高效液相色谱法同时测定保健食品中泛酸、烟酰胺、维生素B1、维生素B2、维生素B6的含量

目的建立高效液相色谱法同时测定保健食品中泛酸、烟酰胺、维生素B_1、维生素B_2、维生素B_6的含量。方法样品经0.2%磷酸溶液超声提取,经Alltima-C18柱分离,以乙腈-5 mmol/L庚烷磺酸钠溶液为流动相进行梯度洗脱,采用二极管阵列检测器(diode array detector,DAD)同时在200 nm、280 nm波长处进行检测。结果泛酸、烟酰胺、维生素B_1、维生素B_2、维生素B_6能实现较好的分离,在各自线性范围内线性关系良好,平均回收率为93.9%~103.2%,相对标准偏差(relative standard deviation,RSD)为0.4%~1.8%。结论该方法操作快速简便、精密度和重复性好,可适用于保健食品中泛酸、烟酰胺、维生素B_1、维生素B_2、维生素B_6含量的同时测定。     

高效液相色谱法测定多种维生素矿物质片中维生素B1的含量

研究多种维生素矿物质片中维生素B₁含量测定的最佳提取工艺。利用高效液相色谱法鉴别并定量分析多种维生素矿物质片中的维生素B₁。以多种生素矿物质片为材料，维生素B₁的含量为评价指标。以盐酸溶液的浓度，提取时间，液料比为因素，设计正交试验优化选出最佳提取工艺。结果显示，1mol/L盐酸溶液50mL，提取30min所得样品中维生素B₁含量最高。     

钛胶RP-HPLC法同时测定5 种维生素

采用钛胶反相色谱柱,建立高效液相色谱法同时测定5 种维生素：烟酸、生物素、烟酰胺、叶酸和钴胺素含量的检测方法。研究5 种维生素的保留行为与磷酸缓冲盐pH值、缓冲盐类型及浓度、柱温和流速的关系,得出了最优色谱条件：于波长210 nm处检测生物素和钴胺素,于波长270 nm处检测烟酸、烟酰胺和叶酸,磷酸盐pH 7.0,浓度5.0 mmol/L,柱温50 ℃,流速0.8 mL/min。分析5 种维生素保留的热力学参数焓、熵和吉布斯自由能。烟酸、生物素、烟酰胺、叶酸和钴胺素标准曲线线性良好（R2＞0.999 0）;烟酸、生物素、烟酰胺、叶酸和钴胺素的检出限分别为6、10、20、22、8 ng/mL;5 种物质的相对标准偏差均低于1.36%;加标回收率范围为92.30%～107.20%。方法的精密度和准确度均可满足高效液相色谱法的测定要求。     

B族维生素对大肠杆菌发酵生产乳清酸的影响

为提高大肠杆菌发酵乳清酸的产率和糖酸转化率，以大肠杆菌(Escherichia coli)Ora-6为供试菌株，在原有培养基的基础上，通过单因素试验及正交试验探究维生素B₁、维生素B₃、维生素B₅、维生素B₆、维生素B₇、维生素B₁₂几种关键B族维生素对菌体生长及产酸能力的影响，并确定最佳组合添加量为维生素B₁ 6.8 mg/L,维生素B₃ 4.8 mg/L,维生素B₅ 4 mg/L,维生素B₆ 3.4 mg/L,维生素B₇ 1.4 mg/L,维生素B₁₂ 4 mg/L。在此条件下，经5 L发酵罐验证对比，此时优化后的培养基菌体量(OD₆₀₀)、乳清酸产量、糖酸转化率分别为134.32、121.41 g/L和25.73%,较原始培养基分别增长了13.16%、15.47%、12.96%。同时研究确定了B族维...     

高效液相色谱法测定蔬菜中B族维生素

建立一种使用高效液相色谱与光电二极管阵列检测器(PDA)联用测定蔬菜中七种B族维生素的方法.色谱柱为ZORBAX SB-C18,以甲醇与缓冲溶液(庚烷磺酸钠、冰乙酸、三乙胺、EDTA、异丙醇)作为流动相进行梯度洗脱,设定267nm为检测波长.结果表明:VB1、VB2、VB6、VB12、叶酸、烟酸、烟酰胺的线性范围较宽,平均回收率为92.55%～116.71%,相对标准偏差在0.003%～0.013%,最低检出限能达到mg/kg级.本方法简单、实用,为测定蔬菜中水溶性B族维生素的含量提供了可靠依据.     

高效液相色谱法测定婴幼儿配方奶粉与保健食品中维生素B12的含量

建立高效液相色谱法检测婴幼儿配方奶粉与保健食品中维生素B₁₂的分析方法。选择SB-AQ柱(4.6 mm×250 mm,5.0μm)作为色谱柱,流动相为0.025%三氟乙酸溶液+乙腈,流速1.0 mL·min^-1,梯度洗脱,进样量100μL,检测波长361 nm。保健品：B族维生素片等样品采用水提取的方式;基质复杂的样品用固相萃取的方法。婴幼儿配方奶粉：含量<4μg/100 g的样品用固相萃取法,含量≥4μg/100 g的样品用直接提取方式,经高效液相色谱仪分析。结果表明,维生素B₁₂标准溶液线性良好,r²> 0.999,加标回收率在86.2%～96.0%,RSD为1.3%～1.8%,检出限为0.4μg/100 g。该方法简便快捷,所用试剂耗材少,灵敏度高,结果准确。     

快速测定婴幼儿配方乳粉中的维生素B1及B2

建立高效液相色谱-荧光法快速测定婴幼儿配方乳粉中维生素B₁及维生素B₂。方法优化了前处理条件,采用高压酸提法提取目标化合物,样品沉淀蛋白后直接测定维生素B₂,取部分清液用碱性铁氰化钾衍生后测定维生素B₁。目标物在对应的浓度范围内呈现良好的线性关系（R²≥0.9998）,样品加标回收率在92.4%～102%之间。该方法快速,准确,适用于婴幼儿配方乳粉中维生素B₁、B₂的测定。     

超高压液相色谱-串联质谱法同时测定婴幼儿配方乳粉中11 种B族维生素

目的：建立一种能够同时测定婴幼儿配方乳粉中11 种B族维生素的超高压液相色谱-串联质谱法。方法：样品用0.1%甲酸溶液溶解,乙酸锌沉淀蛋白,滤液经ACQUITY UPLC HSS T3色谱柱分离,流动相为0.1%甲酸溶液和乙腈,梯度洗脱,采用电喷雾离子源正离子模式,多反应监测进行检测,分析时间12 min。结果：11 种B族维生素在各自质量浓度范围内线性良好,R2均大于0.99,加标回收率在85%～110%之间,相对标准偏差在1.03%～6.75%之间,VB1、VB2、烟酸、烟酰胺、泛酸（VB5）、吡哆醛、吡哆醇、吡哆胺、叶酸、游离生物素和VB12的定量下限分别为40.0、40.0、30.0、30.0、50.0、0.9、1.2、1.2、2.0、2.0、0.2 μg/100 g,与国家标准比较,部分维生素定量限提高了7.7%～60%。结论：该法具有灵敏度高、前处理操作简单快速、分析时间短的特点,而且具有良好的精密度和准确性,可以应用于婴幼儿配方乳粉中11 种B族维生素的同时测定。     

婴幼儿米粉货架期的预测及货架期内营养成分的变化分析

本文设置了2个外部环境37 ℃ 75% RH和47 ℃ 75% RH对婴幼儿米粉的货架期进行预估,并对米粉货架期内维生素和矿物质的衰减情况进行了分析。结果表明,铁听充氮包装米粉在37 ℃ 75% RH和47 ℃ 75% RH下的货架期分别为210~225和75 d,从而计算得出其在25 ℃ 75% RH下的货架期为722~841 d。货架期内维生素A、泛酸的稳定性最差,货架期最高衰减率分别可达28.96%和24.47%;其次,维生素B₁、维生素B₂、叶酸、维生素E和维生素C的稳定性较差,货架期内最高衰减率分别为18.46%、18.97%、18.53%、13.96%和12.67%;维生素D、维生素B₆、维生素B₁₂、烟酸、生物素以及铁的稳定性较好,在整个货架期内基本无衰减。     

维生素B4

维生素B4,又称为腺嘌呤。随着对维生素B4研究的不断深入,科学家们发现,维生素B4的叫法并不能全面体现这种物质的性质和特点,它所表现出的维生素B族功能只是一个方面,而且需要与属于B族维生素的烟酸（B4）与核黄素（B4）组合成烟酰胺腺嘌呤二核苷酸（NAD）及黄素腺嘌呤二核苷酸（FAD）,     

Quantification of water-soluble vitamins in milk-based infant formulae using biosensor-based assays

Vitamin analysis is essential for quality control and development of functional foods. In this study, a biosensor-based technology developed by Biacore AB was evaluated for analysis of water-soluble vitamins B₂, B₁₂, folic acid, biotin, and pantothenic acid used to supplement infant formula samples. Performance parameters such as accuracy, repeatability and recovery for the five vitamins were studied. The repeatability was measured in terms of relative standard deviation (RSD) and HORRAT_r value. The RSD for all vitamins was below 2% and the values of HORRAT_r were 0.16, 0.10, 0.15, 0.11 and 0.22, for B₂, B₁₂, folic acid, biotin, and pantothenic acid, respectively. The recovery of vitamins ranged from 94.7% to 109.1%. Linear analyses indicated that the square of the correlation coefficient (R²) for B₂, B₁₂, folic acid, biotin, and pantothenic acid were 0.993, 0.997, 0.993, 0.993 and 0.995, respectively. The results showed that the biosensor-based vitamin analysis technology is a sensitive, reliable and realistic alternative to other methods.     

特殊食品中3种B族维生素检测方法的研究进展

随着人们对健康和营养的关注,特殊食品的种类越来越多.叶酸、生物素和维生素B12是特殊食品中3种重要的营养添加剂,其准确测定对于特殊食品的质量控制具有重要意义.文章对特殊食品中叶酸、生物素和维生素B12的生理作用以及检测方法进行论述,以期为开展特殊食品中这3种B族维生素的测定研究提供参考.     

高效液相色谱法测定食品中维生素K1和维生素K2的含量

建立高效液相色谱-荧光检测法（HPLC-FLD）测定食品中维生素K₁和维生素K₂含量的分析方法。方法:配方奶粉、酸奶、纳豆冻干粉和鸡胗冻干粉经酶解、异丙醇分散、正己烷萃取、旋转蒸发复溶后,使用Thermo AcclaimTM 120 C₁₈色谱柱（150 mm×4.6 mm,5 μm）分离,锌粉还原柱（50 mm×4.6 mm）衍生,以900 mL甲醇:100 mL四氢呋喃（含冰醋酸0.3 mL,氯化锌1.5 g,无水乙酸钠0.5 g）为流动相,激发波长为243 nm,发射波长为430 nm,分离维生素K₁（Vitamin K₁,VK₁）、四烯甲萘醌（menaquinone-4,MK-4）、七烯甲萘醌（menaquinone-7,MK-7）和九烯甲萘醌（menaquinone-9,MK-9）。结果:VK₁、MK-4、MK-7和MK-9在20~1000 μg/L范围内与峰面积有良好线性关系。配方奶粉、酸奶、纳豆冻干粉和鸡胗冻干粉中VK₁、MK-4、MK-7、MK-9含量的相对标准偏差（RSD）均小于5%,表明精密度好。配方奶粉、酸奶和纳豆冻干粉不同水平加标回收率分别为85.0%~107.8%、85.8%~109.6%、85.1%~102.7%,回收率的RSD均小于5%,表明回收率高,相对标准偏差小。结论:实验建立的方法重复性好、准确度高,可以精准定量食品中维生素K₁和维生素K₂的含量。     

辅食营养补充品货架期内营养素的稳定性及叠加风险研究

本文主要对5种辅食营养补充品(1种辅食营养素撒剂和4种辅食营养补充食品)在货架期内营养素的稳定性及叠加风险进行了分析。稳定性试验结果表明,对于辅食营养素撒剂,维生素B₁的平均衰减率最高,为34.62%,其次是维生素D (30.77%)、B₁₂(30.14%)、B₆(29.41%)和A (29.10%),相对稳定的是钙(5.22%)。对于4种辅食营养补充食品,相对稳定的营养素均为蛋白质(0~0.93%)和钙(2.17%~11.30%),相对不稳定的营养素有维生素A (25.77%~30.74%)、D (22.37%~33.82%)、B₁(17.81%~25.93%)、B₂(25.00%~28.00%)、B₆(26.03%~33.33%)和B₁₂(13.11%~21.54%)。不同的品种其营养素的平均衰减率有一定的差异性。营养素叠加风险研究结果表明,婴幼儿在食用婴幼儿配方奶粉的同时摄入辅食营养补充品,需要根据食用的婴配粉营养素含量,科学选取适合的辅食营养补充品,以免产生某些营养素摄入过量风险。对于未食用婴幼儿配方奶粉的目标人群,同时选择婴幼儿米粉及辅食营养补充品食用则无摄入过量风险,反而对目标人群是一个很好的营养补充。     

Nutrient content of milk and milk products: vitamins of the B complex and vitamin C in retail market milk and milk products

A survey was undertaken to update and extend information on the water-soluble vitamin content of milk and milk products on retail sale. The results are discussed in relation to previously published data. Apart from vitamin C the levels of vitamins in retail pasteurized cows' milk were very similar to those found in milk from the processing dairy. Levels of total vitamin C and folic acid in UHT full cream milk were negligible; vitamin B₆ and vitamin B₁₂ were respectively 73 and 56% of the levels in pasteurized milk. Except for nicotinic acid, pantothenic acid and biotin, the levels of vitamins in sterilized milk were lower than in pasteurized milk, particularly vitamin C, folic acid and vitamin B₁₂. When compared on an equivalent dilution basis, vitamin B₆, thiamine, folic acid and, especially, vitamin B₁₂ in evaporated milk were lower than in pasteurized cows' milk. In comparison, in full cream condensed milk only vitamin B₆ was particularly low; vitamin C was particularly well preserved. With the exception of vitamin B₁₂, vitamin levels in reconstituted spray dried milk were similar to those in pasteurized cows 'milk. Levels in filled' spray dried milk were on average 70% of those in ordinary dried milks. Apart from vitamin B₁₂ the levels of B vitamins in non health food yogurt were generally higher than in pasteurized milk, especially folic acid. The levels of vitamin B₁₂ and folic acid in goats' milk were only 22 and 11 % respectively of those in cows' milk, but the nicotinic acid level was four times higher. The level of vitamin C in raw sheep's milk was about five times that in pasteurized cows' milk; other levels, apart from folic acid which was similar, were between 1.3 and 5.2 times those in cows' milk.     

Fate of supplementary B-vitamins in the gastrointestinal tract of dairy cows

Four lactating Holstein cows equipped with ruminal, duodenal, and ileal cannulas were used in 2 studies to evaluate the disappearance of supplementary B-vitamins before and from the small intestine. The cows were fed a total mixed ration with chromic oxide in 12 daily meals. Each study consisted of a control (no vitamin supplementation) and a treatment period (with vitamin supplementation). Amounts of vitamins (mg/d) supplemented in studies 1 and 2, respectively, were: thiamin: 300 and 10; riboflavin: 1600 and 2.0; niacin: 12,000 and 600; vitamin B₆: 800 and 34; biotin: 20 and 0.02; folic acid: 2600 and 111; vitamin B₁₂: 500 and 0.4. In study 1, vitamins were added to the feed 5 d before and during the 4-d collection period. In study 2, vitamins were infused postruminally 1 d before and during the 4-d collection period. Substantial disappearance before the duodenal cannula was noted in study 1 (67.8% thiamin, 99.3% riboflavin, 98.5% nicotinamide, 41.0% pyridoxine, 45.2% biotin, 97.0% folic acid, and 62.9% vitamin B₁₂). Except for nicotinamide and folate, there was almost no disappearance of postruminally infused vitamins before the duodenal cannula (study 2), suggesting extensive ruminal destruction or use. Apparent intestinal absorption values differed greatly among vitamins, but the proportion of vitamins disappearing from the small intestine was not negatively influenced by supplementation. Except for riboflavin and niacin, absolute amounts disappearing from the small intestine were greater during the treatment than the control periods, suggesting that B-vitamin supply in dairy cows is increased by supplementation, although losses in the rumen are extensive.