Fermented Products Research Articles

Dewatering and drying of Kombucha Bacterial Cellulose for preparation of biodegradable film for food packaging.

Kombucha Bacterial Cellulose (KBC), obtained from waste products of kombucha fermentation, has potential applications in diverse fields. The present study used tea waste as a raw material for producing kombucha-like beverages and bacterial cellulose (BC). The in-situ dewatering and drying operations were performed to remove the high-water content from fermented KBC. Herein, the performance of BC in pressure-driven separation has been investigated as a function of dewatering pressure, drying temperature, and drying time in a multifunctional filtration cell. The Central Composite Design (CCD) was used to optimize the dewatering and drying parameters. The optimum conditions were found to be 4bar pressure, 99°C drying temperature, and 5min drying time with a desirability value of 0.921. The predicted response values agreed with actual responses within 2.3-2.7%. The dried films were prepared at optimized conditions and used to investigate thickness, density, mechanical properties, Fourier transform infrared, and scanning electron microscopy. The properties of KBC film varied as fermentation days increased. The KBC films' transparency decreased as thickness and density increased. The KBC film exhibits excellent mechanical properties such as tensile strength, maximum load, extension at the break, load at the break, and Young's modulus. The KBC films have been reported to be biodegradable and non-toxic and may be used for food packaging. Moreover, the present study successfully demonstrated that KBC packaging material could extend the shelf life of tomatoes by 13-15days under accelerated conditions.

Yeast culture enhances long-term fermentation of corn straw by ruminal microbes for volatile fatty acid production: Performance and mechanism

Ruminal microbes can efficiently ferment biomass waste to produce volatile fatty acids (VFAs). However, keeping long-term efficient VFA production efficiency has become a bottleneck. In this study, yeast culture (YC) was used to enhance the VFA production in long-term fermentation. Results showed that YC group improved the volatile solid removal and VFA concentration to 47.8% and 7.82 g/L, respectively, 18.6% and 16.1% higher than the control, mainly enhancing the acetic, propionic, and butyric acid production. YC addition reduced the bacterial diversity, changed the bacterial composition, and improved interactions among bacteria. The regulation mechanism of YC was to increase the abundance and activity of hydrolytic and acidogenic bacteria such as Prevotella and Treponema, improve bacterial interactions, and further promote expression of functional genes. Ultimately, a long-term efficient ruminal fermentation of corn straw into VFAs was achieved.

Examination of Salmonella Prevalence in Pigs Through Rye-Based Feeding and Coarser Feed Structure Under Field Conditions.

Salmonellosis is the second most commonly occurring bacterial zoonosis in Germany. Rye in pig feeding offers new possibilities for addressing that issue due to its high content of non-starch polysaccharides (NSPs). These are fermented in the intestinal tract to specific fermentation products, which seem to have bacteriolytic effects against Salmonella. A coarse feed structure can display synergistic effects. Seven conventional pig fattening farms increased the rye content (40%-70%) while limiting the amount of fine particles (maximum of 20% ≤0.25mm). Samples from pigs were tested for Salmonella antibodies and compared with samples from 167 farms without any changes to the feed. Rye-based diets had a significant (p<0.05) impact on Salmonella antibody (percentage optical density [OD%]) detection. In this study, it became apparent that significantly fewer positive OD% values could be detected due to the increase in rye compared to farms that did not change the feed (Farm 6 P0: 35.45±36.18; P1: 15.48±16.98; P2: 9.36±8.17). An elimination of Salmonella could not be achieved, but especially farms with high antibody counts were able to strongly reduce those in both phases consecutively (Farm 5 P0: 35.17±35.53; P1: 18.56a±20.96; P2: 13.38a±18.99). That was different on farms without adapted feeding, where an increase in Salmonella antibodies was observed (P0: 17.38±22.21; P1: 20.12±25.39; P2: 18.12±25.44). By increasing the proportion of rye and limiting the proportion of fine particles in the feed, Salmonella antibodies (OD% values) in meat juice and blood can be significantly reduced, especially on farms with an initially high incidence of Salmonella. If that is implemented in feeding across the board on farms, an improvement in food safety and a decreased risk of zoonosis can be expected.

A novel strategy for waste activated sludge treatment: Recovery of structural extracellular polymeric substances and fermentative production of volatile fatty acids

Structural extracellular polymeric substances (SEPS) as valuable biopolymers, can be extracted from waste activated sludge (WAS). However, the extraction yield is typically low, and detailed information on SEPS characterizations, as well as proper treatment of the sludge after SEPS extraction, remains limited. This study aimed to optimize the conditions of heating-Na2CO3 extraction process to increase the yield of SEPS extracted from WAS. Subsequently, SEPS were characterized, and, for the first time, insights into their protein composition were uncovered by using proteomics. A maximum SEPS yield of 209 mg/g volatile solid (VS) was obtained under optimal conditions: temperature of 90°C, heating time of 60 min, Na+ dosage of 8.0 mmol/g VS, and pH required to precipitation of 4.0, which was comparable to that from the aerobic granular sludge reported in literature. Proteomics analysis unveiled that the proteins in SEPS primarily originated from microorganisms involved in nitrogen fixation and organic matter degradation, including their intracellular and membrane-associated regions. These proteins exhibited various catalytic activities and played crucial roles in aggregation processes. Besides, the process of SEPS extraction significantly enhanced volatile fatty acid (VFA) production during the anaerobic fermentation of residual WAS after SEPS extraction. A maximum VFA yield of 420 ± 14 mg COD/g VSadded was observed in anaerobic fermentation of 10 d, which was 77.2 ± 0.1% higher than that from raw sludge. Mechanism analysis revealed that SEPS extraction not only improved WAS disintegration and solubilization but also reduced the relative activity of methanogens during anaerobic fermentation. Moreover, SEPS extraction shifted the microbial population during anaerobic fermentation in the direction towards hydrolysis and acidification such as Fermentimonas sp. and Soehngenia sp. This study proposed a novel strategy based on SEPS extraction and VFA production for sludge treatment, offering potential benefits for resource recovery and improved process efficiency.

Utilization of Aspergillus niger for the fermentative production of azaphilone dye in YEPB medium.

The current research focuses on the production and optimization of a natural yellowish-brown Azaphilone dye using Aspergillus niger. A variety of culture media were tested to ascertain the best conditions for dye synthesis. The formation of the yellowish-brown dye was confirmed by a color shift in the reaction mixture, and UV-Vis spectroscopy detected the dye at 450nm. Static conditions were found to be more favorable than shaking for higher dye yields, and fed-batch fermentation was more effective than batch fermentation. Maximum dye production was achieved after 28days of incubation. Factors such as temperature, pH, and inoculum percentage were shown to influence dye synthesis, with the highest production (2.5ml) occurring at 30°C, pH 7, and a 3% spore suspension in yeast extract peptone broth (YEPB) medium under static conditions. Gas chromatography-mass spectrometry (GC-MS) analysis validated the presence of Azaphilone dye in the culture filtrate. The dye was successfully applied to a pretreated cotton cloth. These findings advance our understanding of optimizing fungal dye production for sustainable and eco-friendly textile coloration applications. This study appears to be the first of its kind to report azaphilone dye production by A. niger in the YEPB medium.

Screening and Selection of a New Medium and Culture Conditions for Diosgenin Production via Microbial Biocatalysis of SYt1

Diosgenin (DSG) is a phytosterol saponin mainly found in Dioscorea zingiberensis C.H. Wright. It has shown promising results in treating various diseases such as cancer, diabetes, arthritis, asthma, and cardiovascular diseases. Diosgenin is also an important medicinal chemical for synthesizing various steroid medicines. The production of diosgenin by acid hydrolysis generates a large amount of wastewater, leading to severe environmental pollution. However, producing diosgenin through microbial fermentation can effectively reduce environmental pollution. Numerous studies have demonstrated that various microorganisms can produce diosgenin via solid-state fermentation. Nevertheless, due to the complexity, high maintenance costs, uneven heat production, and other characteristics of solid-state fermentation, it is not commonly used in the industrial production of diosgenin. In contrast, liquid fermentation offers advantages such as simple operation, easy maintenance, and stable fermentation, making it more suitable for the industrial production of diosgenin. However, few studies have focused on producing diosgenin using liquid fermentation. In this study, endophytic Bacillus licheniformis SYt1 was used to produce diosgenin via liquid fermentation, with Dioscorea tuber powder as a substrate. Soxhlet extraction and silica gel column chromatography were employed to identify the diosgenin from the liquid fermentation products. Suitable fermentation conditions were screened and identified. The environmental variables that significantly affect the diosgenin yield were determined by the Plackett–Burman design (P-BD) with eight factors. The three factors (peptone, yeast extract powder and inorganic salt) with the greatest influence on the diosgenin yield were selected and further optimized using a response surface methodology (RSM). The final culture conditions were determined to be 35.79 g/L of peptone, 14.56 g/L of yeast extract powder, and 1.44 g/L of inorganic salt. The yield of diosgenin under these conditions was 132.57 mg/L, which was 1.8 times greater than the yield under pre-optimization conditions. This effective, clean, and promising liquid fermentation method possesses the potential to replace the traditional acid hydrolysis method for the industrial production of diosgenin.

Biochemical and cytological studies of Typha domingensis used for bioethanol production

AbstractTypha domingensis (cattails) is an emergent invasive aquatic macrophyte; it belongs to Typhaceae family inhabiting multiple Egyptian water bodies like rivers, lakes, and wetlands. Due to the scarcity of food, the depletion of fossil fuels, population growth, and increased industrial development, sustainable renewable bioenergy production has gained a lot of attention lately. Typha is an excellent lignocellulosic biomass for biofuel production because it does not compete with food but rather endangers aquatic life and prevents water from flowing through drainage channels and canals, which rises evapotranspiration. Although it is beneficial in phytoremediation, its removal is a necessity due to previous reasons. Chemical pretreatment has been widely used to degrade complex chains of lignocellulosic materials. Enzymatic hydrolysis is used to enhance fermentable sugars production from cellulose. Fermentation process has been conducted by yeast for centuries. Saccharomyces cerevisiae tolerance to ethanol can be increased by mutation; it is induced either chemically, physically, or biologically. Geneticists frequently utilize gamma radiation, one of the physical mutagenesis mechanisms, to change the DNA of microorganisms. Scanning electron microscope (SEM) is concerned with examination and analysis of microstructure morphology and chemical composition. Changes in internal organelles of Saccharomyces cerevisiae after mutation has been tracked using transmission electron microscope (TEM) in order to distinguish between native and mutant yeast and to examine their ultrastructural changes.

Impact of Natural Phytosanitary Product Residuals on Yeast Fermentation Performance and Wine Composition

Although phytosanitary treatments are necessary to protect grapes from parasitic diseases, consumers are increasingly concerned about the use of synthetic phytosanitary products and their possible residues in wine. Pre-harvest phytosanitary treatments are often inevitable, and consequently downtime is required to avoid possible residues on the grapes. Instead, natural phytosanitary products, such as essential oil (EO)-based products, can be applied close to the harvest without specific restrictions, with results that are not only technically convenient but also more attractive for the consumers. Because of the high antimicrobial activity of EO products, in the present study we evaluated the effect of different residual amounts of two new EO-based phytosanitary products on the alcoholic fermentation and the chemical composition of the final fermented products. In particular, two EO-based new formulations, exploitable in organic viticulture management, were evaluated. Increasing concentrations of each formulation were tested during laboratory scale fermentations and in comparison with synthetic and natural commercial phytosanitary products. Growth and fermentation kinetics of a commercial yeast strain of Saccharomyces cerevisiae and the chemical and sensory profiles of the final products were evaluated. Both new formulations showed no significant impact on the growth and fermentation kinetic of S. cerevisiae at any of the concentrations tested. In all trials, alcoholic fermentation was completed in 15 days. Instead, a different chemical composition of the final products was observed. Therefore, these new products might represent an interesting alternative tool to the conventional phytosanitary treatments, being applicable close to the harvest without negative impacts on the kinetics of alcoholic fermentation and also being more acceptable to wine consumers.

Metabolic engineering of Corynebacterium glutamicum for the production of pyrone and pyridine dicarboxylic acids

Environmental concerns from plastic waste are driving interest in alternative monomers from bio-based sources. Pseudoaromatic dicarboxylic acids are promising alternatives with chemical structures similar to widely used petroleum-based aromatic dicarboxylic acids. However, their use in polyester synthesis has been limited due to production challenges. Here, we report the fermentative production of five pseudoaromatic dicarboxylic acids, including 2-pyrone-4,6-dicarboxylic acid (PDC) and pyridine dicarboxylic acids (PDCAs: 2,3-, 2,4-, 2,5-, and 2,6-PDCA), from glucose using five engineered Corynebacterium glutamicum strains. A platform C. glutamicum chassis strain was constructed by modulating the expression of nine genes involved in the synthesis and degradation pathways of precursor protocatechuate (PCA) and the glucose-uptake system. Comparative transcriptome analysis of the engineered strain against wild-type C. glutamicum identified iolE (NCgl0160) as a target for PDC production. Optimized fed-batch fermentation conditions enabled the final engineered strain to produce 76.17 ± 1.24 g/L of PDC. Using this platform strain, we constructed 2,3-, 2,4-, and 2,5-PDCA-producing strains by modulating the expression of key enzymes. Additionally, we demonstrated a previously uncharacterized pathway for 2,3-PDCA biosynthesis. The engineered strains produced 2.79 ± 0.005 g/L of 2,3-PDCA, 494.26 ± 2.61 mg/L of 2,4-PDCA, and 1.42 ± 0.02 g/L of 2,5-PDCA through fed-batch fermentation. To complete the portfolio, we introduced the 2,6-PDCA biosynthetic pathway to an L-aspartate pathway-enhanced C. glutamicum strain, producing 15.01 ± 0.03 g/L of 2,6-PDCA in fed-batch fermentation. The metabolic engineering strategies developed here will be useful for the production of pseudoaromatic chemicals.

Labneh: A Retail Market Analysis and Selected Product Characterization

Labneh is a popular fermented dairy product, which contemporarily has diversified into a varied range of styles, formulated with the inclusion of multiple additives, and is sourced across the globe. This has driven labneh’s emergence as a complex product with varying textural and rheological characteristics. The lack of scientific literature about labneh products available in the United Arab Emirates (UAE) market and their characterization has prompted this study. A detailed UAE market analysis of labneh for label, formulation, nutrition, and price variability was conducted. Surveyed labneh products were categorized as unpackaged, multinational company (MNC), small and medium enterprise (SME), and specialty products. They differed in manufacturing, such as acid ± enzyme coagulation with/without post-fermentation heat treatment, and contained various stabilizers, emulsifiers, preservatives, and processing aids. Interestingly, almost equal proportions, 64.7% and 67%, of MNC and SME labneh contained additives, respectively. All MNC labneh were post-heat-treated, in contrast to only 7% of SME labneh. Organic labneh and non-bovine milk-based labneh are not yet widely available. The second part of the study involved the physicochemical characterization of a select number of packaged labneh that were categorized in accordance with fat content as high-fat (17–18%), full-fat (7.1–8%), and lite-fat (3.5–4.5%). High-fat labneh showed a significantly higher complex viscosity, complex modulus, hardness, adhesiveness, stringiness, and fracturability, followed by lite-fat labneh compared to full-fat labneh, especially when it contained pectin. Full-fat labneh with added gums (and starch) and high-fat labneh with gums showed a significantly lower complex modulus compared to their respective control labneh. This study highlights the variety of commercial labneh products available and differences in their formulation, manufacturing, and composition, and provides specific dependencies of materials with their physicochemical characteristics.

Thermo-adaptive evolution of Corynebacterium glutamicum reveals the regulatory functions of fasR and hrcA in heat tolerance

BackgroundHigh-temperature fermentation technology is promising in improving fermentation speed and product quality, and thereby widely used in various fields such as food, pharmaceuticals, and biofuels. However, extreme temperature conditions can disrupt cell membrane structures and interfere with the functionality of biological macromolecules (e.g. proteins and RNA), exerting detrimental effects on cellular viability and fermentation capability.ResultsHerein, a microbial thermotolerance improvement strategy was developed based on adaptive laboratory evolution (ALE) for efficient high-temperature fermentation. Employing this strategy, we have successfully obtained Corynebacterium glutamicum strains with superior resistance to high temperatures. Specifically, the genome analysis indicated that the evolved strains harbored 13 missense genetic mutations and 3 same-sense genetic mutations compared to the non-evolved parent strain. Besides, reverse transcription quantitative PCR analysis (RT qPCR) of the hrcA-L119P mutant demonstrated that both groEL genes were upregulated under 42 °C, which enabled the construction of robust strains with improved heat tolerance. Furthermore, a significant increase in FAS-IA and FAS-IB expression of the fasR-L102F strain was proved to play a key role in protecting cells against heat stress.ConclusionsThis work systematically reveals the thermotolerance mechanisms of Corynebacterium glutamicum and opens a new avenue for revolutionizing the design of cell factories to boost fermentation efficiency.

Microorganisms in Fermented Foods and Their Effects on the Human Body

In recent years, microorganisms in fermented foods have shown an important role in regulating human health. Studies have shown that probiotics have significant health benefits in fermented foods, such as improving gut health, stimulating immune function, and promoting metabolism, and mental health. Specifically, lactic acid bacteria in yogurt can increase the number of beneficial bacteria in the intestines and reduce the growth of pathogenic bacteria, and yeasts such as Saccharomyces cerevae have multiple health effects on intestinal microbiota protection and anti-inflammation. In addition, various enzymes and metabolites produced by Aspergillus during fermentation process can improve the nutritional value of food. However, although lots of research has been done, the understanding of the microbial mechanism under different fermentation conditions is still insufficient. In this article, the types and influencing factors of microorganisms in yogurt, wine and seasoner were reviewed. The effects of temperature, pH value, fermentation time and other conditions on microbial activity and product quality were analyzed. The results showed that suitable fermentation conditions could significantly increase microbial activity, improve product flavor and health function, and provide a theoretical basis for optimizing the production process of fermented food. The article provides a theoretical basis for improving the fermented food production process, thus helping to improve product quality and market competitiveness. However, this article has some limitations like the lack of understanding of interactions between different microorganisms. Future research should focus on examining the collaborative relationship between these microbes to improve the health benefits and production efficiency of fermented foods.

Effect of Nattokinase in D-galactose- and Aluminum Chloride-induced Alzheimer's Disease Model of Rat.

Alzheimer's disease (AD) is the most common form of dementia worldwide. Nattokinase is a serine protease extracellularly produced by natto, a fermented product of Bacillus subtilis var. natto. In this study, we investigated the therapeutic effects of nattokinase in a rat model of AD induced by aluminum and D-galactose. Forty Wistar rats were randomly divided into four groups: normal, vehicle, and orally administered nattokinase (NK65 and NK130 groups). Except for the normal group, all groups were treated with AlCl3 and D-galactose for 10 weeks. The NK65 and NK130 groups additionally received 65 mg/kg/day and 130 mg/kg/day nattokinase, respectively. We analyzed β-amyloid levels in the cerebrospinal fluid (CSF), and the spatial reference test was evaluated using the Morris water maze test. After the Morris water maze test, rats of all groups were subjected to micro-computed tomography (μCT) to assess constructional changes in the brain. Aluminum concentration and β-amyloid levels were analyzed by histochemical staining in all brain tissues. Oral administration of nattokinase in the AD rat model increased free-form β-amyloid levels in the CSF and improved aluminum and amyloid plaque accumulation in the brain. Brain μCT images showed enhanced brain volume with fewer constructional changes after treatment with nattokinase. In the behavioral tests, both the escape latency time in the spatial reference test and the time taken to cross the platform area in the spatial probe test improved partially. The results suggest that nattokinase has potential therapeutic applications in the treatment of AD.

Exploring microbial diversity in Kermanshah province’s Kermanshahi oil through DGGE and sequencing analysis

BackgroundGhee, known as “roghane heiwâni,” or “Kermanshahi oil” is a traditional fermented butter-like product highly esteemed for its nutritional value. Ghee is prepared using traditional methods and has substantial potential as a reservoir of probiotic microorganisms. Previous research delved into isolating and identifying lactic acid bacteria (LAB) in Kermanshahi through culture and PCR sequencing. This study seeks to elucidate the microbial profiles and diversity within Kermanshahi using culture, Denaturing Gradient Gel Electrophoresis (DGGE), and sequencing methodologies.MethodsTwenty samples of Kermanshahi oil were meticulously gathered from diverse locales across Kermanshah province. These samples were cultivated under specialized conditions in MRS and M17 environments spanning 24 to 72 h. Following DNA extraction, amplification of the 16SrRNA gene sequences was performed, culminating in sequencing for conclusive identification of the isolates. Furthermore, the DGGE technique was directly employed to separate and identify various species present in the oil samples utilizing bioinformatics software.ResultsSequencing outcomes revealed a diverse array of microorganisms among the isolates, with Lactobacillus constituting 43%, Streptococcus comprising 27.6%, Enterococcus at 4.61%, and yeasts at 7.6%. Other species exhibited lower frequencies, encompassing Rhizobium, Bacillus coagulans, and Staphylococcus hominis.ConclusionsThe isolation of a diverse spectrum of probiotic microorganisms underscores their potential utility in the realm of industrial dairy product production. These findings allude to the possibility of integrating these valuable microorganisms, which have historically been associated with traditional products, into the contemporary dairy industry. As consumer interest in probiotic-enriched products surges, the insights gained from this study pave the way for harnessing the benefits of Kermanshahi-derived probiotics.

Supplementation of Chlorella vulgaris Extracts During Brewing: The Effects on Fermentation Properties, Phytochemical Activity and the Abundance of Volatile Organic Compounds

Chlorella vulgaris, a microalga rich in secondary metabolites and nutrients, offers a promising alternative for promoting microbial growth in food fermentation processes. This study aimed to evaluate the effects of C. vulgaris extracts on fermentation kinetics, sensory characteristics, phytochemical composition, antioxidant activity, and the abundance of volatile organic compounds (VOCs) in treated versus control beers. The bioactive compounds from C. vulgaris were extracted using an ultrasound-assisted method with water as the solvent. A German Pilsner-style lager beer (GPB) was brewed and supplemented with 0.5, 1, and 5 g/L of C. vulgaris extracts prior to primary fermentation. Yeast viability, °Brix, and pH levels were monitored to assess fermentation progress. Phytochemical composition was analyzed by quantifying total polyphenols and flavonoids. The antioxidant activity of the beer was evaluated using both the 2,2-diphenyl-1-picrylhydrazyl (DPPH●) and hydrogen peroxide assays. The addition of C. vulgaris extracts resulted in increased yeast viability and slight variations in gravity during the 7-day fermentation period. Moreover, the beers supplemented with C. vulgaris extracts demonstrated higher levels of total polyphenols, flavonoids, and antioxidant activity compared to the GPB. Specific volatile organic compounds, including 2-methyl-1-propanol, 1-hexanol, isopentyl hexanoate, 2-methylpropyl octanoate, β-myrcene, and geranyl acetate, were significantly more abundant (p &lt; 0.05) in the treated beers than in the control. Sensory evaluations revealed a favorable impact of the treatment on aroma scores compared to the GPB. Overall, the findings indicate that C. vulgaris extracts could be a valuable ingredient for developing functional beers with enhanced health benefits, particularly regarding antioxidant activity. Additionally, the results underscore the importance of exploring innovative approaches that utilize natural sources like Chlorella to enrich the nutritional profile and sensory qualities of fermented products.

Effects of saccharomyces cerevisiae fermentation products on growth performance, fecal short chain fatty acids, and microbiota of pre-weaning calves.

This research aims to explore the effects of incorporating saccharomyces cerevisiae fermentation products (SCFP) on growth performance, nutrient digestibility, antioxidant capacity, fecal SCFAs, and microbial composition of pre-weaning calves. Twenty Holstein calves, 10 days old and weighing an average of 48.63±0.91 kg, were randomly assigned to either the control group (CON) or the SCFP group, with 10 calves in each group. The CON group received only a basal diet, while the SCFP group received the starter diet supplemented with 5 g/head/d of SCFP products (NutriTek, Diamond V Cedar Rapids, IA 52404, United States). The pre-trial period lasted for 5 days, followed by a main experimental period of 45 days. The SCFP group had significantly higher final weight, ADG, and FE compared to the control group (p < 0.05). Moreover, the SCFP group exhibited increased apparent digestibility of DM, CP, EE, ADF, Ca, and P (p < 0.05). Additionally, supplementation with SCFP led to elevated content of GH, IGF-1, and GLP-1 in serum. The inclusion of SCFP also raised serum CAT content and reduced serum MDA content in pre-weaning calves. Furthermore, SCFP supplementation influenced the composition of intestinal microflora by decreasing Actinobacteriota abundance and increasing the abundance of Ruminococcus, Lachnospiraceae_AC2044_group, Parabacteroides, and Butyricimonas. The addition of SCFP has a positive impact on the growth performance, nutrient digestibility, antioxidant capacity, and intestinal microflora composition of pre-weaning calves.

Indigenous Lactic Acid Bacteria as Antioxidant Agents in the Production of Organic Raw Fermented Sausages

The study aimed to assess the impact of lactic acid bacteria (LAB) strains on the antioxidant, physico-chemical properties, and microbiological quality of fermented sausages. Five treatments of raw sausages were prepared: two controls without LAB addition (C, P), and three samples with LAB addition (SCH1, BAL6, KL14). Fatty acid composition, cholesterol content, physico-chemical, microbiological tests, and antioxidant assays, were performed at time 0 and after 1 and 2 months of storage. A significantly higher ability to scavenge free radicals of DPPH (2,2-diphenyl-1-picrylhydrazyl) was found in sausages with all LAB strains. In the case of the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) test, it was noted that KL14 treatment had higher antioxidant activity. The main fatty acids in sausages were monounsaturated and saturated. A significantly lower cholesterol content was observed in sausages with the addition of LAB. Sausages with LAB strains differed significantly in pH value. Water activity decreased significantly during storage. After 2 months of storage, the sausages with BAL6 and KL14 strains were characterized by significantly lower redox potential and a lower TBARS (thiobarbituric acid reactive substances) index. It was found that P sausages had the darkest color. SCH1, BAL6, and KL14 strains were also capable of producing red color. The total number of microorganisms in the sausages was high, which is mainly due to the high LAB content and yeast and mold counts. No spoilage or pathogenic microflora were detected. Indigenous LAB strains have the potential to improve the quality and safety of fermented meat products.

Evaluation of MENAQUINONE‐7 and fat‐soluble vitamin production by starter cultures during fermentation in dairy products using RPLC method

AbstractVitamin K2, also known as menaquinone, has become a significant research focus, particularly in fermented products. This study aims to investigate the content of menaquinone‐7 (MK‐7), an essential form of vitamin K, and other fat‐soluble vitamins (A, D, E) during the fermentation of various fermented milk products. The vitamin contents of six fermented milk products were analyzed: two yogurt samples (produced with commercial starter and probiotic starter), two kefir samples (produced with commercial starter and kefir grain), and milk fermented with Lactobacillus acidophilus or Bifidobacterium bifidum. Throughout the fermentation process, continuous pH monitoring was conducted, and fermentation was terminated based on pH levels. Fat‐soluble vitamins and vitamins K1, K2 were extracted from samples taken at specific fermentation periods and quantitatively determined using the reverse phase liquid chromatography (RPLC) method. The developed method was validated according to ICH guidelines. Simultaneously, the microbial content of the samples was analyzed. Among the fermented dairy products analyzed, the highest MK‐7 content (4.82 μg/100 g) was found in the kefir sample produced with kefir grain (KG). The diverse microorganisms in kefir grains necessitated detailed research to explain their role in this complex mechanism. In yogurt samples, the presence of L. acidophilus in the YB sample suggests that this bacterium may be responsible for the observed differences. This is supported by the LA sample, where production with L. acidophilus strain showed an increase from 0.97 to 1.70 at the 20th hour of fermentation. It was noted that the concentration of menaquinone‐7 increased throughout the fermentation period. Given the critical health effects of essential fat‐soluble vitamins and MKs, determining their content in commonly consumed fermented dairy products and understanding the influence of starter cultures, which are potential probiotics, on vitamin production underscores the importance of this research. It is important to highlight the potential of fermented products in nutritional recommendations.

Exploring the Presence of Cannabinoids in Hemp-Infused Fermented Milk Drinks: An Analysis of Pre- and Post-Fermentation Levels

Yoghurts are the most popular fermented dairy products. Consumer attention is directed towards products containing inputs that enrich the product with bioactive substances. The growing interest in the Cannabis sativa L. plant has resulted in the development of a market for hemp products. The main aim of this research work was to determine the effect of the lactic fermentation process on the stability of cannabinoids in fermented milk beverages containing hemp inputs (hemp oil, dried hemp, ethanolic hemp extract) at 0.5, 1 and 2% (w/v). The effect of the type of hemp input on the technological process (i.e., pH value, viability of LAB during 28 days of storage) was also checked and the sensory quality of the prepared samples was evaluated. It was shown that the choice of type/form and amount of hemp addition influenced the final cannabinoid content of the product after fermentation and post-fermentation, but no effect on the survival of yoghurt bacteria or pH changes during storage was confirmed. Fermented milk drinks containing hemp oil had the highest cannabinoid content. The QDA results of the sensory evaluation of the yoghurts show that the most acceptable product in terms of overall quality is the yoghurt containing 0.5% hemp extract and 2% hemp oil.

Probiotic Characteristics and the Anti-Inflammatory Effects of Lactiplantibacillus plantarum Z22 Isolated from Naturally Fermented Vegetables

Currently, there is increasing interest in the commercial utilization of probiotics isolated from traditional fermented food products. Therefore, this study aimed to investigate the probiotic potential of Lactiplantibacillus plantarum (L. plantarum) Z22 isolated from naturally fermented mustard. The results suggest that L. plantarum Z22 exhibits good adhesion ability, antibacterial activity, safety, and tolerance to acidic conditions and bile salts. We further determined the anti-inflammatory mechanism and properties of L. plantarum Z22 and found that L. plantarum Z22 could significantly reduce the secretion of pro-inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the expression of the pro-inflammatory mediator cyclooxygenase-2 (COX-2) protein in LPS-induced RAW 264.7 cells. In addition, L. plantarum Z22 also effectively inhibited the signaling pathways of nuclear factor κB (NF-κB) and mitogen-activated protein kinases (MAPKs). This effect can be attributed to a decrease in the levels of reactive oxygen species (ROS) and increased heme oxygenase-1 (HO-1) expression. Moreover, whole-genome sequencing revealed that L. plantarum Z22 contains gene-encoding proteins with anti-inflammatory functions, such as beta-glucosidase (BGL) and pyruvate kinase (PK), as well as antioxidant functions, including thioredoxin reductase (TrxR), tyrosine-protein phosphatase, and ATP-dependent intracellular proteases ClpP. In summary, these results indicated that L. plantarum Z22 can serve as a potential candidate probiotic for use in fermented foods such as yogurt (starter cultures), providing a promising strategy for the development of functional foods to prevent chronic diseases.