Alcoholic Fermentation Process Research Articles

The impact of simultaneous inoculation with Torulaspora delbrueckii and Hanseniaspora uvarum combined with Saccharomyces cerevisiae on chemical and sensory quality of Sauvignon blanc wines

Non-Saccharomyces yeasts have great potential in improving wine quality, showing personality characteristics, and highlighting the terroir of wine. In this study, we evaluated the impact of simultaneous inoculation with the non-Saccharomyces yeasts Torulaspora delbrueckii or (and) Hanseniaspora uvarum in combination with Saccharomyces cerevisiae (EC1118 or VL3) on the aromatic compounds and sensory quality of Sauvignon blanc wines. The growth of yeast groups in the alcoholic fermentation process was tracked using fluorescence in situ hybridization. The presence of non-Saccharomyces yeast notably impacted the distribution of S. cerevisiae and was related to the species of yeast. The co-fermentation of H. uvarum and S. cerevisiae improved the content of total esters, especially acetate esters. Simultaneous inoculation of T. delbrueckii or (and) H. uvarum significantly increased the content of total terpenes, especially linalool. Similar results were found for some higher alcohols and organic acids. Sensory evaluation showed that the wines mixed fermentation with H. uvarum had significantly tropical fruit aroma characteristics. Citrus and mineral notes, typical aroma characteristics of Sauvignon blanc wine, were enhanced by mixed fermentation strategies with T. delbrueckii or (and) H. uvarum and different S. cerevisiae. Hence, co-fermentation by T. delbrueckii or H. uvarum combined with S. cerevisiae could significantly improve the sensory quality of Sauvignon blanc wine.

Evaluation of the effect of Torulaspora delbrueckii on important volatile compounds in navel orange original brandy using E–nose combined with HS–SPME–GC–MS

Simultaneous inoculation of non-Saccharomyces cerevisiae during the alcoholic fermentation process has been found to be an effective strategy for enhancing wine flavor. This study aimed to investigate the effect of Torulaspora delbrueckii NCUF305.2 on the flavor of navel orange original brandy (NOOB) using E–nose combined with HS–SPME–GC–MS. The results showed a significant increase (p < 0.05) in the sensitivity of NOOB to W5C, W3C, W1S, and W3S sensors by mixed fermentation (MF). Esters in NOOB increased by 4.13%, while higher alcohols increased by 21.93% (p < 0.001), terpenes and others increased by 52.07% and 40.99% (p < 0.01), respectively. Notably, several important volatile compounds with relative odor activity values above 10 showed an increase. Sensory analysis revealed that a more pronounced citrus-like flavor and higher overall appearance scores were found in MF than in pure fermentation (PF). These findings offer valuable theoretical guidance for enhancing the quality of fruit brandies.

Use of cerrado plants as an alternative in the control of bacterial contamination in the alcoholic fermentation process.

Bacterial contamination causes irreparable losses in the performance of alcoholic fermentation. Antibiotics are used to control these microorganisms, but they generate residues and cause microbial resistance. Today the only commercial product used by the mills is hops, but it is very expensive. As an alternative, the objective of this work was to evaluate the feasibility of using extracts from plants grown in the Cerrado for antimicrobial control during an alcoholic fermentation to replace antibiotics. Hydraethanolic extracts of leaves and essential oil of the following species were tested: Schinus terebinthifolius Raddi, Serjania erecta, Serjania marginata, Campomanesia adamantium and Syzygium cumini. Only the extract of Serjania marginata did not show any activity against the bacterium Bacillus sp. Both the essential oils as well as the hydroalcoholic extracts of S. terebinthifolius and C. adamantium and the extract of S. erecta showed antibacterial activity without harming the yeast, with potential to replace the hops.

Metaheuristic Procedures for the Determination of a Bank of Switching Observers toward Soft Sensor Design with Application to an Alcoholic Fermentation Process

The present work focused on the development of soft sensors for single-input single-output (SISO) nonlinear dynamic systems with unknown physical parameters using a switching observer design. Toward the development of more accurate soft sensors, as compared with hard sensors, an extended design methodology for the determination of a bank of operating points satisfying the dense web principle was proposed, where for the determination of the bank of operating points and the observer parameters, a metaheuristic procedure was developed. To validate the results of the metaheuristic algorithm, the case of an alcoholic fermentation process was studied as a special case of the present approach. For the nonlinear model of the process, an observer-based soft sensor was developed using the metaheuristic procedure. First, the accuracy of the linear approximant of the process with respect to the original nonlinear model was investigated. Second, the I/O reconstructability of the linear approximant was verified. Third, based on the linear approximant, an observer was designed for the estimation of the non-measurable variable. Fourth, considering that the observer is designed upon the linear approximant, the linear approximant model parameters are derived through identification, for different operating points, upon the nonlinear model. Fifth, the observers corresponding to the different operating points, constitute a bank of observers. The design was completed using a data-driven rule-based system, performing stepwise switching between the observers of the bank. The efficiency of the proposed metaheuristic algorithm and the performance of the switching scheme were demonstrated through a series of computational experiments, where it was observed that the herein-proposed approach was more than two orders of magnitude more accurate than traditional single-step approaches of transition from one operating point to another.

A new approach for monitoring the alcoholic fermentation process based on acoustic emission analysis: A preliminary assessment

A new approach for monitoring the alcoholic fermentation process based on acoustic emission analysis: A preliminary assessment

Comparative study of inoculation strategies of Torulaspora delbrueckii and Saccharomyces cerevisiae on the performance of alcoholic and malolactic fermentations in an optimized synthetic grape must

Progress in oenological biotechnology now makes it possible to control alcoholic (AF) and malolactic (MLF) fermentation processes for the production of wines. Key factors in controlling these processes and enhancing wine quality include the use of selected strains of non-Saccharomyces species, Saccharomyces cerevisiae, and Oenococcus oeni, as well as the method of inoculation (co-inoculation or sequential) and the timing of inoculation.In the present work, we investigated the effects of different inoculation strategies of two Torulaspora delbrueckii (Td-V and Td-P) strains followed by S. cerevisiae. Times (two, four, and six days) and types (co-inoculation and sequential) of inoculation were evaluated on the AF of a synthetic grape must. Furthermore, this synthetic medium was optimized by adding linoleic acid and β-sitosterol to simulate the natural grape must and facilitate reproducible results in potential assays. Subsequently, the wines obtained were inoculated with two strains of Oenococcus oeni to carry out MLF. Parameters after AF were analysed to observe the impact of wine composition on the MLF performance. The results showed that the optimization of the must through the addition of linoleic acid and β-sitosterol significantly enhanced MLF performance. This suggests that these lipids can positively impact the metabolism of O. oeni, leading to improved MLF efficiency. Furthermore, we observed that a 4-day contact period with T. delbrueckii leads to the most efficient MLF process and contributed to the modification of certain AF metabolites, such as the reduction of ethanol and acetic acid, as well as an increase in available nitrogen. The combination of Td-P with Oo-VP41 for 4 or 6 days during MLF showed that it could be the optimal option in terms of efficiency. By evaluating different T. delbrueckii inoculation strategies, optimizing the synthetic medium and studying the effects on wine composition, we aimed to gain insights into the relationship between AF conditions and subsequent MLF performance. Through this study, we aim to provide valuable insights for winemakers and researchers in the field of wine production and will contribute to a better understanding of the complex interactions between these species in the fermentation process.

Antibacterial Activity of Apple Vinegar Against the Growth of Streptococcus pyogenes

Apple cider vinegar is a liquid containing acid from the alcoholic fermentation process and acetate fermentation which contains flavonoids and tannins. This study aims to determine the antibacterial activity of apple cider vinegar in inhibiting gram-positive bacteria Streptococcus pyogenes. The method used is a quantitative method using disc paper, this stage starts from sample preparation, and sterilization of media manufacture, bacterial experiments, rejuvenation and manufacture of bacterial suspensions, preparation of sample concentrations, and antibacterial tests. Apple cider vinegar used were brands X, Y, and Z with concentrations of 10%, 20%, 40%, 80% respectively, positive control using 25 g Amoxicillin and negative control using sterile distilled water. The results of this study are the zones of inhibition caused by each brand are; X 6.53 mm, 7.5 mm, 12.01 mm, 16, 66 mm, Y brand 7.41 mm, 8.62 mm, 11.69 mm, 16.82 mm, Z brand 6.35 mm, 11.86mm, 14.25mm, 20.17mm. Data analysis using Two Way Anova, from the results of data analysis it can be said that bacteria have antibacterial activity against Streptococcus pyogenes with the best zone of inhibition in brand Z apple cider vinegar with a concentration of 80%.

The growth of white rot fungi in the biodelignification process of sawdust of Sengon

Sengon-wood sawdust (SWD) is the waste generated from the sawmill industry and can be utilized as making ethanol and pulp because the waste contains high fiber. The material is processed through biodelignification by white rot fungi. The purpose of this study was to observe the growth of Phanerochaete chrysosporium (PC) and Trametes versicolor (TV) in the biodelignification process of wood sawdust Sengon with a single culture and mixed culture with the growth of white rot fungi macroscopic (spread of the mycelium, the color powder, texture powder) and microscopic (surface properties and thickness of mycelium) using Flat Digital Microscope and SEM (Scanning Electron Microscope). This research method used a Completely Randomized Design (CRD) with one factor: the type of white rot fungi; J1: Phanerochaete chrysosporium, J2: Trametes versicolor), J3: a mixture of PC + TV, with each 3 repetitions. The results showed that The growth of single-culture Phanerochaete chrysosporium in the process of biodelignification of sengon sawdust (SWD) is best compared to single-culture TV and co-culture PC+TV. The results of this study provide information on the selection of types of fungi that have the potential to release lignin, which facilitates the process of pulping or alcoholic fermentation for biofuels.

Methods to Improve Alcohol Fermentation Process: A Review

Biofuel has been a hot research topic in the 21st century because it is promising to gradually replace today’s traditionalfuel in the future, which can protect the earth from many aspects. For example, biofuel’s biodegradability can reducepollution and solve the problem of the energy crisis to a certain extent. This paper mainly takes ethanol fuel as theresearch object focuses on the mechanism of yeast production of biofuel, different production methods, and benefits ofyeast, and discusses the future of isobutanol, a more efficient biofuel with more significant potential.

Prediction of Ethanol Content and Total Extract Using Densimetry and Refractometry

This study investigated the interrelationships between the parameters of density, optical refraction, the volume fraction of ethanol and the total extract, using model solutions and samples of wine materials. The regularities of changes in refractometer readings in the process of alcoholic fermentation have been studied. The functional dependence of the value of the volume fraction of ethanol in the finished wine products on the density and scale of refractometer values has been established. A technique is proposed for controlling the process of alcoholic fermentation of grape must, based on the use of refractometry. Finally, we present an algorithm to calculate the composition (volume fraction of ethanol, mass concentration of the total extract) of the fermentation product from its physical properties (density, refractive index), the coefficient of determination was R2 = 0.975.

Pesticide and Yeast Interaction in Alcoholic Fermentation: A Mini-Review

The current investigation briefly reviews previous studies about the fate of pesticides used in wine grape production during the alcoholic fermentation process, and how these could affect the correct functioning of yeast. The present review discusses the fact that yeasts could be used as a biological tool for pesticide dissipation, diminishing the concentration present in the grapes during the production process. The previous have never been directly boarded by other authors. The first part explores the influences of pesticides on yeasts and elucidates their effect on the fermentation process; also, some examples are analyzed of molecular studies involving the effect of pesticides on yeast. The second part discusses the effect of yeast on pesticide residues and their capacity to reduce its concentration during the alcoholic fermentation process, which varies among the different pesticides. In addition, this review discusses the mechanism by which yeast cells adsorb and/or degrade pesticides. In the last part, some examples of using yeasts as a possible remediation tool in wine and how the industry could use this to ensure consumers that a product is without pesticide residues are also discussed. This review shows that there is a natural capacity for the reduction of pesticide residue concentration by yeasts, and the effects of pesticides on yeast development is a variable phenomenon. This information guides advancement in pesticide removal from wine.

Spatially Offset Raman Spectroscopic (SORS) Analysis of Wine Alcoholic Fermentation: A Preliminary Study

Spatially offset Raman spectroscopy (SORS) is a non-invasive analytical technique that allows the analysis of samples through a container. This makes it an effective tool for studying food and beverage products, as it can measure the sample without being affected by the packaging or the container. In this study, a portable SORS equipment was used for the first time to analyse the alcoholic fermentation process of white wine. Different sample measurement arrangements were tested in order to determine the most effective method for monitoring the fermentation process and predicting key oenological parameters. The best results were obtained when the sample was directly measured through the glass container in which the fermentation was occurring. This allowed for the accurate monitoring of the process and the prediction of density and pH with a root mean square error of cross-validation (RMSECV) of 0.0029 g·L−1 and 0.04, respectively, and R2 values of 0.993 and 0.961 for density and pH, respectively. Additionally, the sources of variability depending on the measurement arrangements were studied using ANOVA-Simultaneous Component Analysis (ASCA).

The Use of Giant Miscanthus (Miscanthus × Giganteus) in 2G Bioethanol Production

The study aimed to obtain bioethanol from biomass using chemical treatment and enzymatic hydrolysis. Different concentrations of sodium hydroxide (5 and 10%) were used for the delignification process, and enzymatic hydrolysis was carried out using three commercial cellulolytic preparations (Cellic® CTec2, cellulase from Trichoderma reesei and cellulase from Aspergillus species). The final step involved an alcoholic fermentation process using Saccharomyces cerevisiae TYPE II yeast. After enzymatic hydrolysis, the content of reducing sugars was determined in the samples, and the fermentation yield was controlled by determining the ethanol content by pycnometry. Using chemical pretreatment increased the yield of the whole process by at least 50%. The content of reducing sugars after hydrolysis depended on the type of enzyme preparation used for hydrolysis and the use of NaOH in pretreatment. The highest reducing sugars content (45.8 g/dm3) was achieved in a sample of material purified with 5% NaOH, and enzymatic hydrolysis was carried out using Cellic® CTec2. It means the efficiency of the enzymatic hydrolysis process equals 94.69%. The concentration of bioethanol after alcoholic fermentation in this sample was 0.509 g/l.

Mathematical Modeling of Alcohol Fermentation On Tape Singkong With Monitoring Technology Temperature And Fermentation Controlled Chamber (TFCC)

The purpose of the research produced in this article is to determine mathematical modeling and mathematical analysis in the alcoholic fermentation process on cassava tape which is processed through a Temperature And Fermentation Controlled Chamber (TFCC) tool. TFCC is equipped with an automated system accompanied by sensors that detect food quality and can be directly observed through the LCD screen integrated in the device. Sensors used include MQ-3 as a sensor for detecting alcohol levels, type K thermocouple to detect temperature levels, pH meter to measure acidity levels of fermented foods and equipped with a tft LCD to display notifications of alcohol content measurement results. The research method used is experimental research by designing a tool that can be used to produce/cook fermented foods while monitoring pH, alcohol, glucose levels and temperature which is integrated in a set of tools called the Temperature And Fermentation Controlled Chamber (TFCC) with Hybrid Systems Technology. The alcoholic fermentation reaction of cassava tape with a Temperature And Fermentation Controlled Chamber (TFCC) and engineered through a linear equation from the cassava tape fermentation process data that the alcohol content equation is Y=10.03-1,415 X with mathematical modeling a+(m(S(t)+ K))/(p S(t)) (1-c/M (S(t)-S(0))=-d(S(t))/(d X(t) ) with (Q+dK )=c/S(0) S(t)^2-S(t).

Detection of bacterial spoilage during wine alcoholic fermentation using ATR-MIR and MCR-ALS

A new methodology is proposed to describe the evolution of the main chemical compounds of grape must during wine alcoholic fermentation using Attenuated Total Reflectance Mid Infrared (ATR-MIR) spectra in combination with Multivariate Curve Resolution Alternating Least-Squares (MCR-ALS). In addition, we have developed a process control strategy to detect differences between fermentations running under Normal Operation Conditions (NOC) and fermentations intentionally spoiled with lactic acid bacteria at the beginning of alcoholic fermentation (MLF) to promote deviations from NOC. MCR-ALS models on these data showed a good data fit (R 2 = 99.95% and lack of fit = 2.31%). It was possible to resolve the spectral profiles of relevant molecules involved in the alcoholic fermentation process, including the one related to bacterial spoilage (lactic acid). MSPC charts were built based on the concentration profiles obtained from the MCR-ALS models and using T 2 and Q statistics. Spoiled wines showed off-limit values for T 2 after 96 hours, making it possible to detect lactic acid bacteria spoilage in early stages of alcoholic fermentation. Thus, the use of ATR-MIR spectra and MCR-ALS analysis shows a great potential for a rapid control of the state of the alcoholic fermentation process, making it possible to early detect the appearance of undesired molecules during the process, which allows the winemaker to apply corrective measures and obtain a good final product. • ATR-MIR and MCR-ALS allow resolving main compounds involved in wine fermentation. • T 2 and Q MSPC charts are built using MCR-ALS concentration profiles. • The concept of ‘Inverse’ MSPC charts' is introduced. • Early detection of undesired molecules related to bacterial spoilage is achieved.

Detection of the alcohol fermentation process in vinegar production with a digital micro-mirror based NIR spectra set-up and chemometrics

ObjectiveFabricated a low price NIR spectra set-up for the monitoring of alcohol and reducing sugar contents in vinegar production process to improve the quality of vinegar. MethodA digital Micro-Mirror based NIR spectra set-up was made and used to collect the NIR spectra of the fermentation broths. The competitive adaptive reweighted sampling, genetic algorithm, random frog and successive projections algorithm were used to optimize the wavelength variables to improve the calibration performance of partial least square regression. ResultsThe set-up has high spectra collection performance. RF has the best effect on the wavelength variables selection. For alcohol, the R-square of cross-validation set (Rcv2) were 0.9824, and the root mean square error of cross-validation set (RMSECV) were 0.26 % (v/v). For reducing sugar, the Rcv2 and RMSECV were 0.9884 and 1.52 g/L, respectively. The calibrations were validated by 21 unknown samples, and the R-square of prediction set and root mean square error of prediction set were as similar as those of the cross-validation set. ConclusionThe alcohol and reducing sugar contents in the alcohol fermentation process in vinegar production can be monitored by a digital Micro-Mirror based NIR spectra set-up, which has the advantages of high accuracy and low price.

Agro-residues for clean electricity: in-lab trial of power generation from blended cocoa-kolanut wastes

As a way of wastes-to-voltage conversion, experimental benchtest trial of electricity generation from a blend of cocoa and kolanut harvest by-products is presented in this study. Bioethanol obtained from the blend, through a process of alcoholic fermentation, was mixed with gasoline at specific proportion and employed to fire a spark ignition engine that served as a prime-mover in driving a four-pole three-phase salient-pole synchronous machine. Performance of the driving machine, as the fuel-mix proportion and its speed of rotation varied, was studied. Likewise, the electric power output characteristic of the driven machine, when operated at its rated synchronous speed, was examined. It was found that the driving machine performed better on mixed fuel than pure gasoline. There were gradual increases in the torque and the power developed by the machine as the proportion of ethanol in the fuel-mix and the rotational speed increased. While the highest values of torque and power developed on using pure gasoline were 12.4 Nm and 2574 W respectively at 1900 rpm, 13.1 Nm torque and 2953 W power were obtained from the machine when ignited with 10%-bioethanol fuel-mix at the same speed. Also, with 90 Vdc excitation voltage and rotation at 1500 rpm synchronous speed, the driven machine continuously generated electricity at 207.6 Vrms (line-to-line), 1.169 A, 0.698 power factor, 48.17 Hz, 0.294 kW output. This study demonstrated the possibility of continuous generation of electric power from cocoa and kolanut wastes. Result obtained from the laboratory-based trial indicates that at such agricultural regions that are advantaged in the production of the two crops, harvest residues of the crops can be explored as a steady source of biofuel for off-grid microgrid electrification.

Medium chain fatty acids and fatty acid esters as potential markers of alcoholic fermentation of white wines

AbstractAroma components of wines play an important role in the sensory quality of wines. In our paper we investigate the effect of commercially available yeast nutrients under different fermentation parameters. Caproic acid, caprylic acid, capric acid, and different fatty acid esters were used as markers of the alcoholic fermentation process. The optimal temperature for the fermentation of different white wines was at 15–16 °C, in the case of examined wines lower concentrations of fatty acids and fatty acid esters were found at this temperature. At 25–26 °C fermentation temperature very high concentrations of fatty acids and fatty acid esters were detected. Applying different nitrogen-containing wine additives we managed to achieve better aroma profiles for white wines even using musts of lower quality.

Technological innovation in the winery addressing oenology 4.0: Testing of an automated system for the alcoholic fermentation management

In recent years, the use of automated machine tools in the wine industry has increasingly gained ground to simplify and optimize winemaking, complying with Industry 4.0 requirements. This work aimed to analyse a system for the automatic management of yeast nutrition in alcoholic fermentation in terms of environmental, management, and economic performance in comparison with traditional fermentation management. The automated system is a transportable and easily installable place and start system, equipped with a control unit and rods for the dosage of nutrients, and it works with a memory unit in which fermentative kinetics curves are loaded. The curves are predefined or customized according to oenologists’ needs. Hence, fermentation time, manpower, nutrients, oxygen, water, and energy consumption were evaluated concerning the alcoholic fermentation process. The analysis was carried out considering two different Italian wineries with different working capacities. Furthermore, life cycle assessment methodology and variable costs analysis was performed. Overall, the automated system reveals to be a promising investment, especially if applied to wineries characterized by high-volume tanks, where scale factor played a crucial role. Nutrients used by the automated system are more expensive but more environmentally sustainable than traditional ones.

Fabrication of a fluorescence probe via molecularly imprinted polymers on carbazole-based covalent organic frameworks for optosensing of ethyl carbamate in fermented alcoholic beverages

Ethyl carbamate (EC), which is a group 2A carcinogen, is a byproduct formed in the alcohol fermentation process that can accumulate with heating, transportation, and storage. In this study, molecularly imprinted polymers (MIPs) on carbazole-based covalent organic frameworks (COFs) were prepared as a fluorescence probe for the optosensing of EC in fermented alcoholic beverages. The excellent optical properties of carbazole-based COFs coupled with the good adsorption and selectivity of MIPs provided fast and efficient recognition of EC. MIPs on carbazole-based COFs exhibited advantages of high efficiency, a good separation effect, fluorescence dependence, and reproducibility. A good linear relationship was obtained over the concentration range of 1–200 μg L−1, with a low limit of detection (LOD) of 0.607 μg L−1. The RSD precision and five-cycle reproducibility were lower than 4.91% and 6.38%, respectively, and the recoveries were 85.30%–109.49%. This optosensor was applied to quantify EC contents in several fermented alcoholic beverages, all of which were less than LOD. The results of the optosensors based on MIPs on carbazole-based COFs were then validated using standard gas chromatography–mass spectrometry (GC-MS), which gave results consistent with the proposed method.