► Ethanol is one of the most commonly used recreational drugs worldwide. ► Beer market is witnessing a significant increase in the consumption of low-alcohol beer. ► Strategies to produce low alcohol ...beers can be of physical and biological origin. ► Production methods, sensorial properties and additional improvements are reviewed.
The increasing interest of consumers in health and alcohol abuse issues motivates breweries to expand the assortment of products with low alcohol content. The goal of producing beers with low alcohol content can be achieved by two main strategies; namely by gentle removal of alcohol from regular beer and by limited ethanol formation during the beer fermentation. Within these two basic strategies, there are a number of techniques that vary in performance, efficiency and usability. This paper presents an overview and comparison of these techniques and provides an evaluation of sensorial properties of low-alcohol and an alcohol-free beer produced as well as suggests possibilities for their additional improvement.
►Most of the lactose present in milk was metabolized within 48h. ►Volatile compounds were important to the flavours of these novel beverages. ►Higher alcohols increased from the beginning until the ...end of the fermentation. ►Ethyl acetate was detected during milk, CW and DCW fermentations by kefir grains. ►The use of DCW in kefir fermentation can be considered as a new whey valorisation strategy.
Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefir. The results showed that kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8–8.3g/l), lactic acid (5.0g/l) and acetic acid (0.7g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based kefir and milk kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of kefir-like beverages similar to milk kefir.
To evaluate the potential for fermentation of raspberry pulp, sixteen yeast strains (
S. cerevisiae and
S. bayanus) were studied. Volatile compounds were determined by GC–MS, GC–FID, and GC–PFPD. ...Ethanol, glycerol and organic acids were determined by HPLC. HPLC–DAD was used to analyse phenolic acids. Sensory analysis was performed by trained panellists. After a screening step, CAT-1, UFLA FW 15 and
S. bayanus CBS 1505 were previously selected based on their fermentative characteristics and profile of the metabolites identified. The beverage produced with CAT-1 showed the highest volatile fatty acid concentration (1542.6
μg/L), whereas the beverage produced with UFLA FW 15 showed the highest concentration of acetates (2211.1
μg/L) and total volatile compounds (5835
μg/L). For volatile sulphur compounds, 566.5
μg/L were found in the beverage produced with
S. bayanus CBS 1505. The lowest concentration of volatile sulphur compounds (151.9
μg/L) was found for the beverage produced with UFLA FW 15. In the sensory analysis, the beverage produced with UFLA FW 15 was characterised by the descriptors
raspberry, cherry, sweet, strawberry, floral and
violet. In conclusion, strain UFLA FW 15 was the yeast that produced a raspberry wine with a good chemical and sensory quality.
The solubility of d-glucose in water as a function of temperature in a mixture of ethanol/water containing (50, 60, 70, and 80) % ethanol was evaluated on the basis of the refraction index at 60 °C. ...The results obtained have shown that the solubility in water presents a linear increase with an increase in temperature, whereas for the solutions containing ethanol/water mixtures, this increase is represented by a second-order polynomial. Because glucose shows considerably high solubility, these data can be used to study the glucose crystallization process in mixtures containing antisolvents.
Cheese whey powder (CWP) is an attractive raw material for ethanol production since it is a dried and concentrated form of CW and contains lactose in addition to nitrogen, phosphate and other ...essential nutrients. In the present work, deproteinized CWP was utilized as fermentation medium for ethanol production by
Kluyveromyces fragilis. The individual and combined effects of initial lactose concentration (50–150 kg m
−3), temperature (25–35 °C) and inoculum concentration (1–3 kg m
−3) were investigated through a 2
3 full-factorial central composite design, and the optimal conditions for maximizing the ethanol production were determined. According to the statistical analysis, in the studied range of values, only the initial lactose concentration had a significant effect on ethanol production, resulting in higher product formation as the initial substrate concentration was increased. Assays with initial lactose concentration varying from 150 to 250 kg m
−3 were thus performed and revealed that the use of 200 kg m
−3 initial lactose concentration, inoculum concentration of 1 kg m
−3 and temperature of 35 °C were the best conditions for maximizing the ethanol production from CWP solution. Under these conditions, 80.95 kg m
−3 of ethanol was obtained after 44 h of fermentation.
► Cheese whey powder solution was used for ethanol production by
Kluyveromyces fragilis. ► The effect of temperature and initial lactose and inoculum concentration was verified. ► Lactose concentration had the most significant effect on ethanol production ► By using 200 kg m
−3 initial lactose, 80.95 kg m
−3 of ethanol was obtained after 44 h ► The findings are of importance to decrease the ethanol distillation costs.
Sixteen different strains of
Saccharomyces cerevisiae and
Saccharomyces bayanus were evaluated in the production of raspberry fruit wine. Raspberry juice sugar concentrations were adjusted to 16°Brix ...with a sucrose solution, and batch fermentations were performed at 22
°C. Various kinetic parameters, such as the conversion factors of the substrates into ethanol (
Y
p/s), biomass (
Y
x/s), glycerol (
Y
g/s) and acetic acid (
Y
ac/s), the volumetric productivity of ethanol (
Q
p), the biomass productivity (
P
x), and the fermentation efficiency (
E
f) were calculated. Volatile compounds (alcohols, ethyl esters, acetates of higher alcohols and volatile fatty acids) were determined by gas chromatography (GC-FID). The highest values for the
E
f,
Y
p/s,
Y
g/s, and
Y
x/s parameters were obtained when strains commonly used in the fuel ethanol industry (
S. cerevisiae PE-2, BG, SA, CAT-1, and VR-1) were used to ferment raspberry juice.
S. cerevisiae strain UFLA FW 15, isolated from fruit, displayed similar results. Twenty-one volatile compounds were identified in raspberry wines. The highest concentrations of total volatile compounds were found in wines produced with
S. cerevisiae strains UFLA FW 15 (87,435
μg/L), CAT-1 (80,317.01
μg/L), VR-1 (67,573.99
μg/L) and
S. bayanus CBS 1505 (71,660.32
μg/L). The highest concentrations of ethyl esters were 454.33
μg/L, 440.33
μg/L and 438
μg/L for
S. cerevisiae strains UFLA FW 15, VR-1 and BG, respectively. Similar to concentrations of ethyl esters, the highest concentrations of acetates (1927.67
μg/L) and higher alcohols (83,996.33
μg/L) were produced in raspberry wine from
S. cerevisiae UFLA FW 15. The maximum concentration of volatile fatty acids was found in raspberry wine produced by
S. cerevisiae strain VR-1. We conclude that
S. cerevisiae strain UFLA FW 15 fermented raspberry juice and produced a fruit wine with low concentrations of acids and high concentrations of acetates, higher alcohols and ethyl esters.
is a human pathogen responsible for high mortality rates. The development of new antimicrobials is urgent.
The authors evaluated the activity of hydralazine along with its synergism with other drugs ...and action on biofilms. With regard to action mechanisms, the authors evaluated cell viability, DNA damage and molecular docking.
MIC and minimum bactericidal concentration values ranged from 128 to 2048 μg/ml. There was synergism with oxacillin (50%) and vancomycin (25%). Hydralazine reduced the viability of biofilms by 50%. After exposure to hydralazine 2× MIC, 58.78% of the cells were unviable, 62.07% were TUNEL positive and 27.03% presented damage in the comet assay (p < 0.05). Hydralazine showed affinity for DNA gyrase and TyrRS.
Hydralazine is a potential antibacterial.
Large rivers create major gaps in reef distribution along tropical shelves. The Amazon River represents 20% of the global riverine discharge to the ocean, generating up to a 1.3 × 10(6)-km(2) plume, ...and extensive muddy bottoms in the equatorial margin of South America. As a result, a wide area of the tropical North Atlantic is heavily affected in terms of salinity, pH, light penetration, and sedimentation. Such unfavorable conditions were thought to imprint a major gap in Western Atlantic reefs. We present an extensive carbonate system off the Amazon mouth, underneath the river plume. Significant carbonate sedimentation occurred during lowstand sea level, and still occurs in the outer shelf, resulting in complex hard-bottom topography. A permanent near-bottom wedge of ocean water, together with the seasonal nature of the plume's eastward retroflection, conditions the existence of this extensive (~9500 km(2)) hard-bottom mosaic. The Amazon reefs transition from accretive to erosional structures and encompass extensive rhodolith beds. Carbonate structures function as a connectivity corridor for wide depth-ranging reef-associated species, being heavily colonized by large sponges and other structure-forming filter feeders that dwell under low light and high levels of particulates. The oxycline between the plume and subplume is associated with chemoautotrophic and anaerobic microbial metabolisms. The system described here provides several insights about the responses of tropical reefs to suboptimal and marginal reef-building conditions, which are accelerating worldwide due to global changes.
The present study investigated the antifungal action of dexamethasone disodium phosphate (Dex).
Susceptibility testing was performed using the Clinical & Laboratory Standards Institute protocol; ...M27-A3, checkerboard test and biofilm were evaluated with two isolates of
, hyphal production test, molecular docking analysis and flow cytometry analysis.
Dex and fluconazole (FLC) together had a synergistic effect. Mature biofilm was reduced when treated with Dex alone or in combination. Dex and FLC promoted a decrease in the production of hyphae and changes in the level of mitochondrial depolarization, increased generation of reactive oxygen species, loss of membrane integrity, increased phosphatidylserine externalization and molecular docking; there was interaction with ALS3 and SAP5 targets.
Dex showed antifungal activity against FLC-resistant
strains.
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