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Investigation of overfoaming activities and gushing mechanisms of individual beer ingredients as model substances in bottled carbonated water

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Abstract

Researchers from several disciplines are interested in understanding the spontaneous and eruptive overfoaming (gushing) of carbonated beverages, as it is an essential problem of both brewing and beverage industries. In order to understand the mechanism(s) taking place in gushing-beer, several beer ingredients have been investigated as model substances in much simpler matrix of carbonated water. For this purpose, sinapic acid, vanillic acid, ferulic acid, cinnamic acid and palmitic acid have been chosen as model beer ingredients. Gushing formation of the investigated beer ingredients depends on degree of stabilized solvated molecular carbon dioxide in water. For this purpose, functional groups which are capable of forming hydrogen bonds with electronegative oxygen atoms of carbon dioxide are needed. However, solubility of substances plays an important role in abundance of these functional groups in undissociated form to interact further with solvated molecular carbon dioxide. The reported data provide valuable insights into the gushing problem and help to understand its formation pathways. Each gushing-positive substance has an individual mechanism related to its structural conformation and solubility level. Therefore, possible gushing mechanisms have been proposed with respect to structural changes in model substances to clarify the differences in observed overfoaming and gushing stability levels.

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Beer is one of the most popular alcoholic beverages around the world. It has a very long history, even beyond the record of civilization. Yeast, malt, hops, and water are the main ingredients for beer brewing. Sometimes, other starch adjuncts like rice and syrup are also used as the brewing materials. The brewing process contains several steps, including mashing, fermentation, filtration, and filling. Hops are indispensable in beer, as they supply beer with flavor compounds, antibacterial ability, and health effects. Amylases (α-amylase, β-amylase, α-1,4-glucan glucohydrolase, and deramifying enzyme) and proteases are two main enzymes used in beer brewing. Yeast is the soul of beer brewing, as it plays a decisive role in beer quality. Based on the yeast used in the brewing, the most recognized categories of beer are ale and lager. Because the color, foam, and taste are the critical features that affect the quality of beer, white and smooth foam not only gives drinkers a pleasant feeling and excellent flavor, but also avoids the loss of flavor and direct oxidation. Compounds like CO2, metal ions, proteins, and flavor substances in beer have positive impacts, whereas lipids and alcohols have negative impacts on formation and stabilization of beer foam. Among these compounds, protein Z was the first protein found in beer and has the character of stabilizing beer foam. Moreover, saccharides, as the most abundant material in beer other than water, not only can maintain the nonbiological stability of beer, but also play a very important role in maintaining foam stability. Finally, stability is always the goal for beer brewers, and it is usually referred to as biological stability, nonbiological stability, foam stability, and flavor stability.
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The brewing of beer is a very traditional process, based upon a complex endogenous enzymology occurring during the malting of grain, mashing of grist and fermentation. The relevant cereal-derived enzymes that are involved are reviewed. It is likely that the production of alcoholic beverages in breweries in the projected future will assume different paradigms, procedures which are already realistic for the production of flavoured alcoholic beverages (malternatives) and “near-beer” drinks (happoshu and other beer-like beverages) in Japan. A range of exogenous enzymes—such as glucanases, acetolactate decarboxylase and prolyl endopeptidase—are available for enhancement of the existing brewing process.
Article
Measurements of dissolved CO(2) concentrations from Champagne bottles initially holding the same CO(2) level after having been elaborated (close to 11.5 g L(-1)), but having experienced different periods of aging after having been corked with natural cork stoppers, were done. Losses of dissolved CO(2) close to 3.5 g L(-1) experienced by the oldest Champagne samples aged for about 75 months were reported. This very significant loss of dissolved CO(2) was logically interpreted as a consequence of the continuous diffusion of gaseous CO(2) through the pores of the cork stopper. By combining the diffusion principle through a porous medium with Henry's law (which links the solubility of a gas species in a liquid medium with its partial pressure in the vapor phase), a multiparameter model was built that provides the dissolved CO(2) content found in Champagne during its whole aging period. Both Champagne temperature and bottle volume were found to be key parameters with regard to the kinetics of CO(2) losses through the cork.
Article
Fusarium toxins, secondary metabolites of toxinogenic Fusarium species, are found in a range of cereal grains. In this study the occurrence of the most commonest Fusarium toxins, namely nivalenol (NIV), deoxynivalenol (DON), deoxynivalenol-3-glucoside, fusarenon-X, 3- and 15-acetyldeoxynivalenol, HT-2 and T-2 toxins and zearalenone, in various barley cultivars harvested in 2005-2008 was monitored. The impact of weather, locality, fungicide treatment and barley cultivar (hulless or covered) on contamination was evaluated. The transfer of these mycotoxins into malt was assessed. The most prevalent toxin was DON, which was found in 83% of samples (maximum level 180 µg kg(-1)), while HT-2 was detected in 62% of samples (maximum level 716 µg kg(-1)). Using analysis of covariance, weather was found to be the key factor in all years (P < 0.001). A relationship between cultivar and contamination was confirmed only for HT-2 (P < 0.001) and T-2 (P = 0.037), with higher levels of these toxins being observed in hulless cultivars. With the exception of NIV (P = 0.008), no significant relationship was found between fungicide treatment and contamination. No distinct trend regarding DON levels in malt was found, with both decreases and increases occurring. The results show an inter-annual variation in mycotoxin occurrence in barley cultivars as well as differences in contamination of malt produced from fungicide-treated and untreated barley.
Article
Filtered bright and unfiltered hazy lager beer samples were either treated with high hydrostatic pressure (200, 250, 300, 350 MPa for 3, 5 and 10 min at 10°C and 20°C) or conventional heat pasteurization (60°C for 15 min). Treatments did not affect ethanol, extract, fermentation degree, density and pH in comparison with untreated beers. Both treatments produced microbiologically stable products. Bitterness, color, protein sensitivity and chill haze parameters were affected by both the HHP and heat treatment. A storage period of 56 days showed that HHP and heat pasteurization had similar results in terms of pH and color. However, HHP treated samples had lower bitterness and protein sensitivity and higher chill haze values than the heat pasteurized samples which indicates HHP treatment had a positive effect on bitterness and protein sensitivity at the end of the storage period. The microbiological stability of HHP treated beers was comparable with heat-treated beers, and the development of both lactic and acetic acid bacteria was inhibited for 56 days of storage. Unfiltered beer samples had 7. 48, 7.15 and 2.64 log10cfu/ml of total yeasts, total aerobic and lactic acid bacteria counts, respectively. No colony formation of lactic acid bacteria was observed when the samples were pressurized at pressures equal to or higher than 300 MPa at 10°C and 20°C for 5 and 10 min. Total aerobic and total yeasts counts demonstrated more than 6 and 7 log-cycle reduction when pressurized at 350 MPa at 10°C and 20°C for 10 min, respectively. Heat treatment gave similar results in terms of log reductions as HHP.
Article
Everybody has had the experience of a canned carbonated drink overflowing and soiling their clothes. It is difficult to guess the amount of overflow before opening the can, although the phenomenon can be simply explained as the result of the formation of gas bubbles. In this article, we report the surprising result that intensive shaking using ultrasonic vibration can calm this effect in beer. These experiments showed evidence of a memory effect in liquid. The 'calming down' is due to a fine balancing act between a change in the amount of microbubbles (or embryos) and a change in the pattern of their size distribution. Our experimental evidence shows that modification of the pre-existing microbubbles noticeably influences the subsequent nucleation, and this may open a new route to nucleation studies.
Article
We found that hydroxycinnamic acid (HA) glycerol esters such as 1-sinapoyl glycerol and 1-p-coumaroyl glycerol can be synthesized through a direct esterification reaction using a type A feruloyl esterase from Aspergillus niger. The water solubilities of HA glycerol esters were higher than those of the original chemicals. HA glycerol esters absorbed ultraviolet light and scavenged 1,1-diphenyl-2-picrylhydrazyl radicals.
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Tsuchiyama M, Sakamoto T, Taninori S, Murata S, Kawasaki H, Enzymatic synthesis of hydroxycinnamic acid glycerol esters using type A feruloyl esterase from Aspergillus niger, Biosci Biotechnol Biochem 71: 2606-2609 (2007).
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Das ‘Wildwerden’ des Malzbieres
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Ergebnisse einer Umfrage in deutschen Brauereien zum Thema ‘Gushing’
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CO2-hydrophobin structures acting as nanobombs in beer - Part 1: A critical review of hypotheses and mechanisms
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Das Überschäumen (Wildwerden) des Bieres
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Combined particle analysis as a new tool to predict gushing shown with alcohol-free beverage products
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