Search Results (174)

Melatonin (MEL), also known as N-acetyl-5-methoxytryptamine, has been reported in plants as a secondary messenger involved in regulating abiotic stress responses. MEL treatment, either preharvest or postharvest, regulates several physiological and biochemical processes during fruit growth and ripening in horticultural products. These include reproductive development, tissue and quality maintenance, delayed senescence, and responses to abiotic stress. Due to its natural origin, low toxicity, and multifunctional regulatory capacity, MEL has recently attracted attention as a promising ‘green preservative’ for sustainable postharvest management. Additionally, MEL coordinates through cross-talk with other plant hormones, such as abscisic acid, ethylene, polyamines, jasmonic acid, γ-aminobutyric acid, salicylic acid, and nitric oxide, to regulate postharvest ripening and senescence. Furthermore, MEL enhances antioxidant systems and improves membrane integrity, thereby alleviating chilling injury and enhancing fruit firmness and colour. Notably, recent evidence highlights the innovative regulatory mechanisms of MEL involving redox homeostasis, hormone signalling reprogramming, and transcriptional modulation of stress-responsive pathways. MEL could therefore be considered an emerging, eco-friendly tool for prolonging the shelf-life of fruit and vegetables and maintaining their quality. This review summarises the mechanisms by which MEL contributes to plant stress resistance by regulating the biosynthesis and metabolism of stress tolerance and improving fruit quality. Full article

Plant-based fermented foods are increasingly promoted for glycemic control, yet their mechanisms and clinical impact remain incompletely defined. This narrative review synthesizes mechanistic, preclinical, and human data for key matrices—kimchi and other fermented vegetables, tempeh/miso/natto, and related legume ferments, kombucha and fermented teas, plant-based kefir, and cereal/pulse sourdoughs. Across these systems, microbial β-glucosidases, esterases, tannases, and phenolic-acid decarboxylases remodel polyphenols toward more bioaccessible aglycones and phenolic acids, while lactic and acetic fermentations generate organic acids, exopolysaccharides, bacterial cellulose, γ-polyglutamic acid, γ-aminobutyric acid, and bioactive peptides. We map these postbiotic signatures onto proximal mechanisms—α-amylase/α-glucosidase inhibition, viscosity-driven slowing of starch digestion, gastric emptying and incretin signaling, intestinal-barrier reinforcement, and microbiota-dependent short-chain–fatty-acid and bile-acid pathways—and their downstream effects on AMPK/Nrf2 signaling and the gut–liver axis. Animal models consistently show improved glucose tolerance, insulin sensitivity, and hepatic steatosis under fermented vs. non-fermented diets. In humans, however, glycemic effects are modest and highly context-dependent: The most robust signal is early postprandial attenuation with γ-PGA-rich natto, strongly acidified or low-glycemic sourdough breads, and selected kombucha formulations, particularly in individuals with impaired glucose regulation. We identify major sources of heterogeneity (starters, process parameters, substrates, background diet) and safety considerations (sodium, ethanol, gastrointestinal symptoms) and propose minimum reporting standards and trial designs integrating metabolomics, microbiome, and host-omics. Overall, plant-based ferments appear best positioned as adjuncts within cardiometabolic dietary patterns and as candidates for “purpose-built” postbiotic products targeting early glycemic excursions and broader metabolic risk. Full article

This study was conducted to evaluate the effect of rumen-protected γ-aminobutyric acid (GABA) supplementation on milk productivity of lactating Holstein cows. Eighteen Holstein dairy cows (mean parity, 2.2 ± 1.0 year; mean milk yield, 34.3 ± 5.5 kg) were selected in a commercial dairy farm for the experiment. The experiment was conducted from 17 July 2024 to 11 September 2024 (56 days). Generally, THI 72 is set as a threshold since the productivity of Holstein cows starts to decrease. Animals were exposed to heat stress conditions (THI ≥ 72) during the experimental period. The basal diet was fed as a total mixed ration (TMR), and GABA was top-dressed onto the TMR. The treatments were basal diet (Control), basal diet supplemented with rumen-protected GABA 3 g/d (Treatment 1), and basal diet supplemented with rumen-protected GABA 6 g/d (Treatment 2) as a completely randomized design. Statistical significance was compared between the control and GABA treatment groups using the method of repeated measurement. Increased levels of rumen-protected GABA supplementation tended to mitigate the decline in milk yield associated with heat stress (p = 0.083). Milk fat content in the GABA supplementation groups was significantly greater than that in the control group (p = 0.036). Milk lactose content was significantly increased by GABA supplementation (p = 0.017). Blood metabolic profiles and cortisol did not differ significantly between the control and GABA supplementation groups. Activities in the GABA supplementation groups were significantly greater than those in the control group (p < 0.05). Rest and rumination times in the GABA supplementation group were significantly lower than those in the control group (p < 0.05). These results suggest that rumen-protected GABA can be a practical nutritional intervention for minimizing productivity losses in Holstein cows during periods of elevated ambient temperature. Full article

Bentonite is a multifunctional material widely used in industry, agriculture, food processing, and medicine due to its strong binding and absorption properties. This study investigates the effects of bentonite pre-treatment at different concentrations (0.5–5%) on soybean sprout growth and nutritional quality. Moderate levels, particularly 1–3% (BP-1 and BP-3), significantly increased sprout yield (up to 16.1%) and vitamin C content (up to 18.91 mg/100 g FW), while maintaining desirable moisture and visual quality. Color evaluation showed higher yellowness (b*), suggesting improved consumer appeal. Mineral profiling indicated substantial enhancement of essential minerals across treatments, with the highest total mineral content recorded in the BP-5 group. Phosphorus, potassium, copper, and iron were notably enriched; however, elevated copper and reduced zinc at higher concentrations indicate potential nutritional risk. Isoflavone analysis revealed increased total isoflavones, especially glucoside forms such as daidzin and genistin, while aglycones like genistein decreased, reflecting bentonite’s selective influence on isoflavone metabolism. Antioxidant properties—including DPPH scavenging capacity, total polyphenols, flavonoids, and SOD-like activity—were significantly enhanced. Amino acid profiling also showed increases in essential amino acids, including methionine and valine, along with higher γ-aminobutyric acid (GABA). Overall, bentonite demonstrates strong potential as a natural additive for improving soybean sprout productivity and functional quality, with the most favorable outcomes observed at 1–3% concentrations. Full article

Lactiplantibacillus plantarum is widely used in fermented foods and as a probiotic, yet the genomic basis underlying its γ-aminobutyric acid (GABA) production capacity and strain-level functional diversity remains incompletely resolved. We analyzed 1240 publicly available genomes to map species-wide genome architecture, the distribution of GABA-related genes, and accessory drivers of phenotypes. Pangenome analysis identified 45,201 gene families, including 622 strict core genes (1.38%) and 444 soft-core genes (2.36%). The accessory genome dominated (3138 shell and 40,997 cloud genes; 97.64%), indicating a strongly open pangenome. In contrast, the GABA (gad) operon was universally conserved: gadB (glutamate decarboxylase) and gadC (glutamate/GABA antiporter) were present in all genomes regardless of isolates source. Accessory-genome clustering revealed ecological and geographic structure without loss of the operon, suggesting that phenotypes variability relevant to fermentation and probiotic performance is primarily shaped by accessory modules. Accessory features included carbohydrate uptake and processing islands, bacteriocins and immunity systems, stress- and membrane-associated functions, and plasmid-encoded traits. Analysis of complete genomes confirmed substantial variation in plasmid load (median = 2; range = 0–17), highlighting the role of mobile elements in niche-specific adaptation. Carbohydrate-Active Enzymes database (CAZy) and biosynthetic gene cluster (BGC) profiling revealed a conserved enzymatic and metabolic backbone complemented by rare lineage-specific functions. Collectively, these results position L. plantarum as a genetically stable GABA producer with extensive accessory-encoded flexibility and provide a framework for rational strain selection. Full article

Fermented vegetables host complex microbiomes that drive flavor and functionality. We compared cowpea pod fermentations produced by a Korean kimchi-style method (HG) versus a Sichuan paocai-style method (SC) to isolate technique-driven effects on community structure and functional potential. Cowpea pods were fermented for 10 days in triplicate, profiled by 16S rRNA (V3-V4) amplicon sequencing, analyzed in QIIME2, and functionally inferred with PICRUSt2. SC exhibited higher alpha diversity (Shannon, Chao1, Simpson) than HG (p < 0.05), and beta-diversity (Bray-Curtis dissimilarity) showed clear separation by fermentation style (PERMANOVA p = 0.001), indicating method-dependent community assembly. Both styles were dominated by lactic acid bacteria, chiefly Leuconostoc, Lactobacillus, and Weissella, but their proportions differed: HG retained higher Leuconostoc/Weissella, whereas SC favored Lactobacillus. Predicted functions diverged accordingly: HG was enriched for carbohydrate-metabolism genes (e.g., β-galactosidase; dextransucrase), consistent with rapid sugar fermentation and possible exopolysaccharide formation; SC showed enrichment of amino-acid-related pathways (e.g., acetolactate synthase; glutamate dehydrogenase), heterolactic fermentation, and γ-aminobutyric acid (GABA) biosynthesis, suggesting broader metabolic outputs relevant to flavor development and potential health attributes. Overall, fermentation technique substantially shapes both the microbiome and its predicted repertoire, with HG prioritizing carbohydrate catabolism and SC showing expanded metabolic potential; these insights can inform starter selection and process control for targeted product qualities. Full article

Enterococcus spp. produce diverse bioactive molecules used for biotechnological purposes or as probiotic agents for livestock and human health. The main aim of this study was to decipher the genetic traits using whole-genome sequencing (WGS) of a bacteriocinogenic Enterococus faecium 1702 strain showing diverse probiotic traits. Genetic traits of the strain were determined by performing WGS using the NovaSeq6000 platform followed by consecutive sequence analysis using appropriate software. WGS showed that the genome of the E. faecium 1702 strain has a size of 2,621,416 bp, with a GC content of 38.03%. The strain belonged to the sequence type ST722 not known as a human clonal lineage. The strain was free of genes encoding clinically relevant antibiotic resistance; in addition, genes encoding sensu stricto virulence factors, plasmids, and prophages were not detected. Annotations through the Prokaryotic Genomes Automatic Annotation Pipeline (PGAP) tool revealed 2413 coding sequencing entries (CDC) out of 2521 predicted chromosomal genes. The functional annotation of the whole genome through the KEGG database using KofaScan revealed several genes related to several biological activities, including metabolic process, carbohydrate metabolism, amino acid metabolism, and nucleotide metabolism. The strain harbored three entero-bacteriocins (enterocins) encoded by entA, entB, and entX (enterocin X-alpha and X-beta) genes. Interestingly, the strain harbored the ansB, glsA, and arcA genes encoding L-asparaginase, L-glutaminase, and arginine deiminase, respectively, known for their anticancer activities. E. faecium 1702 harbored the gadB, gadC, and gadR genes implicated in gamma(γ)-aminobutyric acid (GABA) production, which is known for its analgesic, anti-anxiety, hypotensive, diuretic, and antidiabetic effects. The WGS findings and phenotypic traits of E. faecium 1702 revealed significant features that allow for its use as a probiotic or for biotechnological and pharmaceutical applications. Full article

γ-Aminobutyric acid (GABA) is a bioactive metabolite valued in functional foods, but its microbial production is strongly influenced by nutrient availability. Levilactobacillus brevis CRL 2013 is an efficient GABA producer; however, its biosynthesis depends on culture medium composition. In this study, integrated physiological, proteomic, and transcriptional analyses were applied to assess the influence of nitrogen source composition and concentration on GABA production. No extracellular GABA was detected in a chemically defined medium containing all amino acids and glutamate (CDMg), whereas supplementation with yeast extract or Casitone restored high-level production. The highest GABA accumulation (~250 mM) was obtained in CDMg supplemented with 1% yeast extract or 2% Casitone, and a clear peptide dose-dependent effect was observed. In contrast, other protein hydrolysates or free amino acids alone did not stimulate GABA synthesis. Proteomic analysis revealed overexpression of the key enzyme GadB and changes in nucleotide and fatty acid pathways. Transcriptional analysis confirmed that peptide supplementation was accompanied by increased transcription of the gadRCB–gltX operon, in agreement with GABA accumulation. Overall, these results demonstrated that peptide composition and availability are critical determinants of GABA biosynthesis in Lv. brevis CRL 2013and provide a basis for optimizing peptide-based media to enhance GABA formation in food fermentations. Full article

Depression is a common mood disorder, and growing evidence has revealed the critical role of gut microbiota in its onset and progression. The gut–brain axis, which connects the central nervous system and intestinal microecology, offers new strategies for depression intervention. In this study, an acute depression model was established in mice using lipopolysaccharide (LPS), and the potential antidepressant effects and mechanisms of Bifidobacterium animalis CP-9 were investigated. The results indicated that CP-9 may exert antidepressant effects through multiple pathways, including modulation of peripheral and central inflammatory responses, restoration of gut microbiota balance, enhancement of short-chain fatty acid (SCFA) production, and regulation of neurotransmitter metabolism such as γ-aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT). Notably, intervention with CP-9 at a dose of 10⁸ CFU/mL significantly alleviated depressive-like behaviors in mice, suggesting its promising potential in the prevention and treatment of mood disorders. Full article

Background: The accumulation of β-amyloid plaques, neurofibrillary tangles, and neuroinflammation are key hallmarks of Alzheimer’s disease (AD). Reactive oxygen species (ROS) act as major triggers and amplifiers of neuroinflammatory responses, contributing to immune dysregulation and neuronal damage. Despite extensive research, no effective therapy halts or reverses AD progression, emphasizing the need for alternative preventive strategies, including the use of natural compounds. Objectives: This study evaluated the neuroprotective effects of simulated digestive fractions (permeate fraction) of mushroom biomass (MB)—Trametes versicolor (TV), Hericium erinaceus (HE), and Pleurotus ostreatus (PO)—and key gut microbiota-derived metabolites, such as short-chain fatty acids (SCFAs) and γ-aminobutyric acid (GABA) on ROS production in human microglial cells (HMC3) and in transgenic Caenorhabditis elegans models exhibiting hyperphosphorylated Tau and β-amyloid-induced toxicity. Methods: Cell viability and ROS production were assessed in HMC3 cells treated with mushroom fractions and metabolites. Chemotaxis and paralysis assays were performed in transgenic C. elegans strains expressing hyperphosphorylated Tau or β-amyloid proteins. Results: Mushroom digestive fractions and SCFAs significantly decreased ROS levels in HMC3 cells. Moreover, mushroom digestive fractions, butyric acid, and GABA improved behavioral outcomes in C. elegans, enhancing chemotaxis and delaying paralysis. These effects were dose-dependent and varied among mushroom species and metabolites. Conclusions: Mushroom-derived digestive fractions and microbiota-related metabolites exhibit neuroprotective activity by modulating oxidative stress and mitigating neurodegeneration-associated behaviors. Diets enriched with such MBs may support preventive strategies for neurodegenerative diseases. Further research is required to elucidate the molecular mechanisms underlying these protective effects and their translational potential for human neurodegenerative diseases. Full article

This study aimed to isolate and screen lactic acid bacteria (LAB) with neuroprotective potential for food applications. Fifteen strains were screened for probiotic potential properties, γ-aminobutyric acid (GABA) production, and acetylcholinesterase (AChE) inhibitory activity. Lactobacillus delbrueckii AY8 and AY15 demonstrated the strongest probiotic potential, AChE inhibitory activity, and GABA production. Whole-genome sequencing confirmed genes linked to these probiotic and neuroprotective traits. To assess their functionality in a food matrix, the strains were used as adjunct cultures in fermented milk with and without jujube kernel powder (JP). Fermentation with the AY8 strain in JP-fortified milk significantly increased bioactive compounds, resulting in higher total phenolic content (235.75 mg GAE/g), flavonoids (114.07 mg RE/g), and superior antioxidant activity (110.24 mg Ascorbic equivalent/100 g). This biotransformation led to a remarkable increase in AChE inhibition, with the AY8-fermented sample achieving 30.66% inhibition, significantly higher than the JP control (18.27%) and the plain control (12.30%). The combination also improved the product’s viscosity and sensory profile. This study highlights the successful discovery of novel L. delbrueckii strains, whose application in a food model, when combined with a plant-based supplement, creates a functional food with enhanced neuroprotective potential, underscoring the role of microbial metabolism in food functionality. Full article

Soybean flour (SF) allergy is a common food allergy reaction that significantly impacts patients’ daily diet and quality of life. This study used a combination of physical ball milling technology and γ-Aminobutyric acid (GABA) treatment to reduce the antigenicity of SF. When the material ball ratio was 1:14 (w/w), SF after ball milling treatment exhibited the smallest average particle size, and the highest solubility, bulk density, and antioxidant capacity. The functional properties of SF were further enhanced by adding GABA. Meanwhile, SF with 0.4% added GABA exhibited the smallest average particle size, the highest solubility, and the highest antioxidant capacity. The antigen content in soybean flour was determined using the soy glycinin ELISA kit and β-conglycinin ELISA kit. Compared with the original SF, the antigen contents of globulin and β-conglycinin decreased by 89.11% and 89.61%, respectively, in SF with the addition of 0.4% GABA after ball milling treatment. These results indicate that the addition of GABA not only further optimizes the solubility and antioxidant properties of SF, but also significantly reduces its antigen content. This study developed a combined treatment method to reduce allergenicity, overcoming the limitations of a single physical or biological treatment and providing a new technical approach for developing soybean flour products with low allergenicity. Full article

This study optimized γ-aminobutyric acid (GABA) formation in Vietnamese fermented pork (nem chua) using a central composite design to tune salt, sugar, and monosodium glutamate (MSG) under co-inoculation with Lactiplantibacillus plantarum CP1.2 and Pediococcus acidilactici CP1.4. Fermentations proceeded at room temperature; pH, titratable acidity, GABA (colorimetry), formal nitrogen, ammoniacal nitrogen (indophenol blue), and microbial counts were measured, with a packaging comparison between polypropylene (PP) and polyethylene (PE). Response surface analysis (R² = 0.8897) predicted an optimum at 2.0% salt, ~15.9–16.0% sugar, and ~2.9–3.0% MSG, yielding 7.44 mg/g GABA. Validation at these conditions achieved higher GABA (8.32 ± 0.24 mg/g), with pH near 4.70 and lactic acid ~18.5 g/kg. Across seven storage days, GABA peaked at day 1 (8.72–8.84 mg/g) and declined to 4.74–5.07 mg/g (day 7) as acidity increased. PE tended to preserve GABA better and reduced aerobic counts relative to PP, whereas PP limited ammoniacal nitrogen later in storage; lactic acid bacteria remained abundant (≥9.4 log CFU/g). Sensory attributes (color, aroma, taste, firmness) decreased over time but were higher in PE. The results show that balanced seasoning ratios, starter cultures, and packaging can maximize GABA enrichment while maintaining safety and quality in nem chua, providing a practical basis for scale-up of GABA-enhanced fermented meat products and tailoring shelf-life with packaging. Full article

This study investigated the combined effects of lactic acid bacteria (LAB) fermentation and different milling methods (wet, semi-dry, and dry) on the physicochemical properties of glutinous rice flour (GRF) and the texture of the final product. A systematic analysis of rice samples treated with three LAB strains (Lactiplantibacillus plantarum CGMCC 1.12974, Limosilactobacillus fermentum CICC 22704, and Lactobacillus acidophilus CICC 22162) revealed that fermentation pretreatment created favorable conditions for subsequent physical milling by degrading the protein network and modifying the starch structure. The results demonstrated that fermentation combined with dry or semi-dry milling significantly improved the whiteness of GRF and the contents of γ-aminobutyric acid (GABA), total phenols, and total flavonoids, while reducing the contents of damaged starch (except in samples fermented with Lb. acidophilus) and protein by 2.91–12.43% and 17.80–32.09%, respectively. The functional properties of the GRF were also optimized: fermented flour exhibited higher peak viscosity, lower gelatinization temperature, and higher gelatinization enthalpy. Texture profile analysis revealed that glutinous dumplings prepared from fermented dry/semi-dry milled GRF, particularly those fermented with Lp. plantarum, showed significantly reduced hardness and chewiness, along with significantly improved cohesiveness and resilience. Consequently, their texture approximated that of high-standard wet-milled products. Correlation analysis based on the top ten discriminative features selected by random forest identified peak viscosity and breakdown viscosity as the most important positive factors associated with superior texture (high resilience, high cohesiveness, and low hardness), whereas damaged starch content and protein content were key negative correlates. In summary, this study confirms that the combination of fermentation and milling exerts a beneficial influence on the functional quality of GRF. Full article

Background/Objectives: This study reports pilot-scale production of gluten-free rice malt extract powder from Thai Chainat 1 rice as a sustainable alternative to barley malt extract. Methods: The process combined controlled malting with sequential enzymatic hydrolysis, optimized through bench-scale validation and scaled up to a 1500 L pilot system. Results: The resulting powder was rich in fermentable sugars (maltose 43.9 g/100 g, glucose 14.3 g/100 g), protein (5.2 g/100 g), γ-aminobutyric acid (GABA, 245.2 mg/100 g), and thiamine (0.64 mg/100 g), while free of detectable gluten, aflatoxins, and heavy metals. Microbiological quality met international safety standards. Shelf-life studies under ambient and accelerated conditions demonstrated chemical stability and bioactive retention for up to three years in laminated and HDPE packaging. Application trials confirmed that the rice malt extract powder supported yeast, bacterial, and mold growth comparably to commercial malt extract in culture media, with optimized yeast–mold agar formulations enabling direct substitution without supplementary glucose. The powder was further applied to a gluten-free malt beverage, yielding a beer-like product with acceptable physicochemical and nutritional quality, though residual alcohol levels exceeded the non-alcoholic threshold and required process optimization. Conclusions: Rice malt extract powder represents a safe, functional ingredient suitable for food, beverage, and industrial microbiology applications, offering opportunities to reduce import dependency and advance gluten-free innovation in emerging markets. Full article