Search Results (3,392)

Sea buckthorn juice (SBJ) has a sour taste and can lead to the demineralization of tooth enamel when consumed over a long period of time, whereas fermentation reduces the acidity of sea buckthorn juice, improves its taste, and enhances its antioxidant activity. Flavor components are important factors that affect the quality of fermented beverages. Yeast is one of the most important factors affecting the flavor of beverages during the fermentation process, where yeast converts sugars into alcohol and produces flavor substances. Therefore, two commercial yeast strains, Angel RW and Angel RV171, were selected in this study for the single and mixed bacterial fermentation of sea buckthorn juice (FSBJ). Physicochemical analyses showed that RV171-FSBJ had the highest total reducing sugar (0.069 ± 0.02 g/L) and total acid content (1.86 ± 0.03 g/L), as well as the highest fermentation efficiency and free radical scavenging capacity (1,1-diphenyl-2-picrylhydrazyl (DPPH) 98.54 ± 0.03%, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) 88.35 ± 0.14%, ·OH 48.61 ± 0.4%). RWRV-FSBJ had the highest content of functional compounds (total flavonoid content (TFC): 176.09 ± 0.44 μg/mL; total phenolic content (TPC): 157.9 ± 1.35 μg/mL; total anthocyanin concentration (TAC): 0.04 ± 0.004 μg/mL) and good color (L* 50.53 ± 0.04, a* 27.98 ± 0.04, b* 173.64 ± 0.34). Among the three FSBJs, a total of 54 volatile compounds were identified, with RV171-FSBJ having the highest content of volatile compounds. OAV analysis showed that 15, 14, and 11 volatile compounds of RW, RV, and RWRV, respectively, were greater than 1. Among them, ethyl hexanoate had the highest OAV, followed by ethyl isovalerate, phenylethyl alcohol, and 3-methylbutyl 3-methylbutanoate, which are characteristic flavor substances common to FSBJ. Full article

High potential is attributed to the concomitant use of probiotics and prebiotics in a single food product, called “synbiotics”, where the prebiotic component distinctly favours the growth and activity of probiotic microbes. This study implemented a detailed comparison between the prebiotic effect of Fructooligosaccharides (FOSs) and Raffinose family oligosaccharides (RFOs) on the viable count of bacteria, hydrolysis into monosaccharides, the biosynthesis of short-chain fatty acids and sensory attributes of soymilk fermented with 1% (v/v) co-cultures of Lacticaseibacillus rhamnosus JCM1136 and Weissella confusa 30082b. The highest viable count of 1.21 × 10⁹ CFU/mL was observed in soymilk with 3% RFOs added as a prebiotic source compared with MRS broth with 3% RFOs (3.21 × 10⁸) and 3% FOS (6.2 × 10⁷ CFU/mL) when replaced against glucose in MRS broth. Raffinose and stachyose were extensively metabolised (4.75 and 1.28-fold decrease, respectively) in 3% RFOs supplemented with soymilk, and there was an increase in glucose, galactose, fructose (2.36, 1.55, 2.76-fold, respectively) in soymilk supplemented with 3% FOS. Synbiotic soymilk with 3% RFOs showed a 99-fold increase in methyl propionate, while the one supplemented with 3% FOS showed an increase in methyl butyrate. The highest acceptability based on the sensory attributes was for soymilk fermented with 2% RFOs + 2% FOS + 2% table sugar + 1% vanillin (7.87 ± 0.52) with high mouth feel, product consistency, taste, and flavour. This study shows that the simultaneous administration of soy with probiotic bacteria and prebiotic oligosaccharides like FOSs and RFOs enhance the synergistic interaction between them, which upgraded the nutritional and sensory quality of synbiotic soymilk. Full article

The rising prevalence of hyperuricemia and gout, driven by dietary purine intake, has intensified demand for healthier alcoholic beverages. Beer, a major contributor to exogenous purines, poses significant health risks despite its cultural and economic importance. This review systematically analyzes purine sources in beer, metabolic pathways leading to uric acid production, and cutting-edge strategies for purine reduction. We evaluate physical adsorption, enzymatic degradation, microbial fermentation, and yeast metabolic engineering, highlighting their efficacy and limitations in industrial applications. Challenges such as flavor preservation, regulatory compliance, and scalability are critically discussed. By integrating multidisciplinary approaches ranging from synthetic biology to process optimization, this work provides a roadmap for developing commercially viable low-purine beers, bridging the gap between public health priorities and brewing industry innovation. Full article

The increasing demand for bio-based chemicals and sustainable materials has placed biomass-derived lactic acid in the spotlight as a key building block for biodegradable polylactic acid (PLA). Perennial ryegrass (Lolium perenne) is a promising feedstock due to its high dry matter (DM) yield, adaptability, and widespread agricultural use. This study investigates an integrated lactic acid–silage cascade process, focusing on how pH regulation, harvest timing, and biomass characteristics influence lactic acid production while maintaining agronomic efficiency. The results highlighted the crucial role of pH management and silage duration in optimizing lactic acid production. A silage period of 21 days was found to be optimal, as peak lactic acid yields were consistently observed at this stage. Maintaining a pH range of 4.5 to 6 proved essential for stabilizing fermentation, with citrate buffering at pH 6 leading to the highest lactic acid yields and minimizing undesirable by-products. Harvest timing also significantly affected lactic acid yield per hectare. While later harvesting increased total DM yield, it led to a decline in lactic acid concentration per kg DM. Tetraploid ryegrass (Explosion) maintained stable lactic acid yields due to higher biomass accumulation, whereas diploid varieties (Honroso) experienced a net reduction. From an agronomic perspective, optimizing harvest timing and variety selection is key to balancing biomass yield and fermentation efficiency. While tetraploid varieties offer greater flexibility, diploid varieties require precise harvest timing to avoid losses. These findings contribute to sustainable forage management, improving lactic acid production, silage efficiency, and agricultural resource use. Full article

Xanthan is a highly relevant commercial microbial biopolymer. Its production occurs in two steps: the bacterium is cultivated in a nitrogen-rich medium for cell multiplication, and the obtained biomass is used as an inoculum for the polymer production phase. Different media compositions for cell growth were investigated, seeking to reduce or replace the peptone used in the standard medium. Peptone (P), yeast extract (YE), and rice parboiling water (RPW) concentration combinations were tested in cultivating Xanthomonas arboricola pv. pruni 101. A CRD 2³ design, performed in a shaker, was used to assess the effects of independent variables on xanthan pruni microbial growth, N consumption, yield, viscosity, pseudoplasticity, and xanthan mineral content. After 24 h an increase in N was observed, without any significant impact on cell growth. Xanthan yield increased as a result of the alternative treatments, with P and YE influencing positively. However, T1, with the lowest levels of P, YE, and RPW increased viscosity and pseudoplasticity of xanthan pruni. RPW increased phosphorus, silicon, calcium, and magnesium, and P and YE increased potassium. These results indicate that partial replacement of P by RPW and YE is an economically viable and sustainable approach for the xanthan pruni production. Full article

This study examines the physicochemical and biological changes in meads produced from five honey types sourced from the Mekong region: Tree Marigold (Tithonia diversifolia, Myanmar), Coffee (Coffea canephora, Vietnam), Kapok (Ceiba pentandra, Cambodia), Rubber (Hevea brasiliensis, China), and Mixed Floral (Thailand). Honey musts were fermented with Saccharomyces cerevisiae at 25 °C for two weeks. After fermentation, meads exhibited lighter coloration, a stable pH (3.5–4.5), and varying bioactivities. All meads showed antimicrobial activity against Escherichia coli, while activity against Staphylococcus aureus and Klebsiella pneumoniae varied by honey source and depended on fermentation. Antioxidant activity ranged from 19.25 to 68.11% inhibition, and peaked in Tree Marigold honey after fermentation. Total phenolic and flavonoid contents fluctuated, with Mixed Floral mead showing the highest post-fermentation phenolic levels. The results of a sensory analysis ranked Tree Marigold mead the highest across taste, mouthfeel, aftertaste, and overall preference. These findings underscore the influence of honey origin and fermentation on the physicochemical, antimicrobial, and sensory properties of mead. Full article

Three wastewater sources, namely slaughterhouse wastewater, cheese whey, and wine lees, were used for volatile fatty acid (VFA) production with the aim of reducing polluted wastewater discharge to the water bodies and creating a useful product. Cheese whey and wine lees were proved to be good substrates to produce VFAs, obtaining maximum bioconversion percentages in g COD-VFA/g TCOD initial of 90% and 72% for cheese whey and wine lees, respectively. The composition of the VFAs produced from each wastewater stream varied, with acetic, propionic, isobutyric, and isovaleric acids being the most dominant. These VFAs were used as an environmentally friendly fungicide against Fusarium culmorum, resulting in a reduction of the radial mycelial growth of Fusarium culmorum for all the effluents tested. A thermal pretreatment of the VFAs resulted in an improved antifungal efficiency if compared to the untreated VFAs or a UV pretreatment. Full article

This study evaluated the impact of heat treatment on the microbiological, chemical, and functional properties of hard cider enriched with cryo-concentrate over 180 days of storage. The experimental protocol for the hard cider was assessed under three conditions: room temperature (18–23 °C, CA), refrigeration (7–8 °C, CR), and pasteurization at 60 °C for 15 min (P60) and 80 °C for 15 min (P80). The heat treatment employed was mild to preserve the hard cider’s quality. Microbiological results confirmed proper processing conditions. Pasteurization reduced the initial populations of molds and yeasts by 92.9% (P80) and 83.3% (P60), while lactic acid bacteria decreased by over 99.0%. Microbial counts in P60 and P80 continued to decline during storage. Sugar content was the main indicator of instability in P60, particularly at 60 days. Both P60 and P80 ciders exhibited similar reductions in antioxidant activity, with DPPH showing a reduction of 43–45% and ABTS exhibiting a decrease of 50–51%. Additionally, a twofold increase in color intensity (darkening) was observed during storage in heat-treated samples. These findings demonstrate that pasteurization at 80 °C for 15 min effectively extends the shelf life of hard cider with cryo-concentrate to six months at room temperature, offering a practical solution for commercial production. Full article

In this study, we optimized the initial concentrations of glycerol and (NH₄)₂SO₄ to enhance 1,3-propanediol (1,3-PDO) production by Clostridium beijerinckii strain Br21. A central composite rotational design (CCRD) was employed, varying glycerol concentrations between 158 and 441 mmol L⁻¹, and (NH₄)₂SO₄ concentrations between 4.4 and 25.8 mmol L⁻¹. The CCRD identified optimal conditions at 441.42 mmol L⁻¹ for glycerol and 25.8 mmol L⁻¹ for (NH₄)₂SO₄. The optimized medium resulted in a 112% increase in 1,3-PDO production compared to the original medium. Analysis of NH₄⁺ and SO₄²⁻ ions under optimal conditions revealed a higher consumption of NH₄⁺ than SO₄²⁻. Furthermore, a quantitative gene expression analysis revealed that while the expression of genes responsible for glycerol uptake and ATP sulfurylase remained unchanged, the expression of the dhaM gene, which encodes the oxidative phosphoenolpyruvate:dihydroxyacetone phosphotransferase, increased approximately 6-fold. In the reductive pathway, the expression of the dhaB1 gene, encoding glycerol dehydratase, and the dhaT gene, encoding 1,3-propanediol dehydrogenase, increased 2.5- and 5-fold, respectively. The upregulation of these genes supports the hypothesis that the optimal concentrations of glycerol and (NH₄)₂SO₄ enhance the 1,3-PDO production by C. beijerinckii Br21. Full article

Saccharomyces cerevisiae var. boulardii is a probiotic yeast widely recognized for its ability to enhance gut health and modulate a host’s microbiome. However, there are limited data on its large-scale cultivation in stirred tank bioreactors and subsequent downstream processing into a functional probiotic product. Different recipe formulations were evaluated and the recipe with the highest biomass yield and lowest process time was selected. Once the optimised batch was validated in the replicate batches, the statistical analysis indicated a high level of reproducibility, with low variability across key performance indicators such as biomass concentration (unit), CFU production (CFU.mL⁻¹), and substrate utilization efficiency (g.g⁻¹). The mean growth age in the bioreactor was 25.33 ± 1.16 h, with a CV of 4.56%, indicating minimal deviation between batches. Similarly, the final viable concentration exhibited a mean of 1.46 × 10⁸ CFU.mL⁻¹ with a CV of 11.68%, remaining within an acceptable range for biological processes, while the final biomass concentration had the lowest variability (CV of 3.94%) and a 95% CI of 12.134–13.266 g.L⁻¹, highlighting the accuracy and consistency of the process. Productivity indicators, including cell productivity (growth time—biomass) and YPP (biomass), maintained low CV values (3.933% and 3.389%, respectively), reinforcing process efficiency and stability. The overlapping 95% confidence intervals across batches further confirmed that no statistically significant deviations existed, ensuring minimal batch-to-batch variability, and validating the scalability and robustness of the fermentation process. These findings provide strong evidence for the feasibility of large-scale probiotic yeast production that meets industrial production standards. The final freeze-dried product retained an 81% viability post-exposure to simulated gastrointestinal conditions, meeting WHO probiotic viability standards. These findings establish a scalable, optimized process for probiotic yeast production, with potential applications in biopharmaceutical manufacturing and functional food development, as confirmed by the techno-economic evaluations performed using SuperPro Designer^®. Full article

Jackfruit residues represent 70% of the total by-products generated from the processing of the fruit. The seeds, which are composed of proteins, fibers, and starch, are widely used in human nutrition; however, its potential in animal nutrition should be further investigated. Thus, the objective was to study the protein enrichment of jackfruit seeds by semi-solid fermentation using Saccharomyces cerevisiae and applying an experimental design to verify the effects of yeast concentration (1, 3, and 5%) and process temperature (30, 35, and 40 °C) on the protein increase. Physical and chemical analysis of the substrate was performed at intervals of 0, 24, 48, 72, and 96 h. A decrease in water content and water activity was observed during the fermentation time. The total soluble solid content also declined due to the consumption of carbohydrates by yeast. After 96 h of the process, the crude protein content of the fermented substrate increased approximately 2.5 times, corresponding to a protein increase of 357%, with the use of 5% of yeast at 40 °C. Through semi-solid fermentation, the protein content and the concentration of mineral nutrients in the jackfruit seeds increased, making it an alternative product for animal feed with high added value. Full article

The use of autochthonous yeast strains from viticultural environments represents a novel approach in the brewing industry. Probiotic-fermented beers have generated growing interest as they combine traditional brewing with the increasing demand for health-oriented functional beverages. The application of mathematical modeling to fermentation kinetics becomes a crucial tool to adequately describe and subsequently improve the performance of functional beer fermentation. The Saccharomyces cerevisiae PB101 autochthonous yeast from San Juan (Argentina) was previously selected for its probiotic potential and its exceptional technological traits in beer wort production. It was subsequently used to ferment a Kölsch-style brewer’s wort in order to evaluate both its probiotic potential and its resistance to the human digestive system. The results showed a survival percentage of 73.49 ± 0.54 and 80.17 ± 3.73 in fermentations conducted in 2024 and 2025, respectively. These fermentation assays were used to explore kinetic microbial growth, ethanol production, and critical fermentation parameters. Traditional modeling approaches often fail to adequately capture the intricacies of probiotic fermentations, particularly lag phases associated with microbial adaptation and metabolite biosynthesis. To address these limitations, this study develops an innovative and simple modeling system for modeling probiotic beer fermentation by incorporating two state variables: total and dead cells. The dynamics of these two variables were modeled using either a First Order Plus Dead Time model or a logistic growth model. Furthermore, the modified Luedeking–Piret model was used to study the delay time that exists between the production of viable cells and ethanol. The proposed models demonstrate enhanced predictive accuracy and dependability, providing a solid foundation for optimizing fermentation processes and advancing the development of functional beverages with exceptional probiotic properties. Full article

The screening of exopolysaccharides (EPS) produced by 52 isolates of endophytic and basidiomycete fungi was studied on two different media, PDB and PYGM. There were five isolates that could produce dried exopolysaccharide of more than 4 g/L (S. commune LF01962, LF01001, LF01581, Pycnoporus sp. MMCR00271.1, Pestalotiopsis sp. PP0005). The molecular weights of these exopolymers were found to be in the range of 2.5–500 kDa. These five exopolysaccharides, produced by five different fungal isolates, showed non-cytotoxic activity against NCTC clone 929 and HDFn cell lines. The selected fungal isolate of S. commune LF01962 was used for further optimization of different medium compositions affecting exopolysaccharide production using statistical methods. Among four conditions tested in the first step (xylose + peptone, glucose + (NH₄)₂HPO₄, fructose + peptone, and mannose + yeast extract), mannose + yeast extract resulted in the highest exopolysaccharide production of 5.10 ± 2.00 g/L. In the second step using Plackett–Burman design, the optimal medium for S. commune exopolysaccharide production was found to consist of 40 g/L glucose, 5 g/L mannose, 20 g/L (NH₄)₂HPO₄, 5 g/L yeast extract, 3 g/L monosodium glutamate, 0.5 g/L KH₂PO₄, 0.5 g/L K₂HPO₄, 0.2 g/L MgSO₄, 1 mL/L trace elements, and 3 mL/L vitamin solution, which resulted in 8.16 g/L exopolysaccharide production. Exopolysaccharide production in a 5 L bioreactor using small pellets as seed inoculum was found to produce 18.28 g/L exopolysaccharide. Full article

The increasing generation of agro-industrial waste and its improper disposal have raised significant environmental concerns, highlighting the urgent need for sustainable alternatives which would repurpose these materials. In this context, enzymes such as endoglucanase play a critical role in degrading lignin–cellulose biomass by catalyzing the breakdown of β-1,4-glycosidic bonds in cellulose, thereby converting it into fermentable sugars with diverse industrial applications. This study aimed to investigate the production, purification, and characterization of an endoglucanase produced by the fungus Pleurotus djamor PLO13, using coconut fiber, sugarcane bagasse, wheat bran, and pineapple crown as substrates. Endoglucanase activity was measured by the Miller method (1959), using 2% (w/v) carboxymethyl cellulose (CMC) as substrate. Solid-state fermentation (SSF) was found to be highly efficient for enzyme synthesis, with wheat bran emerging as the most effective substrate, yielding an enzyme production of 7.19 U after 120 h of cultivation. The endoglucanase was purified through ethanol precipitation and ion-exchange chromatography using DEAE-Sepharose, achieving a recovery rate of 110%, possibly due to removal of inhibitors present in the crude extract. The purified enzyme exhibited stability across a broad pH range and thermostability, with optimal activity at pH 5.0 and 50 °C. Furthermore, the enzyme was activated by EDTA, Mn²⁺, and Ca²⁺, while being inhibited by Mg²⁺. Notably, the enzyme demonstrated halotolerance, with activity increasing by 60% upon the addition of 3 M NaCl. Kinetic analysis revealed that the purified enzyme showed affinity to the CMC substrate at the analyzed parameters (pH 5.0 and 50 °C), with Km and Vmax values of 0.0997 mg/mL and 112.2 µg/min/mL, respectively. These findings suggest that the endoglucanase from P. djamor PLO13 has promising potential for biotechnological applications, underscoring the feasibility of the use of lignocellulosic waste as sustainable substrates in industrial processes. Full article

The valorization of agricultural residues, particularly corn stover, represents a sustainable approach for resource utilization and protein production in which high-performing microbial strains are essential. This study systematically evaluated fungal lignocellulolytic capabilities during corn stover solid-state fermentation and employed atmospheric and room-temperature plasma (ARTP) mutagenesis to enhance the degradative capacity of Trichoderma longibrachiatum. Comparative screening revealed that T. longibrachiatum exhibited superior comprehensive degradation of the major lignocellulosic components compared to other tested strains. ARTP mutagenesis yielded mutant strain TL-MU07, which displayed significantly enhanced enzymatic capabilities with improvements in FPase (22.1%), CMCase (10.1%), and xylanase (16.1%) activities, resulting in increased cellulose degradation (14.6%) and protein accumulation (14.7%). Proteomic analysis revealed 289 significantly differentially expressed proteins, with pathway enrichment demonstrating enhancement of glycosaminoglycan degradation, amino sugar metabolism, and membrane remodeling. Key mechanistic adaptations included downregulation of Zn(2)-C6 transcriptional repressors, upregulation of detoxification enzymes (ALDH-like proteins), and enhanced secretory pathway components. The ARTP-derived mutant strain TL-MU07 represents a valuable microbial resource for agricultural waste bioconversion, offering enhanced lignocellulolytic capabilities for industrial applications while elucidating specific proteomic changes associated with improved biomass degradation efficiency for sustainable protein production in the circular bioeconomy. Full article