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.     

Microfiltration and Ultrafiltration Ceramic Membranes for Apple Juice Clarification

Depectinized control (CTJ) and ascorbic acid treated (AAJ) apple juices were filtered through microfiltration (MF, 0.2 m) and ultrafiltration (UF, 0.02 m) ceramic tubular membranes. Under optimal conditions (8 m/s, 414 kPa and 50°C), the UF membrane resulted in higher steady state flux and less fouling than the MF membrane for both juices. AAJ produced by addition of AA at milling had lower flux for both MF and UF. The chemical, physical and sensory properties of apple juices from MF and UF membranes were similar and changes during storage were comparable.     

Alternatives to Isinglass for Beer Clarification

Fish products have been identified as serious allergens and people who are allergic to fish must avoid consuming foods made with fish or fish products. There is no evidence that isinglass (which is made from the swim bladders of certain fish) can cause allergenic reactions in people who are allergic to fish, and the European Food Safety Authority (EFSA) has ruled that it is not very likely to do so. However, many people may still wish to avoid drinking beer which has been clarified with isinglass. Two alternative compounds (which had shown promise in earlier experimental trials) for the clarification of cask ales and brewery conditioned beers were investigated. These were avian collagen and a pea protein extract. Both materials were observed to have a good clarification effect in laboratory scale fining trials and performed well in comparison to isinglass. Brewery trials were conducted using isinglass, avian collagen and pea extract as fining agents and sensory evaluation showed that there were few discernable differences between all three beers. The collagen alternative was ideal in that the data obtained from the laboratory, sensory and analytical trials show that it acted in a similar manner to isinglass and has no significant impact on beer quality. However, it was not thought that brewers would be receptive to using animal products in their beer. The pea extract also worked well and would make an excellent vegetarian alternative to isinglass, however further work is needed to scale up the production of the pea extract in order that it should become an economic option for use in the beer and wine industries.     

鱼胶和啤酒的澄清

鱼胶在低pH值环境下能与酵母快速形成较大的颗粒而沉降到容器底部;使罐体内悬浮酵母数减少;也能沉降一些引起啤酒混浊或过滤问题的小颗粒。使用方法:将鱼胶缓慢加入pH2.4～3.0的酸化水中,酸化水温度5～10℃,并搅拌制得鱼胶溶液。添加量为5×10-6～1.0×10-5;可与带负电的多糖物质配合应用,效果更好。(孙悟)     

柿子单宁在啤酒澄清中的应用

本文研究了柿子单宁作为一种啤酒澄清剂,对啤酒的澄清度,色度,浊度、总多酚、蛋白质含量、TBA值及苦味质的影响程度,比较分析了添加柿子单宁的发酵液及添加硅藻土的发酵液的各项指标.结果表明:当单宁的添加剂量为70 mg/L时,发酵液的各项指标者合格,并且优于添加硅藻土的发酵液.同时发现添加柿子单宁明显提高啤酒的稳定性和抗老...     

管式膜超滤生黄酒的研究

本文利用外压管式超滤装置,对生黄酒进行除浊除菌试验,探讨了压力和温度对生黄酒的透液通量的影响,考查了相关质量指标的变化规律。采用切割分子量为5万的有机膜,在0.30MPa、40℃条件下超滤,黄酒平均透液通量可达到75kg/m2•h左右。杂菌总数去除98%以上,不溶性固形物全部去除,粗蛋白仅保留21.55%。超滤过程对酒精度影响极小,对各种氨基酸的保留率有一定差别,总体保留率86.76%。对于多次使用的旧膜,可采用较长时间浸泡清洗。     

电子鼻检测改性聚砜膜用于啤酒澄清处理的研究

为研究膜处理技术对啤酒风味的影响,使用自制的共混改性聚砜膜(孔径100 nm)处理精滤前的啤酒,选用电子鼻PEN3系统对啤酒原液及膜澄清处理过的2种啤酒的芳香成分进行分析。通过电子鼻系统动态采集啤酒芳香成分,得到电子鼻的响应值,使用PCA、LDA模式识别方法进行数据分析。分析结果表明电子鼻能够快速、无损地检测到不同处理工艺对啤酒风味的影响,为检测共混改性聚砜膜对啤酒的澄清效果提供技术支持。     

陶瓷膜过滤生啤酒的研究

探讨了无机陶瓷膜孔径、压力对生啤酒透液通量的影响,及对过滤除菌/除浊的效果。结果表明,膜孔径越大,在初始阶段啤酒的通量越大,随后稳定在0.8￣1.0kg/m2.h之间;孔径越大,压力对通量的影响越大,当压力超过一定值时,通量趋于稳定;膜过滤对生啤酒的理化指标有改善作用;3种膜均有显著的除菌/除浊效果,以0.5μm膜更适合生产实际,但孔径为0.1μm的膜除菌/除浊更为彻底。     

Clarification of Apple Juice Using Polymeric Ultrafiltration Membranes: a Comparative Evaluation of Membrane Fouling and Juice Quality

The aim of this study was to evaluate the performance of three different commercial polymeric ultrafiltration (UF) membranes during clarification of raw apple juice, comparatively. The influence of membrane pore size, roughness, and hydrophobicity on flux profile and fouling was investigated. The initial flux was simultaneously decreased at the beginning of the process, and quite steady flux was obtained in the membranes with rougher surface and more hydrophobic nature. As the pore size and hydrophobicity increased, the reversible fouling became the major resistance, while cake formation was more prominent for the membranes with narrower pore size. The overall quality results revealed that the main quality characteristics of the raw juice can be better retained by using the membranes that have higher resistance to fouling.     

Novel Procedure for Lager Beer Clarification and Stabilization Using Sequential Enzymatic,Centrifugal, Regenerable PVPP and Crossflow Microfiltration Processing

In this work, the crossflow microfiltration (CFMF) performance of different lots of lager beer, produced in a pilot scale at the Italian Brewing Research Centre (CERB, Perugia, Italy), was assessed in a bench-top plant, equipped with a 0.8-μm ceramic tubular membrane module, under constant crossflow velocity of 6 m s^?1, transmembrane pressure difference of 3.74 bar, temperature of ~10 °C, and periodic CO₂ backflushing. By feeding different beer samples (i.e., as such, precentrifuged (C), or pretreated with a commercial enzyme preparation to degrade the original arabinoxylans and β-glucans and then centrifuged (EC) to minimize the fouling contribution of yeast cells, aggregates, and polysaccharides), it was possible to increase the average permeation flux (expressed as mean value?±?standard deviation) from 112?±?13 to 199?±?17 or 330?±?22 L m^?2 h^?1, respectively. Only when using the EC-pretreated beer specimens, the permeate turbidity at 20 °C approached the limiting one (<0.6 EBC unit) recommended by the European Brewery Convention standards. As expected, the permeate chill haze at 0 °C was generally higher than the above haze target. By submitting EC-pretreated beer seeded with 0.5 g L^?1 of regenerable polyvinylpolypyrrolidone (PVPP) to CFMF, it was possible to reduce the initial total polyphenol content by 30 % and permeate chill haze to 0.60?±?0.01 EBC unit, but the average permeation flux fell to 84?±?4 L m^?2 h^?1. By performing sequentially EC pretreatments, PVPP stabilization, cartridge filtration, and CFMF, it was possible not only to re-enhance the average permeation flux at about 230 L m^?2 h^?1 near to those achievable with DE filters, but also to obtain a chill haze-free permeate ready for aseptic packaging.     

小型多台化贯流式锅炉在啤酒企业的应用

近年来随着我国国力的增强，人们的消费水平和啤酒的消费量也不断提高。国内各大型啤酒企业纷纷扩大自己的市场份额，投巨资在各地扩建、新建和兼并收购啤酒企业。目前我国已成为世界第一大啤酒生产国。同时啤酒产能过剩，市场竞争激烈、价格偏低、企业效益下滑，降低生产成本已成为各企业确保效益、提高竞争力的重要手段。     

6种国产膜在苹果汁加工中的应用比较

以小国光苹果为原料 ,采用聚砜 (PS)、磺化聚砜 (SPS)、聚砜 磺化聚砜共混膜 (PS SPS)、聚丙烯腈 (PAN)、羧基化改性的PAN板式膜、中空纤维PAN膜等 6种国产膜材料对苹果汁进行超滤澄清处理 ,比较了 6种国产膜在苹果汁澄清超滤中通量的变化、不同清洗方式对膜通量的恢复情况和不同膜材料对苹果汁理化指标和感官指标的影响。结果发现 ,6种国产膜均适合对苹果汁进行超滤澄清 ,其中PS SPS混膜在苹果汁的超滤工艺中具有更好的应用前景 ;PS SPS共混膜和改性PAN膜具有较高的抗污染能力。另外 ,采用 0 .1 %酶清洗(NOVOFERM5 8)与 0 .5 %碱液 (pH 1 2 )结合的方式 ,能显著性地提高膜清洗后的通量。     

小孔径陶瓷膜澄清甜叶菊提取液的工艺研究

该文研究了小孔径陶瓷膜澄清甜叶菊提取液的效果.通过比较4、5、8、10 nm孔径的陶瓷膜过滤甜叶菊的甜菊糖提取液时的过滤通量、脱色率和收率的区别,确定较优的陶瓷膜孔径;再优化陶瓷膜操作参数.结果表明,5 nm陶瓷膜较优,在40℃时,操作压力5 bar,膜面流速4 m/s,浓缩10倍,加30％原液体积水洗滤效果最佳,陶瓷...     

无机陶瓷膜分离技术在食用油脂废水处理中的应用

对无机陶瓷膜处理废水的原理及其在食用油脂废水处理中的应用进行了综述，指出无机陶瓷膜在食用油脂废水治理中有着良好的应用前景。     

被生酱油污染后的陶瓷膜再生方法的研究

从可逆及不可逆污染的角度,研究了被生酱油污染后陶瓷膜的清洗再生方法,考察了水冲洗时间、化学清洗条件以及单步和多步骤化学清洗对清洗效果的影响。结果表明,在低压,高流速条件下,经过4个步骤清洗,即先在(20±3)℃下水冲30min;再在(40±3)℃下以质量分数为1.5%的NaOH溶液循环清洗40min;进而在(40+3)℃下以0.15mol/L HNO_3循环清洗40min;最后用水冲洗装置至中性,可以达到比较理想的清洗效果,膜通量恢复到新膜通量的85%以上。     

陶瓷膜分离技术及其在食品工业中的应用

综述了陶瓷膜分离技术的发展过程及其主要的优缺点,并分类介绍了陶瓷膜分离技术在食品工业中的应用,最后对其的发展趋势进行了展望。     

大豆酶解产物复合含氮糖浆用于啤酒发酵的研究

本文主要对大豆蛋白水解产物用于部分替代麦汁进行啤酒发酵的可行性进行了实验研究,并对发酵液的理化指标进行了检测分析.实验证明酵母在添加了大豆蛋白酶解液中的发酵液里可以正常发酵,所得啤酒各项指标均符合国家标准.     

Apple Juice Clarification using Mineral Membranes: Fouling Control by Backwashing and Pulsating Flow

New mineral membranes of ceramic (Ceraflo) and carbon (Carbone Lorraine), were used for apple juice clarification using cross flow microfiltration. Effect on performance of the parameters transmembrane pressure, inlet flow velocity, membrane nature, and temperature were studied. Optimum permeate flux was at a transmembrane pressure of about 3.5 bar for both membranes. Formation of a concentration layer of rejected particles was reduced by using techniques backwashing and pulsating inlet flow. These techniques provided a major flux restoration and steady state permeate flux increased by 30–50% with backwash and up to 100% with pulsating inlet flow.     

气浮工艺中使用壳聚糖絮凝剂的研究

用壳聚糖絮凝剂对复筛原糖浆进行气浮清净试验。通过实验确定了气浮最佳工艺条件,试验结果表明,壳聚糖用量为(90～130)×10-6时,可取得良好的脱色效果。     

无机陶瓷膜错流超滤海水污染机理研究

目前,膜污染已成为制约膜技术在海水淡化领域应用的主要障碍,本文对陶瓷膜在海水预处理过程中的污染机理进行了研究.通过小试试验,分析了不同操作时间膜污染的情况,研究了0.1 μm陶瓷膜过滤阻力的形成,用膜的可逆污染、半可逆污染和不可逆污染取代已有研究结果中的膜表面沉积污染、膜内污染、极化层污染等来研究0.1 μm陶瓷膜各部分占总阻力的比例大小,更具有实际指导意义,并考察了操作条件对膜污染程度的影响,为确定最佳工艺条件和膜清洗方法提供了可靠的依据.