二氢杨梅素纳米乳液的制备及性能评价

通过乳化法制备了二氢杨梅素纳米乳液。对其粒径、分散度、包封率、抗氧化能力以及体外释放进行了研究。试验结果显示,制备的二氢杨梅素纳米乳液的平均粒径为86.85±0.54 nm,分散度为0.099±0.002,包封率为92.4%±0.4%,稳定性、抗氧化性较好。体外释放的考察结果表明,二氢杨梅素纳米乳液对活性物具有缓释的效果。二氢杨梅素纳米乳液在功能化食品领域发挥更好的作用。     

维生素E对β-胡萝卜素纳米乳液性质及其饮料稳定性的影响

为提高β-胡萝卜素的水溶性和稳定性,本研究以吐温80、吐温60和磷脂为乳化剂,维生素E为抗氧化剂制备了纳米乳液.测定了纳米乳液的粒径、透光率、色价、储藏稳定性和应用稳定性.结果显示,维生素E对纳米乳液粒径和透光率有轻微影响,对包埋率和色价没有影响.在25、37℃和光照下储藏28 d期间纳米乳液的透光率没有发现明显变化,...     

界面结构对叶黄素纳米结构脂质载体生物可及性及稳定性的影响

为探究界面结构对叶黄素纳米结构脂质载体(Lutein-NLCs)稳定性及生物可及性的影响,通过乳清分离蛋白和小分子表面活性剂吐温80复配,构建复合界面、双界面以及单界面的Lutein-NLCs,对3种界面结构的Lutein-NLCs的基本性质、界面吸附特性、生物可及性以及稳定性进行研究,结果表明:3界面结构Lutein-NLCs粒径为127.60~180.86 nm,包封率最高达97.78%,其叶黄素生物可给率显著高于普通纳米乳液和游离叶黄素(P < 0.05),其中,单界面Lutein-NLCs的叶黄素生物可给率显著高于复合界面和双界面(P <0.05)。3种界面结构Lutein-NLCs中叶黄素释放速率显著低于普通纳米乳液,且与单界面Lutein-NLCs相比,复合界面和双界面Lutein-NLCs的缓释效果更为显著。在贮藏过程中,Lutein-NLCs提高了叶黄素的保留率,其中复合界面Lutein-NLCs的保留率最高,是叶黄素对照组的12.06倍。     

包覆花色苷W_1/O/W_2型乳液的消化特性及其缓释效果

研究体外消化对包埋葡萄皮花色苷(anthocyanins,ACNs)W_1/O/W_2型乳液控释和抗氧化性能的影响。W_1/O/W_2型乳液粒径约为(149.33±1.44)nm,并且呈双峰分布,ACNs的包封率为(82.99±2.38)%。体外口腔消化对W_1/O/W_2型乳液液滴结构无明显影响。经口进入模拟胃消化后,W_1/O/W_2型乳液因蛋白质水解失去双层结构,释放的W1/O液滴聚集在一起而使粒径显著增加(P0.05)。经胃进入模拟肠道消化后,W1/O液滴破碎,平均粒径(d150 nm)显著减小(P0.05),此时具有最高的抗氧化活性。结果表明,W_1/O/W_2型乳液能有效地保护ACNs免受体外口腔和胃消化的影响,并可靶向地在模拟小肠内传递和释放。     

茶黄素-3’-没食子酸酯-壳聚糖纳米乳液的制备及其性能分析

纳米乳液系统实现了生物活性分子的高效运输、传递,解决了营养物质不稳定、易氧化、生物利用率低等问题。本实验以三聚磷酸钠(Sodium Triphosphate,TPP)作为交联剂,采用离子交联法制备茶黄素-3’-没食子酸酯-壳聚糖(Theaflavin-3’-gallate-Chitosan,TF2B-CS)纳米乳液,所制得乳液粒径为(241.31±6.92)nm,Zeta电位为(13.36±1.03)mV,包埋率为80.34%。通过体外模拟消化研究TF2B-CS纳米乳液的消化规律,对其进行粒径、Zeta电位和微观结构检测,并考察TF2B在小肠消化阶段的生物利用率。在体外模拟消化过程中,胃阶段粒径显著高于原始乳液,各阶段Zeta电位均小于原始乳液;经过口腔-胃-小肠三阶段体外模拟消化后的TF2B生物利用率为9.71%。研究通过制备纳米乳液作为递送TF2B的良好体系,有效地发挥TF2B的生物活性,为进一步优化纳米乳液的制备工艺及其应用提供理论依据。     

维生素E纳米乳液冻干粉末的制备及结构特性研究

联合真空冷冻干燥技术与高压均质技术制备一种水包油型(O/W)真空冷冻干燥维生素E纳米乳液粉末复原乳液,通过单因素试验及响应面分析法优化该复原乳液的最佳工艺条件,并通过扫描电子镜、流变仪、红外光谱等手段对维生素E纳米乳液、冷冻干燥粉末以及复原乳液的物理化学性质进行研究。结果表明:维生素E纳米乳液粉末复原乳液最佳工艺条件为:大豆分离蛋白质量浓度15 mg/mL,葵花籽油质量浓度45 mg/mL,均质压力100 MPa,均质4次。所得维生素E纳米乳液粉末复原乳液平均粒径232.66 nm,包埋率90.82%。冻干粉末复原乳液稳定性良好,扫描电镜结果显示冻干粉末结构致密均匀、表面光滑;流变仪扫描结果显示冻干粉末复原乳液呈典型的剪切变稀流变行为,具有牛顿流体特征;红外光谱试验结果显示冻干粉末的蛋白α-螺旋、β-转角结构增加,β-折叠、无规则卷曲结构降低。真空冷冻干燥的维生素E纳米乳液粉末复原乳液,提高了维生素E吸收率且乳液体系稳定性良好。     

BSA-葡聚糖-叶黄素纳米颗粒的制备及其抗氧化活性

采用高压均质法制备牛血清白蛋白-叶黄素(bovine serum albumin-lutein,BSA-lutein)和牛血清白蛋白-葡聚糖-叶黄素(dextran-bovine serum albumin-lutein,DBSA-lutein)两种纳米颗粒,并对比了两者的体外抗氧化性能。研究结果表明:DBSA-lutein纳米颗粒的包封率、平均粒径、聚合物分散性指数以及Zeta电位分别为(95.86±0.83)%、(176.8±6.5)nm、0.176±0.07、(-30.5±0.6)mV;体外抗氧化性能(清除DPPH自由基、清除ABTS+自由基、清除羟基自由基、总还原力以及细胞内抗氧化能力)方面,DBSA-lutein均高于BSA-lutein。     

pH梯度法制备维生素C脂质体

制备维生素C脂质体,并考察其包封率的影响因素。采用pH梯度法制备维生素C脂质体,以紫外分光光度法和粒度仪分别测定脂质体的包封率和粒径,并考察外水相pH、超声时间、载药温度及药脂比对包封率的影响。结果显示包封率随外水相pH的降低而增加,最佳超声时间为15 min,随着载药温度的增加包封率有提高的趋势,最佳药脂比为1∶5。该条件下pH梯度法制备的维生素C脂质体的包封率为(49.79±1.6)%(n=3),平均粒径为(118.3±9.6)nm。     

维生素E-大豆蛋白微胶囊的制备及特性分析

为生产包封效率高、稳定性好的维生素E微胶囊产品,以大豆分离蛋白/硫酸葡聚糖复合颗粒或大豆分离蛋白与麦芽糊精作为复合壁材,大豆油和维生素E为芯材,通过冷冻干燥法制备维生素E-大豆蛋白微胶囊,通过对微胶囊包封效率、粒径、傅里叶红外光谱（FT-IR）、水分含量、润湿性、溶解度、吸湿性、堆积密度、振实密度、流动性、内聚性等理化性质的探究,考察壁材组成对微胶囊特性的影响。结果表明：壁材组成对微胶囊的理化性质具有显著影响;微胶囊最佳壁材组成为大豆分离蛋白/硫酸葡聚糖复合颗粒含量4 g/100 mL（以乳液体积计）和麦芽糊精含量12 g/100 mL（以乳液体积计）,在此条件下微胶囊的包封效率为89.31%,粒径为1.39 μm,且颗粒较为均一,水分含量较低,润湿性较低,溶解度较高,吸湿性较小,流动性较差,内聚性较强。综上,以大豆分离蛋白/硫酸葡聚糖复合颗粒和麦芽糊精作为复合壁材制备的维生素E-大豆蛋白微胶囊包封效率高,粉末特性好。     

特种油脂纳米乳液超声制备工艺优化及其特性研究

为了得到富含绿茶叶籽油和分提椰子油的特种油脂纳米乳液,研究了主要因素表面活性剂含量、超声功率、超声时间及其交互作用对超声制备的纳米乳液平均粒径的影响,利用响应面法优化了制备条件并对纳米乳液的稳定性及生物利用率进行评价。结果表明最佳工艺参数为:表面活性剂含量2.2%、超声功率351 W、超声时间12 min,所得纳米乳液的平均粒径(183.00±1.58)nm。所制备的纳米乳液在pH6~8、热处理温度40~80℃条件下以及5、27℃的长期贮藏中具有良好的稳定性,纳米乳液体系显著提高了绿茶籽油和分提椰子油的体外消化率,游离脂肪酸释放率最终达到87%。     

不同加热处理对花生维生素含量的影响研究

以花生为原料,研究加热处理(水煮、蒸煮、油炸)对花生中维生素的影响.结果 表明:以湿基计,油炸处理后维生素E含量未发生显著变化,其他处理均使维生素E含量下降,花生中的烟酸在水煮处理之后保留率最低;以干基计,加热处理前后维生素E含量无显著变化,花生中的维生素B1在油炸处理之后保留率最低.不同加热处理后花生中烟酸、维生素B...     

维生素D缺乏对新生儿健康影响的研究进展

维生素D是一种脂溶性维生素,不仅具有抗菌抗炎、免疫调节的作用,还参与了人体多种细胞的增殖、分化、凋亡。维生素D缺乏已成为全球性的公共卫生问题,孕妇维生素D缺乏对母婴二人均有直接影响,是新生儿健康的危险因素之一。本文主要综述了维生素D的代谢及生理功能、影响新生儿维生素D水平的因素、维生素D缺乏与新生儿疾病的关系、维生素D水平评价标准、维生素Ｄ的推荐剂量及膳食补充。以期达到提高孕妇补充维生素D的意识的目的,为提高我国新生儿生存质量提供保障,同时为新生儿相关疾病的预防和治疗提供新思路。     

Vitamin Fortification of Fluid Milk

Vitamin concentrates with vitamins A and D are used for fortification of fluid milk. Although many of the degradation components of vitamins A and D have an important role in flavor/fragrance applications, they may also be source(s) of off‐flavor(s) in vitamin fortified milk due to their heat, oxygen, and the light sensitivity. It is very important for the dairy industry to understand how vitamin concentrates can impact flavor and flavor stability of fluid milk. Currently, little research on vitamin degradation products can be found with respect to flavor contributions. In this review, the history, regulations, processing, and storage stability of vitamins in fluid milk are addressed along with some hypotheses for the role of vitamin A and D fortification on flavor and stability of fluid milk.     

维生素B1、B2含量测定方法比较

目的:比较维生素B1、B2含量测定方法。方法:采用紫外分光光度法中三种不同方法测定维生素B1、B2含量。结果:1、按E值测标示量维生素B1:98.3±2.51,维生素B2:94.8±0.308,复合维生素B片中维生素B1:102.1±1.70,维生素B1平均回收率为100.4%,RSD为2.13%(n=6),维生素B2平均回收率为94.9%,RSD为6.5%(n=6)。2、标准曲线法维生素B1、B2浓度分别在3～18、1～8μg/ml范围内,均呈良好线性关系,标示量分别为:102.9±0.661,98.4±0.152。3、双波长法测维生素B1标示量:94.2±1.97。结论:三种方法用于维生素B1、B2含量测定,操作简便、快速、准确,精密度好。     

How Safe is Vitamin E Supplementation?

The safety of large doses of vitamin E went virtually unquestioned until the early 2000s, when several studies were published showing that consumption of vitamin E from dietary supplements increased mortality, as well as the risk of gastrointestinal cancer and heart failure. These studies prompted numerous letters to the editors of medical journals and widespread coverage in the media. Both the medical community and the general public became confused and concerned about the use of vitamin E supplements. The purpose of this article is to review the medical literature and to explain these unusual findings. First we provide an overview of the earlier literature on vitamin E. Second, we provide a critical assessment of three meta-analyses that were neutral or negative toward vitamin E supplementation. Third, we review the limitations of meta-analyses in general. Fourth, we assess the individual studies that comprised one of the three meta-analyses. Since all three meta-analyses used many of the same studies, the individual critique should further the understanding of the limitations of these meta-analyses, and the meta-analysis approach in general. Lastly, we offer some guidance for healthcare professionals to give to the general, healthy public and those with chronic conditions who are no doubt left puzzled as to what to do regarding vitamin E supplementation.     

乳粉中主要B族维生素检测的GB和AOAC方法比较分析

为探究维生素B1、B2、B3（烟酸）、B6的国家标准方法和AOAC官方方法检测结果的可比性和误差来源,该研究通过对测试结果的F检验、显著性差异检验对维生素B1、B2、B3、B6的国家标准方法和AOAC官方方法进行了等效分析、并通过双向单侧t检验（TOST）对维生素B2进行了详尽的比较分析。分析结果表明,维生素B1、维生素B3和维生素B6国家标准方法和AOAC官方方法之间无显著性差异,而维生素B2国家标准方法和AOAC方法之间机理存在差异,通过等效性分析后数据结果表明两种方法等效不好;实验中发现在乳粉基质中添加酸性磷酸酶能够获得更接近可比性数据结果。     

Short communication: effect of vitamins E and C on cortisol production by bovine adrenocortical cells in vitro

The aim was to determine if vitamins E and C inhibit the release of cortisol from bovine adrenocortical cells when stimulated with ACTH in vitro. A factorial arrangement of treatments was used to culture bovine adrenocortical cells with different concentrations of vitamins E and C [(+)-α-tocopherol at 0, 2.3, and 16 μM and l-ascorbic acid at 0, 15, and 50 μM]. After 3 and 7 d of vitamin treatments, cell cultures were stimulated with ACTH (1 nM) for 24 h and the culture medium extracted to measure cortisol released by the cells using HPLC with UV detection. Vitamin E, vitamin C, or their combination did not affect the amount of cortisol released by the adrenal cultures to the media. Cortisol released by the adrenal cultures ranged from 33.6 ± 6.85 to 49.7 ± 8.01 nmol per 10⁷ cells. The modulation effect of vitamins E and C on the stress response does not take place at the cortex of the adrenal gland.     

Selected Vitamin Contents and Retentions in Bison Patties as Related to Cooking Method

Contents and retentions of selected vitamins in broiled and grilled bison patties from four producers were determined. Mean vitamin contents of uncooked bison patties were (per 100 g wet weight): 0.038 mg thiamin, 0.220 mg vitamin B-6, 1.457μg vitamin B-12, and 0.286 mg vitamin E; no differences were observed among producers. Differences were found (P<0.05) among producers for vitamins B-6, B-12, and E (broiled only), but not for thiamin contents of cooked bison patties. The mean retention values in cooked patties were: 68.9% thiamin; 67.5% vitamin B-6; 67.0% vitamin B-12; and 76.1% vitamin E. Bison patties are rich sources of vitamin B-12 and good sources of vitamin B-6.     

Dietary Intake of Natural Antioxidants: Vitamins and Polyphenols

Oxidative stress is a condition in which oxidant metabolites exert their toxic effect because of an increased production or an altered cellular mechanism of protection; oxidative stress is rapidly gaining recognition as a key phenomenon in chronic diseases. Antioxidants terminate these chain reactions by removing free radical intermediates, and inhibit other oxidation reactions by being oxidized themselves. Endogenous defence mechanisms are inadequate for the complete prevention of oxidative damage, and different sources of dietary antioxidants may be especially important. This article calls attention to the dietary antioxidants, such as vitamins A, C, and E and polyphenols. Compelling evidence has led to the conclusion that diet is a key environmental factor and a potential tool for the control of chronic diseases. More specifically, fruits and vegetables have been shown to exert a protective effect. The high content of minerals and natural antioxidant as vitamins A, C, and E and polyphenols in fruits and vegetables may be a main factor responsible for these effects.     

柱切换法液相色谱测定保健食品中的VA、VD、VE

建立柱切换法液相色谱测定保健食品中VA、VD、VE含量的方法.参照GB 5009.82-2016《食品中维生素A、D、E的测定》样品前处理方法,以Agilent Poroshell 120 PFP(4.6 mm×100 mm,2.7 μm)为一维色谱柱,甲醇、水为流动相梯度洗脱,分离VA和VE的4种异构体,以Agile...