Beer Clarification by Novel Ceramic Hollow‐Fiber Membranes: Effect of Pore Size on Product Quality

In this work, the crossflow microfiltration performance of rough beer samples was assessed using ceramic hollow‐fiber (HF) membrane modules with a nominal pore size ranging from 0.2 to 1.4 μm. Under constant operating conditions (that is, transmembrane pressure difference, TMP = 2.35 bar; feed superficial velocity, v_S = 2.5 m/s; temperature, T = 10 °C), quite small steady‐state permeation fluxes (J^*) of 32 or 37 L/m²/h were achieved using the 0.2‐ or 0.5‐μm symmetric membrane modules. Both permeates exhibited turbidity <1 EBC unit, but a significant reduction in density, viscosity, color, extract, and foam half‐life with respect to their corresponding retentates. The 0.8‐μm asymmetric membrane module might be selected, its corresponding permeate having quite a good turbidity and medium reduction in the aforementioned beer quality parameters. Moreover, it exhibited J^* values of the same order of magnitude of those claimed for the polyethersulfone HF membrane modules currently commercialized. The 1.4‐μm asymmetric membrane module yielded quite a high steady‐state permeation flux (196 ± 38 L/m²/h), and a minimum decline in permeate quality parameters, except for the high levels of turbidity at room temperature and chill haze. In the circumstances, such a membrane module might be regarded as a real valid alternative to conventional powder filters on condition that the resulting permeate were submitted to a final finishing step using 0.45‐ or 0.65‐μm microbially rated membrane cartridges prior to aseptic bottling. A novel combined beer clarification process was thus outlined.     

Hermetic storage for control of common bean weevil,Acanthoscelides obtectus (Say)

This study evaluated hermetic storage as a method of controlling Acanthoscelides obtectus (Coleoptera: Chrysomelidae: Bruchinae) in stored beans. Recently harvested “vermelhinho” cultivar of the common red bean was used, which had already been infested by A. obtectus in the field. Beans with a moisture content of 15.0% wet basis were stored in silo bags (3 kg), plastic bottles (1.5 L), or non-hermetic glass containers (3 L) (control) for 120 days. The packages were stored in an acclimatized chamber at 25 °C with a relative humidity of 70 ± 5%. At time intervals of 0, 30, 60, 90, and 120 days, three packages of each treatment were opened, and analyses were performed to assess the infestation percentage by insect pests, moisture content, density, electrical conductivity, germination percentage, and cooking time. There was no increase in infestation by A. obtectus in the grains stored in the silo bags and plastic bottles during the 120 days of storage; however, there was a significant increase in infestation in the grains in non-hermetic storage (control). The quality of the beans correlated with infestation; it was not altered in the hermetic storage systems and decreased in the control sample. Hermetic storage of common beans is an effective tool in the control of A. obtectus.     

Beer choice and consumption determinants when craft beers are tasted: An exploratory study of consumer preferences

The aim of this paper is to study the emerging craft beer industry from a consumer preference perspective. The craft beer industry is one of the growing segments in the beverage industry and its increasing popularity also affects individuals’ commercial beer preferences and consumption trends, although no empirical study has yet been carried out in Europe on this topic. Our exploratory study is aimed at comparing the “purely” commercial beer consumer profile with that of commercial beer consumers who have already tasted craft beers. It was observed that aroma and perceived quality, as well as the preference for draft beer, drinking beer frequently or by oneself are all factors that explain the propensity of “purely” commercial beer drinkers to taste craft beer. It was also found that beer consumers’ evaluations of characteristics and brands differed depending on whether they had previously tasted craft beer or not. Moreover, craft beer is chosen according to different flavor preferences compared to commercial beer, it is mainly drunk by frequent beer drinkers in pubs and with family members and it is perceived to be of higher quality than commercial beer due to the raw materials used for brewing and its overall quality. These results can help both new entrepreneurs in the craft beer segment as well as big manufacturing firms in trying to better understand this new consumption trend in order to meet the new needs and preferences of beer consumers.     

Preparation and characterization of bottle‐brush polymer via host−guest self‐assembly between β‐cyclodextrin and adamantane

Supramolecular assemblies with a bottle‐brush structure are obtained by inclusion complexation between β‐cyclodextrin and adamantane. β‐cyclodextrin‐modified chitosan is synthesized via the aldimine condensation reaction between β‐cyclodextrin monoaldehyde and chitosan as the host. The guest is prepared through the esterification reaction between methoxypoly(ethylene glycol) and 1‐adamantanecarboxylic acid chloride. The supramolecular assemblies are formed through the inclusion of adamantane‐modified methoxypoly(ethylene glycol) into the β‐cyclodextrin cavity on the chitosan chain. Fourier transform infrared and ¹H NMR spectra were used to prove that the host, guest and assemblies were successfully obtained. UV?visible spectra were employed to confirm the formation of assemblies. Furthermore, the size of the particles in the assembled solution, the change before and after self‐assembly, and the effect of the addition of competitive molecules were studied by dynamic light scattering measurements. The results indicate that supramolecular assemblies have formed successfully which might be used to realize the biomimetic structure of the articular cartilage proteoglycan. © 2014 Society of Chemical Industry     

Light-induced changes in bottled white wine and underlying photochemical mechanisms

Bottled white wine may be exposed to UV-visible light for considerable periods of time before it is consumed. Light exposure may induce an off-flavor known as “sunlight” flavor, bleach the color of the wine, and/or increase browning and deplete sulfur dioxide. The changes that occur in bottled white wine exposed to light depend on the wine composition, the irradiation conditions, and the light exposure time. The light-induced changes in the aroma, volatile composition, color, and concentrations of oxygen and sulfur dioxide in bottled white wine are reviewed. In addition, the photochemical reactions thought to have a role in these changes are described. These include the riboflavin-sensitized oxidation of methionine, resulting in the formation of methanethiol and dimethyl disulfide, and the photodegradation of iron(III) tartrate, which gives rise to glyoxylic acid, an aldehyde known to react with flavan-3-ols to form yellow xanthylium cation pigments.     

Phytochemical Constituents,Attenuated Total Reflectance Fourier Transform Infrared Analysis and Antimicrobial Activity of Four Plant Leaves Used for Preparing Rice Beer in Assam,India

Phytochemicals content and antimicrobial activity of Artocarpus heterophyllus, Cyclosorus extensa, Oldendia corymbosa, and Alpinia malaccensis were investigated. Maximum alkaloids and terpenoids were found in A. heterophyllus; tannins and saponins in C. extensa; flavonoids, polyphenols, and phytosterols in O. corymbosa and anthraquinone, glycosides, and anthocyaninin A. malaccensis. Aqueous, methanolic, ethyl acetate, and hexane extracts were prepared from all the leaves. Attenuated total reflectance Fourier transform infrared spectrophotometric (ATR-FTIR) analysis revealed that alkanes and alkyl halides were prevalent in all the extracts and the ethyl acetate extracts contained comparatively higher number of functional groups, which were also more effective against Candida albicans, Escherichia coli, and Staphylococcus aureus. The minimum inhibitory concentration values of A. malaccensis against the tested pathogens were found to be lesser than the other species.     

煤中全硫测定方法的探讨

煤炭中全硫的分析，采用高温燃烧中和法进行测定，其中所用氧气采用纯氧瓶来供氧。因此，在试验中有很多不便。本文通过大量试验，从理论和实践中提出了直接以空气中氧来代替目前所用氧气钢瓶是完全可行的。     

地方煤矿隔爆设施安装方法探讨

通过对地方煤矿隔爆设施现状的深入了解，结合地方煤矿生产布局和开采条件等实际情况，阐述了适合地方煤矿的隔爆水袋和岩粉棚安装的基本要求、方法及特点。     

The effect of monoethylene glycol on the stability of water-in-oil emulsions

It is important from both a strategic and economic standpoint to study the mechanism of formation of water/oil emulsions, to predict their increase of viscosity with respect to that of the crude oil, and to obtain information about the stability vs separation of these substances (since their presence can impair oil processing and distribution). The objective of this work was to ascertain the influence of monoethylene glycol (MEG) on these parameters and its action mechanism. The addition of MEG in different proportions in the oil emulsions significantly changed the flow curve of the emulsion, passing from a quasi-Newtonian one to a shear thinning behaviour. Besides this, when MEG was present at low concentrations, the demulsification process was slow and an increase in concentration made the emulsions more stable than samples containing the same aqueous phase proportion. Under the conditions studied, the addition of MEG did not reduce the quantity of the aqueous phase separated compared to the emulsions free of MEG, but significantly delayed the demulsification process. Rheology provided important information regarding the phase separation process of the aqueous phase in oil phase emulsions, and dynamic testing suggested that the most relevant effect of the addition of MEG is an increase of the emulsion elasticity that can be correlated with the increase in the emulsion stability observed by bottle test and Turbiscan.     

中国常见酒中生物活性物质研究进展

我国常见的饮用酒主要分为4类:红酒、啤酒、黄酒和白酒。本文综述了这4类酒中对人体有益的生物活性物质如多酚、美拉德反应产物、有机酸及其酯类、活性肽、低聚糖、氨基酸等的研究进展,分析总结了酒中主要生物活性物质的种类和含量,并指出了这些生物活性物质对人体的有益功能。