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%.     

响应曲面法优化超声叶黄素的制备工艺

以叶黄素酯为原料,在超声条件下系统地考察了由叶黄素酯制备叶黄素的条件。在单因素实验的基础上,用响应曲面法对叶黄素的制备工艺进行优化,以液固比、超声皂化温度以及皂化时间为因素,分析了各因子与叶黄素得率的关系。确定最佳皂化反应条件是:皂化时间138min、超声皂化温度48℃、液固比15mL/g。在此条件下叶黄素得率达到75.8mg·g-1。     

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。     

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%.     

南瓜中游离叶黄素的制备及抗氧化活性

为了探究南瓜提取物中叶黄素酯的皂化工艺条件和其体外抗氧化能力,在单因素试验基础上,以皂化液浓度、皂化温度和皂化时间为响应因子,采用Box-Behnken中心组合实验原理进行三因素三水平设计,优化南瓜叶黄素的皂化工艺;利用高效液相色谱（HPLC）和质谱（MS）分析检测皂化产物;经硅胶柱色谱分离得到纯化的南瓜叶黄素;采用分光光度法,通过比较DPPH·和·OH的清除能力评价南瓜中游离叶黄素的体外抗氧化活性。结果表明,南瓜提取物中叶黄素酯的最佳皂化工艺条件为皂化液质量浓度33 g/dL,温度33 ℃,时间5.5 h。在最优工艺条件下,南瓜提取物中游离叶黄素得率为0.4175%,与预测值相近,说明该优化工艺稳定可行。高效液相色谱（HPLC）和质谱（MS）分析检测表明皂化产物为叶黄素。硅胶柱色谱纯化后,游离叶黄素的纯度可提高到91.39%。南瓜中游离叶黄素清除DPPH·和·OH的半抑制质量浓度IC₅₀分别为0.021 4 mg/mL和0.038 3 mg/mL,抗氧化活性较高,可作为一种良好的天然抗氧化剂。     

大孔树脂纯化万寿菊花中叶黄素的工艺优化

目的:提高万寿菊花中叶黄素的纯度。方法:以葵花籽油微乳液作为提取剂提取万寿菊中的叶黄素。利用KOH-C₂H₅OH溶液对叶黄素粗提物进行皂化,再用大孔树脂进一步纯化。结果:静态试验中,HP-20型大孔树脂对叶黄素的吸附及解析效果最好,以80%乙醇溶液作为吸附溶剂,无水乙醇溶液作为解析溶剂,上样质量浓度为0.01 mg/mL,最佳静态吸附条件为温度30℃,吸附时间2.0 h, pH 7.0;最佳静态解析条件为温度40℃,解析时间1.0 h, pH为7.0。动态试验中,最佳上样质量浓度为0.01 mg/mL,上样流速为0.4 mL/min。经大孔树脂吸附后的叶黄素纯度可达61.72%。结论:大孔树脂纯化后的万寿菊中叶黄素的纯度明显提高。     

酶法合成咖啡酸叶黄素酯的研究

以叶黄素和咖啡酸为原料,在脂肪酶Novo435的催化下,首次合成了咖啡酸叶黄素酯。研究了脂肪酶催化叶黄素与咖啡酸合成咖啡酸叶黄素酯的影响因素,考察了酶量、溶剂、体系水分、温度、时间等因素对酯化反应的影响。结果表明,适宜的工艺条件是:酶量10mg/mL,溶剂为氯仿,水含量10mg/g,温度40℃,反应时间24h,在上述条件下咖啡酸转化率可达88%。采用IR对目标产物的结构进行了表征。     

高效液相色谱法检测婴幼儿奶粉中的叶黄素

建立了一种使用高效液相色谱技术检测婴幼儿配方奶粉中游离、包埋叶黄素和叶黄素酯的方法。样品经室温皂化后用乙醚∶正己烷∶环己烷(40∶40∶20,体积比)组成的提取溶剂进行提取,以甲醇和甲基叔丁基醚为流动性,在C30色谱柱上采用梯度洗脱,可以很好的将13、13’-顺势叶黄素及反式叶黄素分离。对检测方法进行方法验证,在质量浓度为0.05~1.0 mg/L范围内其线性相关系数≥0.999,检出限为0.06μg/g,回收率在97.61%~108.6%之间,相对标准偏差为2.64%~4.54%。本方法操作简单、结果准确,适用于婴幼儿配方奶粉中游离、包埋叶黄素和叶黄素酯的测定。     

Technical note: Simultaneous carotenoid and vitamin analysis of milk from total mixed ration-fed cows optimized for xanthophyll detection

Concentrations of retinol, α-tocopherol, and major carotenoids in dairy products are often determined simultaneously by liquid chromatography. These compounds have different polarity and solubility; thus, extracting them simultaneously can be difficult and inefficient. In milks with low carotenoid concentrations, the xanthophylls lutein and zeaxanthin may not be completely resolved using common extraction techniques. A simplified method was developed to optimize extraction efficiency and the limit of detection and limit of quantification (LoQ) of lutein and zeaxanthin in bovine milk without decreasing sensitivity to other vitamins or carotenoids. The developed method evaluates lutein, zeaxanthin, β-carotene, retinol, and α-tocopherol simultaneously by ultra-high performance liquid chromatography–photodiode array detection. Common saponification temperatures (40–60°C) and concentrations of KOH in water (10–50% KOH wt/vol) were evaluated. Multiple solvents were evaluated for optimal xanthophyll extraction (diethyl ether, dichloromethane, hexane, and tetrahydrofuran) following saponification. The limit of detection and LoQ were defined as 3:1 and 10:1 signal-to-noise ratio, respectively. All experiments were performed in triplicate. The optimal saponification procedure was a concentration of 25% KOH at either 40 or 50°C. Saponified extracts solubilized in solutions containing diethyl ether had greater concentrations of lutein- than hexane- or tetrahydrofuran-based solutions, with peak areas above LoQ values. The solution containing diethyl ether solubilized similar concentrations of retinol, α-tocopherol, and β-carotene when compared with other solutions. The proposed optimized method allows for the simultaneous determination of carotenoids from milk with increased lutein and zeaxanthin sensitivity without sacrificing recovery of retinol, α-tocopherol, and β-carotene.     

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%。     

A Novel Sample Preparation Method Using Rapid Nonheated Saponification Method for the Determination of Cholesterol in Emulsified Foods

Abstract: In this study, nonheated saponification was employed as a novel, rapid, and easy sample preparation method for the determination of cholesterol in emulsified foods. Cholesterol content was analyzed using gas chromatography with a flame ionization detector (GC‐FID). The cholesterol extraction method was optimized for maximum recovery from baby food and infant formula. Under these conditions, the optimum extraction solvent was 10 mL ethyl ether per 1 to 2 g sample, and the saponification solution was 0.2 mL KOH in methanol. The cholesterol content in the products was determined to be within the certified range of certified reference materials (CRMs), NIST SRM 1544 and SRM 1849. The results of the recovery test performed using spiked materials were in the range of 98.24% to 99.45% with an relative standard devitation (RSD) between 0.83% and 1.61%. This method could be used to reduce sample pretreatment time and is expected to provide an accurate determination of cholesterol in emulsified food matrices such as infant formula and baby food. Practical Application: A novel, rapid, and easy sample preparation method using nonheated saponification was developed for cholesterol detection in emulsified foods. Recovery tests of CRMs were satisfactory, and the recoveries of spiked materials were accurate and precise. This method was effective and decreased the time required for analysis by 5‐fold compared to the official method.     

影响雨生红球藻中虾青素的提取条件的研究

冻干的雨生红球藻粉为原料,采用乙醇和乙酸乙酯混合溶剂进行虾青素酯的提取。L9(33)正交试验筛选获得虾青素酯的最佳条件为:温度25℃,提取时间为6h,乙酸乙酯和乙醇的配比为1:2,固液比为1:120(g/ml)。对提取的虾青素酯进行皂化,分别研究了4℃和40℃时碱的浓度及皂化时间对提取效果的影响。结果表明:0.06mol/LKOH甲醇溶液于4℃皂化12h效果最好,从100mg藻粉可以得到(575.86±5.68)μg虾青素单体。     

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。     

温度控制对微波萃取叶黄素酯的影响

探索温度控制对微波辅助萃取叶黄素酯萃取率的影响。首先测定不同输出功率对萃取溶媒升温的影响,然后以万寿菊干花颗粒为样品,探讨升温功率、萃取时间和萃取温度对萃取率的影响,并比较相同温度条件下微波萃取与溶剂法的萃取率。结果表明：分子中含有O－H键的溶媒升温较快;升温功率的变化对萃取率的影响有限。萃取时间的延长可导致萃取率下降;在1600W、20min和分别为50、50、40℃条件下,正己烷、乙酸乙酯和四氢呋喃萃取率分别为83%～95.23%、81.44%～96.59%和91.72%～94.40%。在相同温度条件下,微波萃取可有效地提高叶黄素酯的萃取率。     

玉米胚芽油脂肪酸衍生化工艺

以玉米胚芽油为原料,对其中亚油酸进行酯化衍生化,实现亚油酸的富集。分别考察碱用量、反应时间、反应温度及酸化程度对水解反应和H2SO4-甲醇溶液体积分数、用量、反应时间和温度对酯化反应的影响。结果表明：醇油比(95%乙醇-玉米胚芽油,mL/g)为2:1,KOH用量为玉米胚芽油皂化当量的1.1倍、80℃水浴回流100min时,水解反应最完全,酸值最大为207.85mg KOH/g,所得脂肪酸在催化剂5% H2SO4-甲醇溶液用量为5mL/g、70℃水浴30min条件下甲酯化反应最完全,气相色谱检测甲酯化程度为100%。经尿素包合进行富集得到纯度为96.98%的亚油酸。     

响应面优化粟米糠油溶剂萃取工艺及理化性质分析

以粟米糠为原料,采用正己烷为提取剂,对粟米糠油进行提取,并分析粟米糠油的理化特性和脂肪酸组成。在单因素试验的基础上,通过Box-Behnken试验设计对提取工艺进行响应面优化。结果表明,最佳提取工艺条件为：料液比1∶7（g/mL）、提取时间6 h、提取温度55 ℃。在此条件下,粟米糠油的实际提取率为83.3%,与理论值基本吻合。所得粟米糠油的凝固点19.0 ℃、酸值5.7 mg KOH/g、过氧化值2.1 mmol/kg、皂化值185.1 mg KOH/g、碘值118.9 g I2/100 g。通过气相色谱-质谱法确定了10 种脂肪酸,不饱和脂肪酸含量为82.5%,其中亚油酸含量63.6%、油酸含量14.8%、α-亚麻酸含量2.7%。