高效液相色谱-电感耦合等离子体质谱法测定保健食品类袋泡茶中5种砷形态

目的采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP/MS)联用技术建立保健食品类袋泡茶浸泡液中亚砷酸根[As(Ⅲ)]、砷酸根[As(Ⅴ)]、一甲基砷酸(MMA)、二甲基砷酸(DMA)和砷甜菜碱(AsB)5种砷形态的分析方法。方法样品经热浸提后,采用Dionex IonPac AS19(4 mm×250 mm,10μm)阴离子交换柱,30 mmol/L碳酸铵(pH=9.5)为流动相等度洗脱,10 min内进行5种砷形态的分析测定。结果 5种砷形态的浓度在0.2～300μg/L范围内线性良好,相关系数(r)均0.999,检出限为0.04～0.08μg/L,采用精密度考察方法重复性,相对标准偏差(RSD)均5%,加标回收率在80.3%～121.1%之间。结论本方法适用于保健食品类袋泡茶浸泡液中砷形态的测定,试验表明保健食品类袋泡茶中砷形态主要以As(Ⅲ)和As(Ⅴ)为主,应关注其无机砷的风险性。     

烟草及其制品中砷的形态分析

为了测定烟草中砷(As)的形态,采用超声溶剂萃取、高效液相色谱(HPLC)与电感耦合等离子体质谱(ICP-MS)联用技术建立了亚砷酸[As(III)]、砷酸[As(V)]、二甲基胂酸(DMA)、甲基胂酸(MMA)、砷甜菜碱(AsB)和砷胆碱(AsC)6种形态As的分离分析方法。结果表明:采用Hamilton PRPX-100(250 mm×4.1 mm,10μm)阴离子交换柱、15 mmol/L(NH4)2HPO4(pH6.0)等度洗脱,6种不同形态As在15 min内实现了基线分离,线性范围不小于两个数量级,检出限0.44~0.98μg/L,加标回收率85.19%~87.31%,相对标准偏差(RSDs,n=5)2.45%~3.56%。烟草中As含量较低,且部分以低毒的DMA、MMA形态存在;超声溶剂提取能同时提取烟草中的有机As和无机As,较客观地反映样品中As的形态分布。该方法准确、可靠,适合于评价烟草中As的形态,可为烟草的安全性评价提供参考。     

离子色谱-电感耦合等离子体质谱联用测定茶叶中4种砷形态

建立了茶叶中砷酸根As(V)、亚砷酸根As(III)、一甲基砷(MMA)和二甲基砷(DMA)的离子色谱-电感耦合等离子体质谱(IC-ICP-MS)检测方法。比较了3种提取方式对茶叶中4种砷形态的提取效率,优化分离条件,通过加标回收试验考察了方法准确度及精密度。以0.1 mol/L硝酸水溶液为提取试剂,石墨消解仪100℃消解2h,上清液供IC-ICP-MS分析。4种砷形态采用Dionex Ion Pac AS7阴离子交换柱(250 mm×2 mm)分离,使用ICP-MS检测。通过加标回收试验考察方法准确度及精密度,在3个加标水平上各形态的回收率在90.9%~125.0%范围,RSD(n=4)小于5.7%。As(V)、As(III)、MMA和DMA的检测限分别是0.1,0.2,0.3,0.3μg/L,即2.5,5.0,7.5,7.5μg/kg茶叶。采用该方法对市售茶叶中的4种砷形态含量进行调查分析,As(V)、As(III)、MMA和DMA本底含量分别在0~545.1,0~147.0,0~95.2,0~86.6μg/kg之间。无机砷含量与有机砷之间差异显著(P0.05),平均含量从高到低依次为As(Ⅴ)、As(Ⅲ)、MMA和DMA。本结果表明,该方法简单、精确,可用于茶叶中4种砷形态的准确定量和风险评估。     

液相色谱-氢化物发生-原子荧光光谱法测定干制食用菌中5种砷形态

目的 建立液相色谱-紫外消解-氢化物发生-原子荧光光谱法(liquid chromatography-ultraviolet digestion-hydride generation-atomic fluorescence spectrometry,LC-UV-HG-AFS)测定干制食用菌中砷甜菜碱(AsB)、砷酸根[As(Ⅴ)]、亚砷酸根[As(III)]、一甲基砷(MMA)和二甲基砷(DMA)的分析方法。方法 样品用水于60 ℃水浴超声提取1.5 h,离心10 min取上清液,经0.45 ?m滤膜过滤。采用Hamilton PRP-X100阴离子交换柱(250 mm×4.1 mm,10 μm),以8 mmol/L磷酸氢二铵(pH=8.5)为流动相进行分离,用LC-UV-HG-AFS法测定5种砷形态。结果 AsB、MMA、DMA和As(III)在2.5～200.0 μg/L范围内线性关系良好,As(Ⅴ)在5.0～200.0 μg/L范围内线性关系良好,5种砷形态标准曲线相关系数均大于0.999;5种砷形态加标回收率为85.0 %～107.0%,相对标准偏差均小于5.0%;AsB、MMA、DMA、As(III)和As(Ⅴ)的检出限分别为0.02、0.02、0.01、0.02和0.03 mg/kg,定量限分别为0.04、0.04、0.03、0.06和0.08 mg/kg。结论 对干制食用菌分析表明,食用菌中无机砷含量较低,砷含量高的食用菌主要以AsB为主。所建方法简便、准确、快速,适用于干制食用菌中AsB、MMA、DMA、As(III)和As(Ⅴ)的检测。     

液相色谱-原子荧光法测定大米中4种砷形态

目的建立以0.3 mol/L硝酸为提取剂提取大米中4种砷形态(亚砷酸根AsⅢ、砷酸根AsⅤ、一甲基砷MMA和二甲基砷DMA)的液相色谱-原子荧光(liquid chromatography-atomic fluorescence spectrometry,LC-AFS)分析方法。方法在60℃条件下,超声40 min提取大米样品,上清液供LC-AFS测。比较2种提取方法对稻米中4种砷形态的提取效率,并对提取温度和提取时间等条件进行优化。结果 4种砷形态化合物的检出限为0.002~0.01μg/mL,加标回收率为89.03%~100.70%,RSD不大于4.36%(n=5)。结论此方法可以在1h时内完全分离大米样品中的四种砷形态,操作简单、灵敏,适用于大米中重金属砷的风险评估。     

高效液相色谱-电感耦合等离子体质谱法测定不同膳食基质中5种砷形态的方法研究

目的应用高效液相色谱(HPLC)和电感耦合等离子体质谱(ICP-MS)联用技术优化完善不同膳食基质中五价砷(As5+)、砷甜菜碱(As B)、三价砷(As3+)、二甲基砷酸(DMA)和一甲基砷酸(MMA)5种砷形态的检测方法。方法通过比较不同浓度的乙酸、盐酸、硝酸水溶液在热提取条件下对不同膳食基质(谷类、饮料类、水产类、蛋类、豆类、水果类、糖类)及对NIST标准参考物质Rice Flour1568b中5种砷形态化合物的提取效果,确定最佳提取试剂和最佳提取浓度,同时比较不同p H、不同流动相下砷化合物的分离效果,确定最终分离条件。结果膳食样品中砷形态分析的最佳提取方法为0.15 mol/L硝酸水溶液浸泡提取;以20 mmol/L柠檬酸和5 mmol/L己烷磺酸钠的混合溶液为流动相(p H=4.3),5种砷形态的线性范围线0~100μg/L相关系数(r)均大于0.999,检出限为0.4~1.2μg/L,精密度好,RSD均小于5%。不同膳食样品(谷类、饮料类、水产类、蛋类、豆类、水果类、糖类)加标回收率为80%~113%(无机砷)、81%~122%(MMA)、80%~124%(DMA)、77%~121%(As B);采用本方法测定的NIST标准参考物质Rice Flour 1568b测定值跟标示值相吻合。结论本实验优化了砷形态分析的前处理方法和分离条件,不仅具有省时、快速高效,而且可以保证测定结果的准确性。     

液相色谱-原子荧光光谱法测定大米中无机砷形态

建立了液相色谱-原子荧光法测定大米中无机砷形态的检测方法,对流动相种类、流速、pH值、硼氢化钾浓度及盐酸浓度进行了优化。在8 min内可完成As(Ⅲ)和As(Ⅴ)的分离。当砷酸根和亚砷酸根浓度为0~100ng/ml时,2种形态均可得到良好的线性关系,线性相关系数均大于等于0.999 5,实验室检出限分别为0.006mg/kg和0.009mg/kg,精密度RSD≤6.0%,加标回收率为85.0%~110.7%。该方法减少了样品的分析时间和试剂用量,具有简便、高效和可靠等特点,可用于大米中无机砷形态的检测。     

炭黑氨基柱净化HPLC-ICP-MS测定黄酒中砷形态及含量

建立了一种同时测定黄酒中亚砷酸根、砷酸根、砷甜菜碱、一甲基砷酸和二甲基砷酸等5种砷形态的高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析方法。黄酒经炭黑氨基柱净化,体积分数为10%甲醇水溶液洗脱,采用Hamilton PRP-XIO0阴离子交换色谱柱(4.1 mm×250 mm,10 μm),60 mmol/L硝酸铵梯度洗脱,高效液相色谱分离,电感耦合等离子体质谱进行定性和定量分析。在0.5～20.0 μg/L范围内各砷形态线性良好,相关系数R均＞0.999;加标回收率85%～92%,相对标准偏差(RSD)1.4%～5.2%;5种砷形态的定量限均为0.10 μg/L,检出限均为0.03 μg/L。利用该方法对不同年份、不同企业及不同类型的黄酒进行了检测,该方法适用于黄酒中砷残留的分析检测。     

高效液相色谱- 电感耦合等离子体质谱联用测定婴幼儿辅食中的无机砷

目的：拟建立婴幼儿辅助食品中无机砷含量的测定方法。方法：以0.15mmol/L硝酸溶液为提取剂,90℃热浸提取婴幼儿辅助食品(米粉类及罐头类)中无机砷,采用Hamilton PRP-X100(250mm×4.1mm,10μm)色谱柱分离,建立高效液相色谱-电感耦合等离子体质谱(high performance liquid chromatography-inductively coupled plasma mass spectrometry,HPLC-ICP/MS)联用技术测定其含量的方法。结果表明：As(Ⅲ)与As(Ⅴ)的线性范围为0.5～400μg/L,线性相关系数(r)优于0.9990,检出限分别为0.06μg/L和0.08μg/L,无机砷的加标回收率在80.5%～128.5%之间,相对标准偏差(RSD)＜5%。结论：方法简便、准确、灵敏,适用于婴幼儿辅助食品中无机砷含量的测定。     

阴离子交换色谱-氢化物发生-原子荧光光谱联用测定片剂类富硒保健品中4种形态硒

目的建立了阴离子交换色谱-氢化物发生-原子荧光光谱联用测定富硒保健品中硒酸根[Se(Ⅵ)]、亚硒酸根[Se(Ⅳ)]、硒代胱氨酸(SeCys_2)和硒代蛋氨酸(SeMet)的方法。方法采用Hamilton PRP-X100阴离子交换柱(250 mm×4.1 mm,10μm),以40 mmol/L磷酸氢二铵(pH=6.0)为流动相,在12 min内可完全分离4种硒形态。结果 Se(Ⅳ)、Se(Ⅵ)、SeCys_2和SeMet的检出限分别为0.85、1.07、0.91和1.73μg/L,标准曲线相关系数均0.999 5,加标回收率为80.2%~108.7%,相对标准偏差(RSD)均5.0%。比较了不同提取方法对片剂类富硒保健品中4种硒形态的提取效果,以亚硒酸盐为硒源的样品采用0.6 mol/L盐酸提取效果理想,提取率92%;含有有机硒的保健品采用蛋白酶K提取,提取率82%。结论本方法快速、简单、准确,适用于测定片剂类富硒保健品中硒形态,为监督富硒保健食品的质量提供技术支持。     

Probiotics and prebiotics--perspectives and challenges

Owing to their health benefits, probiotics and prebiotics are nowadays widely used in yogurts and fermented milks, which are leader products of functional foods worldwide. The world market for functional foods has grown rapidly in the last three decades, with an estimated size in 2003 of ca US$ 33 billion, while the European market estimation exceeded US$ 2 billion in the same year. However, the production of probiotics and prebiotics at industrial scale faces several challenges, including the search for economical and abundant raw materials for prebiotic production, the low-cost production of probiotics and the improvement of probiotic viability after storage or during the manufacturing process of the functional food. In this review, functional foods based on probiotics and prebiotics are introduced as a key biotechnological field with tremendous potential for innovation. A concise state of the art addressing the fundamentals and challenges for the development of new probiotic- and prebiotic-based foods is presented, the niches for future research being clearly identified and discussed.     

常用消毒灭菌法及其机理与应用

介绍了采用消毒灭菌方法,有加热消毒法,紫外线辐射法和化学药剂消毒法。常用化学药剂有醛类、含氯消毒剂、醇类消毒剂以及高锰酸钾、生石灰等,阐释了消毒与灭菌两个概念的区别。     

益生素、益生菌与结肠癌

介绍了益生素和益生菌及其作用机理。在动物模型中，有大量的数据证实益生素和益生菌能够预防癌症．而在人体内还没有直接实验证据。它们抑制癌症的确切机理目前尚不清楚，其抑制机理可能是：肠道菌群代谢活动的改变，肠道理化环境的改变，潜在的致癌物质的黏附和降解，肠道菌群的改变、抗癌或抗诱变物质的形成、提高宿主的免疫应答、影响宿主的生理活动以及发酵不能被消化的食物并形成有益代谢产物。     

节能节水型印染助剂和设备的现状

从节能、节水、缩短工艺流程和环保的角度出发，介绍了国内外研制开发的一系列新型节能、节水型印染助剂和染整设备。     

原花色素及其开发应用

对原花色素的结构、化学特性、制备、分析方法、应用前景作一综述,并重点讨论其生理功能,为在功能性食品、药物、化妆品等领域的深入研究和开发提供参考。     

天然香精香料与生物技术

天然香精香料是高价值的精细化工产品和食品添加剂,但原料来源有限且提取成本高。利用生物技术生产这类产品具有广阔的前景。简述了发酵工程、酶工程、细胞工程和基因工程在香精香料中的应用,并探讨了生物技术在香精香料中的应用前景。     

毛霉型低盐速成豆豉工业化生产工艺与设备

本文介绍了毛霉型低盐速成豆豉的工业化生产工艺及生产线的关键设备。     

European citizen and consumer attitudes and preferences regarding beef and pork

This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries.     

Heritability and correlations for body condition score and dairy form within and across lactation and age

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.     

酚类物质的结构与性质及其与葡萄及葡萄酒的关系

酚类物质是一类大而复杂的化合物。葡萄与葡萄酒中常见的酚类物质可分为类黄酮和非类黄酮两大类，它们是葡萄中重要的次生代谢产物，与葡萄的抗病性、采后生理、贮存、保鲜等密切相关。葡萄酒中的酚类物质来自于葡萄果实、果梗、酵母代谢以及橡木桶，参与形成葡萄酒的味道、骨架、结构和颜色等，对红葡萄酒的特征和质量尤其重要。