化学发光法测定啤酒中的双乙酰

本报道了双乙酰被引入到鲁米诺－过氧化氢化学发光体系中可以增强发光强度的实验事实，建立了测定双乙酰的分析方法，地线范围为６．０×１０＾－７－１．２×１０＾－５ｍｏｌ／Ｌ，相对标准偏差为２％；检出限为４．１×１０＾－７ｍｏｌ／Ｌ，并应用于啤酒样品中双酰的分析，结果良好。     

固定化生长细胞生物催化的若干动态性质

通过啤酒发酵实验研究了以海藻酸盐为载体的固定化生长细胞生物催化作用的若干动态特性．在分批出料的填充柱循环反应器中，产物抑制型的啤酒发酵、其Ｓ～ｔ，Ｐ～ｔ曲线与批式发酵罐的Ｘｔ／Ｘｓｔ～Ｋｔ理论曲线相似，Ａ（λ＝５２０ｎｍ）的变化可作为简便的检测方法．发酵周期的缩短呈现τｎ＝ｎ－１（τ１－Ｃ）关系，式中ｎ＝２～４．这对生产上前期的成功应用是有力的支持．但在ｎ≥５时出现载体的崩解和起泡现象，因相催化剂不能继续使用．     

Radicaloid-type oxidative decomposition of beer bittering agents revealed

trans-Isohumulones, dihydroisohumulones, tetrahydroisohumulones, and humulinones, which are important hop-derived flavor components of beer, were found, by using electrolysis of organic solutions, to be stable against oxidation, like weak acids; however, they are readily oxidized in their anionic forms as present in beer. Oxygen- and carbon-centered radicals were formed by oxidation and identified by using spin trapping under aerobic and anaerobic conditions, followed by EPR (electron paramagnetic resonance) spectroscopy. Generated radicals were reactive, most likely degrading into products lacking the tricarbonyl chromophore; this is typical of five-membered-ring hop derivatives. Thus, flavor-active beer constituents may degrade oxidatively in the absence of oxygen, thereby leading to reaction products that escape UV detection.     

啤酒瓶清洗剂去污力评价方法的研究

模拟啤酒瓶污垢，采用与啤酒瓶材质相同的玻片，用白度值反映玻征污染前后及洗涤前后透光率的变化，研究出一种啤酒瓶清洗剂去污力评价方法。用该法在实验室通过去污力测试比较进行啤酒瓶清洗剂品配方的选择与调整是可行的，试制的产品完全达到实洗效果的要求。     

壳聚糖-g-丙烯腈固定化木瓜蛋白酶的研究

接枝共聚物;啤酒;壳聚糖-g-丙烯腈固定化木瓜蛋白酶的研究     

电感耦合等离子体质谱测定不同酒类中铬、砷、镉、汞、铅含量

应用微波消解处理酒样,不经富集直接用ICP—MS测定Cr、As、Cd、Hg、Pb含量,方法快速,干扰少．测定的33种不同酒样中Cr、As、Cd、Hg、Pb的含量均值分别为45．84、19．53、2．22、1．92μg·kg^-1和115．06μg·kg^-1,其中白酒中含量最高,葡萄酒和啤酒居次,黄酒含量最低．Cr、As、Cd、Hg、Pb的检出限分别为0．063、0．082、0．007、0．001μg·L^-1和0．080μg·L^-1,各元素的加标回收率基本在90%～110％,RSD（n=10）在0．25％～6．76％．     

基于冷冻熔炼的液-液萃取/气相色谱法测定啤酒中的N-二甲基亚硝胺

建立了一种新型的冷冻熔炼液-液萃取法直接提取啤酒中的N-二甲基亚硝胺（N-nitrosodimethylamine,NDMA）,萃取液经GC-FID分析,双柱法定性,外标法定量。优化的前处理条件为：以二氯甲烷为萃取溶剂,啤酒样品和萃取溶剂的体积比为9：1,-19 ℃下冷冻16 h。结果表明：NDMA在5~200 mg/L范围内具有良好的线性关系（r²=0.9996）;在5、10和20 mg/L 3个加标水平下的回收率分别为84.94%、83.24%、85.14%,平行7次测定的相对标准偏差（RSD）分别为3.06%、3.19%、2.63%。与常规液-液萃取方法（需要经过蒸馏、萃取、旋蒸、氮吹4个步骤）相比,本方法稳定、可靠,且操作简单,有机溶剂消耗量少。     

啤酒中挥发性成分的测定及产地鉴别

采用自动固相微萃取提取啤酒中的挥发性成分,并利用快速气相色谱/质谱联用对其挥发性物质成分进行分析,样品分析时间仅为10min,并且整个分析过程实现了自动化。通过检索NIST谱库鉴定出42种挥发性成分,其中含10种酯类、10种烃类、9种醇类、7种酸类及一些其他类化合物。对不同产地的啤酒进行主成分分析,不同厂家的产品在投影图上得到很好的聚类。通过载荷分析,发现对鉴别厂家贡献最大的是卡必醇以及乙酸、辛酸、癸酸三种有机酸。更多还原     

Effect of Hop Varieties and Forms in the Hopping Process on Non-Alcoholic Beer Quality

The aim of this study was to determine how the hopping technique affects the quality of non-alcoholic beer (NAB). A series of NABs were brewed and tested for basic physicochemical characteristics, profiles of selected volatile compounds, and microbial contamination. The brewing process yielded 13 experimental groups of beers, all of which had an ethanol content of <0.5%v/v. Among the batches brewed with ‘Marynka’ hops, the pellet form was found to provide the highest concentrations of hop-derived volatile compounds, whereas in the ‘Magnum’ groups, the extracts and whole hops proved superior. Humulene and caryophyllene were the primary volatiles in terms of quantity. All the brews were contamination-free—no microbes other than yeast cells were detected. Their microbiological purity was also supported by an assay of beer-defect indicators (volatile compounds), which only showed low levels of acetaldehyde, 1-propanol, 2-methylbutanol, and 3-methylbutanol. The hopping technique deployed was found not to affect the physicochemical parameters of NABs, but did have a significant impact on their volatile compound profile.     

Use of Coffee Bean Bagasse Extracts in the Brewing of Craft Beers: Optimization and Antioxidant Capacity

Coffee bean bagasse is one of the main by-products generated by industrial coffee production. This by-product is rich in bioactive compounds such as caffeine, caffeic and chlorogenic acid, and other phenols. The aims of this work are to optimize the extraction conditions of phenolic compounds present in coffee bean bagasse and incorporate them into stout-style craft beers, as well as to determine their effect on the phenol content and antioxidant capacity. The optimal conditions for extraction were 30% ethanol, 30 °C temperature, 17.5 mL of solvent per gram of dry sample, and 30 min of sonication time. These conditions presented a total phenol content of 115.42 ± 1.04 mg GAE/g dry weight (DW), in addition to an antioxidant capacity of 39.64 ± 2.65 μMol TE/g DW in DPPH^• and 55.51 ± 6.66 μMol TE/g DW for FRAP. Caffeine, caffeic and chlorogenic acids, and other minor compounds were quantified using HPLC-DAD. The coffee bean bagasse extracts were added to the stout craft beer and increased the concentration of phenolic compounds and antioxidant capacity of the beer. This work is the first report of the use of this by-product added to beers.