固相萃取-气质联用法测定啤酒中9种有机磷农药残留

建立啤酒中9种有机磷农药的固相萃取-气质联用分析方法.采用C18固相萃取小柱对啤酒中的有机磷农药进行提取、净化,用乙酸乙酯洗脱后供气相色谱-质谱分析,用基质匹配标准校正方法补偿基质效应.当添加浓度为50 μg/kg和100μg/kg时,平均回收率为80.3%～95.0%;测量结果的相对标准偏差为1.97%～8.28%(n=6);方法的检出限为1.20～15.3μg/kg.该方法可用于啤酒中痕量有机磷农药残留的测定.     

Results of a beer game experiment: Should a manager always behave according to the book?

We investigate the effect of the literature suggested optimal values of the parameters of a dynamic decision‐making heuristic in the presence of semirationally managed supply chain echelons using a soft coded one‐to‐one version of The Beer Game as an experimental platform. According to the counterintuitive results obtained in this study, it is possible for a “rational manager” to obtain higher costs than the costs generated by a “semirational manager.” Thus, the results do not support the use of the well‐established decision parameter values for the echelon of concern if the other echelons' inventories are managed suboptimally. © 2015 Wiley Periodicals, Inc. Complexity 21: 190–199, 2016     

Detection of probiotic microbes in probiotic cheese spreads by isothermic calorimetry

Summary The probiotic cheese spreads developed by the Hungarian Dairy Research Institute (HDRI) have a better Ca:P ratio than traditional brands and spread easily and without sticking even cold, further, their live lactic acid bacteria content gives them additional advantages as well. These advantages derive from the fact that a probiotic culture may also be employed during fermentation, through which the cheese spread may become probiotic if the culture proliferates. The international specification is a probiotic cell count of at least 10⁶/g. However, during fermentation the probiotic cheese spread must also use other non-probiotic cultures to produce the right taste. Given that the microorganisms in the cultures are all cocci, their indication in a mixed environment is difficult and time-consuming. It appears possible, therefore we have used the isothermic DSC method due to their differences in heat production. In order to analyze the calorimetric curves a deconvolutional program was devised which decomposed them into Gaussian curves. It was confirmed that probiotic bacteria proliferated in the probiotic cheese spreads, and their ratio was greater than 40% with a total plate count of 2-7·10⁸/g. Accordingly, the probiotic cheese spread developed by HDRI contains an order of magnitude more probiotic bacteria than the internationally accepted cell count of 10⁶/g.     

微生物电极法测定啤酒中乙醇含量

用自制的乙醇微生物电极建立了一种测定啤酒中乙醇含量的新方法。该法具有良好的精密度和准确度，其测定结果与比重瓶法和气相色谱法相一致，回收率为９７．３％－１０４．９％。该电极线性范围为０．３－１２．０ｍｇ／Ｌ，６０天测定６００余次，其灵敏度基本稳定。测试的最适酸度范围为ｐＨ６．４－７．３，温度为３２－３４℃，测定一个样品需５－８ｍｉｎ。     

Rapid fermentation of beer using an immobilized yeast multistage bioreactor system

A multistage bioreactor system for rapid beer fermentation was developed. The main fermentation process, which conventionally requires 7 d, could be shortened to 2 d by this system. The concentration of esters and higher alcohols are major factors in brewery fermentation, their production being closely related to the yeast growth phase. Yeast metabolism was successfully subdivided into a growth and a restricted phase through a combination of a continuous stirredtank reactor (CSTR) and an immobilized yeast packed-bed reactor (PBR). Production of higher alcohols was high in the CSTR because of its association with the level of biosynthetic activityde novo. A small amount was also produced in the PBR, however, possibly a result of an overflow in carbohydrate metabolism. Ester formation mainly occurred in the PBR, a linear increase in the level of ester being observed with flow through the PBR. The reactor system control strategy was to maximize the level of both higher alcohol and ester formation. The CSTR/PBR control range, based on extract consumption, was varied between 1:1 and 1:2. A ratio of 1:1 tended to create a flat beer, whereas a ratio 1:2 gave a beer of richer quality. Amino acid uptake by the yeast directly contributed to a reduction in the wort pH, whereas no relation could be observed between the level of organic acid production and pH.     

A study of the aroma profiles of non-alcohol beer by thermal desorption and GC-MS

The aroma profiles of different types of low alcohol and non-alcohol beer have been compared by collection of volatile headspace compounds on Tenax resin and GC-MS analysis following thermal desorption. Some aroma compounds have been tentatively identified by NBS library search.     

The Role of Bioactive Phenolic Compounds on the Impact of Beer on Health

This review reports recent knowledge on the role of ingredients (barley, hop and yeasts), including genetic factors, on the final yield of phenolic compounds in beer, and how these molecules generally affect resulting beer attributes, focusing mainly on new attempts at the enrichment of beer phenols, with fruits or cereals other than barley. An entire section is dedicated to health-related effects, analyzing the degree up to which studies, investigating phenols-related health effects of beer, have appropriately considered the contribution of alcohol (pure or spirits) intake. For such purpose, we searched Scopus.com for any kind of experimental model (in vitro, animal, human observational or intervention) using beer and considering phenols. Overall, data reported so far support the existence of the somehow additive or synergistic effects of phenols and ethanol present in beer. However, findings are inconclusive and thus deserve further animal and human studies.     

非抑制电导阳离子色谱法测定啤酒中的阳离子和胺类化合物

建立了以甲基磺酸(MSA)和乙腈混合淋洗,离子交换色谱分离,非抑制电导检测,分析分离啤酒中阳离子和胺类化合物的方法.色谱条件经优化,在25 min内分离出啤酒中的7种阳离子和胺类化合物,方法的回收率和相对标准偏差分别为94.31%～109.9%和0.10%～1.2%.     

酵素菌肥的金属元素营养分析

在磷酸根、硅酸根存在下以2％硝酸镧作机体改进剂,测定了酵素菌肥中多种金属元素的含量,各元素的平均回收率分别为：K98．69％,Ca100.37%,Mg97．81％,Na96．06％,Cu98．26％,Fe96．45％,Zn99．78％,Sr93．54％,Li94．22％。方法简便,快速可靠,肯定 酵素菌肥的金属元素营养价值。