Lactiplantibacillus Plantarum Research Articles

Metabolite profiling highlights the effect of microbial intervention in the soaking step of tempe

SummarySoaking of soybeans is an essential step in tempe fermentation. Owing to the uncontrolled microflora, spontaneous soaking during tempe production leads to inconsistencies in tempe quality. Common methods to control it include the addition of acids or microbial starters. Despite knowing the benefits, their impact on tempe's composition was less understood. In this study, prior to tempe fungal fermentation, soybeans were soaked with Lactiplantibacillus plantarum NBRC 101978 and Pichia burtonii NBRC 0844. Tempe samples were subjected to comprehensive analysis using a widely targeted gas chromatography–mass spectrometry (GC–MS) metabolomics approach and evaluation of physical characteristics. A total of 100 metabolites of sugars, amino acids, fatty acids, and organic acids were annotated in all samples. Principal component analysis (PCA) explaining 47.6% of the variance showed that microbial interventions led to alterations in the metabolome of all samples, including the accumulation of amino acids in lactic acid bacteria (LAB)‐soaked soybean tempe and tyramine in yeast‐soaked soybean tempe. Unlike chemically added soaked soybean tempe, microbial intervention significantly reduced the relative intensity levels of several sugars by more than twofold. Furthermore, microbial interventions in the tempe‐soaking step significantly elevated the levels of bioactive metabolites more than twofold. The introduction of microbial interventions in the tempe‐soaking step also influences the physical characteristics of the end product. These findings merit further consideration for tempe development and the food industry.

Lactiplantibacillus plantarum ZJ316 alleviates the oxidative stress and cellular apoptosis via modulating Nrf2/HO-1 signaling pathway

Oxidative stress is vital in gastrointestinal diseases, but how lactic acid bacteria protect human gastric adenocarcinoma cells (AGS) is unclear. Here, we aimed to investigate Lactiplantibacillus plantarum ZJ316 (L. plantarum ZJ316) for its potential to alleviate oxidative stress in AGS cells and elucidate mechanisms involved. Treatment with L. plantarum ZJ316 and fermentation supernatant (ZJ316 FS) bolstered cell viability under hydrogen peroxide (H2O2)-induced oxidative stress, boosting antioxidant enzymes like superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) while reducing reactive oxygen species (ROS) and malondialdehyde (MDA). Oral probiotics also alleviated oxidative damage from D-galactose in mice. Additionally, L. plantarum ZJ316 and ZJ316 FS alleviated H2O2-induced inflammation and apoptosis by modulating the expression of inflammatory and apoptotic factors. However, the protective effect was hindered when pretreated with the Nrf2 inhibitor ML385. These findings suggest that L. plantarum ZJ316 and fermentation supernatant alleviate oxidative damage by activating the Nrf2/HO-1 pathway, showing promise in development of antioxidant functional foods.

Evaluating the dynamic effects of complex probiotics as cellulase replacements during fermentation of apple pomace

Apple pomace, an abundant agricultural by-product with low utilization rates, often leads to environmental pollution if not properly managed. This study aimed to enhance the nutritional value of apple pomace by comparing the effects of solid-state fermentation using complex probiotics and cellulase preparation. Additionally, the study investigated the dynamic changes in various components throughout the fermentation process with complex probiotics. The results of single-strain solid-state fermentation tests indicated that Lactiplantibacillus plantarum DPH, Saccharomyces cerevisiae SC9, and Bacillus subtilis C9 were the optimal strains for fermenting the most effective substrate combination, comprising 73 % apple pomace and 20 % millet bran. The strains (complex probiotics) and a cellulase preparation were used for the solid-state fermentation of the apple pomace mixture for nine days, respectively. The contents of acid detergent fiber, neutral detergent fiber, hemicellulose, and insoluble dietary fiber decreased by up to 9.99 %, 9.59 %, 23.21 %, and 14.34 %, respectively. In contrast, the content of soluble dietary fiber significantly increased by up to 29.74 %. Both methods reduced cellulose crystallinity and modified the substrate's surface structure, resulting in a looser arrangement. Fermentation with complex probiotics for three or six days increased the abundance of lactic acid bacteria, which comprised >87 % of the total microbial population. Concurrently, the abundance of detrimental bacteria, such as Salmonella, Acetobacter, Escherichia, and Pantoea, significantly decreased. Furthermore, fermentation with complex probiotics for six or nine days enhanced antioxidant properties, leading to a significant increase in beneficial metabolites, including amino acids, organic acids, gamma-aminobutyric acid, serotonin. In conclusion, complex probiotics can effectively substitute for cellulase preparation in the solid-state fermentation of apple pomace, with a six-day fermentation period yielding optimal results. This study provides valuable insights into enhancing the value of apple pomace in the feed industry and the effective application of agro-industrial by-products.

Impact of pre-treatments and bioprocessing on the carbohydrate and polyphenol profile of brewers’ spent grain

Brewers’ spent grain (BSG), the solid waste of the brewing industry, is high in fibres, proteins and health-beneficial compounds such as polyphenols. This research investigated bioprocessing with enzymes and microbes to modify the properties of BSG for its utilisation as a food ingredient. Pre-treatment studies showed that wet milling performed better than dry milling, and heat and homogenisation either before or after the enzyme hydrolysis did not significantly influence the release of reducing sugars and free amino nitrogen (FAN). Four treatments were applied to wet-milled BSG: fermentation with Lactiplantibacillus plantarum POM1 with or without the enzyme Ondea pro and enzymatic bioprocessing without any fermentation. Control was the condition without enzyme and starter. Without the enzyme, there was negligible free sugar and FAN, and the starter had limited growth and organic acid production. Only the combination of enzymatic hydrolysis and fermentation reached a pH of 4 and 10 mg/g DW lactic acid. The microbial preference for monosaccharides was evident, and the enzyme influenced the release of oligosaccharides that can have a prebiotic effect. Bioprocessing impacted the phenolic acid composition and microbial consumption, with a significant release of ferulic acid during enzyme hydrolysis.

Heterofermentative Lentilactobacillus buchneri and low dry matter reduce high-risk antibiotic resistance genes in corn silage by regulating pathogens and mobile genetic element

The study of antibiotic resistance in the silage microbiome has attracted initial attention. However, the influences of lactic acid bacteria inoculants and dry matter (DM) content on antibiotic resistance genes (ARGs) reduction in whole-plant corn silage remain poorly studied. This study accessed the ARGs’ risk and transmission mechanism in whole-plant corn silage with different DM levels and treated with Lactiplantibacillus plantarum or Lentilactobacillus buchneri. The macrolide and tetracycline were the main ARGs in corn silage. The dominant species (Lent. buchneri and Lactobacillus acetotolerans) were the main ARGs carriers in whole-plant corn silage. The application of Lent. buchneri increased total ARGs abundance regardless of corn DM. Whole-plant corn silage with 30 % DM reduced the abundances of integrase and plasmid compared with 40 % DM. The correlation and structural equation model analysis demonstrated that bacterial community succession, resulting from changes in DM content, was the primary driving factor influencing the ARGs distribution in whole-plant corn silage. Interestingly, whole-plant corn silage inoculated with Lent. buchneri reduced abundances of high-risk ARGs (mdtG, mepA, tetM, mecA, vatE and tetW) by regulating pathogens (Escherichia coli), mobile genetic elements (MGEs) genes (IS3 and IS1182), and this effect was more pronounced at 30 % DM level. In summary, although whole-plant corn silage inoculated with Lent. buchneri increased the total ARGs abundance at both DM levels, it decreased the abundance of high-risk ARGs by reducing the abundances of the pathogens and MGEs, and this effect was more noticeable at 30 % DM level.

Medium Formulation and Optimisation of Fermentation Condition Enhancing γ-aminobutyric Acid (GABA) Biosynthesis by Lactiplantibacillus plantarum B7

Extensive studies on γ-aminobutyric acid (GABA) over decades highlight its significant physiological and pharmacological effects on humans. GABA produced using microbe is favoured compared to enzymatic and chemical methods due to operational ease and reduced harmful pollutant formation. This study focused on increasing γ-aminobutyric acid (GABA) biosynthesis from Lactiplantibacillus plantarum B7, employing a multi-step optimisation strategy. An unoptimised cultivation approach yielded a maximum GABA of 11.68 ± 0.04 g/L and viable cell count of 10.47 ± 0.01 log CFU/mL at 48 h. A nutrient-rich medium was developed through single-parameter optimisation, comprising 1%, 2.5% and 0.0002% of glucose, yeast extract and each trace element (CaCO3, KI, and Tween 80) respectively. Temperature, pH, incubation period, initial concentration of monosodium glutamate (MSG) and pyridoxal-5’-phosphate (PLP) demonstrated significant contributions towards GABA production and cell growth as determined using a two-level factorial design. Steepest ascent identified optimal conditions (36°C, pH 5.5, 370 mM MSG, and 0.7 mM PLP), resulting in 30.50 g/L GABA and 11.51 log CFU/mL at 60 h. Further refinement via a central composite experiment yielded optimal conditions (temperature-35.6°C, pH-5.66, initial MSG concentration-335.61 mM, PLP concentration-0.723 mM) with improved GABA production (32.18 g/L) and cell growth (11.52 log CFU/mL) over 63.66 h. Therefore, this approach utilising lactic acid bacteria capable of GABA synthesis holds promise for mass-produced, enhanced-functional foods.

Human milk fat globule delivers entrapped probiotics to the infant's gut and acts synergistically to ameliorate oxidative and pathogenic stress

The human milk fat globule membrane (hMFGM) and Lactobacillus modulate the infant's gut and benefit health. Hence, the current study assesses the probiotic potential of Lactiplantibacillus plantarum (MRK3), Limosilactobacillus ferementum (MK1) isolated from infant feces, and its interaction with hMFGM during conditions mimicking infant digestive tract. Both strains showed high tolerance to gastrointestinal conditions, cell surface hydrophobicity, and strong anti-pathogen activity against Staphylococcus aureus. During digestion, hMFGM significantly exhibited xanthine oxidase activity, membrane roughness, and surface topography. In the presence of hMFGM, survival of MRK3 was higher than MK1, and electron microscopic observation revealed successful entrapment of MRK3 in the membrane matrix throughout digestion. Interestingly, probiotic-membrane matrix interaction showed significant synergy to alleviate oxidative stress and damage induced by cell-free supernatant of Escherichia coli in Caco-2 cells. Our results show that a probiotic-encapsulated membrane matrix potentially opens the functional infant formula development pathway.

Improved Functions of Fermented Coffee by Lactic Acid Bacteria

Coffee is one of the most popular beverages in the world, and at present, specialty coffees are developing for better tastes, flavors, or functions. Fermented coffees also reflect this trend and some brands are commercialized. Unlike general fermented coffees, we tried to ferment coffee extract with several lactic acid bacteria. Finally, we selected three strains that persisted in the coffee extract, and show strong antimicrobial activity, for the fermentation starters. The strains were identified as Pediococcus pentosaceus (KNUT 0384), Lacticaseibacillus paracasei (CJNU 1840), and Lactiplantibacillus plantarum (CJNU 0441) based on 16S rRNA gene sequences. During the fermentation process, the total acidities (p < 0.05 vs. the control, non-fermented coffee extract) and cell masses increased, which indicates that the bacteria metabolized properly in the extract. Furthermore, the fermented coffee extracts showed increased antimicrobial activities against Listeria monocytogenes (p < 0.05 vs. the control) and Streptococcus mutans (p < 0.05 vs. the control), increased anti-oxidative activities (p < 0.05 vs. the control, except for the KNUT 0384 sample), decreased caffeine content (p < 0.05 vs. the control, except for the KNUT 0384 sample), and increased chlorogenic acid content (p < 0.05 vs. the control). Taken together, the fermented coffee extracts with the selected lactic acid bacteria could be specialty coffees where several functions are improved when compared with a control coffee extract.

Impact of enzymatically derived manno-oligosaccharides on the growth of select lactobacillus strains under aerobic and anaerobic conditions

This study highlights the ability of beta-MOS derived from coconut processing residues (copra meal) to promote the in vitro growth of Lactobacillus probiotics. Enzymatic hydrolysis conditions were manipulated to produce Low Molecular Weight (LMW) and (HMW) Manno-oligosaccharide (MOS) extracts. The LMW MOS contained more mannose and mannobiose, and the HMW MOS contained more mannotriose and higher molecular weight oligosaccharides. The growth of Limosilactobacillus reuteri, Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus GG on the MOS Extracts was evaluated and compared with growth on Inulin, FOS and XOS. There was significant growth of each probiotic on the MOS extracts. Probiotic growth was similar on MOS extracts and on FOS, while growth was much lower on XOS and Inulin. Probiotic growth was greater under anaerobic than under aerobic conditions. The results confirm the value of a bioactive compound from copra meal to support human and animal health, while contributing to a circular bioeconomy.

Lactiplantibacillus plantarum IS-10506 Supplementation Improves Clinical Outcome and Immunology Markers in Psoriasis Vulgaris Patients: A Randomized Controlled Trial

BACKGROUND: Probiotics may modify the gut microbiome and have been proven to improve psoriasis vulgaris. Lactiplantibacillus plantarum IS-10506 is a probiotic strain of Indonesian origin. It offers a safe and effective probiotic for psoriasis patients in Indonesia. This study was conducted to evaluate the effect of L. plantarum IS-10506 on clinical and immunology markers in psoriasis vulgaris.METHODS: This randomized, placebo-controlled, and double-blind trial compared L. plantarum IS-10506 (2×1010 CFU/day) and placebo in 49 patients mild-moderate psoriasis vulgaris, which were divided into intervention (n=24) and control groups (n=25). The interventions were given twice daily for 12 weeks. Both groups received topical corticosteroid and emollient as standard treatment. Psoriasis area and severity index (PASI), dermatology life quality index (DLQI), interleukin (IL)-10, IL-17, and forkhead box protein (Foxp3) were then assessed.RESULTS: Mean PASI score for the the subjects in probiotic group was significantly reduced compared to placebo at week-6 (p=0.024), and was sustained until week-12 (p=0.049). At week-12, DLQI scores in the probiotic group were lower than placebo (7.57±5.77 vs. 7.79±5.48). IL-17 level was significantly decreased (p=0.013), while the IL-10 and Foxp3 were significantly increased (p≤0.001 and p=0.048, respectively) in probiotic group. Six months after the completion of study, subjects in probiotic group had a lower probability of flares (52.2%) compared to placebo (79.2%). Two subjects receiving probiotics and one receiving placebo noticed changes in defecation frequency, while another subject in the placebo group complained of mild nausea.CONCLUSION: L. plantarum IS-10506 might effectively improve clinical outcomes and immune biomarkers in psoriasis vulgaris patients, potentially acting as an adjuvant therapy.KEYWORDS: psoriasis, probiotic, clinical severity, immune marker, human and health

Molecular identification of lactic acid bacteria from traditional fermented foods and screening exopolysaccharide production by using food wastes.

In this study, lactic acid bacteria (LAB) isolation from fermented foods and molecular identification using magnetic bead technology were performed. And then exopolysaccharide (EPS) production possibility was tested in agar medium, and the positive ones were selected for the next step. The bacteria that could produce higher carbohydrate level were grown in MRS medium fortified with whey and pumpkin waste. In our study, 19 different LAB species were identified from fermented products collected from different places in Hatay(Türkiye) province. In molecular identification, universal primer pairs, p806R/p8FPL, and PEU7/DG74 were used for PCR amplification. After that, PCR products purified using paramagnetic bead technology were sequenced by the Sanger sequencing method. The dominant species, 23.8% of the isolates, were identified as Lactiplantibacillus plantarum. As a technological property of LAB, exopolysaccharide production capability of forty-two LAB isolate was tested in agar medium, and after eleven isolates were selected as positive. Two LAB (Latilactobacillus curvatus SHA2-3B and Loigolactobacillus coryniformis SHA6-3B) had higher EPS production capability when they were grown in MRS broth fortified with pumpkin waste and whey. The highest EPS content (1750mg/L glucose equivalent) was determined in Loigolactobacillus coryniformis SHA6-3B grown in MRS broth fortified with 10% pumpkin waste. Besides the produced EPS samples were validated with FTIR and SEM methods.

Inhibition of Salmonella typhimurium infection in mice fed with live or heat‐killed Lactiplantibacillus plantarum MWFLp‐182

The effects of both live and heat‐killed states of Lactiplantibacillus plantarum MWFLp‐182 (L. plantarum MWFLp‐182) isolated from the faeces of long‐lived humans on preventing and relieving Salmonella infection were studied. Evaluation methods included RT‐qPCR measurement of inflammatory factors, histopathological analysis and non‐targeted metabolomics. The results showed that L. plantarum MWFLp‐182 in both states improved body weight loss, organ swelling and ileocolon pathological damage. They also protected against Salmonella infection by regulating key KEGG enrichment pathways and the expression levels of TNF‐a and IL‐6. It is worth noting that the function of live bacteria was better than that of heat‐killed bacteria.

Genomic insights of Lactiplantibacillus plantarum CNPC024: a potential probiotic strain producing immune-boosting tryptophan-derived metabolites.

Probiogenomics can provide important insights bout probiotic candidate bacteria. This study aimed to perform an in-depth genomic characterization of the probiotic candidate Lactiplantibacillus plantarum CNPC024 to investigate its probiosis mechanisms, identify metabolic pathways that might benefit the host, and improve the safety assessment for this strain to be effectively used as a probiotic. After whole-genome sequencing in Illumina MiSeq platform, the de novo genome assembly resulted in a 3.2Mb draft genome. According to the Average Nucleotide Identity (ANI) analysis with 46 randomly validated probiotic LAB belonging to the Lactobacillaceae family, the strain showed a 99% nucleotide identity with other L. plantarum probiotic species. We identified a set of determinants conferring tolerance to bile salts and low pH conditions, as well as temperature, oxidative and osmotic stressors via the glutathione-glutaredoxin system (Grxs). As a β‑galactosidase‑producing strain, it has the potential to be used in fermented dairy products for lactose-intolerant individuals. There were no significant hits for transferable antibiotic-resistance genes. We also identified gene clusters associated with production of bacteriocins (plantaricins E, F and K). Lastly, we detected metabolic pathways associated with the production of tryptophan-derived metabolites that could potentially modulate the host's immune responses.

Fermented soy milk enhances survival and acid tolerance of Lactiplantibacillus plantarum LP-6 in an in vitro human stomach digestion system

This study aimed to compare the efficacy of fermented cow milk and fermented soy milk as protective carriers for the probiotic strain, Lactiplantibacillus plantarum LP-6 (LP-6), during upper gastrointestinal digestion. Using a near-real dynamic in vitro human stomach system, we evaluated the survival of LP-6 in fermented soy milk and fermented cow milk under simulated upper gastrointestinal conditions. Additionally, we conducted metabolomics analysis at different digestion stages to investigate the potential mechanisms of probiotic survival. Our results revealed that soy milk outperformed cow milk as a carrier, significantly improving the survival of LP-6 throughout digestion. The metabolomics analysis revealed notable enrichment in aspartic acid, glutamate, glutamine, phenylalanine metabolism, and ABC transporter proteins in digested fermented soy milk compared to digested fermented cow milk. These changes likely contribute to enhanced acid tolerance and bacterial cell protection in fermented soy milk. Our findings suggest that soy milk is an optimal carrier for LP-6, effectively protecting specific strains from acid stress while ensuring efficient delivery.

Characterization and Identification of Potential Lactic Acid Bacteria as Biological Control Agent against Ralstonia syzygii subsp. celebesensis of the Banana Blood Disease

Banana is one of the primary fruits cultivated in Malaysia and currently decimated by the emergence of a disease, known as banana blood disease (BBD) which caused by Ralstonia syzygii subsp. celebesensis (Rsc). The BBD has significantly affected the yield and profits of the worldwide banana industry. To date, various approaches including chemical and biological controls have been attempted to manage this disease but none of them succeed in controlling the disease. The uses of lactic acid bacteria (LAB) in managing plant diseases have been reported earlier but little information is available. Therefore, this project is designed to identify and investigate potential plant-associated LAB as biological control agent (BCA) against Rsc by using agar well diffusion method. The inhibition zones of each well were observed after 72h and the isolated LAB that showed inhibition zones were proceed for molecular characterization using PCR amplification followed by gel electrophoresis. The sequences were used for phylogenetic analysis. In addition, each of the potential LAB were used to identify their morphological characterizations and biochemical testing. Throughout the study, the highest inhibition zones of LAB from kimchi and fermented milk achieved a diameter of 21.30 mm and 28.70 mm, respectively. Kimchi isolates showed the highest similarity which is 97% as Lactiplantibacillus plantarum species. Among the fermented milk isolates, the highest similarity which is 98% identified as Lacticaseibacillus paracasei.

Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System.

Many bacteria perform extracellular electron transfer (EET), whereby electrons are transferred from the cell to an extracellular terminal electron acceptor. This electron acceptor can be an electrode and electrons can be delivered indirectly via a redox-active mediator molecule. Here, we present a protocol to study mediated EET in Lactiplantibacillus plantarum, a probiotic lactic acid bacterium widely used in the food industry, using a bioelectrochemical system. We detail how to assemble a three-electrode, two-chambered bioelectrochemical system and provide guidance on characterizing EET in the presence of a soluble mediator using chronoamperometry and cyclic voltammetry techniques. We use representative data from 1,4-dihydroxy-2-naphthoic acid (DHNA)-mediated EET experiments with L. plantarum to demonstrate data analysis and interpretation. The techniques described in this protocol can open new opportunities for electro-fermentation and bioelectrocatalysis. Recent applications of this electrochemical technique with L. plantarum demonstrated an acceleration of metabolic flux towards producing fermentation end-products, which are critical flavor components in food fermentation. As such, this system has the potential to be further developed to alter flavors in food production or produce valuable chemicals.

Comprehensive physiological and genomic characterization of a potential probiotic strain, Lactiplantibacillus plantarum ILSF15, isolated from the gut of tribes of Odisha, India

Characterizing probiotic features of organisms isolated from diverse environments can lead to the discovery of novel strains with promising functional features and health attributes. The present study attempts to characterize a novel probiotic strain isolated from the gut of the tribal population of Odisha, India. Based on 16S rRNA-based phylogeny, the strain was identified as a species of the Lactiplantibacillus genus and was named Lactiplantibacillus plantarum strain ILSF15. The current investigation focuses on elucidating this strain’s genetic and physiological properties associated with probiotic attributes such as biosafety risk, host adaptation/survival traits, and beneficial functional features. The novel strain was observed, in vitro, exhibiting features such as acid/bile tolerance, adhesion to the host enteric epithelial cells, cholesterol assimilation, and pathogen exclusion, indicating its ability to survive the harsh environment of the human GIT and resist the growth of harmful microorganisms. Additionally, the L. plantarum ILSF15 strain was found to harbor genes associated with the metabolism and synthesis of various bioactive molecules, including amino acids, carbohydrates, lipids, and vitamins, highlighting the organism’s ability to efficiently utilize diverse resources and contribute to the host’s nutrition and health. Several genes involved in host adaptation/survival strategies and host-microbe interactions were also identified from the ILSF15 genome. Moreover, L. plantarum strains, in general, were found to have an open pangenome characterized by high genetic diversity and the absence of specific lineages associated with particular habitats, signifying its versatile nature and potential applications in probiotic and functional food industries.

Determination of strain variability and kinetics of food-associated microorganisms following ultrasound treatment

Ultrasound is a promising emerging technology known for its antimicrobial efficacy. However, existing studies have not fully addressed the impact of strain variability and inactivation kinetics on US efficacy. Ten strains of Listeria monocytogenes, Lactiplantibacillus plantarum, Saccharomyces cerevisiae and Escherichia coli were exposed to US treatment (26 kHz, 200 mL, 100 % amplitude, 200 W, 65–71 W/cm2) under dynamic conditions to investigate their resistance profile. Furthermore, the inactivation kinetics of selected resistant/sensitive strains were assessed. The result showed significant intra-species variability in resistance (p < 0.05) for the four target microorganisms evaluated in this study. L6 and NCTC 10357 were the most resistant and sensitive L. monocytogenes strains respectively, having a reduction difference of ∼3.4 log CFU/mL. Regarding L. plantarum, FBR04 emerged as the most resistant strain (4.4 log reduction), while E. coli FAM21845, FAM21805 and FAM21843 (∼2 log reduction) emerged as the most resistant strains. On the other hand, the most resistant strains of S. cerevisiae were CBS 1544, AD 1890 and 077.0001 (<1 log reduction) while S. cerevisiae AD 2913, 028.0404 and 028.0315 were the most sensitive (>5 log reduction). The survival curves of most of the strains exhibited an initial phase of insignificant microbial inactivation followed by a relatively fast log-linear inactivation period. The estimated D-value showed that L. monocytogenes strains exhibited higher resistance to US treatment than any other species, while other species displayed comparable resistance. The findings on strain variability resistance and inactivation kinetics following US treatment are essential for food safety and will pave the way for further research on microbial response to US stress, risk assessment and optimisation studies.

Phytochemical and Flavor Characteristics of Mulberry Juice Fermented with Lactiplantibacillus plantarum BXM2.

Fermentation of mulberry juice not only improves its shelf life, but also effectively enhances their flavor and nutritional quality. This study elucidated the phytochemical and flavor characteristics of mulberry juice fermented with Lactiplantibacillus plantarum BXM2, originally isolated from naturally fermented fruit beverage, through widely targeted metabolomics. The fermentation produced the unique flavor of fermented juice and decreased the pH from 4.15 to 3.19. The metabolomic analysis detected 907 non-volatile metabolites, from which 359 significantly different non-volatile metabolites (up 238, down 121) were screened out. Among 731 identified volatile metabolites, 26 flavor substances were the major contributors to the flavor differences between fermented and unfermented mulberry juices. It is hypothesized that lipid metabolism and amino acid catabolism are crucial pathways for the flavor enhancement of mulberry juice fermented with L. plantarum BXM2. Meanwhile, significant increases of the contents of a variety of bioactive substances, such as indole-3-lactic acid, octadeca-9,12,15-trienoic acid, di-/tri-peptides, etc., conferred additional health potential to BXM2-fermented mulberry juice.

The effect of Lactiplantibacillus plantarum fermentation and blanching on microbial population, nutrients, anti-nutrients and antioxidant properties of fresh and dried mature Moringa oleifera leaves

Moringa oleifera is an excellent source of nutrients and functional ingredients of human health significance. This study was conducted to determine the role of lactic acid fermentation and blanching in improving nutritional attributes and functional properties of M. oleifera leaves. Submerged lactic acid fermentation of M. oleifera was carried out for 24 h by using a Lactiplantibacillus plantarum strain. The results showed that fermentation resulted in a microbial population of M. oleifera leaves dominated with higher count of L. plantarum i.e., 4.06 log10 CFU/g after 24 h fermentation. L. plantarum count was reduced from 4.06 to 1.61 log10 CFU/g in fermented M.oleifera leaves powder after cabinet dehydration. Higher levels of protein (29.87 %), and fiber (32.26 %) were observed in fermented M. oleifera leaves while the levels of carbohydrates (10.74 %), fat (7.72 %), and energy (232.06 kcal) were lower than the levels observed in raw and blanched leaves. Lactic acid fermentation also anticipated reduction in anthocyanin (14.50–10.37 mg/100g), chlorophyll A (52.64–45.35 mg/100g), and lycopene (11.94–9.13 mg/100g) content of M. oleifera leaves. Fermentation significantly (p ≤ 0.05) increased level of total phenolic content i.e., 55.48 mg gallic acid equivalents (GAE)/g, total flavonoid contents i.e., 70.81 mg quercetin equivalent (QE)/g and flavonols i.e., 36.97 mg QE/g. Lactic acid fermentation reduced the levels of intrinsic nutrient inhibitors such as alkaloids (2.74–1.94 g/100g; 29 % ↓), saponins (3.80–2.98 g/100g: 20 % ↓), oxalates (2.43–1.85 g/100g; 24 % ↓), tannin (0.83–0.44 g/100g; 47 % ↓), and phytic acid (1.94–1.02 g/100g; 47 % ↓) compared with the raw leaves. The results suggest lactic acid fermentation is a cost-effective technique to improve nutritional and health perspectives of M. oleifera leaves.