Fermentation is thought to be born in the Fertile Crescent, and since then, almost every culture has integrated fermented foods into their dietary habits. Originally used to preserve foods, fermentation is now applied to improve their physicochemical, sensory, nutritional, and safety attributes. Fermented dairy, alcoholic beverages like wine and beer, fermented vegetables, fruits, and meats are all highly valuable due to their increased storage stability, reduced risk of food poisoning, and enhanced flavor. Over the years, scientific research has associated the consumption of fermented products with improved health status. The fermentation process helps to break down compounds into more easily digestible forms. It also helps to reduce the amount of toxins and pathogens in food. Additionally, fermented foods contain probiotics, which are beneficial bacteria that help the body to digest food and absorb nutrients. In today’s world, non-communicable diseases such as cardiovascular disease, type 2 diabetes, cancer, and allergies have increased. In this regard, scientific investigations have demonstrated that shifting to a diet that contains fermented foods can reduce the risk of non-communicable diseases. Moreover, in the last decade, there has been a growing interest in fermentation technology to valorize food waste into valuable by-products. Fermentation of various food wastes has resulted in the successful production of valuable by-products, including enzymes, pigments, and biofuels.
The rapid growth of the global population and the impending depletion of fossil fuels, currently meeting approximately 80% of the world’s power needs, have intensified interest in biofuels derived from renewable biomass. This editorial refers to the Special Issue, “Biofuel Production and Processing Technology, 3rd Edition,” which highlights the transition of fermentation-based technologies from isolated processes into integrated, multifunctional biorefinery platforms. The collection includes nine contributions (eight original articles and one review) covering diverse advancements, including: The valorization of industrial intermediates, strategies to improve anaerobic digestion through co-digestion and heat recovery integration, mechanistic insights into syngas fermentation and the development of multi-product microbial systems, emerging frontier technologies, such as biological hydrogen production in depleted oil and gas reservoirs. Collectively, these studies emphasize that the future of sustainable energy relies on system-level optimization, balancing feedstock flexibility, energy integration, and environmental performance within a circular bioeconomy.
Valorization of food waste or food by-products into higher-value products can benefit the food industry by contributing to the food supply chain. This study aimed to investigate the potential for using waste ice cream as a fermentation substrate for production of ethanol by yeast. Results showed that 2 Saccharomyces cerevisiae strains, Lalvin EC-1118 (Lallemand Inc.) and Ethanol Red (Lesaffre), were able to ferment an aqueous by-product of waste ice cream, resulting in the production of ethanol, ~7% (wt/vol). This most likely occurred due to the utilization of free monosaccharides or sucrose, because they were unable to ferment lactose. Lactase and glucoamylase were added, to increase the availability of fermentable carbohydrates, resulting in 9.77% and 9.30% (wt/vol) ethanol produced by Lalvin EC-118 and Ethanol Red strains, respectively. Both strains were also shown to not utilize the galactose released following the hydrolysis of lactose. Maximum ethanol production, above 13% (wt/vol), was seen in samples treated with a combination of lactase and a protease, suggesting that a lack of nitrogen was stalling the fermentation. A benchtop-scale distillation was performed using a fermented vanilla ice cream treated with protease, lactase, and diammonium phosphate. The distillation was successful, and several fractions with various aromas and odors were collected. Results from this study suggest that that ethanol production is a viable valorization strategy to produce distilled beverage alcohol from waste ice cream, which is expected to be free of protein allergens.
Aims: To assess changes in total alcohol consumed over time, changes in consumption of different alcoholic beverages and the utility of industry sales data to evaluate the impact of policy changes related to a packaging ban on wine products in September 2007 and bans on alcohol sales during the Covid-19 pandemic in 2020 and 2021 in South Africa. Design. Alcohol industry sales data as a proxy for consumption was assessed using statistics presented in South African Wine Industry Information & Systems (SAWIS) booklets released annually between 1995 and 2022 and used to describe changes over time in consumption overall, and by product, and the impact on consumption from changes in policy. Results. Per capita consumption of alcoholic beverages overall has held steady or declined over time, but declines were noted in the market share of wine and beer (especially) and a massive increase for RTDs. The consumption data also indicated short term effects of Covid-19 interventions (especially in 2020) in terms of reducing overall alcohol consumption, with a return to prior levels in 2022. Industry data on packaging for wine was able to show the immediate and longer-term impact of the 2007 ban on wine sold in foil-bags. Conclusion. Industry data are a useful adjunct to consumer measures of alcohol use, as well as in detecting the impact of policy changes related to availability and packaging, notwithstanding gaps in information on illicit/unrecorded sales and other limitations.
Alexandr Mikyška, Lucie Dolejší, Kateřina Dubnová
et al.
The alpha acids content of the 2024 hop crop in the Czech Republic was evaluated using a pre-harvest forecast, a harvest forecast and a reality. The alpha-acids value in the Saaz variety was 2.72% w/w, in the Žatec (2.87% w/w) and Tršice (2.47% w/w) hop growing regions the content was well below the long-term averages, and in the Úštěk region (3.38% w/w) it was in line with the average. In Žatec and Úštěk, the alpha acids of the most widely cultivated hybrid varieties Sládek (7.5 and 6.7% w/w) and Premiant (7.5 and 8.5% w/w) were significantly higher than in Tršice (Sládek 4.8% w/w, Premiant 6.0% w/w). The values of the varieties Saaz Late and Saaz Special were below the average, while Kazbek (6.49% w/w) showed a good tolerance to weather conditions and the alpha acids content slightly above the average. The bitter varieties Agnus, Rubín and Vital with alpha acids content of 11–13% w/w give very stable alpha acids values over the long term, with 2024 corresponding to previous vintages. The harvest forecasts for alpha acids this year were in a very good agreement with reality. The year 2024 was relatively rich in water, but the distribution of rainfall over time was not optimal. Average monthly temperatures during the growing season were 1–2 °C above long-term averages, and the year as a whole was very warm. The Czech Republic's hop harvest (total of 6494 tonnes, yield 1.34 t/ha) was average in 2024. The total alpha acids production from the 2024 harvest was average at 242.5 t. The Saaz hops (82.1 % of the harvested area) accounted for 55% of the total. Bitter hop varieties cope better with adverse weather conditions than aromatic varieties.
The use of sorghum is currently limited to its basic potential, particularly the sorghum grain, which is used as a food ingredient. Sorghum stalks, which produce sap, are typically used as animal feed because they have no economic value. Sorghum is commonly consumed in the form of porridge, bread, chips, and drinks. However, so far, sorghum stalks have only been used for animal feed. Sorghum sap derived from sorghum stalks can be used to make wine, as its composition is higher than sugarcane sap. Wine is made through a fermentation process with the help of Saccharomyces cerevisiae. This study aims to determine the alcohol and glucose levels, organoleptic properties, and polyphenol levels. This study used a Completely Randomized Design (CRD). In this study, the fixed variables used were the glucose content of raw materials, the type of yeast, and pH, while the variable that changed was the % volume of the starter. The experiment was carried out by preparing sorghum sap, then the sorghum sap was poured into an Erlenmeyer flask with nutrients, and added starter (5%, 6%, 7%, 8%, 9%, 10%), operating 21 days and pH 4.3 then analysis of alcohol content and glucose content. The results showed that at % volume of starter 10% and fermentation time 21 days gave the highest alcohol content of 19.5%, glucose content 5.8 brix and total polyphenols 0.3449 mg/mL.
Giulia Roselli, Daniel W M Kerruish, Matthew Crow
et al.
The production of alcoholic beverages is intrinsically linked to microbial activity. This is because microbes such as yeast are associated with the production of ethanol and key sensorial compounds that produce desirable qualities in fermented products. However, the brewing industry and other related sectors face a step-change in practice, primarily due to the growth in sales of no- and low-alcohol (NoLo) alternatives to traditional alcoholic products. Here we review the involvement of microbes across the brewing process, including both their positive contributions and their negative (spoilage) effects. We also discuss the opportunities for exploiting microbes for NoLo beer production, as well as the spoilage risks associated with these products. For the latter, we highlight differences in composition and process conditions between traditional and NoLo beers and discuss how these may impact the microbial ecosystem of each product stream in relation to microbiological stability and final beer quality.
Brewer’s spent yeast (BSY) is one of the brewing industry’s most plentiful side-streams. Abundant, low-cost and high in nutrients, it has great potential for application in food technology and human nutrition. With the ever-increasing interest in sustainability, waste reduction and circular food systems, the use of BSY as a novel food ingredient may be the route to add exponential value while reducing the environmental impact. However, negative flavour characteristics and high amounts of alcohol severely limit the current applications of BSY. This study explores the use of processing involving lactic acid bacteria (LAB) fermentation technology as a means of improving BSY quality characteristics and examines the effects of this process on the chemical, nutritional and sensory characteristics of BSY. The results reveal that BSY is a suitable substrate for LAB fermentation, successfully supporting the growth of Lactobacillus amylovorus FST 2.11. Compared to the unfermented BSY (CBSY), fermentation significantly reduced the perceptible bitterness of the BSY as detected by a sensory panel, from 6.0 ± 2.8 units to 0.9 ± 0.7 units, respectively. Fermented BSY (PBSY) had enhanced sour and fruity flavours, and a variety of other volatile compounds and metabolites were determined. Protein profiles showed significant protein degradation, and free amino acid levels were greatly increased following fermentation, from 2.8 ± 0.2 g/100 g to 10.5 ± 0.4 g/100 g, respectively. Protein quality was high, with the CBSY and PBSY providing well over the required level (>100%) of essential amino acids per gram protein, with the exception of sulphur amino acids (98%). Major physical differences were observed using scanning electron microscopy. This study concludes that LAB fermentation positively affects the sensory and nutritional characteristics of BSY and can aid in the incorporation of brewer’s spent yeast into foods for human consumption.
Handray Fernandes de Souza, Eduardo Novais Souza Freire, Giovana Felício Monteiro
et al.
Mead is a fermented alcoholic beverage produced from a diluted solution of honey and yeast activity. The objectives of this study were to produce a potentially probiotic mead through mixed fermentation by Saccharomyces cerevisiae var. boulardii and kombucha microorganisms and to evaluate fermentation kinetics, microbial cell survival and their in vitro resistance to simulated gastrointestinal transit, color parameters and the phenolic and antioxidant potential of the product. The main results of this study show that in order to develop a potentially probiotic mead utilizing the mixed fermentation of S. boulardii and kombucha microorganisms, the best condition was a concentration of 25 mL/L (v/v) of kombucha and 0.75 g/L (w/v) of S. boulardii with fermentation for 9 days at a temperature of 25 °C. In addition, at the end of fermentation, mead with kombucha and S. boulardii presented physicochemical characteristics with a pH of 3.48, 0.67% total acidity, 18.76 °Brix soluble solids and 4.77% alcohol content. The S. boulardii and lactic acid bacteria (LAB) present in the mead survived conditions reproducing those of the gastrointestinal tract, with counts of more than 6 Log10 CFU/mL for both microorganisms after the intestinal phase. In the color analysis, the mead with kombucha and S. boulardii had a yellow color with the b* parameter corresponding to 35.93, luminosity (L*) equal to 76.09 and 1.82 for a*. In addition, the mead we produced contains quantities of phenolics and antioxidants. In conclusion, kombucha and S. boulardii are presented as alternative microbial sources for obtaining potentially probiotic mead.
Mary T. Serviss, Nicholas A. Wendrick, Andrew J. MacIntosh
et al.
Berries and their products can enhance the antioxidant profile, color, and sensory characteristics of beverages, resulting in competitive, value-added products. However, a complete overview of how fermentation affects these compounds is lacking. The American black elderberry, Sambucus canadensis, is an excellent candidate for studying how berry juices are affected during fermentation due to high concentrations of color compounds, anthocyanins, and volatile compounds. Gravity, pH, titratable acidity, total anthocyanins, color, and GC-MS analyses were performed on two varieties of elderberries to examine the physical and chemical qualities of elderberry juice before and after wine fermentation. A commercial product with elderberry adjuncts added post fermentation was also analyzed. The concentration of anthocyanins degraded by ~40% as the color of the elderberry wine shifted from blue to red after fermentation. Products that added elderberries post fermentation did not see the same degradation, however, also did not incorporate the same changes to volatile compounds as observed in the fermented wine. The fermentation industry can use this study’s findings to decide how best to use fruits to improve commercial products.
Beer is one of the most popular alcoholic beverages globally, leading to continuous efforts to enhance its production methods. Raw materials and the production process are crucial in the brewing industry, with fermentation being a vital stage that significantly impacts beer quality. The aim of this study is to optimize the beer fermentation process by maximizing the ethanol concentration while minimizing species that adversely affect the organoleptic properties of beer. A novel optimization approach has been developed to derive an optimal, smooth, and continuous temperature profile that can be directly applied in real-world processes. This method integrates Fourier series and orthogonal polynomials for control action parameterization, in combination with evolutionary algorithms for parameter optimization. A key advantage of this methodology lies in its ability to handle a reduced parameter set efficiently, resulting in temperature profiles that are continuous and differentiable. This feature eliminates the need for post-smoothing and is particularly advantageous in biotechnological applications, where abrupt changes in temperature could negatively affect the viability of microorganisms. The optimized profiles not only enhance fermentation efficiency, but also improve the ethanol yield and reduce undesirable flavor compounds, providing a substantial improvement over current industrial practices. These advancements present significant potential for improving both the quality and consistency of beer production.
Jeisa Farias Santana, Guilherme de Freitas de Lima Hercos, Josemar Gonçalves de Oliveira Filho
et al.
The Brazilian Cerrado region has a rich plant diversity, with fruits that have peculiar and unique sensory characteristics. For these reasons, using these fruits for biotechnological production is a promising alternative, mainly to protect this biome from deforestation and degradation. The production of fermented acetic acid is an option to add value to native fruits and offer the market beverages with better nutritional quality and bioactive compounds. This work aimed to characterize fruits and to develop cagaita (Eugenia dysenterica DC.) acetic fermented beverage. The fruits were subjected to physical-chemical analyses in the first part. Subsequently, different treatments for fermentation were tested using two types of enzymes (amylase and pectinase), two subspecies of Saccharomyces cerevisiae yeast (UFLA CA11 and thermoresistant LNF Angel), and the chaptalization of the must with sucrose (16 °Brix). Alcoholic fermentation was carried out in an incubator with temperature control at 34 ± 1 °C. The pH, total soluble solids, titratable acidity, alcohol content, and density of the fermented products were monitored daily. The chaptalized must with amylase addition and thermoresistant yeast had the best performance during alcoholic fermentation, demonstrating that thermoresistant yeast is an economically advantageous and efficient alternative for the cagaita juice fermentation process. Subsequently, acetic fermentation was carried out using the slow method. Heat-resistant yeast without added enzymes was used to produce cagaita acetic fermented beverages within the parameters of the Brazilian legislation. Furthermore, phenolic compounds and antioxidant activity in the final product were observed. The work demonstrated the possibility of using cagaita fruits in biotechnological processes to produce new food products.
Malolactic fermentation (MLF) is a biological process of deacidification of wines that may also help to increase the microbiological stability of the product and to enhance its sensorial attributes, in particular its aromatic profile. MLF can occur spontaneously due to the presence of indigenous bacteria in the environment of fermented beverages such as wines and ciders. However, the inoculation of lactic acid bacteria (LAB) starter cultures could prevent potential losses and standardize the process. The industrial-scale production of these starter cultures requires cost-effective, sustainable, and feasible approaches. A possible approach to acquire bacterial biomass, while addressing waste disposal concerns, is the use of by-products from the apple juice industry, such as apple pomace. Moreover, to ensure the long-term viability and activity of starter cultures, appropriate preservation methodologies need to be developed. Thus, the aim of the present study was to evaluate the growth of two Lactiplantibacillus plantarum strains, UNQLp11 and UNQLp155, in supplemented apple pomace and to optimize the preservation conditions. Cultures were either frozen or freeze dried (trehalose (20% m/v) as a protective agent, potassium phosphate buffer (pH 7), and a combination of trehalose and buffer), and then cell viability and malolactic activity were analyzed under wine stress conditions. Notably, the combination of phosphate buffer at pH 7.0 and trehalose emerged as the most effective preservation strategy for freeze drying, exhibiting enhanced viability and malic acid consumption for the two strains evaluated. These findings underscore the inexpensive and sustainable viability of using a semi-solid medium formulated with apple pomace for LAB biomass production and subsequent preservation.
Suzane Meriely da Silva Duarte, Allysson Kayron de Carvalho Silva, Katia Regina Assunção Borges
et al.
Cervical cancer is caused by a persistent and high-grade infection. It is caused by the Human Papillomavirus (HPV), which, when entering cervical cells, alters their physiology and generates serious lesions. HPV 18 is among those most involved in carcinogenesis in this region, but there are still no drug treatments that cause cure or total remission of lesions caused by HPV. It is known that L-asparaginase is an amidohydrolase, which plays a significant role in the pharmaceutical industry, particularly in the treatment of specific cancers. Due to its antitumor properties, some studies have demonstrated its cytotoxic effect against cervical cancer cells. However, the commercial version of this enzyme has side effects, such as hypersensitivity, allergic reactions, and silent inactivation due to the formation of antibodies. To mitigate these adverse effects, several alternatives have been explored, including the use of L-asparaginase from other microbiological sources, which is the case with the use of the fungus <i>Aspergillus niger</i>, a high producer of L-asparaginase. The study investigated the influence of the type of fermentation, precipitant, purification, characterization, and in vitro cytotoxicity of L-asparaginase. The results revealed that semisolid fermentation produced higher enzymatic activity and protein concentration of <i>A. niger</i>. The characterized enzyme showed excellent stability at pH 9.0, temperature of 50 °C, resistance to surfactants and metallic ions, and an increase in enzymatic activity with the organic solvent ethanol. Furthermore, it exhibited low cytotoxicity in GM and RAW cells and significant cytotoxicity in HeLa cells. These findings indicate that L-asparaginase derived from <i>A. niger</i> may be a promising alternative for pharmaceutical production. Its attributes, including stability, activity, and low toxicity in healthy cells, suggest that this modified enzyme could overcome challenges associated with antitumor therapy.
Lorenzo Pasotti, Ilaria Massaiu, Paolo Magni
et al.
Poly-γ-glutamic acid (γ-PGA) is an attractive biopolymer for medical, agri-food, and environmental applications. Although microbial synthesis by <i>Bacilli</i> fed on waste streams has been widely adopted, the obtainment of efficient sustainable production processes is still under investigation by bioprocess and metabolic engineering approaches. The abundant glycerol-rich waste generated in the biodiesel industry can be used as a carbon source for γ-PGA production. Here, we studied fermentation performance in different engineered <i>Bacillus subtilis</i> strains in glycerol-based media, considering a <i>swrA<sup>+</sup> degU32<sup>Hy</sup></i> mutant as the initial producer strain and glucose-based media for comparison. Modifications included engineering the biosynthetic <i>pgs</i> operon regulation (replacing its native promoter with P<sub>hyspank</sub>), precursor accumulation (<i>sucCD</i> or <i>odhAB</i> deletion), and enhanced glutamate racemization (<i>racE</i> overexpression), predicted as crucial reactions by genome-scale model simulations. All interventions increased productivity in glucose-based media, with P<sub>hyspank</sub>-<i>pgs</i> ∆<i>sucCD</i> showing the highest γ-PGA titer (52 g/L). Weaker effects were observed in glycerol-based media: ∆<i>sucCD</i> and P<sub>hyspank</sub>-<i>pgs</i> led to slight improvements under low- and high-glutamate conditions, respectively, reaching ~22 g/L γ-PGA (26% increase). No performance decrease was detected by replacing pure glycerol with crude glycerol waste from a biodiesel plant, and by a 30-fold scale-up. These results may be relevant for improving industrial γ-PGA production efficiency and process sustainability using waste feedstock. The performance differences observed between glucose and glycerol media also motivate additional computational and experimental studies to design metabolically optimized strains.
Sludge alkaline fermentation liquid (AFL) is a potential carbon source for biological denitrification. However, its effectiveness is limited due to the presence of nutrients and heavy metals. In this study, acid-modified sepiolite (MSEP) was used to extract short-chain fatty acids (SCFAs) from AFL under optimized conditions and then with the prepared MSEP-AFL as a carbon source for denitrification. The optimal condition with an MSEP dosage of 1.96 g/L and pH 7.93 at 30 °C was obtained based on single-factor experiments and response surface methodology (RSM). Carbon balance revealed that 96.2% of the SCFAs, including 43.7% acetate and 23.5% propionic acid, was retained in the MSEP, demonstrating its high selectivity. The adsorption process followed the pseudo-second-order kinetic and Langmuir isothermal model, indicating dominant physical adsorption on the surface or in the fiber pores. This was further supported by the changes in the morphological features and surface properties of the MSEP. In the batch nitrate utilization experiments, the prepared MSEP-AFL was proven to be efficient as a carbon source, with a nitrate removal efficiency of 88.7% and a specific denitrification rate of 8.2 mg NOx-N/g VSS·h, which was 22% higher than that of the AFL. This was due to the establishment of a delicate “release–utilization” balance. These findings contribute to our understanding of the use of AFL for denitrification.
Research is limited on consumers’ ability to detect perceptible sensory differences between low- and high-strength alcoholic beverages. This study, therefore, conducted three pilot experiments using ISO sensory analysis methods to assess accuracy for evaluating beverages of different strengths. Participants were food production professionals trained in sensory analysis. Experiment 1 used a wide-range discrimination test to estimate low- to high-strength beverages (0–60% alcohol by volume (ABV) in 10% intervals). Experiment 2 included a narrower range of intermediate to high strengths (25–45% ABV in 5% intervals). Experiment 3 used 3-alternative forced choice tests (ISO 13301) to discriminate between beverages of varying strengths. Experiment 1 (n = 16) indicated that estimation ability was dependent upon the beverages’ ABV; as ABV increased, estimation significantly decreased (p < 0.005). These findings were not replicated in Experiment 2 (n = 13). In Experiment 3 (n = 17), a significant perceptible difference between high- and low-strength samples was observed in two of nine conditions (35% vs. 31% ABV (p = 0.009); 41% vs. 37% ABV (p = 0.037)). While people can detect large differences in beverage ABVs, they may have a moderate to poor ability to discriminate between beverages of similar strengths. These findings provide support for public health interventions that promote lower-strength alcoholic beverages.
This article deals with the analysis of the condensates which are formed from fermentation gases during the fermentation of grape must. The experiment was divided into two parts. In the first part, the evolution of the individual volatiles was monitored throughout the whole fermentation process of the Riesling variety. In the second part, the condensates from three different grape varieties (Riesling, Merlot, Sauvignon blanc) were investigated and the total content of the selected volatile substances was measured at the end of the fermentation. Attention was focused on the measurements using a GC-MS (gas chromatography-mass spectrometry) for the volatile substances: isoamyl alcohol, isobutyl alcohol, 1-propanol, ethyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, acetaldehyde, acetic acid, and acetoin. In addition, changes in the alcohol content of the condensate, with respect to the fermentation phase, were analysed. From the results of part 1, the quantity of the substances under investigation produced during fermentation was determined. The highest concentration of flavour compounds was during the fourth and fifth days of fermentation. The most dominant substance was isoamyl alcohol with a concentration of 1267 mg−1.The results of part 2 led to a comparison of the overall profile of volatiles between the varieties. The results showed that the condensates have both a high content of volatile substances and of alcohol. It was also shown that the Sauvignon blanc variant had the highest number of volatile compounds in the representation. The Merlot and Riesling variants were very similar. This product has an exceptionally high potential for further use in the wine or food industry.