High Ethanol Concentrations Research Articles

Preparation of ethanol-gels as hand sanitizers formed from chitosan and silica nanoparticles

The application of chitosan as a gelling agent in hydro-alcoholic hand sanitizers has rarely been studied due to its insolubility in ethanol. In this study, high-ethanol-content gels were prepared with chitosan in combination with silica nanoparticles. The properties of the gels were investigated by FTIR, XRD, SEM, rheological measurement and the zone of inhibition test against bacteria. The results showed that the adsorption of silica nanoparticles on the chitosan inhibited the precipitation of chitosan in ethanol. The chitosan/silica fibres entangled with each other, and gelation occurred in the solvent with high ethanol concentration due to the solvent-driven effect. The gelation process was related to the concentrations of ethanol, chitosan, and silica nanoparticles. A stable gel could be formed at a chitosan concentration as low as 0.5%, with an ethanol concentration up to 80%. All the gels exhibited pseudoplastic behaviour and had frequency-dependent profiles in the viscoelastic spectrum of non-Newtonian liquids, behaving in a solid-like manner. The limited linear viscoelastic region of all samples was<1%. The optimal silica concentrations (OSCs) for various chitosan concentrations in 75% ethanol were proposed by rheological analysis as a reference to optimize the sensory and textural properties of gels. These gels showed antibacterial activity, which introduced a potential application as hand sanitizers. This research provides a method of preparing novel high-ethanol-content gels, highlights the application of solvent-driven effects in gelation, and identified some suggestions for future research.

Binary Mixture Droplet Evaporation on Microstructured Decorated Surfaces and the Mixed Stick-Slip Modes.

The interactions between liquid droplets and solid surfaces during wetting and phase change are important to many applications and are related to the physicochemical properties of the substrate and the fluid. In this work, we investigate experimentally the evaporation of pure water, pure ethanol, and their binary mixture droplets, accessing a wide range of surface tensions, on hydrophobic micro-pillared surfaces varying the spacing between the pillars. Results show that on structured surfaces, droplets evaporate following three classical evaporative behaviors: constant contact radius/pinning, stick-slip, or mixed mode. In addition, we report two further droplet evaporation modes, which are a mixed stick-slip mode where the contact angle increases while the contact radius decreases in a stick-slip fashion and a mixed stick-slip mode where both the contact angle and the contact radius decrease in a stick-slip fashion. We name these evaporation modes not yet reported in the literature as the increasing and decreasing contact angle mixed stick-slip modes, respectively. The former ensues because the fluid surface tension increases as the most volatile fluid evaporates coupled to the presence of structures, whereas the latter is due to the presence of structures for either fluid. The duration of each evaporation mode is dissimilar and depends on the surface tension and on the spacing between structures. Pure water yields longer initial pinning times on all surfaces before stick-slip ensues, whereas for binary mixtures and pure ethanol, initial pinning ensues mainly on short spacing structures due to the different wetting regimes displayed. Meanwhile, mixed stick-slip modes ensue mainly for high ethanol concentrations and/or pure ethanol independent of the solid fraction and for low ethanol concentrations on large spacing. Contact line jumps, changes in contact angle and pinning forces are also presented and discussed. This investigation provides guidelines for tailoring the evaporation of a wide range of surface tension fluids on structured surfaces for inkjet printing, DNA patterning, or microfluidics applications.

Probiotic potential of Lactiplantibacillus plantarum ZFM4 isolated from pickles and its effects on human intestinal microecology

Lactic acid bacteria have received worldwide attention because of their fermentative properties and their great significance for the balance of microbial homeostasis in the intestine. In this study, we isolated a strain of Lactiplantibacillus plantarum ZFM4 from pickles and evaluated its probiotic properties. The results indicated that ZFM4 was suppressive to most pathogenic bacteria, especially Staphylococcus aureus and Pseudomonas aeruginosa, and showed good tolerance to high osmotic pressure (8.0% NaCl), high ethanol concentration (5.0%), high temperature (42 °C) and bile salts (0.3%, 4 h). The effect of ZFM4 on human intestinal microbiota was investigated through the fecal slurry fermentation model in vitro. Sequencing of the 16S rDNA gene demonstrated that the addition of ZFM4 significantly raised the abundance of phylum Bacillota, while increased the proportion of beneficial genera, such as Lactiplantibacillus and Bifidobacterium. Furthermore, ZFM4 contributed to the enhanced production of acetic acid, butyric acid, valeric acid, and isovaleric acid. In summary, ZFM4 could be considered a potential probiotic candidate.

Performance improvement and CO and HC emission reduction of variable compression ratio spark-ignition engine using n-pentanol as a fuel additive

This study tests binary and ternary n-pentanol, ethanol, and petrol blends to increase spark-ignition (SI) engine performance and minimize CO and HC emissions. To improve brake thermal efficiency (BTE) and reduce emissions, adding ethanol into gasoline is one of the practices used in Automobiles. But the literature reported some performance limitations and problems with adding a high ethanol concentration to gasoline as phase separation problem occurs in fuel tank due to the hygroscopic nature of ethanol, a higher ethanol concentration may corrode some parts of the fuel supply system. Ethanol has a lower calorific value than gasoline, so a higher ethanol concentration in blends beyond a specific limit reduces BTE. N-pentanol as a fuel additive in gasoline can better solve these problems due to its high caloric value compared to ethanol. Also, when n-pentanol is mixed with gasoline and exposed to moisture, it does not separate in stages as in the ethanol case. Accordingly, this research aims to evaluate n-pentanol's viability as a fuel additive in petrol and ethanol-gasoline blends at different compression ratios. The experiments were carried out on a single-cylinder, four-stroke spark-ignition engine running at a constant speed. Different blends of n-pentanol with gasoline and ethanol were tested, and results were compared against gasoline and E10 (the optimal blend of ethanol-gasoline, 10/90 v/v %). Various parameters were examined, including BTE, brake-specific fuel consumption (BSFC), and different exhaust pollutants. The effects of compression ratio values on these parameters were also recorded. The 1.5 vol% pentanol with E10 (E10P1.5) mix has the best overall characteristics, including low BSFC, high BTE, and low CO and HC emissions compared to petrol and E10 fuels. E10P1.5 shows a maximum enhancement in BTE, low BSFC, CO reduction, and HC reduction by 23.79%, 19.80%, 37.79%, and 19.46%, respectively, over gasoline. Compared to E10, the improvement is 3.64% for BTE, 4.59% for BSFC, 8.88% for CO emission reduction, and 4.13% for HC emission reduction.

Impact of the Addition of Fruits of Kamchatka Berries (L. caerulea var. kamtschatica) and Haskap (L. caerulea var. emphyllocalyx) on the Physicochemical Properties, Polyphenolic Content, Antioxidant Activity and Sensory Evaluation Craft Wheat Beers.

Kamchatka berry (Lonicera caerulea var. kamtschatica) and haskap (Lonicera caerulea var. emphyllocalyx) fruit are important sources of bioactive compounds, mainly polyphenols, but also macro- and microelements. Physico-chemical analysis showed that wheat beers with added fruit were characterised by an average 14.06% higher ethanol content, lower bitterness and intense colour compared to the control, which was a wheat beer without added fruit. Wheat beers enriched with kamchatka berry fruit, including the "Aurora" variety, had the highest polyphenolic profile (e.g., chlorogenic acid content averaged 7.30 mg/L), and the antioxidant activity of fruit-enriched wheat beers determined by the DPPH method showed higher antioxidant activity of wheat beers enriched with kamchatka berry fruit, while those determined by the FRAP and ABTS methods showed higher antioxidant activity of wheat beers enriched with haskap fruit, including the "Willa" variety. Sensory evaluation of the beer product showed that wheat beers enriched with kamchatka berry fruits of the "Duet" variety and haskap fruits of the "Willa" variety were characterised by the most balanced taste and aroma. On the basis of the conducted research, it follows that both kamchatka berry fruits of the "Duet" and "Aurora" varieties and haskap fruit of the "Willa" variety can be used successfully in the production of fruity wheat beers.

Untargeted metabolomics reveal sex-specific and non-specific redox-modulating metabolites in kidneys following binge drinking

Graphical abstract Abstract Binge drinking is a growing health concern among all age groups. The ability of individuals to handle ethanol in their systems differs not due to differences in enzyme expression but also due to other factors. Vital organs including brain, liver, heart, and kidneys are at high risk following repeated exposure to high concentrations of ethanol from binge drinking. The impact of chronic binge drinking on kidneys is not well studied. Using a mouse model of chronic binge drinking, we have identified major metabolic alterations that could set the stage for detrimental effects in the kidneys of male and female mice. We have deciphered that even though there are pathway overlaps, the different sexes exhibited unique and divergent metabolic pathway dysregulations as per the metabolite panels following binge drinking. We have reported that binge drinking could negatively influence renal redox homeostasis in both sexes through the regulation of different metabolite clusters. In male mice by downregulation of pantothenic acid and riboflavin synthesis, and in female mice by upregulation of α-aminoadipic acid and formyl kynurenine level. Interestingly, the uric acid biosynthesis pathway has been upregulated independent of the sex-specific effects, portraying the significance of uric acid as a potential marker for binge drinking-induced injury in both sexes. Thus, by altering renal metabolome, binge drinking sets the stage for renal damage by disturbing renal redox balance. Our data has high translational potential and will aid in finding ideal therapeutics in a sex-specific manner for subjects exposed to binge drinking- induced renal injury.

Metabolomics Study Reveals Biomarker L-Proline as Potential Stress-Protectant Compound for High-Temperature Bioethanol Fermentation by Yeast Pichia kudriavzevii 1P4.

High-temperature ethanol fermentation (> 40°C) can be applied as effective bioprocess technology to increase ethanol production. Thermotolerant yeast Pichia kudriavzevii 1P4 showed the ability to produce ethanol at optimum 37°C. Thus, this study evaluated the ethanol productivity of isolate 1P4 at high-temperature ethanol fermentation (42 and 45°C) and the identification of metabolite biomarkers using untargeted metabolomics with liquid chromatography-tandem mass spectrometry (LC-MS/MS). 1P4 showed tolerance to temperature stress up to 45°C and thus relevant for high-temperature fermentation. As measured by gas chromatography (GC), bioethanol production of 1P4 at 30, 37, 42, and 45°C was 5.8g/l, 7.1g/l, 5.1g/l, and 2.8g/l, respectively. The classification of biomarker compounds was based on orthogonal projection analysis to latent structure discriminant analysis (OPLS-DA), resulting in L-proline being a suspected biomarker compound for isolate 1P4 tolerance against high-temperature stress. Indeed, supplementation of L-proline on fermentation medium supported the growth of 1P4 at high temperatures (> 40°C) than without L-proline. The bioethanol production with the addition of the L-proline resulted in the highest ethanol concentration (7.15g/l) at 42°C. Supplementation of L-proline as a stress-protective compound increased ethanol productivity at high-temperature fermentation of 42 and 45°C by 36.35% and 83.33%, respectively, compared without the addition of L-proline. Preliminary interpretation of these results indicates that bioprocess engineering through supplementation of stress-protective compounds L-proline increases the fermentation efficiency of isolate 1P4 at higher temperatures (42°C and 45°C).

Solvent effects and mass transfer on aroma extraction during solid-state distillation

Steam distillation is an important unit operation to extract valuable compounds from natural solid-state substrates. Solid-state distillation with steam can extract aroma from fermented solid substrate such as fermented grains of Chinese liquor fermentation. However, this procedure is still operated based on generations of empirical skills rather than a technique under process control based on scientific principles. The resulting drawback is poor mass and heat transfer with undesired consequences concerning productivity, quality and sustainability. Mathematical modelling can be a powerful tool to get insight into such an empirical process for potential rational design, optimization and control. Therefore, we established a mathematical model to describe the mass transfer based on kinetic parameters. The simulation results show that the distillation had a natural column plate structure that more effectively concentrated compounds. Furthermore, this structure resulted in a high ethanol concentration in the distillate. To evaluate subsequent effect of high ethanol concentration, we analysed aroma compounds in the distillates under simulated conditions with or without ethanol. The hydrophobic compounds were fitted well under conditions with ethanol, whereas hydrophilic compounds had similar outcomes under both conditions. The results show that ethanol could accelerate the release of hydrophobic compounds in Chinese liquor distillation. Therefore, solvent could be one of the important factors to optimize the distillation process. Our findings provide a reference for improving the extraction during solid-state distillation.

Reduction-Responsive Docetaxel Prodrug Encapsulated within Human Serum Albumin Nanoparticles for Cancer Therapy.

Docetaxel (DTX), a semisynthetic analogue of paclitaxel, is often used to treat cancers. Owing to its poor aqueous solubility, the current formulation of DTX for clinical applications involves using high surfactant and ethanol concentrations, causing hypersensitivity reactions. To overcome this issue, we developed a reduction-responsive DTX prodrug encapsulated within human serum albumin (HSA) nanoparticles (DTX-SS-COOH/HSA NPs). First, the DTX prodrug was conjugated to undecanoic acid through a disulfide bond (DTX-SS-COOH) via a four-step reaction. Subsequently, DTX-SS-COOH/HSA NPs were prepared via the desolvation method. The NPs exhibited a spherical structure with a diameter range of 140-220 nm, as revealed by dynamic light scattering and transmission electron microscopy. Fluorescence quenching analysis confirmed the formation of DTX-SS-COOH/HSA, which was ascribed to electrostatic interactions and hydrophobic forces. Notably, NPs with a feed mole ratio corresponding to DTX-SS-COOH/HSA = 9:1 demonstrated high drug-loading and encapsulation efficiency of 12.84 and 93.11%, respectively, alongside good stability. Moreover, the reduced responsiveness experiment revealed an accelerated DTX release in the presence of glutathione. An in vivo pharmacokinetic study indicated that DTX-SS-COOH/HSA NPs demonstrated considerably a prolonged circulation time (6.2-fold) compared to that of free DTX. Ultimately, the antitumor test of MDA-MB-231 tumor-bearing mice revealed that DTX-SS-COOH/HSA NPs were superior to DTX/HSA NPs for tumor growth inhibition. Thus, DTX-SS-COOH/HSA NPs represent a promising DTX nanoformulation for clinical application.

Microwave irradiation: Reduction of higher alcohols in wine and the effect mechanism by employing model wine

Reduction of higher alcohols contributed more to the aromatic characteristics of wine. In this paper, response surface methodology was used to optimize the parameters of microwave time, temperature, and power to obtain optimal microwave processing conditions for the maximum degradation rate of higher alcohols in model wine solution, and the maximum degradation rate of higher alcohol was 11.21% under optimized microwave conditions of 100 W, 50 °C and 3 min. The possible mechanism of microwave reducing on the higher alcohols was studied at optimized microwave conditions, the results showed that high concentrations of tartaric acid, glyoxylic acid, and ferrous ions could obviously decrease the content of higher alcohols; the content of higher alcohols in low concentrations ethanol and cupric ions was obviously lower than that in high concentration of ethanol and cupric ions; the appropriate (+)-catechin concentration had more obvious effect on higher alcohols content; the mannitol inhibited the degradation of higher alcohols and its subsequent reactions by scavenging free radicals in model wine solution. In summary, all these results could help understand the influence of improvement effect of microwave irradiation on the aromatic characteristics in wine by reducing the contents of higher alcohols.

Regulation of Ethanol Assimilation for Efficient Accumulation of Squalene in Saccharomyces cerevisiae.

Squalene is a triterpene that can be obtained from fish and plant oils. It is important in cosmetics and vaccines and is a precursor for many high-value terpenes and steroids. In order to increase squalene accumulation, the mevalonate pathway was systematically enhanced. Accumulation of squalene tended to increase when ethanol was added as a carbon source during fermentation, but a high concentration of ethanol affected both the strain growth and accumulation of products. By overexpressing the key trehalose synthesis gene TPS1 and the heat shock protein gene HSP104, the content of trehalose by Saccharomyces cerevisiae (S. cerevisiae) was enhanced, and stress caused by ethanol was relieved. The OD600 value of the modified S. cerevisiae strain was increased by 80.2%, its ethanol tolerance was increased to 30 g/L, and it retained excellent activity with 50 g/L ethanol. After optimizing the fermentation conditions, the squalene titer in a 5 L bioreactor reached 27.3 g/L and the squalene content was 650 mg/g dry cell weight, the highest squalene production parameters reported to date for a microorganism.

Calcium carbonate from chicken eggshells as filler in composite Nafion membrane for direct ethanol fuel cell: a molecular dynamics study

AbstractBACKGROUNDDirect ethanol fuel cells (DEFC) need fillers to mitigate the issue of ethanol crossing over from the anode to the cathode, which lowers performance. Therefore, this study developed calcium carbonate (CaCO3) from chicken eggshells as a filler in a Nafion composite membrane for DEFC. Three cluster models of CaCO3 filler were developed, namely (CaCO3)2, (CaCO3)3, and (CaCO3)4, to form the Nafion composite membranes. The properties of composite membranes, such as proton conductivity, ethanol permeability, and selectivity, were studied using the molecular dynamics method. In addition, the three main factors influencing the composite membranes’ properties were analyzed in this study; these were cluster size of CaCO3, mass loading of the filler, and ethanol concentration.RESULTSThe results show that filler has reduced proton conductivity and ethanol permeability in the DEFC application compared to the Nafion membrane. However, the selectivity is used as a trade‐off between ion conductivity and ethanol permeability in the composite membrane, thus requiring a suitable size structure and mass loading to balance the high ion conductivity rate and reduce the ethanol permeability rate. The composite membrane C‐(CaCO3)4, which has a large cluster size in this study, shows that it is necessary to restrict ethanol permeability at a high ethanol concentration of 5 mol L−1. However, the structure size in cluster B – (CaCO3)3 – can reduce ethanol permeability but requires high mass loading by 5 wt%. Analysis of variance showed significant values for ion conductivity, ethanol permeability, and selectivity responses.CONCLUSIONCaCO3 successfully reduced ethanol crossover in DEFC, with all three composite membranes being suitable for use at low ethanol concentrations. However, specific size structure and mass loading are required to overcome ethanol crossover at high ethanol concentration. © 2023 Society of Chemical Industry (SCI).

A review of hydrogen production optimization from the reforming of C1 and C2 alcohols via artificial neural networks

Hydrogen production from different fuels has received extensive study interest owing to its environmental sustainability, renewability, and lack of carbon emission. This research aims to investigate how artificial neural networks (ANNs) are employed to optimize operating parameters for the catalytic thermochemical conversion of methanol and ethanol and their impact on hydrogen production. According to the ANN model, peak methanol conversion (99%) occurs at lower temperatures of 300 °C with a maximum hydrogen yield of 2.905 mol, whereas peak ethanol conversion (85%) occurs at 500 °C owing to dehydrogenation and the C-C bond-breaking process. A steam-to-carbon (S/C) ratio of (3.5) was advantageous for methanol steam reforming (MSR), and a high ethanol concentration of 10–15 vol% was favorable for ethanol steam reforming (ESR). Ni (10 wt%), and Co (10 wt%) were the optimum metal combinations in the catalyst for ethanol reformation at a reforming temperature of 450 °C. The optimum metal catalysts for producing hydrogen and converting ethanol were those synthesized through co-precipitation. The peak hydrogen yield was attained at the sintering temperature of 560–570 °C. ANN technique is cost-effective, quick, and precise, with vast potential to produce hydrogen energy, and may give significant benefits for industrial applications.

Research on the aroma properties and microbial succession patterns in the processing of Chinese yellow sticky rice jiuqu steamed bread

To investigate the aroma properties and microbial succession patterns of Chinese steamed bread (CSB) prepared with yellow sticky rice and Baijiu Qu, several important stages were determined in processing, including yellow sticky rice, fermented rice, fermented juice, sourdough, and steamed bread by solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS) and high-throughput sequencing (HTS). The composition of volatile compounds varied significantly in different stages. The highest content of 2-methyl-butane (9.69%) and hexanal (6.34%) was detected in yellow sticky rice while the high content of ethanol (39.60%–42.14%), phenylethyl alcohol (9.01%–15.70%) and 3-methyl-1-butanol (8.91%–10.19%) endowed other samples sweet, rose and brandy aroma. Bacterial community mainly consisted of Chloroplast (10.83%–70.20%) and Weissella (0.43%–51.49%), and fungal community was primarily composed of Saccharomyces (1.22%–64.25%). Phenylethyl acetate was positively related to Saccharomyces, and phenylethyl alcohol and 1-hexanol were positively related to Lactobacillus. This paper provided a new prospect for the industrialization of traditional Chinese steamed bread.

Effects of Sorghum Grain and Wort Composition on Dry Grind Fermentation Performance: A Model for Baijiu Production

Sorghum grain is the principal raw material for Baijiu production, but the effects of grain and wort composition on fermentation performance are unclear. Ethanol production at laboratory scale using grains of 11 commercial sorghum cultivars from a field trial was investigated using dry grind fermentation. Initial wort glucose content was 141–150 g/L and fermentability (glucose-to-ethanol conversion rate) was 87–90%. Ethanol production rate among sorghum genotypes ranged from 1.18 to 2.04 mL of ethanol per litre wort per hour of fermentation. The cultivars were categorised into four groups according to a fermentation endpoint of 60–69 h, 70–79 h, 80–89 h and &gt;90 h. All but one of the sorghums produced a final ethanol content of 9.47–9.76% v/v. Cultivars with high-starch and low-protein grains were the most suitable for fermentation due to the high final ethanol content and fermentability achieved. Initial wort glucose content and yeast assimilable nitrogen content were not correlated with grain starch content, protein content, ethanol content, fermentability, ethanol production rate or glucose consumption rate. Knowledge of the effects of sorghum grain quality on fermentation performance can pave the way for further research to optimise solid-state fermentation for Baijiu production.

Association between Compliance with COVID-19 Restrictions and the Risk of SARS-CoV-2 Infection in Poland.

During the coronavirus disease 19 (COVID-19) pandemic it has become very important to comply with preventive measures. We aimed to assess compliance with applicable restrictions and to explore the links between the level of compliance and the risk of COVID-19. This cross-sectional study included Polish adults who were asked to complete a validated questionnaire. The study period was from 1 November 2020 to 31 January 2021 and a computer-assisted web interview method was chosen to perform the survey. The study involved 562 women and 539 men. COVID-19 was reported in 11.26% of participants. A good level of compliance with the sanitary restrictions was reported for 38.87% of participants, an average level of compliance for 47.96%, and a low level of compliance for 13.17%. A reduced risk of COVID-19 was associated with the following preventive measures: regular use of protective masks, social and physical distancing in public places, regular use of hand sanitizers with high ethanol content, and the use of disposable gloves in public places. Our survey revealed satisfactory public compliance with the pandemic restrictions. Sanitary and epidemiologic measures to prevent the pandemic were shown to be adequate and effective.

Fermentation of Agave americana L. sap produced in Cayambe – Ecuador

Fermentation of agave sap, also known as exudate, has become an ancestral practice throughout Ecuadorian Andean. In Cayambe, located in this region, grows Agave americana L., which is recollected, and its sap is fermented. The agave-based fermented beverage, locally named "tzawar mishki", exhibits variable features, mainly ethanol concentration. In this work, fermentation conditions of agave sap were studied to enhance ethanol yield. Two thermal treatments for raw exudate were evaluated, pasteurization at boiling point for 30 minutes and sterilization at 121°C for 15 minutes; fermentation temperature, 30°C and room (around 18°C); and two yeast strains. Thermal pretreatments have a positive impact on reducing sugars and sucrose concentration. In the first case, an increase of 76 % and 30 % has been reported, while sucrose concentration quadrupled and doubled in pasteurized and sterilized samples, respectively. The highest ethanol concentration (63,31 g/L) and the best yield (66,21 %) were accomplished through agave sap pasteurized and fermented for 96 hours at 30°C. Negligible differences have been evidenced in ethanol and other volatile compounds content between the two yeast strains evaluated. Keywords: agave sap, ethanol, fermentation, fermentable sugars, yeast

Transforming Spent Coffee Grounds' Hydrolysates with Yeast Lachancea thermotolerans and Lactic Acid Bacterium Lactiplantibacillus plantarum to Develop Potential Novel Alcoholic Beverages.

In the present work, the modification of spent coffee grounds (SCG) hydrolysate composition by mixed cultures of a non-Saccharomyces yeast, Lachancea thermotolerans, and a lactic acid bacterium, Lactiplantibacillus plantarum, as well as their interactions, were evaluated. It was found that L. plantarum inhibited the growth and survival of L. thermotolerans as compared with that in the yeast alone. On the other hand, the growth and survival of L. plantarum was slowed in sequential fermentation, but not in co-culture. Compared with co-culture, higher ethanol content, less residual sugars, and less acetic and succinic acids were found in sequential fermentation. In addition, lower amounts of caffeine and phenolic acids (e.g., ferulic, caffeic, and p-coumaric acids) were obtained in mixed (co- and sequential) cultures with corresponding levels of volatile phenols relative to the yeast monoculture. Moreover, co-culturing resulted in the highest contents of total alcohols (ethanol excluded) and total esters. Therefore, mixed culturing of L. plantarum and L. thermotolerans presented positive effects on the chemical constituents of fermented SCG hydrolysates, which might be a new alternative approach to valorizing the SCG into novel alcoholic drinks with different ethanol and flavor constituents.

Effects of simultaneous inoculation of non-Saccharomyces yeasts and Saccharomyces cerevisiae jiangnan1# on overall quality, flavor compounds, and sensory analysis of huangjiu

Non-Saccharomyces yeast (NSY) co-fermentation with Saccharomyces cerevisiae has been widely used to produce high-quality fermented alcoholic beverages. In this study, we evaluated the feasibility of 24 NSY strains belonging to 13 different genera co-fermentation with S. cerevisiae jiangnan1# in huangjiu brewing. Different fermentation trials were set up and the effects on huangjiu fermentation were also analyzed. Results indicated that simultaneous inoculation could realize the application of NSY, while the appropriate proportion of S. cerevisiae and NSY (1:1 or 1:10) showed differential effects. Finally, three types of NSY strains (Zygosaccharomyces rouxii Non-Sc11, Kloeckera apiculata Non-Sc17, and Candida tropicalis Non-Sc21) with high ethanol content (>16% vol), moderate concentration of higher alcohols (<400 mg/L, 14% vol), higher production of esters (P < 0.05), and lower organic acid (P < 0.05) were obtained ultimately. The sensory evaluation demonstrated that using no less than one kind of the three NSY strains in simultaneous fermentation with S. cerevisiae jiangnan1# (1:1) resulted in sensory diversity of new huangjiu styles. In addition, the method for evaluation and application of NSY in co-fermentation with S. cerevisiae jiangnan1# in huangjiu brewing had been established for the first time, which could be directly applied in industrial production of huangjiu.

Cellulose hydrolysis and bioethanol production from various types of lignocellulosic biomass after microwave-assisted hydrotropic pretreatment

This study examined the impact of microwave-assisted hydrotropic pretreatment using sodium cumene sulfonate on the enzymatic hydrolysis of cellulose contained in pine chips, beech chips and wheat straw biomasses as well as the effectiveness of the production of bioethanol from the obtained hydrolysates. The effectiveness of enzymatic hydrolysis of cellulose contained in beech chips and wheat straw subjected to pretreatment in optimised process conditions amounted to ca. 55–60%. As a result of this, hydrolysates containing glucose in the concentration of 76–84 g/L were acquired, which is a significant achievement in the case of cellulosic hydrolysates. A lower efficiency of the process was recorded when cellulose from pine chips was used (maximum hydrolysis efficiency was 17.21 ± 0.09%), which confirms a higher resistance of softwood biomass to the process of biodegradation. The highest concentration of ethanol, at the level of 41.44 ± 0.55 g/L, was achieved through the fermentation of the medium being a hydrolysate of wheat straw after microwave-assisted hydrotropic pretreatment. The developed raw material and hydrolysate preparation method indicates the possibility of using wheat straw after microwave-assisted hydrotropic pretreatment for efficient cellulosic ethanol production using high-gravity (HG) technology.