How Foam Appearance Influences the Italian Consumer's Beer Perception and Preference

The current study presents the results of a survey performed to investigate whether different patterns of foam and lacing affect consumer beer preference and the perception of beer characteristics. The impact of three different levels of foam (huge, medium and little) at pouring, and two lacing patterns (very laced to not laced) during consumption, was evaluated on a set of 26 attributes by a panel of Italian beer consumers. Overall, beers which delivered a medium level of foam at pouring were considered by Italian consumers as the best dispensed, the most liked for their visual appearance, the most attractive to consume and the most likely to be purchased. Cluster analysis determined four groups of consumers with different preference patterns for beer foam and expectations for sensory characteristics of the beer. It was found that 80% of consumers preferred a medium level of foam and no lacing, whereas 20% of consumers preferred a high level of foam and lacing. Furthermore, for nearly 40% of consumers, foam and lacing patterns generated expectations regarding beer sweetness, bitterness, fruitiness, perceived level of alcohol, effervescence and the thirst quenching character of the beer.     

石墨炉原子吸收法用于测定啤酒中的铅

研究了采用石墨炉原子吸收法测定啤酒中的重金属铅的含量,研究结果表明:该方法的检出限为0.22μg/L,相对标准偏差为0.56%～3.73%,样品加标回收率为96.45%～103.14%,测定结果的精密度和准确度令人满意。通过对市场上的9种啤酒进行抽样检测,检测结果表明啤酒中的铅含量为0.0343～0.0762mg/L满足国家相关标准的要求。     

玉米淀粉在糖化中的应用

本文介绍了玉米淀粉的特性，比较了使用玉米淀粉作辅料的优势及糖化生产中应满足的设备、工艺要求，分析了玉米淀粉代替大米作辅料对啤酒质量的影响。     

超声波辅助清洗啤酒发酵液污染微滤膜的研究

采用超声波技术清洗由啤酒发酵液污染的聚偏氟乙烯（PVDF）微滤膜,实验中所用的超声波频率为40kHz,超声波的强度为1.43～2.85 W/cm^2.实验结果表明：超声波辅助水洗只能部分恢复膜的水通量,而且超声波强度的提高,只是缩短了达到水通量恢复率的清洗时间;而超声波辅助NaOH＋SDS＋H2O2混合洗液化学清洗的效果较好,在强度为2.85 W/cm^2的超声波辅助作用下,清洗10min其水通量恢复率达到93%.     

风送泵及其在糖厂中的应用

电机泵在糖厂中长期使用，暴露出许多它本身无法克服的缺陷．用压缩空气替代电机泵作动力源输送液体物料，则可以从根本上杜绝目前糖厂液体输送中的泄露等现象．本文对当前我区糖厂中最先进的风送泵结构作了说明．同时，提出了风送泵在糖厂内进一步推广应用要注意解决的问题，对解决方法作了初步探讨．     

啤酒发酵过程计算机控制系统

介绍了啤酒发酵过程计算机控制系统的设计原理、安装过程和调试方法,该系统的结构是分级递阶安排的,系统的上一级是一个监督管理计算机,系统的下一级是STD总线工业控制机。实际使用表明,该系统达到了稳定的、精确的、可靠的啤酒发酵过程控制。     

THE FLASH PASTEURISATION OF BEER*

The theory of beer pasteurisation is discussed in terms of thermal death time and logarithmic death. Over-pasteurisation can adversely affect flavour and the control of temperature and holding time which is necessary in order to minimise such effects is described. A temperature control band of 3°C and a holding time such that the fastest material through the system is just pasteurised are recommended. Overall pasteurisation plant design is then considered including flowsheet configuration, heating method and automatic control system. The heat exchanger is the single most critical item in the system. Its specification including materials of construction, mechanical design features and pressure rating are discussed and recommendations are made regarding the prevention of corrosion-induced failures by monitoring chloride levels in operating fluids and by regular inspection and replacement of plates. Finally, data on capital and operating costs are presented and the optimisation of a typical pasteuriser is described. It is shown that the extra capital cost of increasing heat recovery to 95% can usually be justified.     

A MEANS TO REDUCE FORMATION OF PRECURSORS OF 2-TRANS-NONENAL IN BREWING*

A method is described whereby the precursors of 2-trans-nonenal may be estimated in worts and beers. Treatment of malt grist or malt with a variety of polar substances is shown to reduce or eliminate the production of nonenal precursors during mashing. Beers made from worts so treated have enhanced flavour stability over those made conventionally.     

Identification and characterization of Saccharomyces cerevisiae strains isolated from West African sorghum beer

The occurrence and characterization of yeasts isolated from sorghum beer produced in Ghana and Burkina Faso, West Africa, were investigated. The yeasts involved in the fermentations were found to consist of Saccharomyces spp. almost exclusively. Of the isolates investigated, 45% were identified as Saccharomyces cerevisiae, whereas more than half of the isolates (53%) had physiological properties atypical of S. cerevisiae or any other member of the complex sensu strictu, as they were able to assimilate only glucose, maltose and ethanol as carbon sources. Both ITS-PCR RFLP and PFGE strongly indicated that these isolates were related to S. cerevisiae, regardless of their phenotypic characteristics. Sequencing of the D1/D2 domain of the 26S rDNA confirmed the close relatedness to S. cerevisiae with 0.5% nucleotide differences. The MAL1 and MAL3 loci were found for all isolates as the only recognized MAL loci. Besides, for 40% of the isolates the MAL61 probe hybridized to a position of about 950 kbp, which has not formerly been described as a MAL locus. The results showed that the spontaneous fermentation of West African sorghum beer is dominated by a variety of strains of S.cerevisiae not previously described, among which starter cultures should be selected.     

高阻隔聚酯啤酒瓶专用料的研究

在PET的聚合过程中加入纳米添加剂,得到高阻隔聚酯瓶用料,解决了纳米添加剂在聚酯中的分散问题,考察了切片及高阻隔聚酯瓶用料各种指标.