Increasing Alcohol Concentration Research Articles

Nutrient Consumption Patterns of Saccharomyces cerevisiae and Their Application in Fruit Wine Fermentation

This study aimed to evaluate the nutritional requirements of Saccharomyces cerevisiae to improve low ethanol production in some fruit wines. The growth kinetics, ethanol production and nutrient requirements of S. cerevisiae were analyzed in chemically defined media. The results revealed that Ca2⁺, Fe2⁺, Co2⁺, Mo2⁺, Cu2⁺ and BO₃3− were predominantly utilized during the late lag phase, whereas free amino acids, nicotinic acid, calcium pantothenate, Na⁺ and Mg2⁺ were mainly consumed during the logarithmic phase. Compared with the control medium, supplementation with threonine, inositol, calcium pantothenate, thiamine hydrochloride, riboflavin, biotin, MgSO4 or KH2PO4 significantly increased the ethanol content by 1.10-fold (p < 0.05). Furthermore, adding key nutrients to noni-, guava- and mango juice significantly shortened the fermentation time and increased the final alcohol content of the fruit wines (p < 0.05). This study provides scientific insights and effective methods for shortening fermentation time and increasing alcohol content with S. cerevisiae in some fruit wines.

Elucidating core microbiota in yellow wine (Huangjiu) through flavor-oriented synthesis and construction of microbial communities

Huangjiu, a traditional Chinese alcoholic beverage with a history spanning thousands of years, holds significant cultural and economic value in China. Despite its importance, the complexity of Huangjiu fermentation and the intricate interactions within its microbial community remain underexplored. This study addresses this gap by identifying the core volatile organic compounds (VOCs) and key microorganisms that define the flavor profile of Huangjiu. We employed HS-SPME-GC–MS along with aroma reconstitution and omission experiments to identify core VOCs, including Isobutanol, Isoamyl alcohol, β-Phenylethanol, and others. Metagenomic sequencing combined with QPCR was used to analyze microbial communities, revealing the temporal and spatial dynamics during fermentation. A synthetic microbial community model was constructed using the core microbes identified: Saccharomyces cerevisiae, Lactobacillus brevis, Saccharopolyspora rectivirgula, Bacillus subtilis, Leuconostoc citreum, Lactobacillus plantarum, Lactobacillus curvatus, Lactobacillus casei, and Aspergillus oryzae. This model successfully replicated Huangjiu’s core VOCs and sensory characteristics, increased alcohol content, and reduced acidity. Our study contributes valuable insights into the microbial influences on Huangjiu quality, paving the way for its enhanced production and providing a foundation for future research in fermented beverages.

Inhibition of diastatic yeasts by Saccharomyces killer toxins to prevent hyperattenuation during brewing.

Secondary fermentation in beer can result in undesirable consequences, such as off-flavors, increased alcohol content, hyperattenuation, gushing, and the spontaneous explosion of packaging. Strains of Saccharomyces cerevisiae var. diastaticus are a major contributor to such spoilage due to their production of extracellular glucoamylase enzyme encoded by the STA1 gene. Saccharomyces yeasts can naturally produce antifungal proteins named "killer" toxins that inhibit the growth of competing yeasts. Challenging diastatic yeasts with killer toxins revealed that 91% of strains are susceptible to the K1 killer toxin produced by S. cerevisiae. Screening of 192 killer yeasts identified novel K2 toxins that could inhibit all K1-resistant diastatic yeasts. Variant K2 killer toxins were more potent than the K1 and K2 toxins, inhibiting 95% of diastatic yeast strains tested. Brewing trials demonstrated that adding killer yeast during a simulated diastatic contamination event could prevent hyperattenuation. Currently, most craft breweries can only safeguard against diastatic yeast contamination by good hygiene and monitoring for the presence of diastatic yeasts. The detection of diastatic yeasts will often lead to the destruction of contaminated products and the aggressive decontamination of brewing facilities. Using killer yeasts in brewing offers an approach to safeguard against product loss and potentially remediate contaminated beer.IMPORTANCEThe rise of craft brewing means that more domestic beer in the marketplace is being produced in facilities lacking the means for pasteurization, which increases the risk of microbial spoilage. The most damaging spoilage yeasts are "diastatic" strains of Saccharomyces cerevisiae that cause increased fermentation (hyperattenuation), resulting in unpalatable flavors such as phenolic off-flavor, as well as over-carbonation that can cause exploding packaging. In the absence of a pasteurizer, there are no methods available that would avert the loss of beer due to contamination by diastatic yeasts. This manuscript has found that diastatic yeasts are sensitive to antifungal proteins named "killer toxins" produced by Saccharomyces yeasts, and in industrial-scale fermentation trials, killer yeasts can remediate diastatic yeast contamination. Using killer toxins to prevent diastatic contamination is a unique and innovative approach that could prevent lost revenue to yeast spoilage and save many breweries the time and cost of purchasing and installing a pasteurizer.

Alcohols as Biofuel for a Diesel Engine with Blend Mode—A Review

In the era of decarbonization driven by environmental concerns and stimulated by legislative measures such as Fit for 55, the industry and transportation sectors are increasingly replacing petroleum-based fuels with those derived from renewable sources. For many years, the share of these fuels in blends used to power compression ignition engines has been growing. The primary advantage of this fuel technology is the reduction of GHG emissions while maintaining comparable engine performance. However, these fuel blends also have drawbacks, including limited ability to form stable mixtures or the requirement for chemical stabilizers. The stability of these mixtures varies depending on the type of alcohol used, which limits the applicability of such fuels. This study focuses on evaluating the impact of eight types of alcohol fuels, including short-chain (methanol, ethanol, propanol) and long-chain alcohols (butanol, pentanol, hexanol, heptanol, and octanol), on the most critical operational parameters of an industrial engine and exhaust emissions. The engines being compared operated at a constant speed and under a constant load, either maximum or close to maximum. The study also evaluated the effect of alcohol content in the mixture on combustion process parameters such as peak cylinder pressure and heat release, which are the basis for parameterizing the engine’s combustion process. Determining ignition delay and combustion duration is fundamental for optimizing the engine’s thermal cycle. As the research results show, both the type of alcohol and its concentration in the mixture influence these parameters. Another parameter important from a usability perspective is engine stability, which was also considered. Engine performance evaluation also includes assessing emissions, particularly the impact of alcohol content on NOx and soot emissions. Based on the analysis, it can be concluded that adding alcohol fuel to diesel in a CI engine increases ignition delay (up to 57%), pmax (by approximately 15–20%), HRRmax (by approximately 80%), and PPRmax (by approximately 70%). Most studies indicate a reduction in combustion duration with increasing alcohol content (by up to 50%). For simple alcohols, an increase in thermal efficiency (by approximately 15%) was observed, whereas for complex alcohols, a decrease (by approximately 10%) was noted. The addition of alcohol to diesel slightly worsens the stability of the CI engine. Most studies pointed to the positive impact of adding alcohol fuel to diesel on NOx emissions from the compression ignition engine, with the most significant reductions reaching approximately 50%. Increasing the alcohol fuel content in the diesel blend significantly reduced soot emissions from the CI engine (by up to approximately 90%).

Transcending Lifshitz Theory: Reliable Prediction of Adhesion Forces between Hydrocarbon Surfaces in Condensed Phases Using Molecular Contact Thermodynamics.

Lifshitz theory is widely used to calculate interfacial interaction energies and underpins established approaches to the interpretation of measurement data from experimental methods including the surface forces apparatus and the atomic force microscope. However, a significant limitation of Lifshitz theory is that it uses the bulk dielectric properties of the medium to predict the work of adhesion. Here, we demonstrate that a different approach, in which the interactions between molecules at surfaces and in the medium are described by a set of surface site interaction points (SSIPs), yields interaction free energies that are correlated better with experimentally determined values. The work of adhesion W(Lifshitz) between hydrocarbon surfaces was calculated in 260 liquids using Lifshitz theory and compared with interaction free energies ΔΔG calculated using the SSIP model. The predictions of these models diverge in significant ways. In particular, ΔΔG values for hydrocarbon surfaces are typically small and vary little, but in contrast, W(Lifshitz) values span 4 orders of magnitude. Moreover, the SSIP model yields significantly different ΔΔG values in some liquids for which Lifshitz theory predicts similar values of W(Lifshitz). These divergent predictions were tested using atomic force microscopy. Experimentally determined works of adhesion were closer to the values predicted using the SSIP model than Lifshitz theory. In mixtures of methanol and benzyl alcohol, even greater differences were found in the interaction energies calculated using the two models: the value of ΔΔG calculated using the SSIP model declines smoothly as the benzyl alcohol concentration increases, and values are well correlated with experimental data; however, W(Lifshitz) decreases to a minimum and then increases, reaching a larger value for benzyl alcohol than for methanol. We conclude that the SSIP model provides more reliable estimates of the work of adhesion than Lifshitz theory.

SURFACE PROPERTIES AND MICELLIZATION OF SODIUM ALKYLSULPHATES IN THE PRESENCE OF LOW-MOLECULAR ALCOHOLS

The process of micellization of sodium alkyl sulfates (SAS : sodium decyl- (SDS) and dodecylsulfate (SDDS)) of formation in aqueous solution without or with alcohols including propanol-1, propanol-2 and butanol-1 and their adsorption behavior at air-liquid interface were investigated with both the tensiometry and the conductometry at 298 K. The effect of chain length of alcohol on micellar and interfacial properties were discussed. Some parameters including surface excess concentration (Γmax), minimum area per surfactant molecule (Smin) at air-liquid interface, degree of ionization of micelle, and standard free energy of adsorption and micellization, etc. are estimated. It was experimentally established that the introduction of 0.5-1.0 mol/dm3 of alcohols into surfactant solutions contributes to the process of micellar formation of SAS and increases the stability of the micellar phase, as evidenced by the observed synergistic effect on the critical micelle concentration (CMC). The addition of different alcohols changes the values of Γmax, Smin, CMC of SDS and SDDS and induces an increase in degree of ionization (β) of micelle relative to that in pure water. When alcohols are introduced into SDS and SDDS solutions, the degree of ionization of micelles at a constant length of the alkyl radical of surfactant moderately increases with increasing alcohol content in the solution and ranges from 0.50-0.73 and 0.38-0.75, respectively. Also, the effect of alcohol was discussed. The obtained thermodynamic parameters were used to confirm these behaviors of interfacial adsorption or micellization. An increase in chain length of alcohol promotes the micellization process. The CMC values decrease with increasing length of the alkyl radical of alcohols. Propanol-1, compared to propanol-2, somewhat reduces the value of SDS and SDDS CMC to a greater extent. Standard free energy of micellization ∆G0mic, also confirms the micellization behavior. Standard free energy of adsorption (∆G0адс) indicates that an increase in the chain length of alcohol in aqueous solution is favorable to the adsorption of SDS and SDDS at air-liquid interface. A comparison of the values of the standard free energy of adsorption and micelle formation in sodium alkyl sulfates – alcohols – water systems showed that adsorption is the most thermodynamically advantageous process in the studies systems, and the packing of surfactant “molecules” in micelles is less dense, compared to packing in a mixed adsorption layer.

Greater inhibition of female rat binge alcohol intake by adrenergic receptor blockers using a novel Two-Shot rat binge drinking model

Binge drinking (BD) contributes strongly to the harms of alcohol use disorder. Most rodent models do not result in binge-level blood alcohol concentrations (BACs), and to better understand individual and sex differences in neurobiological mechanisms related to BD, the use of outbred rat strains would be valuable. Here, we developed a novel BD model where after 3+ months of intermittent access to 20% alcohol Wistar rats drank, twice a week, with two 5-min intake (what we called Two-shot) separated by a 10-min break. Our findings showed during Two-Shot that most animals reached ≥ 80 mg% BAC levels (when briefly food-restricted). However, when increasing alcohol concentrations from 20 to 30%, 40%, or 50%, rats titrated to similar intake levels, suggesting rapid sensing of alcohol effects even when front-loading. Two-Shot drinking was reduced in both sexes by naltrexone (1 mg/kg), validating intake suppression by a clinical therapeutic agent for human problem drinking. Further, both propranolol (β-adrenergic receptor antagonist) and prazosin (α1-adrenergic receptor antagonist) reduced female but not male BD at the lower dose. Thus, our results provide a novel model for BD in outbred rats and suggest that female binging is more sensitive to adrenergic modulation than males, perhaps providing a novel sex-related therapy.

Physical properties and diesel engine combustion of blends of alcohols with military jet fuel JP-5

Military operations may involve the use of jet fuel in a diesel engine, and the blending of alcohols with jet fuel is a way to introduce decarbonization into military operations. This study explored the effect of blending n-alcohols with navy jet fuel JP-5 on physical properties and combustion in a diesel engine. Blends containing 10 %, 20 %, and 30 % of ethanol, propanol, butanol, pentanol, hexanol, octanol, and one mixture of 10 % methanol/80 % octanol had densities (0.80 to 0.81 g/mL) that fell within military specifications for diesel. Most mixtures' flash points (16.5 to 65.0 °C) were below the military spec of 60 °C, which is higher than that of commercial aviation fuel. Most mixture viscosities (4.74 to 9.99 mm2/s) were within the jet fuel specifications at −20 °C but below the diesel fuel specification at 40 °C. Combustion of the alcohol/JP-5 mixtures in a diesel engine showed that increasing alcohol content lengthened the ignition delay (IGD). For some of the alcohols, shortening the carbon chain length on the alcohol led to longer IGDs with later combustion phasing that was most noticeable at lighter engine loads. The longer IGDs associated with the shorter alcohol fuels (and increased alcohol percentage) rapidly led to very high rates of energy release. The relative IGDs (IGD mixture/IGD JP-5) were less than 1.2 for the 10 % alcohol mixtures, between 1.0 and 1.4 for the 20 % alcohol mixtures, and between 1.0 and 1.9 for the 30 % alcohol mixtures excluding the 30 % ethanol mixture that did not combust. From the combustion metrics perspective, the longer carbon chain alcohols were most similar to the base jet fuel. Overall, the larger alcohols had physical properties and combustion metrics that were closer to those of the JP-5 jet fuel.

Greater inhibition of female rat binge alcohol intake by adrenergic receptor blockers using a novel Two-Shot rat binge drinking model.

Binge drinking (BD) contributes strongly to the harms of alcohol use disorder. Most rodent models do not result in binge-level blood alcohol concentrations (BACs), and to better understand individual and sex differences in neurobiological mechanisms related to BD, the use of outbred rat strains would be valuable. Here, we developed a novel BD model where after 3+ months of intermittent access to 20% alcohol Wistar rats drank, twice a week, with two 5-minute intake (what we called Two-shot) separated by a 10-minute break. Our findings showed during Two-Shot that most animals reached ≥ 80mg% BAC levels (when briefly food-restricted). However, when increasing alcohol concentrations from 20% to 30%, 40%, or 50%, rats titrated to similar intake levels, suggesting rapid sensing of alcohol effects even when front-loading. Two-Shot drinking was reduced in both sexes by naltrexone (1mg/kg), validating intake suppression by a clinical therapeutic agent. Further, both propranolol (β adrenergic receptor antagonist) and prazosin (α1 adrenergic receptor antagonist) reduced female but not male BD at the lower dose. Thus, our results provide a novel model for BD in outbred rats and suggest that female binging is more sensitive to adrenergic modulation than males, perhaps providing a novel sex-related therapy.

Total Dealcoholisation of Wines by Very Low Temperature Vacuum Distillation Technology Called GoLo

The use of wine dealcoholisation has multiplied in recent years as a result of various factors, including the increase in alcohol content due to global warming and changes in consumer drinking habits. There are several post-fermentation dealcoholisation methods in the literature which allow for the partial or total elimination of the alcohol content of wine. However, there are no studies on the patented very low temperature vacuum wine distillation technology called GoLo. Therefore, for the first time, this paper evaluates the quality of dealcoholised white, rose and red wines using GoLo technology. For this purpose, alcohol content, pH, total SO2, free SO2, total acidity and volatile acidity were measured. There were no significant differences in the variations in pH, total acidity and volatile acidity after the dealcoholisation process using GoLo technology and dealcoholised wines showed a reduction of 22.1% in total SO2 and a complete absence of ethanol and free SO2. A model for predicting the total SO2 content of dealcoholised wines and a model for predicting the amount of sulphites to be added after dealcoholisation were found after the statistical treatment of the data. GoLo dealcoholisation delivers 100% removal of alcohol and free SO2 in less time, with less loss and energy than other dealcoholisation technologies. The verification and extension of these results will be the focus of future studies.

Alcohol-Induced Denaturation of Hen Egg White Lysozyme Studied by Infrared, Circular Dichroism, and Small-Angle Neutron Scattering.

In aqueous binary solvents with fluorinated alcohols, 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), and aliphatic alcohols, ethanol (EtOH) and 2-propanol (2-PrOH), the denaturation of hen egg white lysozyme (HEWL) with increasing alcohol mole fraction xA has been investigated in a wide view from the molecular vibration to the secondary and ternary structures. Circular dichroism (CD) measurement showed that the secondary structure of α-helix content of HEWL increases on adding a small amount of the fluorinated alcohol to the aqueous solution, while the β-sheet content decreases. On the contrary, the secondary structure does not significantly change by the addition of the aliphatic alcohols. Correspondingly, the infrared (IR) spectroscopic measurements revealed that the amide I band red-shifts on the addition of the fluorinated alcohol. However, the band remains unchanged in the aliphatic alcohol systems with increasing alcohol content. To observe the ternary structure of HEWL, small-angle neutron scattering (SANS) experiments with H/D substitution technique have been applied to the HEWL solutions. The SANS experiments were successful in revealing the details of how the geometry of the HEWL changes as a function of xA. The SANS profiles indicated the spherical structure of HEWL in all of the alcohol systems in the xA range examined. The mean radius of HEWL in the two fluorinated alcohol systems increases from ∼16 to ∼18 Å during the change in the secondary structure against the increase in the fluorinated alcohol content. On contrast, the radius does not significantly change in both aliphatic alcohol systems below xA = 0.3 but expands to ∼19 Å as the alcohol content is close to the limitation of the HEWL solubility. According to the present results, together with our knowledge of the alcohol cluster formation and the interaction of the trifluoromethyl (CF3) groups with the hydrophobic moieties of biomolecules, the effects of alcohols on the denaturation of the protein have been discussed on a molecular scale.

Molecular dynamics simulation, thermodynamic parameters and solute–solvent molecular interactions of cilostazol (form A) dissolution in (ethylene glycol / ethanol + water) mixtures

This research work reports the cilostazol (form A) dissolution in (ethylene glycol / ethanol + water) mixtures. The co-solvency phenomenon only occurs in mixture of ethanol + water, the maximum solubility in mole fraction is 3.034 × 10-3 at the composition of 0.85. It was found that the solvation performance of cilostazol in two mixtures mainly depend on the ability of forming hydrogen bond (H-bond) of the solutions and van der Waals interaction. According to the preferential solvation results, it is conjecturable that cilostazol molecules are preferentially solvated by water in water-rich regions. With the increase of alcohol concentration, the destruction of water molecular ordered structure by alcohol through hydrogen bond, and solute molecules are preferentially solvated by ethanol and EG. Nonetheless, when 0.86 < x1 < 1 in mixture of ethanol + water, solute molecules are preferentially solvated by water again. The calculation of radial distribution function (RDF) between the atoms of H and O for ethanol and the atoms of N and H for solute is to achieve the interaction of the solute and solvents. The correlation fitting was performed for the solubility data through Jouyban Acree model and its derivative models, and the statistical analysis showed that the Apelblat-Jouyban Acree model is more suitable to present the solubility correlation. Meanwhile, the values of apparent molar standard dissolution enthalpy (ΔHsolo) and apparent molar standard dissolution entropy (ΔSsolo) are positive in each solvents, which reveals that the dissolution process of cilostazol form A is endothermic and entropy favorable within the given temperature range.

Comparison of Binary Alcohol/Water Solvent Systems to Blood for Extractions of Blood-Contacting Medical Devices.

The analysis of extractables and leachables and subsequent risk assessment is an important aspect of the determination of biocompatibility for many medical devices. Leachable chemicals have the potential to pose a toxicological risk to patients, and therefore it is required that they be adequately characterized and assessed for potential safety concerns. One important consideration in the assessment of leachables is the choice of a suitable simulating solvent intended to replicate the use condition for the device and its biological environment. This aspect of study design is especially difficult for blood-contacting medical devices due to the complexity of simulating the biological matrix. This publication reports a comparison of the extracting power of different binary solvent mixtures and saline in comparison with whole blood for a bloodline tubing set connected to a hemodialyzer. Ten different known extractables, spanning a range of physicochemical properties and molecular weights, were quantified. The results indicated that for low-molecular-weight analytes, a suitable exaggeration for whole blood can be obtained using a low-concentration ethanol/water mixture (≈20%), and in general, extracted quantity increases with the concentration of alcohol cosolvent. For polyvinylpyrrolidone, the opposite trend was observed, as solubility of the polymer was found to decrease with increasing alcohol concentration, resulting in lower extracted quantities at high alcohol concentrations. Analysis of ethanol/water concentrations in the extract solutions post extraction indicated no change in solvent composition.

Photophysical, rotational and translational properties of Radachlorin photosensitizer upon binding to serum albumins

IntroductionAlthough photophysical properties of Radachlorin photosensitizer (PS) were extensively studied in solutions and cells, no data is available on variations of its characteristics upon binding to serum albumins, which are major transporters in blood and nutrients in cell culture media. ObjectivesThe primary objective of this study was to analyze changes in photophysical properties of Radachlorin molecules upon their binding to human and bovine serum albumins at different microenvironment properties. MethodsExperiments were performed using time-resolved fluorescence spectroscopy and fluorescence recovery after photobleaching. Variations in fluorescence spectra and lifetime, fluorescence anisotropy, rotational and translational diffusion of PS molecules upon binding to albumins were studied in normal, basic and acidic conditions and at different concentrations of albumin and PS molecules. ResultsRadachlorin molecules effectively bind to both types of serum albumins, which causes changes in photophysical properties of the PS. A minor red shift of the fluorescence spectrum, an increase in fluorescence lifetime and anisotropy and substantial decrease of translational and rotational mobility of PS molecules were observed upon their binding to albumins. The analysis of rotational diffusion time provided robust evaluation of the bound fraction of PS molecules. Both the highly acidic microenvironment and increase in alcohol concentration above 40% resulted in detachment of PS molecules from albumins. Photophysical properties of Radachlorin in complexes with BSA and HSA were found to be slightly different. ConclusionsBinding of Radachlorin photosensitizer to either BSA or HSA affects significantly its photophysical properties, which may also vary with microenvironment acidity and alcohol concentration.

Carbonic maceration vinification: A tool for wine alcohol reduction.

The increase in alcohol content in wine due to climate change is one of the main challenges that winemakers face today. Previous studies have indicated that carbonic maceration processing can be used to obtain a wine fraction with lower alcoholic strength. The aim of this study was to determine the effectiveness of this technique in obtaining wines with lower alcohol content. For this purpose, seven trials were carried out, studying a total of 63 wines. The physico-chemical, phenolic and aromatic composition of the wines was analysed using official methods and gas chromatography. The results showed that it is possible to obtain a fraction of carbonic maceration wine (25-35% of the total) with a reduction in alcohol content of up to almost 4% depending on the vinification conditions and the grape variety used. Therefore, this CM fraction, marketed on its own, could be a low-alcohol alternative to red wines.

PENGARUH LAMA FERMENTASI DAN JENIS GULA TERHADAP KADAR ALKOHOL MINUMAN BERBAHAN DASAR GANDARIA (Bouea macrophylla Griff)

Background: Alcoholic beverages can be derived from palm sap or fruit juice. The fruit most widely used as a base for alcoholic beverages by the fermentation is generally grapes. The Gandaria (Bouea macrophylla Griff) can be used as raw material for substitute grapes for the process of making alcoholic beverages. Sugar is one of the important factors, because sugar is fermented by yeast into ethanol and CO2. The purpose of this research was to know the effect of fermentation time and types of sugar on alcohol content in gandaria(Bouea macrophylla Griff)-based drinks and organoleptic tests as a support for practicum in Ethnobotany courses. Methods: The research was conducted on 13 February-06 March 2023 at the Basic Chemistry Laboratory FMIPA and used destilation method. Results: The results showed that the combination of fermentation time and sugar type gave a very significantly different effect on each treatment. This can be seen from the results of the Least Significant Difference test where every week there is an increase in alcohol content. While, the organoleptic test showed the level of liking of the colour with the highest score of 2.9 in treatment f3g1, for the odor with the highest score of 2.9 in treatment f3g2 and for the taste with the highest score of 3.6 in treatment f2g1. Conclusion: Based on the results of the study, it was concluded that the time of fermentation and the type of sugar influenced the alcohol content of gandaria (Bouea macrophylla Griff). -based drinks

Changes in volatile and nutrient components of mango juice by different Lactic acid bacteria fermentation

This study investigated the changes in volatile and nutrient compounds of mango juice fermentation by lactic acid bacteria (LAB) (Lactobacillus plantarum NCU116, Lactobacillus acidophilus NCU402, and Lactobacillus casei NCU215). All strains grew well and L. plantarum NCU116 yielded the highest acidity and lactic acid content during fermentation. Meanwhile, L. plantarum NCU116 and L. acidophilus NCU402 fermentation significantly decreased L* and a* values. L. acidophilus NCU402 fermented mango showed the lowest levels of nitrite (0.01 μmol/g) and carotenoids (44.98 μg/g). Additionally, LAB fermentation enhanced aroma of mango juice by elevating alcoholic compounds and reducing terpenoids and aldehydes, with L. plantarum NCU116 demonstrating the most notable impact, increasing alcohol concentration from 5% to 17%. Correlation analysis revealed that key alcohols production was associated with amino acids, sugar, aldehydes, and terpenoids. According to the sensory analysis, the mango juice inoculated with L. casei NCU215 had the highest acceptability score. Thus, the type of LAB strains determined the nutrient component, volatile and sensory profile of mango juices and further research is needed to understand the fermentation mechanisms.

Analysis of the Calorific Value and Specific Gravity of Breadfruit Peel Bioalcohol (Artocarpus Altilis) as an Alternative Fuel at Various Distillation Temperatures

The objective of this study was to investigate how distillation temperature affected the specific gravity (SG) and calorific value of bioalcohol derived from breadfruit peels (Artocarpus altilis) as an alternative fuel. The process of producing bioethanol from breadfruit peels begins with pretreatment of the peels, followed by hydrolysis with hydrochloric acid, fermentation, and finally distillation. The hydrolysis process used 20% hydrochloric acid in a volume of 25 ml, and the fermentation took 6 days with a mass of 30 gr of yeast Saccharomyces cerevisiae. The distillation process lasted two hours, with temperatures varying between 70, 80, and 90°C. This study yielded the highest alcohol content of 72.80% at 70°C and the highest volume of bioalcohol of 35.67 ml at 90°C. Meanwhile, the best Specific Gravity (SG) at 70°C was 0.8393. Furthermore, the calorific value test results revealed that the calorific value increased with increasing alcohol content. The highest calorific value obtained was 23003.406 J/gr, which was close to the ethanol calorific value of 29700 J/gr, while the lowest calorific value obtained was 22339.008 J/gr at a distillation temperature of 90°C

Reduction of ethanol content in wine with an improved combination of yeast strains and process conditions

One interesting strategy to address the increasing alcohol content of wines, associated with climate change, is to reduce the ethanol yield during fermentation. Within this strategy, the approach that would allow the clearest reduction in alcohol content is the respiration of part of the grape sugars by yeasts. Non-Saccharomyces species can be used for this purpose but suffer from a limited ability to dominate the process and complete fermentation. In turn, Saccharomyces cerevisiae shows a high production of acetic acid under the growth conditions required for respiration. Previously proposed procedures used combinations of non-Saccharomyces and S. cerevisiae starters, or a strain of S. cerevisiae (PR1018), with unique metabolic properties. In both cases, precise management of oxygen availability was required to overcome the acetic acid problem. In this work, we have developed a laboratory scale process to take advantage of the properties of PR1018 and a strain of Metschnikowia pulcherrima. This process is more robust than the previous ones and does not rely on strict control of oxygenation or even the use of this particular strain of S. cerevisiae. Aeration can be interrupted instantly without impairing the volatile acidity. Under the selected conditions, an ethanol reduction of around 3% (v/v) was obtained compared to the standard fermentation control.

Effect of Drought on the Future Sugar Content of Wine Grape Varieties till 2100: Possible Adaptation in the Hungarian Eger Wine Region.

The most significant risk for viticulture is that the sugar content of the grapes will increase in the future due to rising temperatures. As a result, it will be possible to produce wines with increasing alcohol content in the future. Excessively high alcohol content can significantly reduce the wines' marketability and viticulture's profitability. Our study seeks to answer how the expected drought in the Southern and Central regions of Europe will affect the future change in the sugar content of grapes. The degree of dryness was examined using the dryness index in the study. Finally, it was analyzed how the dryness index affects the past and future occurrence of maximum sugar content for six grape varieties. The probability of the occurrence of maximum sugar content for most vine grape varieties will decrease in the near future. However, in the distant future, there is a likelihood that the occurrence of maximum sugar content will increase again. If we can maintain the DI ≥ -10 condition with regulated deficit irrigation, the probability of the occurrence of maximum sugar content may decrease significantly in the near future. Ensuring moderate dryness is the only way to achieve the proper sugar content.