Search Results (44)

Probiotic microorganisms from sugary kefir were incorporated into Brazilian non-alcoholic beers to enhance their functional and nutritional properties through aerobic static fermentation over 24 h. Non-alcoholic beers inoculated with sugary kefir showed appropriate acidity (pH reduction from ~3.74 to ~3.52), color, and microbial balance, along with excellent sensory acceptance (scores of 6.9–8.4 on a 9-point hedonic scale). The kefir microbiota included Lacticaseibacillus paracasei, Lacticaseibacillus casei, Lacticaseibacillus paracasei subsp. paracasei, Lacticaseibacillus paracasei subsp. tolerans, Lactobacillus delbrueckii subsp. lactis, Lentilactobacillus parabuchneri, Lentilactobacillus kefiri, Lactococcus lactis, Leuconostoc citreum, Acetobacter lovaniensis, and yeasts such as Saccharomyces cerevisiae, Kluyveromyces lactis, Lachancea meyersii, and Kazachstania aerobia. Genetic analysis confirmed the absence of undesirable or pathogenic microorganisms. Fermentation led to reductions in sucrose (~0.35 to ~0.22 g/L) and °Brix (~5.55 to ~3.80), with increases in lactic acid (~0.55 to ~1.25 g/L) and acetic acid (~0.08 to ~0.14 g/L), confirming active microbial metabolism. Ethanol levels remained within legal limits for non-alcoholic beverages. The process preserved sensory attributes while enriching the beverage with well-documented kefir microorganisms. These findings highlight sugary kefir as a promising biotechnological tool to enhance the functional profile of non-alcoholic beers without compromising their sensory quality. Full article

The consumption of microalgae-based foods is growing due to their exceptional nutritional benefits and sustainable cultivation. However, their strong off-flavors and odors hinder their incorporation into food products. Lactic acid fermentation, a traditional method known for modifying bioactive and aromatic compounds, may address these challenges. This study aims to evaluate the impact of lactic acid fermentation on the aromatic profiles of four distinct Chlorella vulgaris biomasses, each varying in protein, carbohydrate, lipid, and pigment content. Six lactic acid bacteria (LAB) strains, Lacticaseibacillus casei, Lcb. paracasei, Lcb. rhamnosus, Lactiplantibacillus plantarum, Lactobacillus delbrueckii subsp. bulgaricus, and Leuconostoc citreum, were used for fermentation. All biomasses supported LAB growth, and their volatile profiles were analyzed via HS-SPME-GC-MS, revealing significant variability. Fermentation notably reduced concentrations of compounds responsible for off-flavors, such as aldehydes. Specifically, hexanal, associated with a green and leafy aroma, was significantly decreased. Lcb. paracasei UPCCO 2333 showed the most effective modulation of the volatile profile in Chlorella vulgaris, significantly reducing undesirable compounds, such as aldehydes, ketones, pyrazines, and terpenes, while enhancing ester production. These results highlight lactic acid fermentation as an effective method to improve the sensory characteristics of C. vulgaris biomasses, enabling their broader use in innovative, nutritionally rich food products. Full article

This study aimed to isolate and characterize microorganisms from water kefir beverage for their functional properties. Five lactic acid bacteria (LAB) strains were isolated: three Leuconostoc citreum strains (LB4, LB6, LB13) and two Lactococcus lactis strains (LB5, LB25), identified via 16S rRNA sequencing, along with three Saccharomyces cerevisiae yeast strains (Y7, Y9, Y10), confirmed by 18S rDNA sequencing. Due to the high genetic and phenotypic similarity within each species, one representative strain from each (LB4, LB5, Y9) was selected for further analysis. These strains showed potential probiotic properties, including tolerance to acid and bile, high auto-aggregation, and hydrophobicity. The LAB strains were sensitive to gentamicin, and their supernatants inhibited the growth of tested pathogenic bacteria. The cumulative probiotic potential (CPP) scores were 93.33% for Lc. citreum LB4 and L. lactis LB5, and 100% for S. cerevisiae Y9. Furthermore, the fermentation potential of these strains was evaluated in a green tea beverage using three co-culture formulations. Among the formulations tested, the BF1 beverage, fermented by F1 (40% LB4, 40% LB5, and 20% Y9), demonstrated optimal physicochemical, microbiological, and sensory properties. Notably, while the individual strains did not show anti-inflammatory activity, the BF1 beverage formulation exhibited this effect, suggesting a synergistic interaction during fermentation. Full article

Urogenital infections impact millions of individuals globally each year, with vulvovaginal candidiasis (VVC) being one of the most prevalent conditions affecting women. Candida albicans is the primary pathogen responsible for VVC. The utilization of probiotics as an alternative therapeutic approach to antibiotics in managing such infections has gained increasing attention. This study aimed to evaluate the potential of THY-F51, a lactic acid bacterium isolated from kiwi, as a probiotic to support vaginal health through its antifungal, anti-biofilm, and anti-inflammatory properties against C. albicans. The identification of THY-F51 was confirmed through 16S rRNA gene sequencing. A series of evaluations were performed to determine its antifungal efficacy against C. albicans, biofilm-inhibitory activity, antioxidant properties, and effects on inflammatory cytokines. Cytotoxicity assays and assessments of bacterial survival under vaginal pH conditions (pH 3.8–4.5) were also conducted. The results demonstrated that THY-F51, identified as Leuconostoc citreum, exhibited potent antifungal activity against C. albicans, with an MIC of 1.25 mg/mL and an MFC of 2.5 mg/mL. Furthermore, THY-F51 displayed a strong inhibition of C. albicans biofilm formation, as well as notable antioxidant activity in the supernatant. Additionally, THY-F51 demonstrated high survival rates under vaginal pH conditions, an absence of cytotoxic effects, and a significant reduction in C. albicans adhesion to HeLa cells. Moreover, THY-F51 effectively suppressed C. albicans-induced inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-8. These findings suggest that THY-F51, isolated from kiwi, holds substantial promise as a safe and effective probiotic for reducing vaginal inflammation and promoting vaginal health. Full article

A plant-based beverage enhanced with GABA was developed through serial co-fermentation using Leuconostoc citreum S5 and Lactiplantibacillus plantarum KS2020. The first lactic acid fermentation was performed by Leu. citreum S5 with a vegetable mixture consisting of sliced radish, ginger, garlic, red pepper, bell pepper, and sucrose. The viable cell count of Leu. citreum S5 increased to 9.11–9.42 log CFU/mL with higher sucrose contents, indicating the highest value of 9.42 log CFU/mL at 5% sucrose on day 1. Mannitol and dextran production levels in the first fermented vegetable mixture were 6.66–14.54 mg/mL and 0.44–2.26%, respectively. A higher sucrose content produced more dextran, resulting in a concomitant increase in viscosity of 49.4 mPa·s. The second co-fermentation for the kimchi beverage base was performed by Lb. plantarum KS2020 for 5 days, resulting in 8.22–9.60 log CFU/mL. The pH of the co-fermented kimchi beverage base increased to 6.19–9.57 with an increasing monosodium glutamate (MSG) content (3–7%), while titratable acidity significantly decreased to 0.0–0.8%. The final co-fermented kimchi beverage base was enriched with 2.6% GABA. Consequently, a GABA kimchi beverage base with probiotics, a red pigment, and a pleasant flavor was developed using only vegetable ingredients by serial co-fermentation using lactic acid bacteria. Full article

Antibiotic susceptibilities, hemolytic activities, and technological properties of 46 Leuconostoc citreum isolates from kimchi were evaluated to select starter candidates. All strains were susceptible to clindamycin and erythromycin, while some exhibited resistance to ampicillin, chloramphenicol, gentamicin, streptomycin, and tetracycline; all were resistant to kanamycin based on the EFSA breakpoint values for Leuconostoc species. PCR analysis did not detect resistance genes for these six antibiotics in any strain. None of the strains demonstrated clear α- or β-hemolytic activity. All strains thrived in a medium supplemented with 6% NaCl, displaying protease activity and acid in media containing 6% and 3% NaCl, respectively. Consequently, five strains, AK5T17, AK5T19, AK10M04, DMLC16, and YK10T20, were identified as starter candidates, with L. citreum strain DMLC16 emerging as the top choice due to its elevated protease and acid production capacities. These findings support the safe application of L. citreum strain DMLC16 as a starter candidate in fermented food production. Full article

Wheat starch fermentation slurry is the main substrate for producing Ganmianpi, a traditional Chinese fermented wheat starch-based noodle. In the present work, the microbial population dynamics and metabolite changes in wheat starch fermentation slurry at different fermentation times (0, 1, 2, 3, and 4 days) were measured by using high-throughput sequencing analysis and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME/GC-MS) methods. The texture and sensory properties of Ganmianpi made from fermented starch slurry are also evaluated. The results showed that Latilactobacillus curvatus and Leuconostoc citreum were the dominant bacteria in wheat starch fermentation slurry, while Saccharomyces cerevisiae and Kazachstania wufongensis were identified as the main species of fungi. With the extension of fermentation time, the reducing sugar content first increased and then decreased, when the titratable acidity content showed an increasing trend, and the nonvolatile acid was significantly higher than the volatile acid. A total of 62 volatile flavor compounds were identified, and the highest content is alcohols, followed by acids. Fermentation significantly reduced the hardness and chewiness of Ganmianpi, and increased its resilience and cohesiveness. Ganmianpi made from fermented starch slurry for two and three days showed a higher sensory score than other samples. The present study is expected to provide a theoretical basis for exploiting the strains with potential for commercial application as starter cultures and quality improvement of Ganmianpi. Full article

The demand for meat alternatives in different forms is increasing due to consumers’ awareness of climate change and the health benefits of plant-based ingredients compared to animals. However, current alternatives on the market do not fulfil consumers’ acceptance for taste and texture. Hence, different physical and biological processes, such as thermal treatment and fermentation, need to be investigated. This study reveals that the thermal treatment of legume flours (soy, pea and lentil) prior to single-strain fermentation with Leuconostoc citreum TR116 has a major impact on acidification, colour, texture and sensory properties due to the pregelatinisation of starch and denaturation of proteins. The thermal treatment of soy flour resulted in liquification, and it could not be used as a fermentation substrate. However, non-heat-treated soy flour was fermented for comparison. The highest total titratable acidity (TTA) was determined in fermented pea flour (PF) and fermented lentil flour (LF) after 48 h with 24.35 ± 0.29 mL 0.1 M NaOH/10 g and 24.98 ± 0.33 mL 0.1 M NaOH/10 g, respectively. Heat treatment prior to fermentation led to a reduction in TTA by 20 mL 0.1 M NaOH/10 g for both PF and LF. The loss of colour pigments during thermal treatment led to a lighter colour of the spreadable alternatives. Moreover, a harder texture (+13.76 N in LF; +15.13 N in PF) and a lower adhesiveness (−0.88 N in LF; −0.43 N in PF) were detected in spreadable meat alternatives that were treated with heat prior to fermentation. Cohesiveness was decreased by thermal treatment, and fermentation did not impact it. Fermentation without pre-heat treatment increased adhesiveness by 4.37 N in LF and by 2.36 N in PF—an attribute typical for spreadable meat. Descriptive sensory analysis showed that thermal treatment significantly decreased bitterness but increased crumbliness and reduced juiciness. On the other hand, fermentation without pre-heat treatment mainly influenced flavour by increasing fruitiness and decreasing beaniness, earthiness and off-flavours. In summary, thermal treatment prior to fermentation is powerful in reducing legume-typical off-flavours but is not suitable for the development of spreadable meat alternatives due to texture changes. However, this process can be very beneficial when producing sausage-like alternatives. Full article

This review highlights Leuconostoc citreum’s promising possibilities as a proficient mannitol producer and its potential implications for sugar reduction, with a focus on its use in sourdough-based baked good products. Mannitol, a naturally occurring sugar alcohol, has gained popularity in food items due to its low calorie content and unique beneficial qualities. This study summarizes recent research findings and investigates the metabolic pathways and culture conditions that favor increased mannitol production by Leuconostoc citreum. Furthermore, it investigates the several applications of mannitol in baked goods, such as its function in increasing texture, flavor and shelf life while lowering the sugar content. Sourdough-based products provide an attractive niche for mannitol integration, as customer demand for healthier and reduced-sugar options increases. Full article

With the increasing number of people affected by gluten consumption-related diseases, adhering to a gluten-free (GF) diet is the most effective preventive measure. Herein, we aimed to isolate and characterize the functional properties of autochthonous lactic acid bacteria (LAB) and yeast from various GF sourdoughs to determine their suitability in starter cultures for sourdough preparation. Three LAB, Weissella confusa BAQ2, Lactobacillus brevis AQ2, Leuconostoc citreum YC2, and Saccharomyces cerevisiae BW1, were identified. The isolated LAB exhibited greater TTA, faster acidification rates, and higher acid tolerance than commercial LAB. W. confusa BAQ2 exhibited the highest EPS production, W. confusa BAQ2 and L. brevis AQ2 showed high maltose utilization, and S. cerevisiae BW1 exhibited the highest CO₂ production rate. Accordingly, all four microbial strains were mixed for the starter culture. The sourdough prepared with starter cultures exhibited differences in gas production depending on fermentation time, which influenced the volume of GF bread dough. GF bread prepared with fermented sourdough exhibited a 16% higher specific volume and enhanced crumb firmness and elasticity than that prepared using non-fermented sourdough. Thus, autochthonous LAB strains isolated from various GF sourdoughs can be used together to improve the quality of sourdough bread, demonstrating their potential for use in starter cultures for GF sourdough production. Full article

Baking bread is currently experiencing a profound transformation, propelled by an escalating interest in health and wellness, global cuisines, and sustainability efforts. The surface of fruits harbors various microbes, such as yeasts and lactic acid bacteria (LAB). In contrast to Saccharomyces cerevisiae, a commercial yeast, the microbial flora present on the surface of fruits allows bread with greater flavor, texture, and health benefits as seen in sourdough starters. In this research, sourdough starters were created using dried longan and raisin. The microbial flora of the sourdough starters and the fermentation profile were examined, and possible bacteriocin genes were identified. The dried longan starter exhibited bubbling, stickiness, and a drop in pH value from 5.80 to 4.45 at the third day of fermentation. Meanwhile, the raisin starter began bubbling on the sixth day with no change in fluid viscosity, and a small pH value decreased from 4.00 to 3.82. The dried longan starter contained Weissella cibaria, W. paramesenteroides, S. cerevisiae, Pediococcus pentosaceus, Torulaspora delbrueckii and Leuconostoc citreum. On the other hand, raisin starter only contained Candida krusei and T. delbrueckii. To detect antibacterial property in W. paramesenteroides and P. pentosaceus, four bacteriocins, Gassericin A (gaaA), Lactacin F (lafA), Plantaricin S (pls) and Pediocin (ped) were explored. Polymerase chain reaction (PCR) results revealed that gaaA and lafA were present in W. paramesenteroides, which suggested that this strain possessed antimicrobial properties. Full article

Lactic acid bacteria (LAB) are pivotal in shaping the technological, sensory, and safety aspects of dairy products. The evaluation of proteolytic activity, citrate utilization, milk pH reduction, and the production of organic compounds, acetoin, and diacetyl by cheese associated LAB strains was carried out, followed by Principal Component Analysis (PCA). Citrate utilization was observed in all Leuconostoc (Le.) mesenteroides, Le. citreum, Lactococcus (Lc.) lactis, Lc. garvieae, and Limosilactobacillus (Lm.) fermentum strains, and in some Lacticaseibacillus (Lact.) casei strains. Most strains exhibited proteolytic activity, reduced pH, and generated organic compounds. Multivariate PCA revealed Le. mesenteroides as a prolific producer of acetic, lactic, formic, and pyruvic acids and acetoin at 30 °C. Enterococcus sp. was distinguished from Lact. casei based on acetic, formic, and pyruvic acid production, while Lact. casei primarily produced lactic acid at 37 °C. At 42 °C, Lactobacillus (L.) helveticus and some L. delbrueckii subsp. bulgaricus strains excelled in acetoin production, whereas L. delbrueckii subsp. bulgaricus and Streptococcus (S.) thermophilus strains primarily produced lactic acid. Lm. fermentum stood out with its production of acetic, formic, and pyruvic acids. Overall, cheese-associated LAB strains exhibited diverse metabolic capabilities which contribute to desirable aroma, flavor, and safety of dairy products. Full article

In this study, lactic acid bacteria (LAB) strains were isolated from traditional fermented pickles, and among the identified strains, Leuconostoc citreum HE29 with a strong slimy colony profile was further selected to determine the physicochemical and techno-functional properties of its exopolysaccharide (EPS). Glucose was the only sugar monomer in the core unit of EPS HE29 detected by HPLC analysis, and glucan HE29 revealed 7.3 kDa of molecular weight. Structural characterization of glucan HE29 by ¹H and ¹³C NMR spectroscopy analysis demonstrated that EPS HE29 was a dextran-type EPS containing 5.3% levels of (1 → 3)-linked α-D-glucose units. This structural configuration was also supported by FT-IR analysis, which also demonstrated the functional groups within the dextran HE29 structure. In terms of thermal properties detected by TGA and DSC analysis, dextran HE29 demonstrated a degradation temperature of around 280 °C, showing its strong thermal features. A semi-crystalline nature was observed for dextran HE29 detected by XRD analysis. Finally, AFM and SEM analysis revealed tangled network-like properties and web-like branched structures for dextran HE29, respectively. These findings suggest the importance of plant-based fermented products as LAB sources in obtaining novel EPS structures with potential techno-functional roles. Full article

Hurood cheese (namely Hurood) is a traditional acid-coagulated cheese in China. This work investigated key aroma compounds and their potential correlations with dominant species of Hurood sampled from three distinct geographical origins. Key aroma compounds were determined according to Gas chromatography–mass spectrometry (GC–MS), gas chromatography–olfactometry (GC–O), and relative odor active values (ROAVs) analyses. In addition, 16S rDNA sequencing was used to identify the dominant species. Furthermore, Pearson correlation analysis was used to determine the potential relationships between key aroma compounds and dominant species. A total of 31 key aroma compounds were identified in the Hurood samples from three regions. Lactobacillus paracasei, Lactobacillus crispatus, and Leuconostoc citreum were found to be significantly correlated with the key aroma compounds (p < 0.05) and were identified as the core species. This study shows the link between the presence of presumptive functional core microbes and the unique aroma profiles of this traditional dairy product. Full article

Momordica charantia (MC; commonly known as bitter melon) was fermented with Leuconostoc mesenteroides MKJW, MKSR, and KCTC 3719 (LM), and Leuconosoc citreum KCTC 3526 (LC), and their anti-diabetic, anti-dementia, and antioxidant activities were evaluated. The fermentation was performed for 24 h at 30 °C, and non-fermented MCs (CON1 and CON2) were included for comparison. All fermented MCs produced lactic acids, mannitol, dextran, and oligosaccharides. The highest amount of mannitol (34.76 mg/mL) and lactic acids (10.42 mg/mL) were produced in MKSR-MC, and the highest amount of dextran (22.37%) was produced in MKJW-MC. MKSR-MC showed complete α-glucosidase inhibition (99.91%), but it did not show a significant change in α-amylase inhibition (24.43%) compared to non-fermented MC (20.14%) (p > 0.05). It was also high in acetylcholinesterase inhibition (55.24%) compared to other fermented MCs (31.21–44.46%). Fermentation increased butyrylcholinesterase inhibition, but no significant differences were observed among the groups. Therefore, our results indicated that MKSR-fermented MC might be used as a non-dairy probiotic plant extract to achieve multi-health functional activities such as anti-diabetic, anti-dementia, and antioxidant activities. Full article