Development of low-alcohol isotonic beer by interrupted fermentation

Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L⁻¹), osmolality (mOsmol kg⁻¹), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L⁻¹ gallic acid), reducing and total sugars (%) and Na and K contents (mg L⁻¹). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences.     

啤酒标签用铝箔力学性能研究

分析研究了连续铸轧坯料的合金成分，冶金组织和热处理工艺对啤酒标用铝箔力学性能的影响，选定成形性优良的合金系列，并优化铸轧工艺和热处理工艺是提高铝箔力学性能的关键。     

The Loss of Hydrophobic Polypeptides during Fermentation and Conditioning of High Gravity and Low Gravity Brewed Beer

The object of this study was to investigate the loss of hydrophobic polypeptides, which are important for foam quality and stability in finished beer. Loss of hydrophobic polypeptide due to fermenter foaming occurs during transfer of fermented wort since a gradient of hydrophobic polypeptides towards the surface is created during fermentation. Due to higher polyphenol levels in high gravity (20°Plato) wort, more hydrophobic polypeptides are lost due to cold break (cold trub) precipitation compared to low gravity (12°Plato) wort. Another important factor affecting the loss of hydrophobic polypeptides could be proteinase A activity during fermentation, especially in high gravity fermentation where the yeast is exposed the higher stress. During high gravity fermentation, where osmotic pressures are higher, ethanol levels become greater, and nitrogen‐carbohydrate ratios are lower, more proteinase A is released by the yeast. This release of proteinase A into fermenting wort could have implications for the foam stability of the finished product.     

The Subjective and Reinforcing Effects of Visual and Olfactory Stimuli in Alcohol Drinking.

Nonpharmacological cues associated with drug intake may influence subjective and reinforcing effects of those drugs. Social drinkers (N = 80) participated in 2 sessions in which they rated and then consumed ad lib their preferred beer (with participants blind to brand). Visual and olfactory stimuli were obscured during 1 session (blocked) and not obscured during the other (unblocked). Dependent measures included ratings of "liking", "want another", and "desire to drink"; subjective mood; and ad lib beer consumption (reinforcement). Most ratings and ad lib consumption were lower during the blocked versus the unblocked condition. There were no interactions of blockade condition with sex and no effect of blockade on mood. These findings show that nonpharmacological stimuli associated with alcohol consumption influence alcohol's subjective and reinforcing effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Solubilisation and Degradation of Wheat Gluten Proteins by Barley Malt Proteolytic Enzymes

Solubilisation and degradation of wheat gluten proteins by barley malt proteolytic enzymes (BMPE) was investigated with a model buffer system at pH 4.0 and pH 5.6, representing optimal pH for proteolysis and a pH value typical for beer brewing conditions respectively. Under the experimental conditions, incubation of commercial wheat gluten with BMPE solubilised 70% and 20% of the gluten proteins at pH 4.0 and pH 5.6 respectively. Gel permeation chromatography profiles and SDS‐PAGE showed that wheat gluten proteins were more degraded by BMPE at pH 4.0 than at pH 5.6. In a laboratory scale barley malt brewing experiment, proteins of worts, prepared with and without wheat gluten, were characterised. Results comparable to those in the model buffer system at pH 5.6 were obtained, which indicated that BMPE indeed solubilise wheat gluten during mashing, but that further degradation is rather limited under these conditions.     

The Impact of Lightstruck and Stale Character in Beers on their Perceived Quality: A Consumer Study

The relative liking or disliking that beer drinkers have for characteristics generally regarded as off‐flavours by brewers, namely lightstruck and stale, has been explored in a consumer trial where products are presented branded and unbranded. Drinkers display a significant preference for fresh over lightstruck product, irrespective of branding. By contrast, drinkers seemed to be less clear about their liking or otherwise for stale character, although in this case they clearly prefer the branded product over the unbranded product when the beers are fresh and vice‐versa when the beer is aged. A stale version of a beer that consumers are familiar with fails to meet expectations for that product. Significant numbers of drinkers do declare a liking for lightstruck and aged character.     

啤酒中测定双乙酰含量的EBC法的改进

EBC法是测定啤酒双乙酰的常规方法,但大量报道此法再生性和重复性较差,本文对影响此方法的一些因素进行了考查,发现酸碱度是影响EBC法的一个重要因素,并对EBC法进行改进。     

COMMERCIAL BREWING TRIALS WITH ZENITH HOPS

Commercial brewing trials with Zenith hops from the 1982 and 1983 crops have shown that these hops are suitable for producing both ales and lager beers.     

乙酰丙酮分光光度法测定啤酒中甲醛

建立了检测啤酒中甲醛含量的新方法。在酸性条件下将溶解于水中的游离甲醛随水蒸出,馏出液中甲醛与乙酰丙酮作用,在100℃水浴中加热生成稳定的二乙酰基二氢吡啶化合物,冷却后在415nm处测吸光度,即可测的啤酒中甲醛含量。方法检出限为0.12μg/10mL,线性范围:0.0-8.0μg/10mL,RSD为0.73%-2.39%。样品加标回收率在98.4%-102.6%。该方法简便,灵敏度高,重线性好,适合啤酒中甲醛的测定。     

塑料啤酒瓶开发现状

介绍了塑料啤酒瓶的优点,详细介绍了各种以PET为基础的改性啤酒瓶材料,并列举了大量的开发实例。