温度及光照对婴幼儿配方乳粉中VA、VD稳定性的影响

为研究不同温度条件下婴幼儿配方乳粉中VA和VD的稳定性,分别考察其在25、40、60℃及80℃储藏条件下乳粉中的含量变化;通过采用透光和避光2种方式储存的乳粉进行光照试验,研究了光照对乳粉中VA和VD稳定性的影响.结果 表明,25℃储藏条件下,乳粉中VA和VD含量均无明显变化;40、60℃和80℃条件下,VA含量有不同...     

紫外光影响食用菌中VD2含量的研究进展

维生素D（vitamin D,VD）对人体健康至关重要,它主要由VD原经紫外光照射转化而来。VD家族中最重要的成员是VD2、VD3。食用菌中含有丰富的VD2原--麦角固醇,经紫外光照射可转化为VD2。本文从VD2的光合成机理出发,介绍不同生长方式的食用菌中麦角固醇和VD2的含量以及紫外光影响食用菌中麦角固醇向VD2转化的主要因素,包括食用菌种类、紫外光的波长、照射剂量和时间、食用菌的照射部位和生长期及食用菌的含水量和温度等,以期为提高食用菌的VD2产率提供一定参考。     

VD2合成新工艺

麦角固醇光化学开环反应是制备VD2的关键步骤。传统的光化学反应生产工艺，需利用多个低功率汞灯进行长时间连续光照，在这样的光化学反应条件下会有大量副产物生成，限制了VD2的收率，并给产品的提纯带来极大难度，影响产品质量。另外，现有工艺中VD2的分离纯化技术（液相色谱或多步结晶），不仅工艺繁琐，增加生产成本，还严重影响生产规模，生产过程中所用的某些试剂也不利于环境保护。中国科学院理化技术研究所基于几十年来在光化学领域的研究积累，在成功研发出VD2生产新工艺的基础上（VD2项目已成功实现成果转化，并产生了显的经济效益）。     

维生素D3补充对大鼠免疫细胞功能影响的实验研究

目的：维生素D（VD）对机体免疫功能作用已引起广泛关注,本实验研究补充不同剂量VD,对大鼠免疫细胞活性的影响。方法：将30只Wistar大鼠随机分为3组,分别为VD,1（对照组）、VD,2和VD,3组,每组10只,雌雄各半。VD,l组大鼠每天摄入VD,20IU／kg（生理剂量,相当于成人每天摄入5txg维生素D,）、VD2组和VD3组分别补充200IU／（kg·d）（10倍量）和1000IU／（kg·d）（50倍量）的VD,;补充时间为4周。实验结束时麻醉无痛处死,取血样（约5mL）离心,采用LC-Ms／MS测定血清VD,浓度、CCK-8法检测淋巴细胞增殖活性、流式细胞术测单核细胞吞噬功能。结果：经过4周VD,补充后,结果显示,VD,1、VD,2和VD。3组大鼠血清VD,浓度分别为14．8ng／mL、34．7n【g／mL和60．7ng／mL,随着补充剂量的增加,机体VD,吸收水平也显著提高;VDl补充后,VD,2组淋巴细胞增殖活性的OD值达到3．04,明显高于VD,1组的2．64（P〈0．05）,但VD33组与VD31组相比淋巴细胞增殖活性无显著性差异（P〉0．05）。采用流式细胞术观察单核细胞吞噬活性（荧光强度）,结果显示VD,2组大鼠单核细胞吞噬活性荧光强度到达19．98,明显高于VD,1组的15．48,而高剂量VD,补充的VD,3组大鼠单核细胞吞噬活性未见明显增强。结论：适宜剂量VD,[200IU／（kg·d）]补充可增强淋巴细胞增殖和单核细胞吞噬活性,而过高剂量（50倍生理剂量）未观察到明显免疫调节作用。     

固相萃取-高效液相色谱法测定婴幼儿食品中的维生素D_2、D_3

目的:建立固相萃取-高效液相色谱法测定婴幼儿食品中的VD2、VD3含量的方法。方法在已有研究基础上对样品前处理方法进行了优化和改进,利用二甲基亚砜、甲醇和正己烷:甲基叔丁基醚(v∶v=2∶1)进行提取,ProElut VDC萃取分离,10%乙酸乙酯正己烷洗脱,甲醇定容后高效液相色谱仪检测。结果维生素D2、D3在0.1-10μg/mL浓度范围内相关系数均为0.999以上,回收率均在90%以上,相对标准偏差小于4%。结论方法快速、灵敏、准确,前处理简单易行,可用于婴幼儿食品中VD2、VD3的含量。     

维生素D_2微囊的制备与研究

以明胶和环糊精为壁材 ,采用凝聚法制备VD2 微囊 ,通过真空干燥制得微囊成品。研究中发现 ,采用真空干燥法制备的微囊粒径较小 ( 0 1～ 0 5mm) ,稳定性好 ,经过 7d的高温 ( 60℃ )加速试验 ,微囊中VD2 的含量超过 83 5 % ,较好地增加了VD2 稳定性 ,可以作为食品的营养添加剂。     

VD3-β-环糊精包合物的制备及质量评价

目的:研究VD3-β-环糊精包合物的制备工艺并考察包合物的有关性质。方法:以包合率为评价指标采用正交试验设计对VD3-β-环糊精包合物的制备方法进行工艺优化,利用IR、1H-NMR鉴定包合物的形成,并考察包合物的稳定性及相对生物利用度。结果:试验证明β-环糊精包合VD3的最佳工艺为β-环糊精与VD3的投料比为15∶1,在80℃条件下搅拌5h;IR、1H-NMR分析证明了包合物的形成;同时包合物提高了原VD3的稳定性及生物利用度。结论:VD3-β-环糊精包合物稳定性及生物利用度明显提高,该方法具有较高的实用价值。     

高效液相色谱-串联质谱联用法与高效液相色谱法同步测定白玉菇麦角固醇和VD2方法比较

建立高效液相色谱-串联质谱（high performance liquid chromatography-tandem mass spectrometry,HPLCMS/MS）联用法与HPLC法同步检测白玉菇样品中麦角固醇和VD2含量方法,经方法学评价确定两种检测方法的线性范围、灵敏度与精确性。通过对经醇碱皂化回流法提取样品中麦角固醇和VD2的分析验证,阐述两种检测方法的差异性,为白玉菇有效生物活性成分与相关产品的质量检测和对白玉菇中麦角固醇与VD2之间转化关系的研究提供技术支持。HPLC-MS/MS法中,采用色谱分离柱Agilent SB-C8 Rapid Res柱（2.1 mm×50 mm,3.5 μm）及在优化的色谱条件下,麦角固醇与VD2之间色谱峰保留时间分别为4.303 min和4.22 min。电喷雾离子源正离子模式下采用多反应选择离子监测模式,分别选择m/z 379.3/125.3与m/z 397.3/125.3离子对麦角固醇与VD2进行定量,结果表明麦角固醇在0.15～6 mg/L、VD2在0.01～1 mg/L范围内与峰面积线性关系良好,平均加标回收率分别为93.51%、90.56%,日内和日间相对标准偏差均小于7%。HPLC法采用COSMOSIL Column 5C18-MS-II（4.6 mm×250 mm,5 μm）柱分离体系,麦角固醇和VD2色谱峰保留时间分别为12.891 min和9.919 min,方法学评价结果显示,麦角固醇在15～750 mg/L、VD2在0.5～50 mg/L范围内与峰面积线性关系良好,两者的平均回收率分别为98.51%、94.05%,日内和日间相对标准偏差均小于1%。采集的样品采用HPLC-MS/MS联用法和HPLC法分别检测实验结果有一定的差异,与HPLC法相比,HPLC-MS/MS联用法具有快速检测时间短、检出限低、更灵敏的优势。     

维生素D3-β-环糊精包合物稳定性及抗回生研究

对维生素O3-β-环糊精(VD3-β-CD)包合物稳定性及抑制淀粉回生特性进行了研究.结果表明,采用包合技术提高了维生素D3(VD3)的稳定性及有效期;VD3-β-CD包合物延缓淀粉回生效果显著,回生抑制机理是该包合物与直链淀粉结合形成络合物,牵制了游离直链淀粉使其处于不规则状态,从而延缓直链淀粉有序结晶,达到抑制淀粉回生的目的.     

爱尔兰和丹麦联合研究增补不同来源VD在猪肉中的沉积及其对猪肉品质的影响

正在欧洲,很多人的VD摄入量远低于推荐值,VD缺乏被认为是一个公共健康问题。基于此,迫切需要开发一种基于食物的VD增补方案,通过生产稳定的天然VD富集产品提升民众的VD摄入量。猪肉是一类含有天然VD的普通消费产品,在猪的饲养过程中,通过有针对性地饲喂VD强化剂,可能是一种较为理想的解决方案。爱尔兰和丹麦的研究人员就饲喂合成和天然来源VD对猪肉VD活性的影响以及对猪肉品质的     

VD3- 壳聚糖复合物的超临界二氧化碳注入法制备工艺

以壳聚糖粒子为载体,VD3 为模型物,采用超临界二氧化碳注入法制备VD3- 壳聚糖复合物。采用紫外测试法考察过程参数压力、温度以及时间对VD3 在VD3- 壳聚糖复合物中负载量的影响。结果表明：随着压力和温度的增加,VD3 负载量均为先增大后减小;当压力20MPa、温度35℃时,VD3 负载量达到最大值;当温度和压力一定时,时间由1h 增至3h,VD3 负载量也有不同程度的增加。     

VA和VD对结核病患者结核杆菌耐药性的实验研究

目的：评价维生素A（VA）和维生素D（VD）对结核杆菌的抑菌活性及其与耐药性的关系。方法：选择2012年2.5月期间就诊于某胸科医院的118例痰培养结果为阳性的结核病患者为研究对象,从痰液中分离并培养出阳性菌株,采用绝对浓度法进行药物敏感试验;将不同浓度vA和VD添加到改良罗氏培养基中,制成实验培养基,并以单纯的改良罗氏培养基为对照接种实验菌株,培养3-4周后,观察菌落生长状况。结果：与对照组相比,添加500IU／mL（VAl）、1000Iu／mL（VA2）和2000IU／mL（VA3）维生素A的各剂量组培养基上的结核杆菌生长都受到不同程度的抑制,菌落生长结果为阳性所占的比例分别为92．37％、81．36％和86．44％,均低于对照组的100％,差异具有统计学意义（P〈0．05）;添加25IU／mL（VDl组）、50IU／mL（VD2组）、75IU／mL（VD3组）和100IU／mL（VD4组）维生素D的各剂量组菌落生长结果为阳性所占的比例分别为94．07％、93．22％、94．92％和91．53％,与对照组相比差异具有统计学意义（P〈o．05）。随着VA剂量的增加,VA2组培养结果为阴性的比例为18．64％,高于VAl组的7．63％,而阳性（2＋）和阳性（3＋）的比例分别为58．47％和2．54％,均低于VAl组的66．10％和6．87％,抑菌效果有所提高（P〈0．0167）;而VA3组与VA2组相比,抑菌效果增加不明显（P〉0．0167）。VD各剂量组相比,抑菌效果无明显差异（P〉0．05）;VA与VD的抑菌效果相比,VA2组及VA3组的抑菌效果优于VD组（P〈0．05）;结合菌株的药敏试验结果,发现维生素AD对结核杆菌生长的抑制效果与菌株耐药性无关（P〉0．05）。结论：适宜剂量的VA（1000IU／mL）和VD（25IU／mE）能抑制结核杆菌的生长．且与结核杆菌的耐药性无关。     

Maillard-conjugate based core-shell co-assemblies for nanoencapsulation of hydrophobic nutraceuticals in clear beverages

Maillard reaction based protein-polysaccharide conjugates (PPC) are typically better emulsifiers than the proteins used to form them. Such conjugates have been proposed as encapsulation agents, but their potential as nanoencapsulation agents in clear beverages has not yet been proposed. In this research we formed casein-maltodextrin (CN-MD) conjugates and co-assembled them with hydrophobic nutraceuticals to create nanovehicles for the enrichment of clear beverages. Conjugation was validated using gel electrophoresis and by ortho-phthaldialdehyde (OPA) assay. Vitamin D (VD) was nano-entrapped by the conjugates, and compared to controls based on an unconjugated CN-MD mixture and unencapsulated VD. The following advantages of the conjugates were shown: the diameters of conjugate-VD nanoparticles was smaller and their solution was more transparent than that of the vitamin dispersion or the protein-polysaccharide mixture with VD. Conjugates conferred better protection against oxidation to both VD and epigallocatechin gallate (EGCG) than the CN-MD mixture. Conjugates were more colloidally stable at the CN original pI, allowing the formation of nanoparticles with mean diameter below 30 nm when mixed with VD, even at the original pI of CN. Conjugates provided protection against degradation at low pH and during shelf life. Entrapment efficiency was measured using Nile red (NR), a fluorescent model for a hydrophobic nutraceutical. Protein affinity to the hydrophobic compound was not diminished due to conjugation, and 90% entrapment efficiency was obtained under the conditions tested. During simulated gastric digestion, Nile red was not released from the conjugates, suggesting potential application in enteric delivery.     

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...     

Associations between inflammatory bowel diseases and vitamin D

Inflammatory Bowel Diseases (IBD) are increasing sharply, and the common medications are not effective for most patients. Vitamin D (VD) has been considerate to reduce inflammatory processes and may be helpful in IBD. The aim of this review was to perform an update on the potential role of VD in the IBD. We performed a search for articles associating VD and IBD published in MEDLINE-PubMed and EMBASE. The focused question used for the search was “What is the association between Inflammatory Bowel Disease and Vitamin D?” The exclusion criteria for this search were studies not in English, editorials, case reports, or poster presentations. VD prevents the inflammatory process such as negatively interfering with the release of Interleukin (IL)-1, IL-6, and Tumour Necrosis Factor-α; enhancing the function of the intestinal epithelial barrier; decreasing the occurrence of apoptosis; stimulating Toll-Like Receptor-4; inducing the production of an antimicrobial peptide in Paneth cells. Furthermore, deficiency of VD is related to the severity of the symptoms and increased the risk of cancer and surgery. In conclusion, VD shows a potential role in the management of IBD, the supplementation is inexpensive, safe, and leads to improvement of the quality of life.     

Short communication: Assessment of biomarkers of inflammation in the vaginal discharge of postpartum dairy cows diagnosed with clinical metritis

Clinical metritis, characterized by the presence of an enlarged uterus and abnormal red-brownish foul-smelling vaginal discharge (VD), is a prevalent condition that causes important economic losses to dairy operations. The accurate diagnosis and treatment of this disease can help decrease its negative effects on the well-being and performance of dairy cows. The objectives of this study were to assess (1) the concentration of haptoglobin (Hp) and neutrophil-derived haptoglobin–matrix metalloproteinase 9 (Hp-MMP 9) in the VD of postpartum cows; and (2) the correlation between Hp and Hp-MMP 9 concentrations in serum and VD. Fifty-three dairy cows from 4 farms in central Pennsylvania were enrolled in this observational study.. Postpartum cows (7 ± 3 DIM) were screened using a Metricheck device to assess VD score (VDS): 1, clear fluid (n = 4); 2, < 50% white purulent fluid (n = 14); 3, > 50% white purulent fluid (n = 8); 4, red-brownish watery fluid without fetid smell (n = 22); and 5, fetid red-brownish watery fluid (n = 5). Blood and VD samples were collected for assessment of Hp and Hp-MMP 9 concentrations. Cows with a VDS of 4 or 5 (VDS4/5) had higher serum Hp concentrations than cows with a VDS of 1, 2, or 3 (VDS1/3; 93 ± 187 µg/mL vs. 59 ± 106 µg/mL, respectively). Similarly, cows with VDS4/5 had higher VD Hp concentrations than cows with VDS1/3 (73 ± 56 µg/mL vs. 17 ± 16 µg/mL, respectively). We found a significant correlation (0.37) between Hp levels in serum and in VD. We found no difference in serum Hp-MMP 9 between VDS4/5 and VDS1/3 cows. The VD concentrations of Hp-MMP 9 were higher in VDS4/5 cows than in VDS1/3 cows (7,629 ± 9,847 ng/mL vs. 1,567 ± 2,165 ng/mL, respectively). The correlation between Hp-MMP 9 in serum and VD was 0.22; nevertheless, it was not statistically significant. Interestingly, Hp and Hp-MMP 9 concentrations were higher in VD samples than in serum, regardless of VDS. Results from this study suggest that inflammatory biomarkers may be increased in cows with a VDS of 4 or 5. Further research should be aimed at elucidating the processes involved in inflammatory biomarker production and transportation in the uterus, as well as the effect of these biomarkers on endometrial cells.     

Metritis diagnosis and treatment practices in 45 dairy farms in California

Minimizing the risk of antimicrobial-resistant organisms and antimicrobial residues in dairy and dairy beef products is a topic of nationwide interest. To design an effective outreach program on judicious use of antimicrobials, it is imperative to describe actual practices on dairies. Thus, our objective was to report current practices for metritis treatment in 45 dairies in California. Data were collected using a survey tool that included questions on systemic antimicrobial treatments, intrauterine treatments, supportive treatments, and treatment records. Researchers collected information based on cow-side observations and responses from fresh cow evaluators. Most dairies (n = 33; 70%) performed rectal exams for vaginal discharge (VD) evaluation and based systemic antimicrobial administration on the presence of (a) abnormal VD (fetid and nonfetid), regardless of fever (n = 11; 25%); (b) fever regardless of the odor of abnormal VD (n = 11; 25%); (c) fetid VD and fever (n = 1; 2%); (d) fetid VD (n = 3; 9%); or (e) fetid VD or fever (n = 3; 9%). Some dairies (n = 11; 24%) only detected abnormal VD if visible on tail, vulva, or floor; treatment decisions were based on the presence of abnormal VD (n = 9; 20%) or abnormal VD and fever (n = 2; 4%). On 3 (6%) dairies, VD characteristics were evaluated after rectal palpation, but no systemic treatments were administered. Cows exhibiting 1 nonspecific sign of health disorder (depressed general appearance, lack of appetite, or drop in milk yield) plus fever (n = 13; 29%), or even regardless of fever (n = 6; 13%), were treated with systemic antimicrobials. Overall, 8 (18%) dairies justified systemic antimicrobial treatment based on fever alone. Systemic antimicrobials used were ceftiofur products [ceftiofur hydrochloride (n = 26; 55%), ceftiofur sodium (n = 3; 7%), and ceftiofur crystalline-free acid (n = 8; 18%)], penicillin procaine (n = 8; 18%), and ampicillin (n = 3; 7%). Intrauterine infusions were done with penicillin procaine (n = 1; 2%) or oxytetracycline (n = 12; 27%). The dose and treatment length varied across dairies for i.m. ceftiofur hydrochloride (15 to 45 mL/d for 3 to 5 d), s.c. ceftiofur crystalline-free acid (20 to 25 mL once or twice), i.m. ceftiofur sodium (15 to 30 mL/d for 3 to 5 d), i.m. penicillin procaine (20 to 60 mL/d for 3 to 6 d), and i.m. ampicillin (25 to 35 mL/d for 3 to 6 d). The antimicrobial drug of choice, the dose, and the treatment length for metritis varied across the study dairies. Based on accepted industry best-management practices for metritis, a need exists to educate fresh cow evaluators on signs of health disorder indicative of metritis and on appropriate antimicrobial treatment regimens.