Biopreservation of beer: Potential and constraints.

The biopreservation of beer, using only antimicrobial agents of natural origin to ensure microbiological stability, is of great scientific and commercial interest. This review article highlights progress in the biological preservation of beer. It describes the antimicrobial properties of beer components and microbiological spoilage risks. It discusses novel biological methods for enhancing beer stability, using natural antimicrobials from microorganisms, plants, and animals to preserve beer, including legal restrictions. The future of beer preservation will involve the skilled knowledge-based exploitation of naturally occurring components in beer, supplementation with generally regarded as safe antimicrobial additives, and mild physical treatments.

The Profiles of Low Molecular Nitrogen Compounds and Fatty Acids in Wort and Beer Obtained with the Addition of Quinoa (Chenopodium quinoa Willd.), Amaranth (Amaranthus cruentus L.) or Maltose Syrup.

Replacement of a part of malt with unmalted materials is a common practice in beer production. These materials may differ in chemical composition than barley malt, which in turn can contribute to changes in the final composition of the wort. Consequently, it may affect yeast metabolism and final parameters of the obtained products. In this research, two unmalted pseudocereals were used: quinoa (Chenopodium quinoa Willd.) and amaranth (Amaranthus cruentus L.). Maltose syrup was tested as a reference material due to its commercial usage as a substitute of malt in production of worts. Replacement of a part of the malt with quinoa or amaranth favorably influenced the profiles of amino and fatty acids. Due to the fact that the type and concentration of individual amino acids and fatty acids in the fermented wort significantly affect the flavor compounds synthesized by yeast, differences in the profiles of esters and higher alcohol have been noted in beers produced with pseudocereals.

Investigating patterns of millennials' interest in gluten-free beer in Poland: A question of beer price and alcohol content.

The quality perception of gluten-free beer was explored using conjoint analysis with a panel of Polish millennials (n = 200; aged 20 to 35), who were given 64 gluten-free beer concepts to evaluate and score on a 9-point scale of interest (1 = not interested at all; 9 = extremely interested). The constituent factors of the beer concepts were alcohol content, color, type of malt, price, drinking location and occasion, bottle size, label claims, type of farming, type of brewer, and bottle closure. Consumers judged price (38.4%) and alcohol (28.8%) five times more important than the other factors. Bottle size (5.3%), claims (4.8%), type of brewer (4.8%), malt type (4.6%), bottle closure (4.0%), beer color (3.6%), drinking location (2.3%), drinking occasion (2.0%), and type of farming (1.3%) were considered of little importance. The interest of Polish Millennials in gluten-free beer resulted moderate and not linked to medical needs. Males were more interested in gluten-free beers and gave more importance to alcohol content and less importance to price, compared to females. However, for both genders, interest and price were inversely correlated, while interest and alcohol content were directly correlated. PRACTICAL APPLICATION: The identification of the product factors that are preferred by consumers is paramount to translate consumers' needs and expectations into a beer designed to produce the best possible product in a relatively short period. Including information directly obtained from consumers before final design decisions are taken on the final beer output, helps ensuring development directions are on target and constitutes a cost-competitive approach to product development.

Suitability of unmalted quinoa for beer production.

BACKGROUND: This study provides the first detailed investigation into the effect of partially substituting barley malt with quinoa (Chenopodium quinoa Willd.) on the characteristics of wort and beer. Quinoa seeds and flakes were compared in terms of their suitability for brewing. The benefits of applying a commercial enzyme mixture during beer production with quinoa were also investigated. RESULTS: These findings show that quinoa is a good starchy raw material for brewing. Even without exogenous enzymes, it is possible to substitute barley malt with up to 30% quinoa. The form in which quinoa is used has a negligible influence on the quality of the wort and beer. The foam stability of beer made with quinoa was better than that of all-malt beer, despite there being a lower level of soluble nitrogen in quinoa beer in comparison with all-malt beer and more than twice the amount of fat in quinoa in comparison to barley malt. CONCLUSION: The addition of unmalted quinoa does not give unpleasant characteristics to the beer and was even found to have a positive effect on its overall sensory quality. This offers brewers an opportunity to develop good beers with new sensory characteristics. © 2018 Society of Chemical Industry.

Metal uptake capacity of modified Saccharomyces pastorianus biomass from different types of solution.

In this paper, we investigate the effect of different biomass pretreatments on metal ion uptake by various biosorbents. Heat-treated as well as caustic-treated and ground biomass of Saccharomyces pastorianus was used to remove copper, lead and cadmium from various solutions. Untreated yeast was used as the control sample. The effect of yeast modification on sorption capacity depended on the different types of heavy metal ions and whether they were in single- or multi-component solutions. The highest uptake of copper and lead from a single-metal solution was obtained from heat-treated cells. Ground biomass was the most efficient at cadmium removal. However, the sorption capacity of the modified biomass did not improve when metal ions were removed from multi-component solutions. Indeed, the results in this paper show that optimizing metal removal from single-cation solutions can lead to decreased sorption capacity in multi-component solutions. Therefore, while adjusting the procedure of biomass modification, not only the nature of the metal ion being sorbed but also the chemical composition of the metal ion solution should be taken into account.