叶黄素的保健功能

叶黄素作为一种天然色素，广泛存在于自然界中。大量的流行病学证据表明，叶黄素在预防人类某些癌症和慢性病的发生方面起着重要的作用，是目前国际上功能性食品成分研究中的一个热点。本详细地介绍了叶黄素的结构、性质及生理功能方面的研究进展，并对其将来在食品中的应用加以展望。     

A Biological Role of Lutein

Lutein, a non-provitamin A carotenoid, is found in dark green, leafy vegetables. Lutein, being fat soluble, follows the same intestinal absorption path as dietary fat and is affected by the same factors that influence fat absorption. Unlike β-carotene, another major carotenoid in diet and tissue, the bioavailability of lutein appears to be less influenced by food processing. Lutein has been strongly implicated as being protective against eye diseases, age-related macular degeneration, and cataracts. In the eye, lutein may act as a blue light filter to protect the underlying tissues from phototoxic damage. The mechanism by which lutein is involved in the prevention of eye diseases may also involve its role as an antioxidant. Dietary surveys indicate that average intakes of lutein in the United States may be below levels that are associated with disease prevention. Therefore, increased intakes of food sources rich in lutein may be warranted.     

万寿菊花中叶黄素酯的提取及皂化工艺

叶黄素具有调节人体的免疫能力、防治老年性视黄斑退化和白内障等作用,目前天然叶黄素的提取原料主要为万寿菊花,万寿菊花的有机溶剂提取物含有大量叶黄素酯,经皂化后可转变为叶黄素,广泛用于食品、食品添加剂、药品及饲料等工业.本文采用甲醇处理万寿菊鲜花后直接用正己烷提取叶黄素酯,并通过L9 (34)正交实验选择了叶黄素酯皂化的最佳条件,即KOH/甲醇浓度为20%,提取液﹕KOH为4 : 1,时间为40min,温度为50℃时,叶黄素酯皂化进行的比较完全.皂化得到的叶黄素在丙酮﹕甲醇(v : v)为1 : 1的混合溶剂中进行重结晶,得到叶黄素晶体,纯度为97.2%.     

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。     

Dietary lutein modulates inducible nitric oxide synthase (iNOS) gene and protein expression in mouse macrophage cells (RAW 264.7)

Lutein is an oxycarotenoid primarily found in dark-green leafy vegetables such as spinach and kale. Other dietary sources which contain moderate amounts of lutein include corn, egg yolks, and fruits like oranges and kiwi. Although a number of in vivo studies have demonstrated the anti-inflammatory effect of lutein, its in vitro anti-inflammatory molecular mechanism of action is unknown. In this study, we have investigated the in vitro anti-inflammatory effect of lutein using LPS-stimulated mouse macrophage cell line (RAW 264.7). The inhibition of LPS-stimulated nitric oxide (NO) was measured and the expression of inducible NO synthase (iNOS) was assessed at the mRNA and protein levels in mouse macrophage cells after treatment with lutein. Lutein decreased the LPS-induced NO production by 50% compared to LPS alone. Real-time PCR analysis showed a 1.9-fold reduction in iNOS expression at the mRNA level. Western blotting revealed that lutein decreased LPS-induced iNOS expression at the protein level by 72.5%. The results of this study suggest the anti-inflammatory properties of lutein demonstrated by the decrease in the expression of iNOS at the mRNA and protein levels in RAW 264.7 mouse macrophage cells.     

Effects of lutein and zeaxanthin on aspects of eye health

Lutein and zeaxanthin are members of the oxygenated carotenoids found particularly in egg yolks and dark‐green leafy vegetables. A great deal of research has focused on their beneficial roles in eye health. The present article summarises the current literature related to the bioactivity of these carotenoids, emphasising their effects and possible mechanisms of action in relation to human eye health. Available evidence demonstrates that lutein and zeaxanthin are widely distributed in a number of body tissues and are uniquely concentrated in the retina and lens, indicating that each has a possible specific function in these two vital ocular tissues. Most of epidemiological studies and clinical trials support the notion that lutein and zeaxanthin have a potential role in the prevention and treatment of certain eye diseases such as age‐related macular degeneration, cataract and retinitis pigmentosa. The biological mechanisms for the protective effects of these carotenoids may include powerful blue‐light filtering activities and antioxidant properties. Although most studies point towards significant health benefits from lutein and zeaxanthin, further large‐scale randomised supplementation trials are needed to define their effects on ocular function in health and disease. Copyright © 2009 Society of Chemical Industry     

高效液相色谱-电喷雾质谱法测定浒苔中的叶黄素

建立反相高效液相色谱- 电喷雾电离质谱法(RP-HPLC-DAD-ESI-MS)定性、定量测定绿潮藻浒苔中叶黄素的新方法。浒苔样品经超声辅助提取后,采用RP-HPLC-DAD-ESI-MS 联用技术对其进行分离鉴定,HPLC 采用Eclipse XDB-C18(150mm × 4.6mm,5μm)色谱柱,以含0.2% 乙酸的甲醇溶液- 水为流动相,线性梯度洗脱,检测波长450nm。在选定的最佳仪器条件下,叶黄素与浒苔中的其他化合物分离良好,叶黄素在0.10～20.0mg/L 质量浓度范围内具有良好的线性关系(R2=0.9994),能对浒苔提取液中的叶黄素进行准确定量;采用电喷雾质谱联用分析能快速获得叶黄素的分子量信息,可为浒苔中叶黄素的快速鉴别提供依据。     

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。     

叶黄素的提取、功效和应用研究进展

叶黄素属于类胡萝卜素色素之一,功效独特,具有多种生物活性,应用广泛,为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、超声波提取法、超临界CO2萃取法、酶介质有机溶剂提取等.随着进一步的深入研究,对于相关机理的认识将不断加深、技术手段迅速进步,叶黄素的功效作用机制将逐步被揭示,为更好地应用叶黄素而奠定基础.     

叶黄素酯在体内消化吸收过程中水解的研究

叶黄素已经证实具有对视网膜黄斑衰退症的防治作用,被认为是一种在食品或药品中有前景的功能因子。叶黄素的制备原料为万寿菊的花,并以叶黄素酯的形式存在。在本研究中,首先从万寿菊干花颗粒中制备叶黄素酯,然后与食用油配制成灌胃液,给SD雄性大鼠一次灌胃,2h后采血,萃取其中的类胡萝卜素,HPLC分析萃取物。分析结果显示:在血清中只能检测到叶黄素单体。这个结果证实:叶黄素酯在消化和吸收过程中被水解成单体,客观上证明了在功能性食品和药品中直接应用叶黄素酯的可能性。     

微藻产叶黄素研究进展

叶黄素是一种对人体健康有益的天然类胡萝卜素,目前工业提取主要来源于万寿菊等植物。因生长周期短、叶黄素含量相对较高等优势,海洋微藻成为叶黄素生产的潜力来源之一。文章综述近年来高产叶黄素藻种、提高叶黄素产量代谢调控策略、叶黄素提取工艺以及功能活性等研究进展,为推动微藻叶黄素早日实现工业化生产提供理论参考。     

叶黄素的视力保护作用及提取工艺

叶黄素(lutein)是一种含氧的类胡萝卜素,分布在黄斑区和整个视网膜,具有蓝光屏蔽和抗氧化功能,具有重要的保护视力的作用。本文介绍了叶黄素与黄斑变性、白内障的关系,揭示其对视觉发育及功能的影响,并总结了叶黄素的提取技术,通过示例探讨了提取条件优化及工艺特点,最后展望了黄素的及提取方法与市场前景。     

The Health Potential of Fruits and Vegetables Phytochemicals: Notable Examples

Fruit and vegetables are essential components of a healthy diet. The World Health Organization (WHO) recommends an intake of five to eight portions (400–600 g) daily of fruits and vegetables to reduce risk of cardiovascular disease, cancer, poor cognitive performance, and other diet-related diseases, as well as for the prevention of micronutrient deficiencies. Much of their potential for disease prevention is thought to be provided by phytochemicals, among which the preventive activity of antioxidants is most well documented. Since numerous meta-studies published indicate variable and often contradictory results about the impact of isolated phytochemicals on health, their consumption as supplements must be carried out with care, because doses may exceed the recommended nutritional intake. Nonetheless, there is a general consensus that whole fruit and vegetable intake is more important in providing health benefits than that of only one of their constituent, because of additive and synergistic effects. This review describes the most recent literature regarding the health benefits of some selected fruits and vegetables. Importantly, since some phytochemicals regulate the same genes and pathways targeted by drugs, diets rich in fruits and vegetables in combination with medical therapies are being considered as novel approaches to treatment. Therefore, phytochemicals in fruits and vegetable might be a promising tool for the prevention and/or amelioration of a wide range of diseases.     

微藻生物合成叶黄素的研究进展

叶黄素不仅是天然色素,而且具有多方面的生理活性功能。目前商业化生产的叶黄素主要是从植物万寿菊中提取,在原料来源和生产效率等方面受到一定限制。作为一种具有良好前景的替代方式,利用微藻生物合成叶黄素近年来受到越来越多的关注。本文综述了国内外关于微藻生物合成叶黄素的藻株筛选、代谢途径、培养参数优化、动力学模型以及提取工艺方面的研究进展。     

Storage stability of lutein during ripening of cheddar cheese

Lutein (3,3'-dihydroxy-alpha-carotene) has been identified as a dietary factor that can delay the onset of age-related macular degeneration (AMD). However, available food sources of lutein contain only modest amounts of the carotenoid. Food fortification with lutein extract has been identified as a low-budget approach to prevent the onset or progression of AMD. The objectives of this study were to 1) incorporate various amounts of lutein into Cheddar cheese; 2) examine the color, pH, microbiological, and sensory characteristics of the Cheddar cheese during storage; and 3) analyze the stability of lutein during the cheese maturation process. Lutein extracted from corn was added to Cheddar cheese in quantities of 1, 3, and 6 mg per serving size. Measurements of the lutein stability were carried out by HPLC using a YMC C30 carotenoid column. Microbiological analyses of cheese samples included aerobic plate count, coliform, and yeast/mold counts. The color attributes a* and b* were significantly different between the treatment and control groups; however, no significant difference was observed in L* value and pH. Significant differences among 1, 3, and 6 mg lutein-enriched cheeses were observed in the aerobic plate count and yeast/mold compared with the control. Cheese samples contained no detectable levels of coliforms (< 10 cfu/g). The HPLC data showed quantitative recovery of lutein during the storage period, and no lutein degradation products were identified. These results indicate that lutein, a functional additive with purported ability to prevent or reduce the onset of AMD, can be incorporated into cheese adding value to this product.     

巯基-烯点击化学法合成两亲性叶黄素

叶黄素是一种含氧的类胡萝卜素,适量摄入叶黄素可以减少白内障的发生,叶黄素还可以调节人和动物的免疫能力并且具有预防癌症的作用,但是,叶黄素的低水溶性限制了其在食品和制药行业中的应用。本文研究了利用巯基-烯点击化学法对叶黄素进行亲水性修饰,为叶黄素的化学改性提供了一种新方法。首先以三乙胺为缚酸剂,使叶黄素与丙烯酰氯酯化反应得到两端以乙烯基为端基的中间体,再在紫外光照射下以2,2-二甲氧基-2-苯基苯乙酮为催化剂,使中间体与L-半胱氨酸通过巯基-烯点击化学反应在叶黄素的两端引入亲水性的氨基和羧基,得到两亲性叶黄素。通过UV、IR对产物进行表征,结果表明成功合成了两亲性叶黄素,通过TEM观察两亲性叶黄素在水中自组装形成球形胶束,平均粒径为85nm,有望会大大增加叶黄素在生物体内的吸收率。     

壳寡糖控制果蔬采后病害及诱导抗病性研究进展

壳寡糖（oligochitosan,OCH）是一类由N-乙酰氨基葡萄糖或氨基葡萄糖通过β-1,4-糖苷键连接起来的低聚合度水溶性的氨基葡聚糖,在农业、食品、医药等领域具有广泛用途。本文综述了OCH对果蔬采后病原菌生长的抑制活性,以及OCH相对分子质量和使用浓度对其抑菌活性的影响。进一步综述了OCH对采后病害的控制作用,对果蔬诱导抗病性、活性氧代谢和抗病相关酶活性的影响。OCH是一种对环境友好的、生物源采后病害诱导剂。OCH及其复配处理在果蔬采后病害防治方面将具有重要应用前景。     

万寿菊叶黄素提取分离研究

本文研究了由万寿菊提取叶黄素的条件,包括皂化处理NaOH浓度,提取时间与次数对提取效率的影响,并通过薄层层析对产品进行了分析。     

叶黄素研究进展

叶黄素属于类胡萝卜素色素之一,近年研究发现其具有保护视觉,预防动脉硬化,抗氧化,抗癌等作用。该文对叶黄素的性状、来源及提取方法,并对叶黄素功能特性及其在医药、食品、饲料中应用进行综述。     

叶黄素 (lutein)及其护眼功能

类胡萝卜素中有一种叶黄素 ,它广泛存在于绿色蔬菜和人体的血浆和眼球中。它不仅有和类胡萝卜素相似的抗氧化活性 ,而且对视网膜色斑褪化引起的视力下降和失明有明显的保护作用。目前在欧美以叶黄素为功能因子的护眼食品已大量商品化。鉴于从蔬菜中提取不仅含量低成本过于昂贵 ,成熟的技术是从叶黄素含量较高的万寿菊 (金盏花 )中提取。本文简要介绍叶黄素性质功用、不同来源含量以及国内外发展状况。