新型液体婴儿配方乳对小鼠免疫功能的影响

本文研究新型液体婴儿配方乳对免疫抑制小鼠免疫功能的影响,利用腹腔注射环磷酰胺制备免疫抑制小鼠模型,将昆明小鼠分为5组,每组10只,经口灌胃给予小鼠0、1、2、4 g/kg·bw新型液体婴儿配方乳连续喂养28 d。分别对小鼠免疫器官脏体比值、刺激指数、抗体生成细胞情况、小鼠腹腔巨噬细胞吞噬率、NK细胞活性进行探讨。与模型对照组相比,高、中剂量组能显著增加（p<0.05）小鼠刺激指数、小鼠腹腔巨噬细胞吞噬、小鼠NK细胞活性,各剂量组能显著增加（p<0.05）小鼠肝脏和胸腺指数、抗体细胞的OD^413nm。结果表明,新型液体婴儿配方乳对免疫抑制小鼠有一定免疫增强作用。      

Evolution of available lysine and furosine contents in milk‐based infant formulas throughout the shelf‐life storage period

The evolution of the Maillard reaction (MR) by measuring the available lysine and furosine (FUR) contents in adapted and follow‐up powdered milk‐based infant formulas over the shelf‐life storage period, at 20 and 37 °C, was studied. Available lysine and FUR contents were determined by fluorimetry and high‐performance liquid chromatography respectively. Statistically significant differences were found between adapted and follow‐up infant formulas with respect to the available lysine and FUR contents. Available lysine contents decreased significantly throughout the storage time, and the contents at 37 °C were lower than at 20 °C. A statistically significant increase in FUR contents was observed during the storage period, with the contents being high at 37 °C than at 20 °C. A simple regression analysis between the available lysine and FUR contents during (a) the first year (b) the second year and (c) the two storage years was applied. The best correlations were obtained during the first year of storage. The results obtained show a clear MR evolution during the storage of infant formulas. Copyright © 2003 Society of Chemical Industry     

Stability of ascorbic acid in adapted milk‐based infant formulae during storage

A study was made of the effects of storage (for up to 17 months at 22 or 37 °C) on the ascorbic acid contents of four adapted milk‐based infant formulae with the same composition except for the iron salt added (lactate or sulphate) and/or the vitamin E source involved (α‐tocopherol (α‐T) or α‐tocopherol acetate (α‐TAc)). Ascorbic acid was measured by a voltammetric method. The ascorbic acid contents of the formulae ranged from 0.77–0.84 g kg^?1 immediately after manufacture to 0.41–0.48 g kg^?1 after 17 months of storage. Samples stored at 22 °C had higher ascorbic acid contents than those stored at 37 °C. A multiple regression analysis performed to evaluate ascorbic acid evolution throughout storage/shelf‐life and the effects of storage temperature and the different components of the samples yielded a model explaining 79.71% of the variability in ascorbic acid content. Iron lactate and α‐tocopherol acetate addition afforded the best preservation of ascorbic acid content. The evolution of ascorbic acid was not linear, exhibiting an important decrease in the first month of storage, followed by stabilisation. Copyright © 2004 Society of Chemical Industry     

Effect of vacuum impregnation on enzymatic browning of fresh-cut potatoes during refrigerated storage

The effect of vacuum impregnation with ascorbic acid (AA) and calcium ascorbate (CaA) on enzymatic browning of fresh-cut potatoes was investigated. Results showed that vacuum impregnation (VI) with AA-CaA treatment for 2 min had a significant anti-browning effect. VI treatment not only maintained cell membrane integrity, inhibited the key enzyme activities of polyphenol oxidase, peroxidase and phenylalanine ammonia-lyase but also retarded generation of phenolic substrate, particularly chlorogenic acid. Meanwhile, VI promoted AA-CaA solution to infiltrate into potato tissue and delayed loss of ascorbic acid. In conclusion, VI treatment was more efficient for preventing browning with a shorter processing time of 2 min compared to traditional impregnation under atmospheric pressure and could be used as a promising method to inhibit browning of fresh-cut potatoes.     

Kinetic models of non‐enzymatic browning in apple puree

The effects of thermal treatments on 11 °Brix apple puree were studied at temperatures from 80 to 98 °C. Colour changes (measured by reflectance spectroscopy, colour difference, L*, a* and b* and the evolution of 5‐hydroxymethylfurfural (HMF) and sugars (hexoses and sucrose) were used to evaluate non‐enzymatic browning. A kinetic model based on a two‐stage mechanism was applied to the evolution of colour difference and a*. A first‐order kinetic model was applied to L* evolution, while the evolution of absorbance at 420 nm (A₄₂₀) of the liquid fraction was described using a zero‐order kinetic model. Thermally treated samples became more reddish and suffered a slight loss of yellow hues. The effect of temperature on the kinetic constants was described by an Arrhenius‐type equation. The presence of pulp in the samples led to activation energies for A₄₂₀ and sucrose which were lower than those found previously for clarified juices with the same soluble solids content. © 2000 Society of Chemical Industry     

高效液相色谱法测定婴幼儿配方乳粉中酪蛋白磷酸肽的含量

目的 建立高效液相色谱法测定婴幼儿配方乳粉中酪蛋白磷酸肽含量的方法.方法 对婴幼儿配方乳粉样品对应生产批次所采用的酪蛋白磷酸肽原料进行测定,得到准确含量后作为参照品,对婴幼儿配方乳粉样品测定前处理中净化、提取条件进行优化,采用二极管阵列检测器(diode array detector,DAD)定量分析.结果 采用混合型...     

反相高效液相色谱法测定婴儿奶粉中乳铁蛋白的含量

建立了反相高效液相色谱法(RP-HPLC)测定婴儿奶粉中乳铁蛋白的含量,采用C4色谱柱洗脱,二极管阵列检测器(波长220nm)测定.流动相A为0.1％三氟乙酸水溶液,流动相B为乙腈-水-三氟乙酸(体积比90∶10∶0.1).线性范围为5mg/L～1000mg/L,相关系数为0.9999,定量下限为30mg/kg,加标回收率为86.0％～91.7％.该方法用于实际样品的测定,样品处理简单,结果令人满意.     

模拟母乳及婴儿配方奶粉的研究

介绍了人乳中的主要功能因子及其对婴儿的生长发育所具有的生理意义。比较、分析了现阶段婴儿配方奶粉与人乳成分中存在的差别及不足，并针对婴儿的生长特点及现阶段生产技术，对婴儿配方奶粉的生产及发展进行了叙述。     

高效液相色谱法测定婴幼儿配方奶粉中酪蛋白磷酸肽含量

目的建立高效液相色谱法(highperformanceliquidchromatography,HPLC)测定婴幼儿配方奶粉中酪蛋白磷酸肽(casein phosphopeptide, CPP)的含量的方法。方法对样品静置温度、静置时间、沉淀分离方式进行优化,用高效液相色谱法对婴幼儿配方奶粉中CPP的含量进行测定。结果最优的前处理条件为样品溶解后调整pH至4.6,于4℃条件下静置1 h,过滤后上清液经0.22μm滤膜过滤,以Ultimate AQ-C_(18)色谱柱(250mm×4.6mm,5μm)分离。经钼蓝比色法鉴定,保留时间为8.387min的组分为CPP。该方法在10～1000mg/L范围内线性关系良好,相关系数为0.9993,定量限为4.40 mg/L,婴幼儿奶粉中添加量为500、1000、5000 mg/kg时, CPP的回收率为96.63%%～101.42%。结论该方法样品前处理简单,稳定性和可靠性良好,检测结果符合定性定量要求,可用于婴幼儿配方奶粉中CPP含量的测定。     

液相色谱-串联质谱法测定婴儿乳粉中的抗坏血酸棕榈酸酯

目的建立液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)快速检测婴儿乳粉中抗坏血酸棕榈酸酯含量的方法。方法样品经0.1%草酸乙醇溶液提取,提取液用乙二胺-N-丙基硅烷(primary secondary amine,PSA)净化后经C₁₈柱分离,三重四极杆串联质谱检测。结果抗坏血酸棕榈酸酯在0.02-0.5μg/mL浓度范围内与峰面积呈良好的线性关系,相关系数(r²)为0.9996,检出限(S/N=3)为0.03 mg/kg,定量限(S/N=10)为0.10 mg/kg。当添加浓度水平为0.5、1.0和10.0 mg/kg时,平均回收率为90.0%~104.1%,相对标准偏差(relative standard deviations,RSDs,n=6)为1.5%~2.7%。结论本方法操作简便、快速、灵敏度高,能够满足婴儿乳粉中抗坏血酸棕榈酸酯的检测要求。     

神经酸在婴幼儿母乳化配方奶粉中的应用

根据婴幼儿的膳食及脑的发育特点，及母乳中所合的脂肪酸和婴幼儿配方奶粉中所含的脂肪酸不同，着眼于母乳中所含有的神经酸(NernonicAcid)在婴幼儿配方奶粉中几乎不含有的问题，叙述了婴幼儿摄入强化添加神经酸的母乳化婴幼儿配方奶粉后，对促进婴幼儿的大脑发育、增强智力水平、提高新生儿、婴幼儿及儿童的智力素质具有重要的意义。介绍了添加神经酸配方奶粉的生产工艺，对添加神经酸的配方奶粉进行了功能性动物试验和人体试食评价测试试验。     

前处理对液相色谱法测定婴幼儿配方奶粉中维生素C含量的影响

目的研究液相色谱操作条件、标准溶液配制及保存、样品提取等前处理对液相色谱法测定婴幼儿配方奶粉中维生素C含量的影响。方法测定不同流动相下维生素C峰面积及保留时间;比较不同酸性溶液配制的标准溶液保存一定时间后峰面积的变化;用不同浓度的乙酸溶液作为提取液,在不同水浴温度、超声时间下对奶粉样品进行提取,测定其峰面积。结果样品溶液在0.05 mol/L磷酸二氢钾(pH=3.0)甲醇流动相下,经Tech Mate ST-C_(18)色谱柱分离,在245 nm条件下进行检测,可获得较大的响应值及合适的保留时间。维生素C的最佳提取条件为:提取液为1%乙酸溶液、水浴温度不宜超过20℃、提取时超声时间为20 min。采用确定的条件对婴幼儿配方奶粉中维生素C含量进行测定,维生素C在1~100 mg/L范围内线性良好,r~2大于0.999。加标回收率在76.5%~91.4%之间,RSD在5%以下。结论本研究建立的前处理方法能够满足维生素C的测定要求。     

Survey of total mercury in infant formulae and oral electrolytes sold in Canada

Total mercury (Hg) was measured in 150 infant formula products (as sold) and oral electrolyte solutions purchased in Canada in 2003. Results less than the limit of detection (LOD) were reported as the numeric value of the LOD. Electrolytes contained the lowest concentrations, averaging 0.026?ng/g. Average levels in milk-based ready-to-use, concentrated liquid and powdered concentrate were 0.028, 0.069 and 0.212?ng/g, respectively. In soy-based formulae, the respective mean concentrations were 0.049, 0.101 and 0.237?ng/g. These concentrations cannot be considered on an absolute basis because 76% of sample concentrations fell below the limit of detection. Despite the inability to measure many of the actual background concentrations, the method was sufficiently sensitive to identify clear cases of low-level Hg contamination (up to 1.5?ng/g) of individual lots of powdered formula. Also, all the different lots of one brand of concentrated liquid infant formulae had significantly higher concentrations of Hg than those of all other concentrated liquid products. After dilution with preparation water, the Hg concentrations in all products would be lower than the Canadian Drinking Water Guideline for Hg of 1?ng/mL and too low to impact on health.     

婴幼儿配方奶粉发展现状及分析

婴幼儿配方奶粉成为越来越多婴幼儿的主要食物,其产品质量和营养价值受到人们广泛关注。介绍了婴幼儿配方奶粉产生的背景、目前消费情况以及国内外生产水平。进而从安全性、营养均衡性、配方针对性等方面分析了婴幼儿配方奶粉的优缺点,提出了解决办法,并综合各方面因素对其发展趋势进行了分析。     

免疫婴儿乳粉的安全毒理学评定

以24株人肠道病原菌(包括病原性大肠杆菌12株、沙门氏菌8株、志贺氏菌3株、小肠结肠炎耶尔森氏菌1株)作为抗原,对乳牛进行系统免疫,免疫乳与非免疫乳乳中IgG含量无显著差异。系统免疫并不增加乳中IgG的含量,但IgG的抗体特异性大大增强,所得的免疫初乳中乳抗体对24种不同病原菌的凝集价为28～212,为普通初乳中乳抗体凝集价的32～256倍。以免疫初乳作为原料制备免疫初乳粉并添加到婴儿乳粉中制成免疫婴儿乳粉。婴儿免疫乳粉LD50>10g/kg;Ames试验及小鼠骨髓微核试验和小鼠精子畸变试验表明婴儿免疫乳粉无致畸变作用。大鼠30d喂养试验表明,婴儿免疫乳粉对大鼠生长无不良影响,大鼠血液指标正常,病理学检查未见任何病变。     

婴幼儿配方奶粉强化DHA和AA的研究

近年来的研究表明DHA和AA对婴幼儿大脑和视力的正常发育有着重要的生理作用，在婴幼儿，特别是早产儿以及人工喂养的婴幼儿配方食品中添加DHA和AA十分必要。目前，婴幼儿配方奶粉强化DHA和AA已越来越受到世界各国的重视，许多国家已批准强化DHA和AA婴幼儿配方奶粉市场销售。不过，生产和摄取DHA和AA婴幼儿配方奶粉，需要考虑DHA和AA平衡以及摄取量，同时还应注意防止二者的氧化，以确保婴幼儿安全、有效地利用DHA和AA。     

市售婴幼儿配方乳粉中脂肪酸组成分析

对市售的10种不同品牌婴幼儿配方乳粉中脂肪酸组成进行了检测及分析。结果表明:共检出脂肪酸24种,不同品牌乳粉的脂肪酸组成及含量差别很大,棕榈酸含量介于14. 77%与35. 72%之间,亚油酸含量最高达27. 07%,最低仅有4. 68%,7种产品可检出DHA、AA,均未检出EPA;除了1种产品的亚油酸及α-亚麻酸含量偏低,其余脂肪酸含量均符合国家标准,检测结果与母乳之间仍存有差异。婴幼儿配方乳粉的脂肪酸仍需要进行优化以接近母乳来满足婴幼儿的营养需求。     

高效液相色谱法测定婴儿奶粉中维生素B12

建立了奶粉中维生素B12的反相高效液相色谱的测定方法,奶粉经去蛋白质-糖分-超声提取-富集浓缩超滤后进高效液相色谱仪,采用C18色谱柱,水-乙腈流动相体系,梯度洗脱能够快速有效地分离奶粉中的维生素B12.线性范围为0.010μg/mL～10μg/mL,相关系数为0.9998,检出限为0.1 μg/100g,加标回收率为78.8％～84.0％.该方法适用于实际样品的测定,速度快、成本低,结果令人满意.     

婴幼儿配方乳粉生产许可制度实施情况研究与对策建议

婴幼儿配方乳粉的监管,是我国食品安全监管落实四个最严要求最集中的体现.2018年国务院机构改革之后,监管机构及职能发生改变.本文基于对全国24个生产婴幼儿配方乳粉的省(自治区、直辖市)的调研,收集整理分析各省婴幼儿配方乳粉生产许可工作在机构人员、材料受理审查、现场核查、许可发证、证书延续及变更等环节的特点,归纳出生...     

高效液相色谱法测定婴幼儿食品和乳品中泛酸的不确定度分析

目的 评定高效液相色谱法测定婴幼儿配方乳粉中泛酸含量的测量不确定度。方法 依据JJF1059.1-2012《测量不确定度评定与表示》和CNAS-GL06-2018《化学分析中不确定度的评估指南》, 考察测定过程引入不确定度的主要因素, 建立不确定度的数学模型, 并对不确定度的各分量进行计算和合成。 结果 当婴幼儿配方乳粉中泛酸含量为939 μg/100 g, 在95%的置信区间下, 扩展不确定度为30.80 μg/ 100 g (k=2)。评定结果表明, 实验过程的不确定度主要来源为标准物质和曲线拟合。结论 该方法准确可靠, 适用于高效液相色谱法测定婴幼儿配方乳粉中泛酸的不确定度评定, 对检测结果准确度的提高具有指导意义。