流动注射分析法测定啤酒中甲醛含量的研究

针对啤酒中甲醛检测方法操作烦琐,不适合在线检测的情况,建立了在线流动注射分光光度法直接测定啤酒中甲醛的方法。此方法快速,简便,精密度高,在0．2～10mg·L^-1范围内甲醛浓度与峰高成良好线性关系,相关系数r=0．9991,检出限为0．068mg／L,相对标准偏差（RSD）为0．67％,结果令人满意。     

用热脱附方法分析哈密瓜香气成分

为探究哈密瓜主要香气成分,该文采用热脱附方法对哈密瓜果肉、哈密瓜果汁的香气进行富集,经气相色谱质谱法(GC-MSD)联机进行检索分析.结果显示,哈密瓜果肉、哈密瓜果汁香气成分和含量存在一定的差异,并从中检测出56种香气成分,其中哈密瓜肉香气成分有31种,哈密瓜汁的香气成分有46种,共同香气物质为乙酸甲酯、乙酸乙酯、丙酸...     

超高效液相色谱-串联质谱法测定啤酒中的真菌毒素

建立啤酒样品中脱氧雪腐镰刀菌烯醇、3-乙酰基脱氧雪腐镰刀菌烯醇、15-乙酰基脱氧雪腐镰刀菌烯醇、玉米赤霉烯酮、去环氧脱氧雪腐镰刀菌烯醇、脱氧雪腐镰刀菌烯醇-3-葡萄糖苷、雪腐镰刀菌烯醇等7种真菌毒素的超高效液相色谱-串联质谱测定方法。啤酒样品经过Mycosep226多功能净化柱净化后,取净化液吹干浓缩后,经Acquity UPLC BEH C18色谱柱（100 mm×2.1 mm,1.7μm）分离,在负离子模式下,用电喷雾电离串联质谱以多反应监测模式（MRM）进行检测分析,同位素内标法进行定量。结果表明,7种真菌毒素在2～1000μg/L浓度范围内线性关系良好（r＞0.999）,最低检出浓度为0.03μg/L,在20μg/L、200μg/L、500μg/L 3个加标水平下进行了验证试验,平均回收率为82.7%～115%,相对标准偏差为1.94%～9.87%。该方法简便、快速、准确,满足实验要求,可用于啤酒样品中真菌毒素的多残留的检测分析。     

采用固相微萃取-气相色谱-质谱法分析啤酒中醛类化合物

建立了顶空固相微萃取-气相色谱-质谱(HS-SPME-GC-MS)结合邻-五氟苄基羟胺(PFBHA)衍生以测定啤酒中与老化味相关的13种醛类化合物的方法。样品前处理不同于文献报道的方法,衍生试剂直接加入到啤酒样品中,然后插入SPME装置,一步完成衍生和萃取过程。经优化的固相微萃取条件为:65μmPDMS/DVB萃取头,萃取温度50℃,萃取时间60min。GC-MS分析采用选择离子模式(SIM)并以内标法定量,所建方法的定量重复性较好,样品重复测定的RSD在2.5%-19.5%;回收率在55.3%-108.8%。在测定新鲜和老化啤酒时,显示出该方法具有较好的适用性。     

Brewing Beer with Enzymes and Starch Analysis

The method of HPLC carbohydrate analysis allows a stepwise and controlled alteration of the mashing technology. Our aim was to find a method for altering a given mashing technology by increasing the amount of digested corn grits by 40% using reduced mashing time and an up-to-date technology with simultaneous application of brewing-enzymes. In the course of these experiments, by means of the HPLC method, the critical stages of carbohydrate decomposition could be revealed; after systematic application of industrial enzyme products under HPLC control the process has been short-cut and, on the basis of analytical data, the entire mashing technology has been simplified and rationalized. As result of industrial-scale experiments mashing time, including the cooking process of the surrogates, was cut down to 5.5 h. The wort produced by means of the elaborated well-controllable combined infusion-decotion mashing process has an attenuation of 85-87% and shows the same carbohydrate composition, organoleptic properties and characteristics observed for the original wort. The results are also supported by tests of significance.     

基于ANSYS的平板塑件注塑模具热应力分析

以平板塑件的注塑模具为研究对象,运用ANSYS对其进行瞬态热分析,模拟注塑过程中各时刻模具的温度分布情况,并在模具温度最大时刻进行稳态静力分析,找出应力集中区域,为模具的疲劳设计提供一定的依据。     

Analysis of Isinglass Residues in Beer

A method has been developed for the detection of trace quantities of residual isinglass present in fined beers. Isinglass residues in beer are concentrated by means of an antibody raised using isinglass as an antigen. The separated isinglass is hydrolysed to its constituent acids and quantified by measuring the content of hydroxyproline. The limit of quantification of this method, that is the concentration of isinglass in beer which can be distinguished from background levels of hydroxyproline, is 0.17 mg of isinglass/litre of beer (on an isinglass dry weight basis). This method has been used to quantify the concentration of isinglass residues which could be present in brewery and cask conditioned beers, and also to determine whether there is likely to be stratification of isinglass residues in casks.     

低产高级醇啤酒酵母在啤酒中试中的应用发酵分析

对选育到的低产高级醇啤酒酵母MS-11进行应用发酵研究分析。结果表明,对比出发菌株SC-2和工业生产菌株DAB,MS-11菌株在保持原啤酒风味的基础上,不仅提高发酵速度,缩短发酵时间5d,降低能耗近10％,增加设备周转率20％左右,降低生产成本;而且生产的成品啤酒防老化效果好。     

啤酒中硅的ICP—AES测定

硅钼蓝化学法测定Ｓｉ繁杂费时,湿法消解时,硅又易形成沉淀。我们用ＩＣＰ－ＡＥＳ地啤酒中的Ｓｉ进行直接稀释测定,回收率１０２－１０８％。     

应用液液萃取分析中度烘烤橡木片中挥发性化合物

运用液液萃取与气相色谱-质谱联用技术,研究美国、法国与中国中度烘烤程度橡木片的挥发性化合物。共分离和检测出85种挥发性化合物,包括2种萜烯醇类、1种醛类、7种有机酸类、2种酯类、3种内酯类、7种芳香族类、6种酮类、15种呋喃类、34种酚类,以及8种其他化合物。酚类化合物在橡木中种类较多,浓度较高。定量结果表明,丁香醛、香兰素、糠醛、5-羟甲基糠醛等物质质量浓度较高,对橡木的整体风味影响较大。从呋喃类、橡木内酯、香兰素和丁香醛等化合物比较看,中国橡木与美国橡木类似。     

Analysis of Aldehyde-bisulfites in Beer by HPLC-Fluorescence Detection with Post-column Derivatization

An analytical method was based on the aldehyde-bisulfite (separated by HPLC) reaction with o-phthalaldehyde in the presence of ammonium acetate, producing a fluorescent compound. Detection limits of alkanalbisulfite (from formaldehyde- to octylaldehyde-bisulfite) and 2-alkenalbisulfite (from trans-2-hexenal- to trans-2-nonenal-bisulfite) ranged from 5 nM to 25 nM. The method was less sensitive for free sulfite (detection limit 100 μM) than for aldehyde-bisulfite. Increasing acetaldehyde-bisulfite with addition of 25 mM acetaldehyde to a beer sample showed free sulfite in the beer. Free sulfite and acetaldehyde-bisulfite were detected in commercial beers but other aldehyde-bisulfites were not.     

气相色谱法在啤酒分析中的应用

采用气相色谱法可对啤酒中的高级醇、酯类、羰基化合物及含硫化合物等挥发性物质进行检测,既可研究啤酒的感官品质,也可用于指导生产,优化啤酒工艺。应用气相色谱法对啤酒中挥发性物质检测的前处理方法主要有顶空进样、蒸馏、有机溶剂萃取3种。针对啤酒酒中不同的挥发性物质可选择PEG柱和氢火焰离子化检测器（FID）法进行检测;还可用内标法和外标法对啤酒中的不挥发组分进行定量检测分析。（孙悟）     

我国啤酒市场竞争之分析

啤酒酒市场的竞争给我国啤酒工业的发展造成正负面影响。竞争促进了啤酒工业的迅速发展，主要是市场资源得以开发和利用，产业结构趋于优化，科技进步较快，同时过度竞争又造成了市场秩序混乱，竞争不会，经济效益下降等现象，规范市场竞争的关键在于加强政府作用，正确引导和替代啤酒市场，加大执法力度，提高企业竞争；突出企业规范化优势，积极参与高层次竞争和国际竞争。     

Determination of Inorganic Elements in Teas Using Inductively Coupled Plasma Optical Emission Spectrometry and Classification with Exploratory Analysis

Multivariate optimization was employed to obtain the best conditions of the inductively coupled optical emission spectrometer (ICP OES) (nebulization gas flow rate of 0.47 L min^?1 and applied power of 1.36 kW) for the determination of Al, Ba, Ca, Cu, Fe, K, Mg, Na, and Mn in 27 green tea samples. In the hierarchical cluster analysis, it was possible to observe the formation of five different groups (imported Japanese samples, samples without specifications, organically cultivated samples, samples in capsules, and ready-to-drink iced tea samples) besides the separation according to brand. In the principal component analysis we verified that the first four main components explained 99.98 % of the total variance. The ICP OES technique and the exploratory analysis were shown effective tools that can be used jointly in the quality control and classification of green tea samples.     

Determination of Carbendazim in Food Products Using a Sequential Injection Analysis Optosensor

Carbendazim (CBZ) is a widely used broad-spectrum benzimidazole fungicide used to control plant diseases in cereals, vegetables, and fruits. It has been recently found that it is useful for the control of aflatoxin contamination in chili peppers (Capsicum annuum). In addition, it is useful against other diseases in peppers and tomatoes (Solanum lycopersicum). A flow-through optosensor using C₁₈ silica gel as solid support is here presented for the fluorimetric (λ _exc/λ _em?=?276/306) determination of CBZ in Capsicum powder and dried tomatoes. The proposed system has been developed using sequential injection analysis, so improving the repeatability and automation of the system and minimizing wastes generation. The method presents a detection limit of 3 μg?L^?1, a sample throughput of 16 samples per hour and interday relative standard deviation lower than 6 %. Taking into account that the maximum residue limit specified in the Codex Alimentarius for dried peppers is 20 mg?kg^?1, recovery experiments have been carried out for CBZ concentrations in the 15–40 mg?kg^?1 range, obtaining satisfactory results. Therefore, the proposed method fulfills the current legislation and could be used as an alternative to other analytical methods, such as chromatographic ones.     

啤酒中硫化物分析方法研究进展

在成品啤酒中含有微量含硫化舍物,包括非挥发性的硫化物和挥发性的硫化物。硫化物是影响啤酒风味的一类重要化合物,在啤酒中适量存在,能使酒体丰满圆润,香气协调;过量硫化物的存在,当啤酒受到光照或氧化时,硫化物不仅使啤酒的口味变差,而且使啤酒发生雾浊。对啤酒硫化物分析中的常规分析法、色谱法和专用性分析方法进行了综述。     

外加酶促啤酒废酵母自溶制备酵母抽提物及理化性质检测

利用啤酒废酵母资源,采用自溶-酶联技术制备酵母抽提物.以氨基氮得率和固形物得率为主要指标考察了影响酵母自溶的外加蛋白酶的种类及添加量、酵母悬浮液浓度、自溶时间、酶解时间因素,并对酵母酶联自溶的相关促进荆进行正交试验优选.优化确定了后续抽提物生产的旋转蒸发及喷雾干燥工艺的参数,并对其金属离子含量、物理性状、溶解性、pH、总氨基酸含量等理化参数指标进行测评.所制酵母抽提物中氨基氮得率和固形物得率分别达到3.937%和59.24%,理化指标大都达到或超过酵母抽提物行业标准的优级指标要求.     

啤酒中硫化物分析的进展

成品啤酒中含有微量含硫化合物,包括非挥发性和挥发性的硫化合物。当啤酒受到光照或氧化时,硫化物不仅使啤酒的口味变坏,而且会使啤酒发生雾浊,因此在啤酒的微量组成分中硫化物占有重要的地位。本文对啤酒硫化物分析中的常规分析法、色谱法和专用分析方法进行了综述。     

啤酒中挥发性风味物质的分析及风味评价

应用气相色谱定量分析啤酒中的挥发性风味物质如醇类,酯类,连二酮,含硫化合物等,通过风味强度进行风味特征评价及风味差别度的判别,达到控制质量的目的,结合应用GC－MS,气相色谱－气味测定法（GCO）,电子自旋共振（ESR）等技术对啤酒,酿造过程及原料中的风味化合物和异味组分进行测定的探讨。     

啤酒中α-氨基酸含量的分析

采用茚三酮吸光光度法测定啤酒中的α-氨基酸含量.结果表明,在一定条件下,α-氨基酸含量(以氨基态氮表示)在0～0.32μg/mL范围内遵守朗伯比耳定律,方法的精密度(RSD)在1.2%～2.6%之间时,回收率在95%～108%之内,检出限为2.9μg/L,表观摩尔吸光系数为1.1×104L/mol·cm.本方法经用于啤酒样品分析,结果符合要求.