Search

The objective of this research was to evaluate the ruminal fermentation parameters and in vitro Greenhouse gas (GHG) production derived from the fermentation of a balanced sheep diet with the addition of vegetable oils (canola, corn, safflower, and sunflower) or glycerol at different proportions (0, 20, and 40 g/kg of dry matter, DM). The fermentations showed that the highest Gmax was obtained with the addition of 40 g/kg of sunflower oil and 20 g/kg of glycerol with values of 180.97 and 179.95 mL/g DM, respectively. The treatment with 40 g/kg DM of corn oil showed the lowest values in CH4 production (7.15 mL/g DM when compared to the control) and it seemed to be a potential feeding strategy for reducing GHG emissions without affecting gas production. However, the N-NH3 content for this treatment in both doses (1.90 and 1.88 mg/dL) indicated that some toxicity for the animal could be expected.

BACKGROUND People brew tea to drink an infusion that only contains 25% water-soluble constituents, leading to most of the insoluble materials being wasted. Tea powder could be drunk directly by mixing with water without producing any waste. Tea powder can also be used as a natural additive to improve the flavour and taste in beverages and foods. Much detailed information on the particle properties of tea powder is required with its increasing consumption. The aim of this study was to investigate the effects of particle size ranging from median diameter D-50 = 4.32 to 26.59 mu m on the composition, physical, rheological, and bioactive properties of black tea powder. RESULTS The results indicate that large powder sizes had high bulk density and flowability, whereas small powder sizes possessed good swelling ability and wettability. The contents of water extract, total polyphenols, crude fibre, catechins, and thearubigins reduced with a decrease in particle size. To change the particle size and concentration could adjust the elastic modulus and the viscous modulus of the black tea powder suspension. Moreover, black tea powder with small particle size could regulate blood lipids in a hyperlipidaemic rat model by lowering triacylglycerols and elevating high-density lipoprotein cholesterol, whereas large particles presented an advantage in reducing body weight. CONCLUSION Our investigation extended the knowledge of commercial black tea powder in composition, physical, rheological, and bioactive properties. These results lay the foundation for future exploration of the use of tea powder in the food industry. (c) 2022 Society of Chemical Industry

Contains fulltext : 283855.pdf (Publisher’s version ) (Closed access)

Chinese rice wine (Huangjiu) has a long history and has been popular in China for thousands of years. During Huangjiu fermentation, many kinds of microorganisms are involved and hundreds of metabolites are produced, which form its unique aroma. The composition of the Huangjiu microbiome has a strong influence on the flavor and quality of the final consumer product. Therefore, this review summarizes the research progress on the main components, quality control indicators and flavor compounds, as well as potential hazards during the fermentation of Huangjiu. The influence of the dominant microbial species on the Huangjiu fermentation, the sensory qualities and the formation of harmful substances are discussed. This helps to provide a theoretical basis for modification of the Huangjiu microbiome to improve control of the fermentation process and the overall sensory quality of the final product.

During the fermentation process, yeast cells face different stresses, and their survival and fermentation efficiency depend on their adaptation to these challenging conditions. Yeast cells must tolerate not only a single stress but also multiple simultaneous and sequential stresses. However, the adaptation and cellular response when cells are sequentially stressed are not completely understood. To explore this, we exposed a multi-stress-tolerant strain (BT0510) to different consecutive stresses to globally explore a common response, focusing on the genes induced in both stresses. Gene Ontology, pathway analyses, and common transcription factor motifs identified many processes linked to this common response. A metabolic shift to the pentose phosphate pathway, peroxisome activity, and the oxidative stress response were some of the processes found. The SYM1, STF2, and HSP genes and the transcription factors Adr1 and Usv1 may play a role in this response. This study presents a global view of the transcriptome of a multi-resistance yeast and provides new insights into the response to sequential stresses. The identified response genes can indicate future directions for the genetic engineering of yeast strains, which could improve many fermentation processes, such as those used for bioethanol production and beverages.

Introducción. Lactobacillus casei se caracteriza por adaptarse al medio durante el proceso fermentativo. Objetivo. Caracterizar con tipificación de secuencias multilocus (MTLS), aislamientos de L. casei presentes en ensilados de cáscara de piña con niveles crecientes de urea. Materiales y métodos. Durante 2017 y con un diseño irrestricto al azar se prepararon veinte silos (2 kg). Cada cinco bolsas, se adicionaron 0, 0,5, 1 y 1,5 % de urea (p/p en base fresca). Después de treinta días, se tomó una muestra de cada repetición para realizar análisis bromatológicos. Se analizó materia seca (MS), proteína cruda (PC), carbohidratos no fibrosos, fibra en detergente ácido (FDA), fibra en detergente neutro (FDN), digestibilidad in vitro de la materia seca (DIVMS), hemicelulosa, extracto etéreo (EE), cenizas, nitrógeno amoniacal y pH. Se determinó el recuento de bacterias ácido-lácticas (BAL) para cada uno de los tratamientos. La identificación de las BAL se realizó con la secuencia del ARNr 16S. Los aislamientos de L. casei fueron analizados con MTLS. Resultados. Los cuatro tratamientos evaluados no presentaron diferencias significativas en la MS (12,10 a 12,86%), FDA (31,44 a 32,18 %), FDN (58,46 a 58,56 %), hemicelulosa (26,36 a 27,02 %), EE (2,45 a 2,96 %), cenizas (4,96 a 5,12%), nitrógeno amoniacal (0,45 a 0,49 %) y pH (3,36 a 3,48). No así, en PC (6,94 a 9,12 %) y DIVMS (82,84 a 84,72 %). La adición de urea se asoció a cambios en las poblaciones de BAL (6,56 a 6,90 UFC). Siete aislamientos de L. casei se identificaron y tipificaron con cinco genes distintos. Se encontraron entre dos (polA) y cinco (nrdD, pgm, mutL) alelos; esto permitió identificar un total de seis secuencias tipo (ST) distintas en los aislados de Costa Rica. Conclusión. Los aislamientos de L. casei se encontraron emparentados a bacterias del tracto gastrointestinal en humanos. Introduction. Lactobacillus casei is characterized by adapting to the environment during the fermentation process. Objective. To characterize with multilocus typing sequences (MTLS) isolates of L. casei present in pineapple peel silage with increasing levels of urea. Materials and methods. During 2017 and using an unrestricted random design, twenty silos (2 kg) were prepared. Every five bags, 0, 0.5, 1 and 1.5 % urea (w/w on fresh basis) were added. After thirty days, a sample was taken from each repetition for bromatological analysis. Dry matter (DM), crude protein (PC), non-fibrous carbohydrates, fiber in acid detergent (ADF), fiber in neutral detergent (NDF), in vitro digestibility of dry matter (IVDDM), hemicellulose, ethereal extract (EE), ashes, ammonia nitrogen, and pH. The Lactic Acid Bacteria (LAB) count was determined for each one of the treatments. Identification of LABs was carried out using the 16S rRNA sequence. The isolates of L. casei were analyzed using MTLS. Results. The four evaluated treatments did not present significant differences in DM (12.10 to 12.86 %), ADF (31.44 to 32.18 %), NDF (58.46 to 58.56 %), hemicellulose (26.36 to 27.02 %), EE (2.45 to 2.96 %), ash (4.96 to 5.12 %), ammonia nitrogen (0.45 to 0.49 %) and pH (3.36 at 3.48). Not so, in CP (6.94 to 9.12 %), and IVDDMS (82.84 to 84.72 %). The addition of urea was associated with changes in the BAL populations (6.56 to 6.90 CFU). Seven isolates of L. casei were identified and typed with five different genes. Between two (polA) and five (nrdD, pgm, mutL) alleles were found. This allowed the identification of a total of six different type sequences (ST) in the Costa Rican isolates. Conclusion. The L. casei isolates were found to be related to bacteria from the gastrointestinal tract in humans. Universidad de Costa Rica/[801-B5-505]/UCR/Costa Rica UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Zootecnia UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigación en Nutrición Animal (CINA) UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiología UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET) UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA) UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigaciones Agronómicas (CIA) UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimentos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)

Nattokinase is a potential new thrombolytic drug because of its strong thrombolytic effect, high safety, and low cost. However, there is no research reporting on bile salt-tolerant nattokinase-producing probiotics. In this study, the bile salt-tolerant nattokinase-producing strain Bacillus mojavensis LY-06 was isolated from local Xinjiang douchi, and the fermentation yield of nattokinase of 1434.64 U/mL was obtained by both a single factor experiment and an orthogonal experiment. A gene responsible for fibrinolysis (aprY) was cloned from the genome of strain Bacillus mojavensis LY-06, and the soluble expression of this gene in Escherichia coli (rAprY, fused with His-tag at C-terminus) was achieved; molecular docking elucidates the cause of insoluble expression of rAprY. The optimal pH and temperature for the fibrinolysis activity of nattokinase AprY fermented by Bacillus mojavensis LY-06 were determined to be pH 6.0 and 50 °C, respectively. However, the optimal pH of rAprY expressed in Escherichia coli was 8, and its acid stability, thermal stability, and fibrinolytic activity were lower than those of AprY. Bioinformatics analysis found that the His-tag carried at the C-terminus of rAprY could affect its acidic stability by changing the isoelectric point and surface charge of the enzyme; in contrast to AprY, changes in the number of internal hydrogen bonds and the flexibility of the loop region in the structure of rAprY resulted in lower fibrinolytic activity and poorer thermal stability.

The presence of antibiotics in milk is a significant problem affecting the technological safety of dairy products. The aim of the study was to determine the sensitivity of yoghurt cultures to residual levels of selected cephalosporin antibiotics (cephalexin, cefoperazone, cefquinome, cefazolin, and ceftiofur). Five yoghurt cultures were selected containing strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Artificially fortified milk samples (whole pasteurized milk; 85 °C; 3–5 s) with cephalosporins at a concentration of the maximum residue limit were used to evaluate the sensitivity of the yoghurt cultures by monitoring the pH, titratable acidity, and the concentration of selected organic acids (lactic, pyruvic, citric, acetic, orotic, oxalic, formic, uric, and succinic acids) at the end of fermentation (43 °C; 4–5.5 h; pH ≤ 4.6). The titratable acidity was determined by the Soxhlet–Henkel method and the organic acid concentration was monitored by reversed-phase HPLC. Ceftiofur had the greatest effect on the yoghurt culture activity, with a statistically highly significant effect (p < 0.05) on the pH, titratable acidity, and the content of lactic, pyruvic, and acetic acids in all cultures. Other cephalosporins also showed an inhibitory effect on yoghurt metabolism as seen by the evaluation of the lactic and pyruvic acid concentrations.

This paper proposes a discrete-time sliding mode controller for the fermentation process, which is adequately approximated by the first-order plus dead time model. The contribution of the paper is an investigation into the suitable approximation of the time delay for discrete-time sliding mode controller. The dead time is considered in two ways by the first-order Taylor series approximation and the first-order Pade approximation. In the first case, the discrete-time sliding mode controller is based on the integral compensation of an output error, and in the second case, the stable system centre method is used. Numerical simulation examples of the yeast fermentation process are given to show the effectiveness of these two methods.

In order to increase yield,take the Bacillus subtilis Asr as the expreession strain, the fermentation process of Bacillus subtilis Asr was optimized by orthogonal test and response surface method. The results show that three main factors affecting bacterial yield are leaching yeast powder, MgSO4 and CaCl2. The best fermentation medium formulation is as following: sucrose 20 g/L, peptone 10 g/L, leaching yeast powder 8.65 g/L, K2HPO4 3.0 g/L, MgSO4 0.27 g/L and CaCl2 0.53 g/L. The optimal culture conditions are as following: 37 ℃, initial pH 7.0, inoculum of 10% and stirring speed of 250 r/min. After the optimization, the highest yield of Bacillus subtilis Asr reaches 7.30×108 cfu/mL, which is 3.95 times higher than that before optimization. The study provides a technical reference for the subsequent bacterial scale-up culture in fermentor and the optimization of fermentation medium from other Bacillus subtilis.

Published online: 14 Jul 2020, Fermented food has been present throughout history, since fermentation not only helps preserving food, but also provides specific organoleptic characteristics typically associated to these foods. Most of the traditional fermented foods and artisanal beverages are produced by spontaneous generation, meaning no control of the microbiota, or the substrate used. Nevertheless, even not being standardized, they are an important source of bioactive compounds, such as antioxidant compounds, bioactive beeps, short chain fatty acids, amino acids, vitamins, and minerals. This review compiles a list of relevant traditional fermented beverages around the world, aiming to detail the fermentation process itselfincluding source of microorganisms, substrates, produced metabolites and the operational conditions involved. As well as to list the bioactive compounds present in each fermented food, together with their impact in the human health. Traditional fermented beverages from Mexico will be highlighted. These compounds are of high interest for the food, pharmaceutical and cosmetics industry. To scale-up the home fermentation processes, it is necessary to fully understand the microbiology and biochemistry behind these traditional products. The use of good quality raw materials with standardized methodologies and defined microorganisms, may improve and increase the production of the desirable bioactive compounds and open a market for novel functional products., The authors acknowledge the National Council of Science and Technology (CONACYT, Mexico) for the financial support (CVU 559365). This study was also supported by the Portuguese Foundation for Science and Technology under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01- 0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte also, Project ColOsH 02/SAICT/2017 (POCI-01-0145- FEDER-030071)., info:eu-repo/semantics/publishedVersion

This research developed a gas bubble counter in which the Arduino mega 2560 controller was changied to the Raspberry Pi3 model B controller. A Photo sensor was also installed in order to provide highly accurate counts at high rate of the number of carbon dioxide gas bubbles generated from the fermentation process. This gas bubble counter can be set to the desired value of the number of gas bubbles to be counted. It can also record images of gas bubbles during the fermentation process by camera and has an alarm (buzzer) activated at the completion of work. The results showed that the error of counting increased with the increase of the rate of gas bubbles from 0% at gas bubble rate of 0-70 bubbles/minute; 0.1-0.25% at gas bubble rate of 70-100 bubbles/minute, 0.25-1.5% at gas bubble rate of 100-130 bubbles/minute and remained constant at 1.5% at gas bubble rate of 130-140 bubbles/minute. The gas bubble counter controlled by the Raspberry Pi3 model B controller provides higher accuracy of gas bubble count than the gas bubble counter controlled by the Arduino mega 2560 controller. In addition, the number of bubble counted by the gas bubble counter indicated that the rate of bubbles produced from the fermentation process corresponded to the growth rate of yeast.

Pests represent a huge problem in crop production causing significant losses. Currently, biocontrol is utilized as an eco-friendly approach for controlling pests and reducing the shortage in crop production. In the current study, the production of a biocontrol agent, which was identified based on sequencing of the 16S rRNA gene as Bacillusvelezensis strain GB1 with GenBank accession No. OM836750, was carried out in the stirred tank bioreactor using a batch fermentation process. For the first time, B. velezensis strain GB1 was tested as a biocontrol agent with soil drench application (109 cfu mL−1) for management of Bemisia tabaci and induction of squash plant systemic resistance under greenhouse conditions. β-1,3-glucanase, chitinase, polyphenol oxidase, and peroxidase activity were measured in squash leaves at 24, 48, 72, 96, and 120 h. The influence of B. velezensis strain GB1 on population density, fertility, and hatchability of B. tabaci on squash plants was studied. The batch fermentation process of B. velezensis strain GB1 maximized the production of secondary metabolites and culture biomass, which reached a maximum value of 3.8 g L−1 at 10.5 h with a yield coefficient of 0.65 g cells/g glucose. Treatment with B. velezensis strain GB1 induced squash plants to boost their levels of β-1,3-glucanase, chitinase, polyphenol oxidase, and peroxidase enzymes. On the other hand, B. velezensis strain GB1 could significantly reduce the mean number of the attracted B. tabaci on squash plants. Additionally, whiteflies laid a lower mean number of 2.28 eggs/female/day on squash plants inoculated with B. velezensis strain GB1 compared to control. The percentage of B. tabaci egg hatchability declined by 5.7% in the B. velezensis-inoculated squash plants.

The objective of this study was to evaluate the effect of harvesting corn at different maturity stages for silage production combined with four storage periods, considering nutrient loss and the chemical composition of silage of the whole plant and also of grainless plants. The experiment was performed in a completely randomized design with a factorial arrangement of six maturity stages of corn [reproductive (R); R1 to R6] and four periods of silage storage (30, 60, 90, and 120 days). At stages R1 and R2, losses by effluents occurred more intensely when compared with the more advanced stages, whereas losses by gases showed the opposite behavior, with stage R6 responsible for the greatest losses. Stage R4 showed a stable dry matter (DM) content during the storage period, 42.08%, and had the lowest levels of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) for the whole plant silage. The ADL in the silage of grainless plant of stage R4 was not the lowest, but it was close to the first reproductive stages, being an important point, since the first reproductive stages can present a vegetative fraction of better quality. The highest DM volumes produced by area occurred in the most advanced stages; however, R5 obtained a greater reduction in volume over the days of storage (20.66 kg day −1 ). The production cost was lower at the advanced stages (R4, R5, and R6) when compared with the first reproductive stages (R1, R2, and R3), and in general, during the storage period the costs did not have great variations. Based on the chemical composition of the silages, DM losses during the storage period, the stability in the costs of DM ton over the days of storage, the R4 stage was the most suitable for silage production.

Mathematical modeling is a powerful and inexpensive approach to provide a quantitative basis for improvements that minimize the negative effects of bioreactor heterogeneity. For a model to accurately represent a heterogeneous system, a flow model that describes how mass is channeled between different zones of the bioreactor volume is necessary. In this study, a previously developed compartment model approach based on data from flow-following sensor devices was further developed to account for dynamic changes in volume and flow rates and thus enabling simulation of the widely used fed-batch process. The application of the dynamic compartment model was demonstrated in a study of an industrial fermentation process in a 600 m3 bubble column bioreactor. The flow model was used to evaluate the mixing performance by means of tracer simulations and was coupled with reaction kinetics to simulate concentration gradients in the process. The simulations showed that despite the presence of long mixing times and significant substrate gradients early in the process, improving the heterogeneity did not lead to overall improvements in the process. Improvements could, however, be achieved by modifying the dextrose feeding profile.

The present work sought to implement a model different from the more traditional ones for the fermentation process of ethanol production by the action of the fungus Saccharomycescerevisiae, using a relevant metabolic network based on the glycolytic Embden–Meyerhof–Parnas route, also called “EMP”. We developed two models to represent this phenomenon. In the first model, we used the simple and unbranched EMP route, with a constant concentration of microorganisms throughout the process and glucose as the whole substrate. We called this first model “SR”, regarding the Portuguese name “sem ramificações”, which means “no branches”. We developed the second model by simply adding some branches to the SR model. We called this model “CR”, regarding the Portuguese name “com ramificações”, which means “with branches”. Both models were implemented in MATLABTM software considering a constant temperature equal to 32 °C, similar to that practiced in sugar and ethanol plants, and a wide range of substrate concentrations, ranging from 30 to 100 g/L, and all the enzymes necessary for fermentation were already expressed in the cells so all the enzymes showed a constant concentration throughout the fermentation. The addition of common branches to the EMP route resulted in a considerable improvement in the results, especially predicting ethanol production closer to what we saw experimentally. Therefore, the results obtained are promising, making adjustments consistent with experimental data, meaning that all the models proposed here are a good basis for the development of future metabolic models of discontinuous fermentative processes.

The objective of this study was to investigate the effect of foliar fertilization of two biostimulants (BS1 and BS2) obtained from sewage sludge by fermentative processes using Bacillus licheniformis during four consecutive seasons in an olive tree crop applied at a dose of 6 L ha-1 divided into three applications (before flowering, beginning of flowering and fruit set). BS2 had a higher number of low molecular weight peptides the BS1. The contents of macro and micronutrients in leaves, photosynthetic pigments and olive yield were higher in plants fertilized with BS2 than BS1. With respect to the control treatment and for the 2017 and 2019 seasons, the olive yield increased by 20–22% in plants fertilized with BS2 and by 28–29% for the plants foliar fertilized with the BS1. For the 2018 and 2020 seasons, the olive yield increased by 35–36% in the plants fertilized with the BS1 and by 42–43% for the plants fertilized with the BS2. These results suggest that the foliar use of these biostimulants, that contain a higher number of low molecular weight peptides, could be of great interest to farmers as regards improving olive crop yield. Ministerio de Economía y Competitividad CTM2015–64354-C3–3-R Ministerio de Ciencia e Innovación RTI2018–097425-B-I00

Within the kingdom of fungi, the division Basidiomycota represents more than 30,000 species, some with huge genomes indicating great metabolic potential. The fruiting bodies of many basidiomycetes are appreciated as food (“mushrooms”). Solid-state and submerged cultivation processes have been established for many species. Specifically, xylophilic fungi secrete numerous enzymes but also form smaller metabolites along unique pathways; both groups of compounds may be of interest to the food processing industry. To stimulate further research and not aim at comprehensiveness in the broad field, this review describes some recent progress in fermentation processes and the knowledge of fungal genetics. Processes with potential for food applications based on lipases, esterases, glycosidases, peptidases and oxidoreductases are presented. The formation and degradation of colourants, the degradation of harmful food components, the formation of food ingredients and particularly of volatile and non-volatile flavours serve as examples. In summary, edible basidiomycetes are foods—and catalysts—for food applications and rich donors of genes to construct heterologous cell factories for fermentation processes. Options arise to support the worldwide trend toward greener, more eco-friendly and sustainable processes.

The instability of the protein expression in Pichia pastoris strains has been an issue for various peptide productions. Some modifications to the traditional fermentation process could potentially solve the problem. Here, we consider a four-stage fermentation process to express the CAP2 (cell-penetrating antimicrobial peptide 2) candidate in P. pastoris KM71H, a slow methanol utilization strain. During the fermentation process, CAP2 productivity is limited (6.15 ± 0.21 mg/L·h) by the low overall methanol consumption (approximately 645 g), which is mainly the result of the slow methanol utilization of the P. pastoris KM71H. To overcome this limitation, we increased the cell concentration two-fold prior to the induction stage. A fed-batch process with exponential and dissolved oxygen tension (DOT) stat feeding strategies was deployed to control the glycerol feed, resulting in an increase in cell concentration and enhancement of the volumetric methanol consumption rate. The improved fermentation process increased the overall methanol consumption (approximately 1070 g) and the CAP2 productivity (13.59 ± 0.24 mg/L·h) by 1.66 and 2.21 times, respectively. In addition, the CAP3 (cell-penetrating antimicrobial peptide 3) candidate could also be produced using this improved fermentation process at a high yield of 3.96 ± 0.02 g/L without any further optimization. Note that there was no oxygen limitation during the improved fermentation process operating at high cell density. This could be due to the controlled substrate addition via the DOT stat system.

The objective of this study was to evaluate the silage produced with different mixtures of melon biomass with urea used as an additive. It adopted a completely randomized design in a 5 × 2 factorial scheme with five replications. The first factor was made up of five mixtures on an as-fed basis (AF) of the melon, including plant (branch and leaf) and fruit (culled melon, after harvest), where the amount of fruit varied as follows: 0% fruit, 5% fruit, 10% fruit, 20% fruit, and 100% fruit. The second factor was represented by the use of urea in the silage as follows: 0% and 1.5% urea AF. The highest silage dry matter (DM) content (200 g/kg DM) was observed in the silage with 20% fruit. Regarding the crude protein, the highest content (69.8 g/kg DM) was found in the silage with the addition of urea. The highest loss through the gas (GAS) was observed in the silages with 0% and 100% fruit (0.6 and 1.13%), with no addition of urea. The silages made with melon biomass and the addition of 20% and 100% fruit showed differences regarding the fermentative pattern, chemical composition, and aerobic stability, thus being the most indicated mixtures for silage making.

Ethanol produced from various biobased sources (bioethanol) has been gaining high attention lately due to its potential to cut down net emissions of carbon dioxide while reducing burgeoning world dependence on fossil fuels. Global ethanol production has increased more than six-fold from 18 billion liters at the turn of the century to 110 billion liters in 2019, only to fall to 98.6 billion liters in 2020 due to the pandemic. Sugar cane and corn have been used as the major feedstocks for ethanol production. Lignocellulosic biomass has recently been considered as another potential feedstock due to its non-food competing status and its availability in very large quantities. This paper reviews recent developments and current status of commercial production of ethanol across the world with a focus on the technological aspects. The review includes the ethanol production processes used for each type of feedstock, both currently practiced at commercial scale and still under developments, and current production trends in various regions and countries in the world.

Fuel ethanol has been consolidated in view of the current energy matrix. However, for an efficient process, the yeast and the quality of the substrate used must be taken into account. Thus, this study aims to evaluate sugarcane juice and sweet sorghum and analyze cell viability, ethanol production and the assimilation of amino acids present in these substrates as a function of temperature. The Industrial yeasts Saccharomyces cerevisiae FT858 and Pedra-2 (Pe-2) were activated with pre-inoculum of 2% YPD. The biomass obtained was inoculated on the substrates and incubated at 30 and 40°C at 250 rpm. Aliquots were collected for feasibility analyses with methylene blue, ethanol by gas chromatography and amino acids by high performance liquid chromatography. Yeasts showed better performance in sorghum broth at 30°C. The viability of 89% for Pe-2 and 85% for FT858 and ethanol concentration of 10% (v v-1) for both yeasts. At 40°C there was a reduction in these parameters. Sorghum had the highest amount of amino acids and serine, arginine, alanine and tryptophan were effectively assimilated by yeasts. The temperature of 40°C interfered in the metabolic capacity of the yeasts, causing thermal stress, inducing a greater consumption of amino acids. DOI: http://dx.doi.org/10.17807/orbital.v13i4.1553

Yogurt is currently the most popular fermented milk product that is produced worldwide due to its multiple benefits for consumer health. Temperature on various technological phases is the determinant factor that influences the structure and texture of yogurt. Another important factor is the quality and dose of lactic bacteria used for starter cultures. By selecting lactic bacteria suitable for the substrate that ferments, at the optimal temperature for their metabolism, highly superior quality products can be obtained. The aim of this study is to highlight the combined effect of fermentation temperature and inoculum dose on finished yogurt under certain predetermined milk composition - raw material and starter culture quality. Yogurt samples were obtained at different fermentation temperatures (37 °C, 41 °C and 45 °C) using different amounts of inoculum (0.1 %, 0.2 % and 0.3 %). After 24 hours of storage at 4 °C the yogurt samples were analyzed for rheological and physico-chemical properties.

In this paper, modelling and control of a batch bioreactor is studied. A main disadvantage of batch bioreactors compared to other types of bioreactors is their inability to introduce biological or/and chemical substances during operation. Therefore, possibility of bioreactor’s control by means of changing temperature was proposed, analyzed, and implemented. A new supplementary input/output dynamical mathematical model, which considers influence of heating and cooling on a bioprocess, was developed. On a basis of this model, a control system was designed and a method for tuning of the controller was suggested. Results show characteristics, applicability, and advantages of the presented approach.

The dough fermentation process is a major step for obtaining good quality bread because the yeast cells, which release CO2, have a major influence on dough rheology, volume, texture and taste of final bread product. The fermentation speed of the dough is strongly influenced by the fermentative performance of the yeast and dough fermentation conditions. Therefore, this paper presents the dynamics of the yeast fermentation process prepared with three commercial types of dry yeast, namely: Pakmaya, Dr. Oetker, Rapunzel. It has been experimentally found that besides the dynamics of the fermentation process, there are also changes in the physico-chemical properties of the dough, but also of the bread obtained from the three types of dough.

In this work, the effect of single fermentation of maize mashes with Fresco DVS 1010 culture ( Lactococcus lactis ssp. lactis , Lactococcus lactis ssp. cremoris , and Streptococcus thermophilus ) was studied for 8 h (37°C) followed by a storage period of 21 days (6°C). Although milk is a typical growth medium for lactic acid cocci of the Fresco culture, fermentation increased its counts by about 3 log CFU/mL after 8 h (37°C), whereas pH of 4.54 and 4.69 was achieved after the fermentation in products with sucrose and caramel, respectively. Fermentation process was observed to significantly increase (p5 log CFU/mL) in combination with the mixed Fresco culture in the prepared maize products within 21 days of storage. Based on the overall sensory acceptance, caramel mashes after 12 days of storage period were evaluated as satisfactory (2.4 to 3.1 from 4.0), while 21-day stored products achieved good acceptability scores (3.0 to 3.6 from 4.0), hence the tendency of the positive effect of prolonged shelf-life was noted.

The selected techniques were reviewed and their technological aspects were characterized in the context of multi-phase flow for biogas production. The conditions of anaerobic fermentation for pig slurry in a mono-substrate reactor with skeleton bed were analysed. The required technical and technological criteria for producing raw biogas were indicated. Design and construction of the mono-substrate model, biogas flow reactor, developed for cooperation with livestock buildings of various sizes and power from 2.5 kW to 40 kW. The installation has the form of a sealed fermentation tank filled with a skeletal deposit constituting a peculiar spatial system with regular shapes and a rough surface. Incorporating a plant in such a production cycle that enables the entire slurry stream to be directed from the cowshed or pig house underrun channels to the reactor operating in the flow mode, where anaerobic digestion will take place, allows to obtain a biogas. The paper presents preliminary results of experimental investigations in the field of hydrodynamic substrate mixing system for biogas flow assessment by the adhesive bed in the context of biogas production. The aim of the study was to assessment and shows the influence of the Reynolds number on the biogas resistance factor for the fermentation process in mono-substrate reactor with adhesive deposit. The measurement results indicate a clear effect of the Reynolds number in relation to the descending flow resistance coefficient for the adhesive bed.

Modelling and predicting of the kinetics of microbial growth and metabolite production during the fermentation process for functional probiotics foods development play a key role in advancing and making such biotechnological processes suitable for large-scale production. Several mathematical models have been proposed to predict the bacterial growth rate, but they can replicate only the exponential phase and require an appropriate empirical data set to accurately estimate the kinetic parameters. On the other hand, computational methods as genetic algorithms can provide a valuable solution for modelling dynamic systems as the biological ones. In this context, the aim of this study is to propose a genetic algorithm able to model and predict the bacterial growth of the Lactobacillus paracasei CBA L74 strain fermented on rice flour substrate. The experimental results highlighted that the pH control does not influence the bacterial growth as much as it does with lactic acid, which is enhanced from 1987 ± 90 mg/L without pH control to 5400 ± 163 mg/L under pH control after 24 h fermentation. The Verhulst model was adopted to predict the biomass growth rate, confirming the ability of exclusively replicating the log phase. Finally, the genetic algorithm allowed the definition of an optimal empirical model able to extend the predictive capability also to the stationary and to the lag phases.

Knowledge of the mathematical models of the fermentation processes is indispensable for their simulation and optimization and for the design and synthesis of the applicable control systems. The paper focuses on determining a dynamic mathematical model of the milk fermentation process taking place in a batch bioreactor. Models in the literature describe milk fermentation in batch bioreactors as an autonomous system. They do not enable the analysis of the effect of temperature changes on the metabolism during fermentation. In the presented extensive multidisciplinary study, we have developed a new mathematical model that considers the impact of temperature changes on the dynamics of the CO2 produced during fermentation in the batch bioreactor. Based on laboratory tests and theoretical analysis, the appropriate structure of the temperature-considered dynamic model was first determined. Next, the model parameters of the fermentation process in the laboratory bioreactor were identified by means of particle swarm optimization. Finally, the experiments with the laboratory batch bioreactor were compared with the simulations to verify the derived mathematical model. The developed model proved to be very suitable for simulations, and, above all, it enables the design and synthesis of a control system for batch bioreactors.

Whole-plant corn silage is a predominant forage for livestock that is processed in Heilongjiang province (Daqing city and Longjiang county), Inner Mongolia Autonomous Region (Helin county and Tumet Left Banner) and Shanxi province (Taigu and Shanyin counties) of North China, it was sampled at 0, 5, 14, 45 and 90 days after ensiling. Bacterial community and fermentation quality were analysed. During fermentation, the pH was reduced to below 4.0, lactic acid increased to above 73 g/kg DM (p &lt, 0.05) and Lactobacillus dominated the bacterial community and had a reducing abundance after 14 days. In the final silages, butyric acid was not detected, and the contents of acetic acid and ammonia nitrogen were below 35 g/kg DM and 100 g/kg total nitrogen, respectively. Compared with silages from Heilongjiang and Inner Mongolia, silages from Shanxi contained less Lactobacillus and more Leuconostoc (p &lt, 0.05), and had a separating bacterial community from 14 to 90 days. Lactobacillus was negatively correlated with pH in all the silages (p &lt, 0.05), and positively correlated with lactic and acetic acid in silages from Heilongjiang and Inner Mongolia (p &lt, 0.05). The results show that the final silages had satisfactory fermentation quality. During the ensilage process, silages from Heilongjiang and Inner Mongolia had similar bacterial-succession patterns, the activity of Lactobacillus formed and maintained good fermentation quality in whole-plant corn silage.

Introduction. Lactobacillus casei is characterized by adapting to the environment during the fermentation process. Objective. To characterize with multilocus typing sequences (MTLS) isolates of L. casei present in pineapple peel silage with increasing levels of urea. Materials and methods. During 2017 and using an unrestricted random design, twenty silos (2 kg) were prepared. Every five bags, 0, 0.5, 1 and 1.5 % urea (w/w on fresh basis) were added. After thirty days, a sample was taken from each repetition for bromatological analysis. Dry matter (DM), crude protein (PC), non-fibrous carbohydrates, fiber in acid detergent (ADF), fiber in neutral detergent (NDF), in vitro digestibility of dry matter (IVDDM), hemicellulose, ethereal extract (EE), ashes, ammonia nitrogen, and pH. The Lactic Acid Bacteria (LAB) count was determined for each one of the treatments. Identification of LABs was carried out using the 16S rRNA sequence. The isolates of L. casei were analyzed using MTLS. Results. The four evaluated treatments did not present significant differences in DM (12.10 to 12.86 %), ADF (31.44 to 32.18 %), NDF (58.46 to 58.56 %), hemicellulose (26.36 to 27.02 %), EE (2.45 to 2.96 %), ash (4.96 to 5.12 %), ammonia nitrogen (0.45 to 0.49 %) and pH (3.36 at 3.48). Not so, in CP (6.94 to 9.12 %), and IVDDMS (82.84 to 84.72 %). The addition of urea was associated with changes in the BAL populations (6.56 to 6.90 CFU). Seven isolates of L. casei were identified and typed with five different genes. Between two (polA) and five (nrdD, pgm, mutL) alleles were found. This allowed the identification of a total of six different type sequences (ST) in the Costa Rican isolates. Conclusion. The L. casei isolates were found to be related to bacteria from the gastrointestinal tract in humans. Introducción. Lactobacillus casei se caracteriza por adaptarse al medio durante el proceso fermentativo.Objetivo. Caracterizar con tipificación de secuencias multilocus (MTLS), aislamientos de L. casei presentes en ensilados de cáscara de piña con niveles crecientes de urea. Materiales y métodos. Durante 2017 y con un diseño irrestricto al azar se prepararon veinte silos (2 kg). Cada cinco bolsas, se adicionaron 0, 0,5, 1 y 1,5 % de urea (p/p en base fresca). Después de treinta días, se tomó una muestra de cada repetición para realizar análisis bromatológicos. Se analizó materia seca (MS), proteína cruda (PC), carbohidratos no fibrosos, fibra en detergente ácido (FDA), fibra en detergente neutro (FDN), digestibilidad in vitro de la materia seca (DIVMS), hemicelulosa, extracto etéreo (EE), cenizas, nitrógeno amoniacal y pH. Se determinó el recuento de bacterias ácido-lácticas (BAL) para cada uno de los tratamientos. La identificación de las BAL se realizó con la secuencia del ARNr 16S. Los aislamientos de L. casei fueron analizados con MTLS.Resultados. Los cuatro tratamientos evaluados no presentaron diferencias significativas en la MS (12,10 a 12,86%), FDA (31,44 a 32,18 %), FDN (58,46 a 58,56 %), hemicelulosa (26,36 a 27,02 %), EE (2,45 a 2,96 %), cenizas (4,96 a 5,12%), nitrógeno amoniacal (0,45 a 0,49 %) y pH (3,36 a 3,48). No así, en PC (6,94 a 9,12 %) y DIVMS (82,84 a 84,72 %). La adición de urea se asoció a cambios en las poblaciones de BAL (6,56 a 6,90 UFC). Siete aislamientos de L. casei se identificaron y tipificaron con cinco genes distintos. Se encontraron entre dos (polA) y cinco (nrdD, pgm, mutL) alelos; esto permitió identificar un total de seis secuencias tipo (ST) distintas en los aislados de Costa Rica. Conclusión. Los aislamientos de L. casei se encontraron emparentados a bacterias del tracto gastrointestinal en humanos.

Legume–cereal mixtures are pivotal in yielding a more balanced forage composition compared to the sole crops, due to the well-adjusted equilibrium of carbohydrate and protein. However, great attention is required in choosing the optimal ratio of the components for the mixtures and other agronomic practices (including N fertilization and stage of harvest), because they can sharply change the forage composition and quality. To fill this gap, the present research compared the herbage and silage qualities and key fermentative and nutritional traits of biomasses obtained by: (i) five mixtures (i.e., 100:0; 75:25, 50:50, 25:75, and 0:100) of hybrid barley (Hordeum vulgare L.) and faba bean (Vicia faba var. minor); (ii) two N barley fertilization rates (0 vs. 140 kg N ha−1); and (iii) three stages of harvest (milky, early dough and soft dough). We found that the presence of faba bean improved the forage quality, either herbage or silage, through different mechanisms. In the herbage mixtures, faba bean inclusion increased crude protein (CP), and, when compared to the fertilized barley, also water-soluble sugar (WSCs) concentration, with small effects on the relative feed values (RFV) and total digestible nutrients (TDN). In the silage, the higher the faba bean share in the mixture, the higher the RFV, the non-fibrous carbohydrates, and total and lactic acid concentrations, and the lower the pH and the hemicellulose and cellulose concentrations, particularly at the early and mid stages of harvest. These improvements were likely due to the high ability of faba bean to attain a vegetative status (i.e., low dry matter concentration) by the end of the cropping season, and to improve the organic acid production. Our results suggest that the inclusion of faba bean in a barley-based silage system can widen the window for silage harvesting, thanks to its ability to sustain the fermentation process, despite a lower WSC to CP ratio compared to the unfertilized barley. These results occurred almost irrespectively of the faba bean share in the mixture and barley fertilization. This implies that when designing intercrop mixtures, the effect of crop densities on yield should be considered more than on quality.

The aim of the present study was to determine the influence of the winemaking process on the antioxidant potential and content of phenolic compounds and L-ascorbic acid in wines from the fruits of Rosa rugosa. The results obtained in this study clearly indicate that the fruits of the Rosa rugosa are a desirable raw material for the production of fruit wine. The parameters of the technological process of producing wines from rose fruits had a diversified influence on the tested quality characteristics. Aged wines contained phenolics levels of 473–958 mg/100 mL GAE. The final concentrations of ascorbic acid ranged from 61 to 155 mg/100 mL for the different variants of the wine. Wines revealed high antioxidant activity in assay with DPPH. On the basis of the obtained results, it can be assumed that all the applied variants of the winemaking process are suitable for rose fruit wine. Each variant ensured at least the stability of the antioxidant capacity.

Made available in DSpace on 2021-06-25T11:10:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-02-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The efficiency of unpressurized ozonolysis (O) and acid washing (A) was investigated as a simple pretreatment procedure to depolymerize sugarcane biomass for posterior enzymatic hydrolysis and alcoholic fermentation to improve cellulosic ethanol production. The fiber chemical compositional analyses showed that the ozonolysis reduces the lignin content by 25%. High-performance anion-exchange chromatography (HPAEC-PAD) analysis showed that the loss of glucose during treatment was less than 1.5%. After enzymatic hydrolysis, the maximum glucose and xylose yield (310 ± 2 and 122 ± 3 mg g−1, respectively) were achieved from the OA treatment sequence and the fermentation yield was three times more ethanol than the yield from untreated bagasse. This simple treatment may be an alternative for improving cellulosic ethanol production using a mild-operational strategy. São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences FAPESP: 2013/06234-3 FAPESP: 2015/11588-4

This work provides a manual design space exploration regarding the structure, type, and inputs of a multilayer neural network (NN) to obtain indirect information about the state variables in the alcoholic fermentation process. The main benefit of our application is to help experts reduce the time needed for making the relevant measurements and to increase the lifecycles of sensors in bioreactors. The novelty of this research is the flexibility of the developed application, the use of a great number of variables, and the comparative presentation of the results obtained with different NNs (feedback vs. feed-forward) and different learning algorithms (Back-Propagation vs. Levenberg&ndash, Marquardt). The simulation results show that the feedback neural network outperformed the feed-forward neural network. The NN configuration is relatively flexible (with hidden layers and a number of nodes on each of them), but the number of input and output nodes depends on the fermentation process parameters. After laborious simulations, we determined that using pH and CO2 as inputs reduces the prediction errors of the NN. Thus, besides the most commonly used process parameters like fermentation temperature, time, the initial concentration of the substrate, the substrate concentration, and the biomass concentration, by adding pH and CO2, we obtained the optimum number of input nodes for the network. The optimal configuration in our case was obtained after 1500 iterations using a NN with one hidden layer and 12 neurons on it, seven neurons on the input layer, and one neuron as the output. If properly trained and validated, this model can be used in future research to accurately predict steady-state and dynamic alcoholic fermentation process behaviour and thereby improve process control performance.

Cellobiose lipids (CL) are extracellular glycolipids that are produced by many microorganisms from the family Ustilaginaceae. The sugarcane smut fungus Sporisorium scitamineum has been long known as a producer of the glycolipids mannosylerythritol lipids (MEL) and was recently described to additionally secrete CL as a byproduct. In fact, we identified 11 homologous genes in S. scitamineum by in silico analysis sharing a high similarity to the CL biosynthesis gene cluster of Ustilago maydis. We here report the first systematic cultivation of S. scitamineum targeting the synthesis of CL with high product titers and its transfer to the bioreactor. In an initial screening we examined different fermentation media compositions, consisting of a mineral salts solution with vitamins and/or trace elements, three carbon sources (glucose, fructose, sucrose), three pH values (2.5, 4.0, 6.7) and three levels of C/N values (42.2, 83.8, 167.2 molC⋅molN–1) with urea as nitrogen source. A pH of 2.5 proved to result in the highest product titers. An increase of urea concentration from 0.6 to 1.2 g⋅L–1 had a positive effect on biomass formation, however the glycolipid formation was favored at a C/N ratio of 83.8 molC⋅molN–1, using 0.6 g⋅L–1 urea. Amongst the examined carbon sources, sucrose resulted in an increase in the secretion of cellobiose lipids, compared to glucose. Comparing different media compositions, vitamins were identified as not necessary for CL synthesis. We obtained a concentration of cellobiose lipids of 8.3 ± 1.0 g⋅L–1 in shaking flasks. This increased to 17.6 g⋅L–1 in the 1 L bioreactor with additional feeding of carbon source, with a final purity of 85–93%. As a side product, erythritol and mannosylerythritol lipids (MEL) were also synthesized. Via HPTLC coupled MALDI-TOF MS we were able to analyze the secreted CL structures. S. scitamineum produces a mixture of acylated low molecular weight D-glucolipids, linked to a 2,15,16-trihydroxy-hexadecanoic acid via their ω-hydroxyl group (CL-B). The produced cellobiose lipids precipitate as needle like crystals at an acidic pH value of 2.5.

V diplomski nalogi smo izdelali načrt eksperimenta procesov v fermentacijski komori. Iz osnovnega popisa fermentacije pekovskih izdelkov z vidika izmenjave snovnih in energijskih tokov smo proučevali procesne parametre za vzdrževanje potrebnih pogojev ambienta v fermentacijski komori pri stacionarnem obratovanju. Ustvarjena sta bila dva fizikalna modela. Prvi model je bio-kemični model fermentacije testa, ki popisuje kaj se dogaja tekom fermentacije v testu. Drugi model je klimatizacijski model, s katerim smo popisali povezavo med ambientom in testom. Določena je bila ustrezna merilna oprema, s katero bomo merili vhodne parametre potrebne za popis numeričnega modela. Rezultat numeričnega modela nam bo služil za razvoj ekspertnega sistema. In this thesis we made a plan of experimental procedures in fermentation chamber. From the basic inventory of fermentation of bakery products in terms of the exchange of energy flows, we studied the process parameters for maintaining the necessary ambient conditions in the fermentation chamber. Two physical models were created. First model is a biochemical model of dough fermentation, that records what is going on in dough. The second model is an air-conditioned model that describes relation between the dough and ambient. Appropriate measuring equipment was identified to measure the input parameters needed to list the numerical models. The result of numerical model will serve us to develop expert system.

Alcoholic fermentation is fundamentally an adaptation process, in which the yeast Saccharomyces cerevisiae outperforms its competitors and takes over the fermentation process itself. Although wine yeast strains appear to be adapted to the stressful conditions of alcoholic fermentation, nitrogen limitations in grape must cause stuck or slow fermentations, generating significant economic losses for the wine industry. One way to discover the genetic bases that promote yeast adaptation to nitrogen-deficient environments are selection experiments, where a yeast population undergoes selection under conditions of nitrogen restriction for a number of generations, to then identify by sequencing the molecular characteristics that promote this adaptation. In this work, we carried out selection experiments in bioreactors imitating wine fermentation under nitrogen-limited fermentation conditions (SM60), using the heterogeneous SGRP-4X yeast population, to then sequence the transcriptome and the genome of the population at different time points of the selection process. The transcriptomic results showed an overexpression of genes from the NA strain (North American/YPS128), a wild, non-domesticated isolate. In addition, genome sequencing and allele frequency results allowed several QTLs to be mapped for adaptation to nitrogen-limited fermentation. Finally, we validated the ECM38 allele of NA strain as responsible for higher growth efficiency under nitrogen-limited conditions. Taken together, our results revealed a complex pattern of molecular signatures favouring adaptation of the yeast population to nitrogen-limited fermentations, including differential gene expression, allele frequency changes and loss of the mitochondrial genome. Finally, the results suggest that wild alleles from a non-domesticated isolate (NA) may have a relevant role in the adaptation to the assayed fermentation conditions, with the consequent potential of these alleles for the genetic improvement of wine yeast strains.

Monte Carlo methods are defined broadly as a statistical approach to provide approximate solutions to mathematically complex optimization or simulation problems by using random sequences of numbers. The two main advantages of Monte Carlo methods are perhaps that the concept is relatively simple and easy to use, and the same method has a sound basis. The Law of large numbers ensures that the Monte Carlo solution converges asymptotically to the true solution of a problem and since its first formulation by Metropolis and Ulam (1949), Monte Carlo methods have seen widespread application across many scientific and engineering disciplines.

Cellobiose lipids (CL) are extracellular glycolipids that are produced by many microorganisms from the family Ustilaginaceae. The sugarcane smut fungus Sporisorium scitamineum has been long known as a producer of the glycolipids mannosylerythritol lipids (MEL) and was recently described to additionally secrete CL as a byproduct. In fact, we identified 11 homologous genes in S. scitamineum by in silico analysis sharing a high similarity to the CL biosynthesis gene cluster of Ustilago maydis. We here report the first systematic cultivation of S. scitamineum targeting the synthesis of CL with high product titers and its transfer to the bioreactor. In an initial screening we examined different fermentation media compositions, consisting of a mineral salts solution with vitamins and/or trace elements, three carbon sources (glucose, fructose, sucrose), three pH values (2.5, 4.0, 6.7) and three levels of C/N values (42.2, 83.8, 167.2 molC⋅molN–1) with urea as nitrogen source. A pH of 2.5 proved to result in the highest product titers. An increase of urea concentration from 0.6 to 1.2 g⋅L–1 had a positive effect on biomass formation, however the glycolipid formation was favored at a C/N ratio of 83.8 molC⋅molN–1, using 0.6 g⋅L–1 urea. Amongst the examined carbon sources, sucrose resulted in an increase in the secretion of cellobiose lipids, compared to glucose. Comparing different media compositions, vitamins were identified as not necessary for CL synthesis. We obtained a concentration of cellobiose lipids of 8.3 ± 1.0 g⋅L–1 in shaking flasks. This increased to 17.6 g⋅L–1 in the 1 L bioreactor with additional feeding of carbon source, with a final purity of 85–93%. As a side product, erythritol and mannosylerythritol lipids (MEL) were also synthesized. Via HPTLC coupled MALDI-TOF MS we were able to analyze the secreted CL structures. S. scitamineum produces a mixture of acylated low molecular weight D-glucolipids, linked to a 2,15,16-trihydroxy-hexadecanoic acid via their ω-hydroxyl group (CL-B). The produced cellobiose lipids precipitate as needle like crystals at an acidic pH value of 2.5.

Phenolic compounds are secondary metabolites produced by plants, and their study has been increased in recent years due to their ability to improve human health. The aim of this work was the determination of phenolic compounds presents in blue corn flour before and after a fermentation process, where different proportions were used of blue corn (Zea mays L.) flour and Czapek Dox culture medium (90 mL of culture medium with 10 g of blue corn flour, 80 mL of culture medium with 20 g of blue corn flour and 70 mL of culture medium with 30 g of blue corn flour) and were fermented at 3 different times (20, 25 and 30 days) with the Colletotrichum gloeosporioides fungus. A determination of the phenolic compounds was carried out with five standard solutions, which were cyanidin 3-glucoside (CYA), pelargonidin 3-glucoside (PEL), chlorogenic acid (CLA), quercetin (QRC) and cinnamic acid (CA). The obtained results showed the presence of CA and PEL. The most abundant phenolic compound in the fermented samples was CLA over the naturally occurring compounds in blue corn, which are CYA and PEL. QRC was the phenolic compound with the lowest concentration in blue corn flour samples fermented with Colletotrichum gloeosporioides.

Submerged fermentation of green tea with the basidiomycete Mycetinis scorodonius resulted in a pleasant chocolate-like and malty aroma, which could be a promising chocolate flavor alternative to current synthetic aroma mixtures in demand of consumer preferences towards healthy natural and ‘clean label’ ingredients. To understand the sensorial molecular base on the chocolate-like aroma formation, key aroma compounds of the fermented green tea were elucidated using a direct immersion stir bar sorptive extraction combined with gas chromatography–mass spectrometry–olfactometry (DI-SBSE-GC-MS-O) followed by semi-quantification with internal standard. Fifteen key aroma compounds were determined, the most important of which were dihydroactinidiolide (odor activity value OAV 345), isovaleraldehyde (OAV 79), and coumarin (OAV 24), which were also confirmed by a recombination study. Furthermore, effects of the fermentation parameters (medium volume, light protection, agitation rate, pH, temperature, and aeration) on the aroma profile were investigated in a lab-scale bioreactor at batch fermentation. Variation of the fermentation parameters resulted in similar sensory perception of the broth, where up-scaling in volume evoked longer growth cycles and aeration significantly boosted the concentrations yet added a green note to the overall flavor impression. All findings prove the robustness of the established fermentation process with M. scorodonius for natural chocolate-like flavor production.

Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria (LAB), which have a large spectrum of action against spoilage bacteria and foodborne pathogens. However, when not entirely characterized, they are alternatively called bacteriocin-like inhibitory substances (BLIS). Pediococcus pentosaceus ATCC 43200 grew and produced BLIS optimally when cultivated anaerobically in bioreactor for 24 h at 30 °C and 200 rpm in De Man, Rogosa and Sharp (MRS) medium supplemented with 1.5% peptone. Under such optimal conditions, the cell mass concentration (3.41 g/L) was 66% higher, the generation time (1.28 h) 38% shorter and the BLIS activity against different indicator strains significantly higher than in MRS medium without any supplement taken as a control, and the exponential phase started 4 h before. The agar diffusion method showed BLIS inhibition halos against LAB strains with diameter in the range 11.0–19.5 mm and specific areas between 377.1 and 2654.6 mm2/mL, while BLIS activity against Listeria strains was better quantified by the liquid medium assay that showed, for the fermented broth without any dilution, 100 and 50% inhibition of Listeria innocua and Listeria seeligeri growth, respectively. These results highlight the potential of P. pentosaceus BLIS as a natural antimicrobial for application in the food industry.

The optimization of an organic acid production process downstream of fermentation is presented. Sodium salt solution of the organic acid (Na salt) solution is the product in the industrial fermentation process for the organic acid production and until today, it has not been attempted to directly crystallize/isolate the Na salt under these circumstances. Evaporation crystallization of Na salt directly from the solid‐free fermentation broth without purification can be realized with high product purity. Parameters limiting the crystallization/separation process are identified and discussed. The above points are considered as a function of viscosity, crystal size, and product purity. Comparison with the existing process completes this evaluation. The impact on the process design and alternatives are illustrated. The modification of hybrid processes using crystallization also as a purification step is investigated.

The aim of this study was to assess the influence of the magnesium ions from lactate salt at the level of 100, 150 and 200 mg/100g addition on the rheological properties of the wheat flour dough of 550 type. For this purpose, the empirical dough rheological properties were investigated during mixing, pasting and fermentation process by using the Farinograph, Falling Number, Amylograph and Rheofermentometer devices. During mixing dough hydration capacity decreases with the increased level of magnesium ions addition whereas the dough stability and dough development time decreases at low levels of magnesium ions addition and increases at high levels. The temperature at peak viscosity, total CO2 volume production and the total volume of CO2 lost decreases with the increased level of magnesium addition. PCA analysis shows that the wheat flour with 100 mg and 150 mg /100g magnesium ions addition presents a similar behaviour slightly different to those with 200 mg /100g magnesium ions addition (P < 0.05).

In this study, molecular markers were used to determine fungal flora in black olive fruits from field surveys to the table, following the fermentation process. Field samples were collected from different locations of Canakkale province, including Gokceada (Imbros), where organic farming is employed. Some of the fruits from field samples were used for black table olive production and then fungal flora was tracked during the fermentation process. Fungal isolation was also conducted on some commercial samples. Fifty seven isolates from field samples, 56 isolates from the fermentation process and 17 isolates from commercial products were obtained. Among these isolates, 41 Alternaria, 43 Penicillium, 19 Aspergillus, 8 Monascus and 19 other genera were determined using amplified sizes of the Beta-tubulin gene region. Species level identification was carried out based on sequences of Beta-tubulin amplicons, which provided accurate identification, especially where the genera were morphologically highly similar. The occurrence and prevalence of fungal species changed in fungal collections from the field to the fermentation process. While Alternaria alternata was common in field samples, they were absent during fermentation. Many of these identified species, such as Penicillium expansum, Aspergillus niger and Monascus pilosus, which are known as potential toxin producers such as aflatoxin, ochratoxin A and citrinin, were found both in natural and fermented samples, even at the end of the fermentation process. These results showed that some fungal species which survive on olives from the field to the table are potential toxin producers and can be successfully characterized by amplification and sequencing of Beta-tubulin gene.

For effective monitoring and control of the fermentation process, an accurate real-time measurement of important variables is necessary. These variables are very hard to measure in real-time due to constraints such as the time-varying, nonlinearity, strong coupling, and complex mechanism of the fermentation process. Constructing soft sensors with outstanding performance and robustness has become a core issue in industrial procedures. In this paper, a comprehensive review of existing data pre-processing approaches, variable selection methods, data-driven (black-box) soft-sensing modeling methods and optimization techniques was carried out. The data-driven methods used for the soft-sensing modeling such as support vector machine, multiple least square support vector machine, neural network, deep learning, fuzzy logic, probabilistic latent variable models are reviewed in detail. The optimization techniques used for the estimation of model parameters such as particle swarm optimization algorithm, ant colony optimization, artificial bee colony, cuckoo search algorithm, and genetic algorithm, are also discussed. A comprehensive analysis of various soft-sensing models is presented in tabular form which highlights the important methods used in the field of fermentation. More than 70 research publications on soft-sensing modeling methods for the estimation of variables have been examined and listed for quick reference. This review paper may be regarded as a useful source as a reference point for researchers to explore the opportunities for further enhancement in the field of soft-sensing modeling.

Changes in volatile compounds of fermented minced pepper (FMP) during natural fermentation (NF) and inoculated fermentation (IF) process were analyzed by the headspace–gas chromatography–ion mobility spectrometry (HS‐GC‐IMS). A total of 53 volatile compounds were identified, including 12 esters, 17 aldehydes, 13 alcohols, four ketones, three furans, two acids, one pyrazine, and one ether. Generally, fermentation time played an important role in volatile compounds of FMP. It was found that most esters, aldehydes, and alcohols obviously decreased with the increase in fermentation time, including isoamyl hexanoate, methyl octanoate, gamma‐butyrolactone, phenylacetaldehyde, methional, and E‐2‐hexenol. Only a few volatile compounds increased, especially for 2‐methylbutanoic acid, 2‐methylpropionic acid, linalool, ethanol, and ethyl acetate. However, no significant difference in volatile compounds was found between NF and IF samples at the same fermentation time. In addition, the fermentation process in all samples was well discriminated as three stages (0 days; 6 day; and 12, 18, and 24 days), and all volatile compounds were divided into two categories (increase and decrease) based on principal component analysis and heat map., Changes in volatile compounds of FMP during NF and IF process were analyzed by HS‐GC‐IMS. Fermentation time played an important role in volatile compounds of FMP. Most esters, aldehydes, and alcohols obviously decreased, and only a few volatile compounds increased during NF and IF, especially for acids. NF and IF posed little effect on volatile compounds of FMP.