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%。     

响应面法优化叶黄素酯皂化工艺及其动力学特性

以叶黄素酯为皂化反应原料,应用薄层分析法计算皂化率,采用响应面法对万寿菊花中叶黄素酯皂化反应的工艺进行优化,确定叶黄素酯皂化的适宜操作条件,并研究了其皂化反应动力学特性。结果表明:皂化最佳工艺为叶黄素酯2.0 g,C2H5OH用量为31.3 m L,皂化温度为60℃,KOH固体用量为2.1 g,皂化时间为4 h,叶黄素酯的平均皂化率为78.4%;皂化反应总级数为2级,对叶黄素酯为2级,对KOH反应级数为0,建立叶黄素酯皂化反应动力学方程。     

万寿菊花中反式叶黄素提取皂化工艺的优化

以万寿菊干花颗粒为原料,对万寿菊花中反式叶黄素进行同时提取皂化工艺研究。考察不同有机溶剂和用量、KOH- 乙醇溶液质量浓度和用量、提取皂化温度和时间等因素对反式叶黄素提取皂化效果的影响。在单因素试验基础上,采用响应曲面法对影响万寿菊花中反式叶黄素提取皂化效果的3 个主要因素即石油醚用量、KOH-乙醇溶液质量浓度和提取皂化温度进行优化,建立并分析各因素与反式叶黄素得率关系的数学模型,同时对反式叶黄素粗品进一步分离纯化。结果表明：采用有机溶剂法进行同时提取皂化的最佳工艺条件为石油醚用量42.6mL/g、温度58.8℃、KOH- 乙醇溶液质量浓度0.099g/mL,在此条件下反式叶黄素得率为1.499%。对反式叶黄素粗品进一步纯化,最终获得纯度达90.42% 的反式叶黄素晶体。     

烘焙类食品中叶黄素酯提取及检测方法建立

为检测烘焙类食品中的叶黄素酯以及筛选无乙醚的萃取溶剂,本文对烘焙产品中的叶黄素酯皂化时间、KOH浓度以及不同萃取溶剂的萃取效果进行研究。结果表明检测烘焙食品中叶黄素酯的皂化最优条件为:2 g样品（面糊/面团）,0.2 g BHT,10 mL无水乙醇,10 mL 60 g/100 mL KOH水溶液,室温振荡3 h。萃取溶剂环己烷:正己烷:乙酸乙酯=1:2:2为最佳萃取剂,回收率为94.31%~103.83%,精密度实验相对标准偏差均小于5%。表明该方法适合于烘焙类食品中叶黄素酯的提取及检测。     

叶黄素油树脂皂化结晶技术制备叶黄素晶体研究

以KOH-乙醇溶液为皂化液,对叶黄素油树脂的皂化和结晶工艺进行了研究.分别考察了皂化时强碱浓度和二元溶剂结晶体系对叶黄素晶体纯度的影响以及水醇混合液中水与无水乙醇的比例对叶黄素提取率的影响.结果表明,叶黄素油树脂皂化、结晶的适宜工艺条件是:采用10.0%(w/v)KOH-乙醇溶液皂化,然后在O～10℃条件下用体积比2:1的去离子水/无水乙醇混合液洗涤,最后在1:1二氯甲妇乞/正己烷的二元溶剂中进行重结晶,此时得到的晶体纯度达91.3%.     

C30柱分离万寿菊花中的叶黄素类化合物初探

应用C30-HPLC-PDA,万寿菊花萃取物中的叶黄素类化合物获得了良好的分离,包括:叶黄素酯的分离和单体几何异构体的分离。色谱条件为:WatersYMCCarotenoidS-5(4.6×250mm)柱;乙腈-甲醇(75:25,V/V)为流动相A,甲基叔丁基醚为流动相B,线性梯度洗脱;流速:1.0ml/min;PDA波长范围:300～600nm;进样量:20μl。根据各组分的色谱行为、光谱特征和在碘催化下发生几何异构的产物分析对各组分进行初步鉴定。实验结果显示:C30固定相在分离万寿菊花萃取物中的叶黄素类化合物的应用中有良好的前景。     

婴幼儿配方食品中叶黄素的提取及测定

比较婴幼儿配方食品中叶黄素的3种提取方法：氢氧化钾皂化法、丙酮提取法和正己烷提取法,从中得出最佳提取方法为正己烷萃取法。选用色谱柱YMC Carotenoid(4.6mm×250mm,5μm)以甲醇、甲基叔丁基醚为流动相进行梯度洗脱,流速为1mL/min,于445nm波长处测定婴幼儿配方食品中叶黄素的含量。该方法操作简便,提取效率高(平均回收率为95.4%),重现性好(RSD为0.93%),检出限为2μg/100g,可以准确的测定婴幼儿配方食品中叶黄素的含量。     

万寿菊提取物中游离叶黄素的制备及纯化

以万寿菊正己烷提取物为原料,系统地考察了由万寿菊提取物制备游离叶黄素的条件,并对粗产品进行纯化。在单因素试验的基础上,用L16(45)正交试验对游离叶黄素的制备工艺进行优化,以皂化液浓度、液料比、皂化温度以及皂化时间为因素,以游离叶黄素的含量为指标进行试验,得到最佳的制备条件;并对硅胶柱层析纯化的梯度洗脱条件进行摸索;采用薄层色谱扫描法进行测定。确定最佳皂化制备条件是:皂化液为35%的KOH-甲醇,液料比20:1(ml/g),皂化温度55℃,皂化时间4h;在此条件下,可使游离叶黄素的含量由原料中的0.25%上升到45.59%,通过硅胶柱层析纯化后,游离叶黄素的含量可提高到93.55%。     

叶黄素的分离纯化及其清除羟自由基活性

运用KOH-甲醇溶液皂化法将叶黄素酯转化为游离叶黄素,进一步采用硅胶柱层析进行分离纯化,并对不同纯度产品中叶黄素的含量进行HPLC法测定;以没食子酸丙酯为参照,采用流动注射化学发光法测定不同纯度叶黄素产品清除.OH的效果。结果表明:叶黄素浸膏通过皂化,游离叶黄素的含量由1.35%提高到30.25%,进一步柱层析处理得到80.32%的叶黄素产品;不同纯度叶黄素产品均具有较强的清除.OH活性,且其抗氧化活性与叶黄素的含量正相关。     

RP-高效液相色谱法测定胡萝卜中的维生素A原及叶黄素

使用石油醚:丙酮=1:1(v:v)提取胡萝卜中的类胡萝卜素,用RP-高效液相色谱测定成熟期的维生索A原(α-胡萝卜素、β-胡萝卜素)和叶黄素.流动相为甲醇:乙腈=90:10(v:v),流速为0.8mL/min,检测波长为450nm.α-胡萝卜素、β-胡萝卜素和叶黄素的回收率依次为:98.8%、99.3%、99.0%.成熟期胡萝卜中检测到α-胡萝卜素、β-胡萝卜素和叶黄素的含量分别为:190.573、308.930、0.325μg/g.     

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。     

Lutein: a valuable ingredient of fruit and vegetables

Lutein is a human serum carotenoid which is not synthesized by humans and thus must be obtained by the ingestion of food containing it such as fruits and vegetables. Lutein is present in different forms in those foods as all-trans-lutein, cis-lutein, epoxi-lutein, and lutein linked to proteins. It discusses if the intake of lutein or diets supplemented with lutein or diets rich in fruits and vegetables are important in the prevention of diseases like some cancers, cardiovascular diseases, etc., that may be affected by the antioxidant effect of lutein; or in the prevention of age-related macular degeneration and other eye diseases. The concentration of lutein in fruits and vegetables depends on the species. We've included the concentration of lutein in 74 species reported by different authors since 1990. Currently the quantification of lutein is mainly performed by HPLC, but more investigations into a quantification method for lutein, lutein isomers, and epoxi-lutein are necessary. Improvement of lutein extraction methods is important as well. Methods commonly used in the vegetable and fruit industry like heat treatment, storage conditions, etc. can change lutein concentrations; other factors depend on the plant, for instance the variety, the stage of maturity, etc.     

叶黄素的微藻生物法生产技术

叶黄素是类胡萝卜素的一种,可作为食品抗氧化剂和着色剂,在食品工业、饲料工业和医药中具有广泛的应用前景。综述天然叶黄素的微藻法生产技术研究进展,为我国叶黄素的开发研究提供参考。     

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。     

高效液相色谱法测定蛋白核小球藻中的叶黄素

采用反相高效液相色谱法(RP-HPLC)分离测定了蛋白核小球藻中的叶黄素。样品制备采用甲醇-二氯甲烷(体积比为2：1)混合溶剂为叶黄素提取剂，所用色谱柱为Nova-Pak~(?)C_(18)不锈钢柱，以甲醇-乙腈-水(体积比为80：10：10)和甲醇-乙腈(体积比为40：60)为流动相，线性梯度洗脱，流速0.8mL／min，在447nm下用光电二极管阵列检测器(DAD)检测。测定结果显示，在0～60mg／L范围内，标准曲线呈良好的线性关系(r=0.9999)，叶黄素的保留时间为11.25min，浓度的相对标准偏差为0.49％(n=6)，平均加样回收率为99.7％。该法简单、快速、准确。     

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。