黄素和β-胡萝卜素含量进行检测。运用定量食物频率表结合HPLC测定结果,计算居民膳食叶黄素、玉米黄素摄入量。结果:被调查的541名45岁以上社区居民中,叶黄素、玉米黄素平均摄入量分别为10201.4±12852.6μg/d和245.0±260.0μg/d。二者的摄入量在月人均收入1000～1999元者中最低。39.1%和30.2%的膳食叶黄素来源于菠菜和韭菜,40.6%和31.9%的膳食玉米黄素来自韭菜和鸡蛋。结论:利用定量食物频率表结合对常见食物的HPLC测定结果,估计了北京社区居民膳食叶黄素、玉米黄素的膳食摄入量。收入水平是影响居民二者摄入量的因素之一。菠菜、韭菜为被调查者膳食叶黄素的主要来源,韭菜、鸡蛋为其膳食玉米黄素最重要的来源。     

富有保健功效的叶黄素和玉米黄素

<正> 近年来,富有保健功效的叶黄素和玉米黄素越来越成为国内外科学家们研究的热点。近日,由中国营养学会营养与保健食品分会举办的"叶黄素和玉米黄素来源与功能作用专家论坛"在京举行。会议邀请了来自国内外的专家就国内外对叶黄素、玉米黄素研究的最新进展情况,同各方专业与会者进行了交流。叶黄素与玉米黄素都属于类胡萝卜素,具有很强的抗氧化作用。叶黄素与玉米黄素是构成玉米、蔬菜、水果、花卉等植物     

谷物色素研究进展

谷物中的色素大部分属于类胡萝卜素、花色素,例如小米、玉米黄色素中叶黄素、玉米黄素属类胡萝卜素,黑米中黑米色素、花色小麦中的色素和高粱中的高梁红色素属花青素类。介绍了玉米、小麦、黑米、高粱和小米等谷物中色素的性质、提取和应用进展。     

制备万寿菊叶黄素技术研究进展

由于叶黄素(lutein)是自然界广泛存在的二羟基类胡萝卜素,也是人眼视网膜黄斑色素主要组成部分。叶黄素可有效预防并辅助治疗老年性黄斑退化病和白内障等眼部疾病,其在生物活性物质利用领域有广泛的应用前景。万寿菊是工业上提取分离叶黄素的理想工业原料。本文从万寿菊叶黄素提取专用品种、叶黄素分子结构及叶黄素稳定性等6个方面综述了近年来国内外有关万寿菊叶黄素的研究工作,并进行了前景展望。     

Reaction Behavior of Glucose and Fructose in Subcritical Water in the Presence of Various Salts

Glucose and fructose were treated in subcritical water in the presence of alkali or alkaline earth metal chlorides. All salts accelerated the conversion of saccharides, and alkaline earth metal chloride greatly promoted the isomerization of glucose to fructose. In contrast, alkali metal salts only slightly promoted this isomerization and facilitated the decomposition of glucose to byproducts such as organic acids. The selectivity of the glucose-to-fructose isomerization was higher at lower conversions of glucose and in the presence of alkaline earth metal chlorides. The pH of the reaction mixture also greatly affected the selectivity, which decreased rapidly at lower pH due to the generated organic acids. At low pH, decomposition of glucose became dominant over isomerization, but further conversion of glucose was suppressed. This result was elucidated by the suppression of the alkali-induced isomerization of glucose at low pH. Fructose underwent decomposition during the treatment of the fructose solution, but its isomerization to glucose was not observed. The added salts autocatalytically promoted the decomposition of fructose, and the reaction mechanism of fructose decomposition differed from that of glucose.     

响应面试验优化万寿菊花中叶黄素酯皂化反应工艺

以叶黄素酯为原料,对万寿菊花中叶黄素酯皂化反应的工艺进行优化,考察反应溶剂种类及用量、皂化温度、皂化时间等因素对皂化反应的影响,采用薄层层析法计算皂化率,确定叶黄素酯皂化的适宜操作条件,对皂化反应工艺进行单因素试验和响应面分析研究。结果表明,叶黄素酯的皂化反应最佳工艺条件为叶黄素酯为2.0 g时,无水乙醇用量31.3 mL、皂化温度60 ℃、KOH用量2.1 g、皂化时间4 h,此条件下叶黄素酯的平均皂化率为78.4%。     

In vitro bioaccesibility of lutein and zeaxanthin from the microalgae Scenedesmus almeriensis

Aim of the study

To assess the in vitro bioaccessibility of lutein and zeaxanthin from lyophilised biomass and lutein-enriched extracts in olive oil produced from a lutein overproducing strain of Scenedesmus almeriensis.

Results

Lutein and zeaxanhin were mostly present in free form (>90–95%). Both xanthophylls were highly stable upon in vitro digestion, with an overall recovery above 75% (lyophilised biomass) and very low isomerization, whilst micellarization was <1% of the amount initially present and cis-isomers of lutein and β-carotene were preferentially incorporated. Using lutein-enriched extracts in olive oil, the micellarization of lutein and zeaxanthin increased dramatically reaching values up to 80–90% of the amounts initially present.

Conclusion

The lyophilised biomass of S. almeriensis constitutes a very rich source of free lutein (and zeaxanthin) but poorly bioaccesible. However, oil extracts from this lyophilised biomass are highly bioaccesible and may supply amounts of lutein and zeaxanthin comparable to or higher than those provided by traditional foods.     

叶黄素及其顺式异构体的快速检测

为了建立分离度好、分离效率高的叶黄素顺、反异构体检测方法。通过对检测波长、流动相、流动相比例和流速等色谱条件的摸索和优化,确定最佳色谱条件,并采用光谱、高效液相色谱、质谱等方法对叶黄素顺、反异构体进行定性定量分析。结果表明：该方法流动相为二氯甲烷-乙腈-甲醇（20∶30∶50,V/V）,流速为1.0 mL/min,叶黄素热异构化样品中各物质在12 min内达到有效分离,无拖尾现象,峰形较好;在叶黄素热异构化样品中鉴定出15-顺式、13/13′-顺式和9/9′-顺式叶黄素顺式异构体及全反式叶黄素,全反式叶黄素在4～260 ng范围内峰面积与进样量呈良好线形性关系,回收率在95%以上,精密度和稳定性相对标准偏差均小于2%。该方法分离度好、准确性高、重现性好。     

Optimizing the Supercritical Fluid Extraction of Lutein from Corn Gluten Meal

Supercritical CO₂ was used to extract xanthophylls from corn gluten meal (CGM). Data from a Box-Behnken experimental design was used to model optimal lutein extraction based on extraction temperature (40–80 °C), pressure (5500–7500 psi), and fraction of ethanol co-solvent added (5–15% by volume of total solvent). Lutein extraction was also strongly correlated with zeaxanthin extraction with a correlation coefficient (r) of 0.995. The response surface model for lutein extraction indicated that the amount of co-solvent had the largest impact (p?<?0.001) on lutein extraction yield. Influence of temperature and pressure were limited to quadratic or interaction effects (p?<?0.15). The optimal lutein extraction conditions predicted with the model were a temperature of 40 °C, pressure of 6820 psi, and co-solvent (ethanol) addition of 15% by volume. At these conditions, lutein recovery from CGM was 2.6 times higher than the amount recovered with a quintuple extraction using ethanol and chloroform/dichloromethane (2:1). The strong linear effect of co-solvent addition suggests the possibility of further increasing lutein extraction with the addition of more co-solvent. CGM protein loss during extraction was also calculated and determined to be negligible.     

水合有机溶液体系中类胡萝卜素聚集体的探究

类胡萝卜素具有多种对人体有益的生理活性,在一定条件下分子可自聚集形成不同类型的聚集体。本文主要以水合有机溶液的比例和加样顺序为关键因素,探究其对三种代表性类胡萝卜素（虾青素、叶黄素、β-胡萝卜素）聚集体的类型（H聚集体、M单体、J聚集体）、形成条件和稳定性的影响。分别将虾青素丙酮溶液、叶黄素乙醇溶液、β-胡萝卜素丙酮溶液以水入有机和有机入水两种不同滴加顺序,按照有机溶剂占总体积比以10%～90%的比例混合,观察类胡萝卜素小分子及其聚集体的状态并进行紫外可见吸收光谱分析。结果表明,在有机入水的加样顺序下,虾青素、叶黄素、β-胡萝卜素溶液体系下形成H聚集体的有机溶剂占总体积比分别为10%～20%、10%～50%和10%～40%,此外,虾青素在30%形成J聚集体,β-胡萝卜素在50%～70%形成J聚集体,叶黄素在60%～90%时为叶黄素单体。在水入有机的加样顺序下,形成聚集体的条件与有机入水相似。但是通过对比发现,在有机入水的加样顺序下,紫外可见光谱上吸收峰移动的现象更明显。探究聚集体稳定性发现,样品在室温（25℃）条件下放置24 h和48 h后,叶黄素的H聚集体类型不变,虾青素、β-胡萝卜...     

叶黄素酯在强化面包制作和贮藏中的稳定性

通过将叶黄素酯水溶性微囊粉添加于面包中,考察面包和面、发酵、焙烤和贮藏过程中总叶黄素酯、总叶黄素及其异构体的变化情况,旨在监测叶黄素酯在强化面包制作和贮藏过程中的稳定性。结果表明：和面和发酵对叶黄素酯的降解影响不大,皂化测得的总叶黄素和全反式叶黄素保留率较高;烘烤引起面包皮和面包芯中叶黄素酯含量的明显降低,随之皂化测得的总叶黄素和全反式叶黄素保留率下降明显。叶黄素酯强化面包制作和贮藏过程中都伴有叶黄素异构体的不断生成和含量变化,和面过程中有少量的13-顺式和13’-顺式叶黄素生成,发酵过程有少量的9-顺式和9’-顺式叶黄素生成,焙烤过程面包皮和面包芯中13-顺式、13’-顺式、9-顺式和9’-顺式叶黄素含量显著累积增加,贮藏过程中面包皮和面包芯中的叶黄素酯、皂化测得的总叶黄素和全反式叶黄素含量,及叶黄素顺式异构体含量均略有下降。     

叶黄素的提取及应用研究进展

叶黄素属于类胡萝卜素类色素,具有多种生物活性,是当今国际上研究的热点之一。叶黄素的提取技术较多,主要有溶剂抽提法、微波提取法、超临界CO2萃取法、酶介质有机溶剂提取等。近年发现其具有保护视力,预防动脉硬化,抗氧化,抗癌等作用。叶黄素的性状及提取方法,功能特性及其在饲料、食品、药品、保健品等中的应用进行综述。