Phenyllactic Acid Research Articles

Conjugates of 3-phenyllactic acid and tryptophan enhance root-promoting activity without adverse effects in Vigna angularis.

3-Phenyllactic acid (PLA) is a common secondary product of Lactobacillus sp. and promotes adventitious-root formation in Azuki beans (Vigna angularis). Root promotion activity of PLA is synergistically enhanced by tryptophan (Trp). In this study, stereoisomers of PLA and Trp amide conjugates and their alkyl esters were synthesized to investigate the structure-activity relationships on root-promotion activity. The rooting activity of D-PLA-L-Trp conjugate shows more than 40 times higher than that of the mixture of D-PLA and L-Trp. Modification of PLA-Trp with ethyl ester showed the highest activity at 3,400 times of a mixture of D-PLA and L-Trp. However, L-or D-PLA-D-Trp conjugate and the isopropyl ester of PLA-Trp conjugates, both lost the root promotion activity and implicated that a requirement for steric structure for PLA related root promotion mechanism. Unlike auxin substances, which are commonly used as rooting agents that displayed high activity in low concentrations, PLA-Trp ethyl ester exhibited far less phytotoxicity at high concentration of 1 mM, despite its high rooting activity. Innovation of PLA-Trp ethyl ester may be expected for agricultural aspects with low environmental impact.

Unique Probiotic Properties and Bioactive Metabolites of Saccharomyces boulardii.

Saccharomyces boulardii (S. boulardii) is a probiotic and is widely used to improve the nutritional and functional value of food. This study aimed to compare the probiotic properties of S. boulardii and Saccharomyces cerevisiae. A series of in vitro probiotic experiments was performed, including simulated gastrointestinal digestion, bile salt tolerance, hydrophobicity, self-aggregation, and antioxidant and antibacterial properties. Self-aggregation and hydrophobic properties of S. boulardii were relatively poor, but they showed high tolerance, antioxidant properties, and broad antibacterial properties. In addition, non-targeted metabolomics was used to comprehensively analyze the active metabolites of S. boulardii and the metabolic differences between S. boulardii and S. cerevisiae were compared. Saccharomyces boulardii produced many bioactive metabolites, which generally showed antioxidant, antibacterial, antitumor, anti-inflammatory, and other properties. In contrast to S. cerevisiae, S. boulardii produced phenyllactic acid and 2-hydroxyisocaproic acid. There were also significant differences in their metabolic pathways. These results may be of great significance in the medical and food industries and provide a basis for understanding the metabolism of S. boulardii. It also shows that metabolomics is an effective and novel method for screening microbial functional metabolites and identifying functional differences between similar microorganisms.

Comprehensive Metabolomic Comparison of Five Cereal Vinegars Using Non-Targeted and Chemical Isotope Labeling LC-MS Analysis.

Vinegar is used as an acidic condiment and preservative worldwide. In Asia, various black vinegars are made from different combinations of grains, such as Sichuan bran vinegar (SBV), Shanxi aged vinegar (SAV), Zhenjiang aromatic vinegar (ZAV), and Fujian Monascus vinegar (FMV) in China and Ehime black vinegar in Japan (JBV). Understanding the chemical compositions of different vinegars can provide information about nutritional values and the quality of the taste. This study investigated the vinegar metabolome using a combination of GC-MS, conventional LC-MS, and chemical isotope labeling LC-MS. Different types of vinegar contained different metabolites and concentrations. Amino acids and organic acids were found to be the main components. Tetrahydroharman-3-carboxylic acid and harmalan were identified first in vinegar. Various diketopiperazines and linear dipeptides contributing to different taste effects were also detected first in vinegar. Dipeptides, 3-phenyllactic acid, and tyrosine were found to be potential metabolic markers for differentiating vinegars. The differently expressed pathway between Chinese and Japanese vinegar was tryptophan metabolism, while the main difference within Chinese vinegars was aminoacyl-tRNA biosynthesis metabolism. These results not only give insights into the metabolites in famous types of cereal vinegar but also provide valuable knowledge for making vinegar with desirable health characteristics.

Postprandial Responses on Serum Metabolome to Milk and Yogurt Intake in Young and Older Men.

The identification and validation of biomarkers of food intake (BFIs) is a promising approach to develop more objective and complementary tools to the traditional dietary assessment methods. Concerning dairy, their evaluation in terms of intake is not simple, given the variety of existing foods, making it difficult to establish the association between specific dairy products consumption and the effects on human health, which is also dependent on the study population. Here, we aimed at identifying BFI of both milk (M) and yogurt (Y) in 14 healthy young (20–35 years) and 14 older (65–80 years). After a 3-week run-in period of dairy exclusion from the diet, the subjects acutely consumed 600 ml of M or Y. Metabolomics analyses were conducted on serum samples during the following 6 h (LC-MS and GC-MS). Several metabolites showing increased iAUC after milk or yogurt intake were considered as potential BFI, including lactose (M > Y, 2-fold), galactitol (M > Y, 1.5-fold), galactonate (M > Y, 1.2-fold), sphingosine-1-phosphate (M > Y from 2.1-fold), as well as an annotated disaccharide (Y > M, 3.6-fold). Delayed serum kinetics were also observed after Y compared to M intake lysine (+22 min), phenylalanine (+45 min), tyrosine (+30min), threonine (+38 min) 3-phenyllactic acid (+30 min), lactose (+30 min), galactitol (+45min) and galactonate (+30 min). The statistical significance of certain discriminant metabolites, such as sphingosine-1-phosphate and several free fatty acids, was not maintained in the older group. This could be related to the physiological modifications induced by aging, like dysregulated lipid metabolism, including delayed appearance of dodecanoic acid (+60 min) or altered postprandial appearance of myristic acid (+70% Cmax), 3-dehydroxycarnitine (−26% Cmin), decanoylcarnitine (−51% Cmin) and dodecanoylcarnitine (−40% Cmin). In conclusion, candidate BFI of milk or yogurt could be identified based on the modified postprandial response resulting from the fermentation of milk to yogurt. Moreover, population specificities (e.g., aging) should also be considered in future studies to obtain more accurate and specific BFI.

Biomedical features and therapeutic potential of rosmarinic acid.

For decades, the use of secondary metabolites of various herbs has been an attractive strategy in combating human diseases. Rosmarinic acid (RA) is a bioactive phenolic compound commonly found in plants of Lamiaceae and Boraginaceae families. RA is biosynthesized using amino acids tyrosine and phenylalanine via enzyme-catalyzed reactions. However, the chemical synthesis of RA involves an esterification reaction between caffeic acid and 3,4-dihydroxy phenyl lactic acid contributing two phenolic rings to the structure of RA. Several studies have ascertained multiple therapeutic benefits of RA in various diseases, including cancer, diabetes, inflammatory disorders, neurodegenerative disorders, and liver diseases. Many previous scientific papers indicate that RA can be used as an anti-plasmodic, anti-viral and anti-bacterial drug. In addition, due to its high anti-oxidant capacity, this natural polyphenol has recently gained attention for its possible application as a nutraceutical compound in the food industry. Here we provide state-of-the-art, flexible therapeutic potential and biomedical features of RA, its implications and multiple uses. Along with various valuable applications in safeguarding human health, this review further summarizes the therapeutic advantages of RA in various human diseases, including cancer, diabetes, neurodegenerative diseases. Furthermore, the challenges associated with the clinical applicability of RA have also been discussed.

Effect of phenyllactic acid on silage fermentation and bacterial community of reed canary grass on the Qinghai Tibetan Plateau

BackgroundThis study aimed to investigate the effect of phenyllactic acid as an additive on silage fermentation and bacterial community of reed canary grass (RCG, Phalaris arundinacea L.) on the Qinghai Tibetan Plateau. At the heading stage, RCG was harvested, chopped and ensiled in small bag silos. The silage was treated without (control, 1.0 g/mL sterile water, on a fresh matter basis (FM)) or with phenyllactic acid (PLA, 3 mg/mL, FM), antimicrobial additive (PSB, a mixture of potassium sorbate and sodium benzoate, 2%, FM), lactic acid bacteria inoculant (LABi, L. plantarum + L. curvatus, 1 × 106 cfu/g, FM) and PLA + LABi, and then stored in a dark room at the ambient temperature (5 ~ 15 °C) for 60 days.ResultsCompared with control, PLA decreased lactic acid, acetic acid and ammonia-N contents, and subsequently increased CP content of RCG silage. PLA enhanced the growth of lactic acid bacteria and reduced the count of yeasts (P < 0.05) in RCG silage, with reduced bacterial richness index (Chao1), observed operational taxonomic units and diversity index (Simpson). In relative to control, moreover, PLA and PLA + LABi increased the relative abundance of Lactococcus in RCG silage by 27.73 and 16.93%, respectively.ConclusionsTherefore, phenyllactic acid at ensiling improved nutritional quality of RCG silage by advancing the disappearance of yeasts and the dominance of Lactococcus.

Impact of the Inoculation Method of Geotrichum candidum, Used as Biocontrol Agent, on T-2 Toxin Produced by Fusarium sporotrichioides and F. langsethiae during the Malting Process.

In malt production, steeping and germination steps offer favorable environmental conditions for fungal proliferation when barley is already contaminated by Fusarium species, T-2 toxin producers. However, the use of G. candidum as a biocontrol agent can prevent this proliferation. Indeed, in previous work, a correlation between phenyllactic acid (PLA) production by G. candidum and the reduction in Fusarium sporotrichioides and F. langsethiae growth and T-2 toxin concentration was demonstrated. In the present study, to improve the efficiency of G. candidum, the effects of the inoculum concentration and the inoculation method of G. candidum on PLA and T-2 toxin concentrations were evaluated. First, co-culture experiments with Fusarium species and G. candidum were conducted in a liquid synthetic medium. The results showed that inoculation of G. candidum in the freeze-dried form at 0.4 g/L allowed the production of PLA from the second day of incubation associated with a reduction in T-2 toxin concentration of 82% and 69% produced by F. sporotrichioides and F. langsethiae, respectively. Moreover, the activated form of G. candidum at 0.4 g/L enhanced PLA concentration leading to better T-2 toxin reduction. Second, experiments were conducted on artificially infected barley kernels with both Fusarium species under conditions mimicking the malting step. As for co-culture experiments, the use of the activated form of G. candidum was established as the best condition for T-2 toxin concentration reduction for a 3 day malting period.

Streptococcus mutans and Candida albicans Biofilm Inhibitors Produced by Lactiplantibacillus plantarum CCFM8724.

Lactiplantibacillus plantarum CCFM8724 inhibits the growth of Streptococcus mutans and Candida albicans in mixed-species biofilm formation. In this study, bioactive compound including cyclo (leu-pro), cyclo (phe-pro), and some organic acids, such as 3-phenyllactic acid, hydrocinnamic acid, and palmitic acid, were identified through GC-MS analysis. At 50μg·mL-1, cyclo (leu-pro) reduced biofilm mass (OD600) from 3.00 to 2.00, and hydrocinnamic acid at 25μg·mL-1 reduced biofilm mass (OD600) from 3.00 to 1.00. The expression of ALS3 and HWP1 was downregulated by cyclo (leu-pro). Furthermore, a mixture of cyclo (leu-pro), cyclo (phe-pro), 3-phenyllactic acid, hydrocinnamic acid, and palmitic acid, had anti-biofilm activity. Overall, the results provide promising baseline information for the potential use of this probiotic and its components in preventing biofilm formation.

Cryogel‐based co‐culture of Lactobacillus paracasei and Lactobacillus buchneri towards phenyllactic acid bioproduction: fundamental hydrodynamics and biotransformation characteristics

AbstractBACKGROUNDPhenyllactic acid is an important monomer for bioplastics, food preservative, feed additive and pharmaceutical agent. However, bioproduction of phenyllactic acid suffers drawbacks regarding the high cost of substrates, poor efficiency and yield of fermentation or conversion, and therefore new bioproduction strategies need to be investigated.RESULTSIn this work, bioproduction of phenyllactic acid was developed by employing semi‐hydrophobic cryogels as cell entrapment matrices to co‐culture Lactobacillus paracasei and L. buchneri strains, and the obtained cell‐loaded cryogels were used as biocatalysts in the biotransformation from phenylalanine. Flow characteristics and permeabilities of fermentation broths through cryogels, co‐culture performance and biotransformation characteristics were studied. Permeabilities of cell‐free fermentation broths through the cryogel bed were correlated as a function of concentrations of glucose and metabolites of organic acids. The flow rate versus pressure drop relationships for these bio‐based broths through cryogels were predicted successfully with a capillary‐based model. The cell growth was enhanced by cryogels and the maximum cell production of 40.6 g L−1 was achieved with cryogels. The maximum yield from phenylalanine of 1.0 mg mL−1 to phenyllactic acid was 39.6%, which was higher than that of 31.4% by co‐culture of L. casei and L. paracasei.CONCLUSIONFlow of fermentation broths through cryogels is crucial to develop a novel cryogel‐based bioproduction strategy for phenyllactic acid and can be characterized by capillary‐based modeling. Semi‐hydrophobic cryogels could be an interesting class of immobilization matrices for high‐cell‐density co‐culture towards the green strategy with these new biocatalysts in phenyllactic acid bioproduction and thus have potential applications in industries. © 2022 Society of Chemical Industry (SCI).

Characterization of Tibetan kefir grain-fermented milk whey and its suppression of melanin synthesis

Tibetan kefir grain as the starter of milk fermentation has been applied as functional food with many bioactive characteristics. In this study, the milk whey product (TKG-MW) was obtained through the milk fermentation of Tibetan kefir grain containing the dominant Lactobacillus, Acetobacter, and Bacillus after 3 and 6 days of cultivation. Antioxidant, anti-inflammatory, and melanogenesis inhibition capacities under TKG-MW treatment were analyzed. Results revealed that the antioxidation of TKG-MW at 6 days of fermentation was higher than that at 3 days of fermentation according to the DPPHand ABTS+ radical scavenging analysis. However, the anti-inflammation of TKG-MW was only observed at 6 days of fermentation by using lipopolysaccharide-stimulated RAW 264.7 macrophages. The inhibition of mushroom tyrosinase activity by TKG-MW was demonstrated. The decrease of melanin content was verified using α-melanocyte-stimulating hormone-stimulated B16-F10cell. The real-time quantitative reverse transcription polymerase chain reaction result indicated that the mRNA levels of Tyr, Trp-1, and Trp-2 of the B16cell involved in melanin synthesis were down-regulated over a two-fold change by the TKG-MW treatment. Additionally, the protein expressions of Tyr, Trp-1, Trp-2, and Mitf of the B16cell were reduced with the TKG-MW treatment. Organic acids, such as lactic acid, succinic acid, 3-phenyllactic acid, l-pyroglutamic acid, and malic acid, were identified by liquid chromatography-mass spectrometry in TKG-MW and were found to significantly inhibit tyrosinase activity. To the best of our knowledge, this work is the first to report melanogenesis suppression by TKG-MW. Results suggested that the fermentation product of TKG could be applied as a depigmenting agent in food and cosmetics.

Polyphenols and Minor Constituents in Honey from North Macedonia and Bulgaria

&#x0D; &#x0D; &#x0D; Honey is a highly concentrated sugar solution that is a rich source of many bioactive compounds including numerous minor constituents. Among them, polyphenols such as flavonoids and phenolic acids are the most important classes of pharmacologically active compounds. Together with other minor constituents they are also considered potential chemical markers for the botanical and geographical origin of honey as well as for its authenticity.&#x0D; A solid-phase extraction procedure and HPLC/DAD/MSn method has been applied for identification and quantification of minor constituents in honey from the region of Bulgaria, North Macedonia, and Greece. Solid-phase extraction using Amberlite XAD-2 as an adsorbent was used for sample preparation enabling purification and concentration of the analysed compounds, mainly polyphenols. In total, 16 compounds were identified in the 21 extracts, 3 of them hydroxycinammic acids (caffeic, p-coumaric and ferulic acid), 5 flavonoids (naringenin, chrysin, galangin, pinocembrin and pinobanksin methyl ether) as well as gluconic acid, quinic acid, ascorbic acid, phenyllactic acid, kynurenic acid and abscisic acid in its two isomeric forms. Quantification of the identified polyphenols was made by an external calibration. The results showed that the developed method presented here is suitable for obtaining qualitative and quantitative data for polyphenols of honey.&#x0D; &#x0D; &#x0D;

Rosmarinic acid production of Ehretia asperula Zollinger &amp; Moritzi cell suspension cultures: effects of cell aggregate size, glucose, and chitosan

Rosmarinic acid (RA) is an ester of caffeic acid and 3,4-dihydroxy phenyl lactic acid with anti-oxidant, anti-bacterial, anti-viral, and anti-cancer properties. It has been found in some plants of the Boraginaceae and Lamiaceae families. Ehretia asperula Zollinger &amp; Moritzi is a medicinal plant, widely distributed in some countries such as China, Vietnam, Myanmar, and Thailand. Cell suspensions were obtained by transferring 1 g of friable callus into 20 mL of B5 liquid medium supplemented with 0.4 mg/L NAA and 0.1 mg/L BA, on orbital shaker at 90 rpm in the dark. The subculture was carried out after each of 21 days along with removing brown cell aggregates. To investigate the effects of cell aggregation, glucose, and chitosan on cell biomass and RA biosynthesis, the yellow cell suspensions were transferred to a new liquid medium. The results showed that non-sieved cell aggregates produced the highest biomass and RA content of E. asperula Zollinger &amp; Moritzi cell suspension cultures. Glucose concentrations had direct effects on RA production. An addition of 45 mg/L glucose showed a significant (1.198 fold) increase in RA yield compared with control (30 mg/L) and other concentrations. On the other hand, the optimum concentration of chitosan for enhancing RA content was found at 50 mg/L after 48 hours of treatment, with an RA concentration 1.17 times greater than the control. These findings suggested that the using of cell clusters which size more than 0.125 mm, the addition of appropriate concentrations of sugar and chitosan could stimulate RA biosynthesis of E. asperula Zollinger &amp; Moritzi cell suspensions

Energy metabolism as the target of 3-phenyllactic acid against Rhizopus oryzae

3-phenyllactic acid (PLA) has broad anti-fungal activity, however, target sites of PLA on fungal cells and its anti-fungal mechanism of action have been poorly studied. In this study, we explored the inhibition mechanism of Rhizopus oryzae (R. oryzae) on rotten lily bulbs by PLA. The minimum inhibitory concentration value of PLA against R. oryzae was 8 mg/mL. We observed the ultrastructure of R. oryzae by scanning electron microscopy and transmission electron microscopy which indicated that PLA did not damage the cell membrane, but destroyed the mitochondria and other organelles. Tandem mass tag proteomes showed that PLA significantly down-regulated (P < 0.05) the expression of hexokinase (HK), phosphofructokinase (PFK), a-ketoglutarate dehydrogenase (a-KGDH), adenylate kinase (ADK1), Cytochrome C oxidase and NADH dehydrogenase, and up-regulated (P < 0.05) the expression of mitochondrial ADP/ATP carrier proteins (AAC) and subunit IV (CCIO IV) in glycolysis, tricarboxylic acid cycle or oxidative phosphorylation metabolism. Following these findings, down-regulated HK and a-KGDH activity of aforementioned pathways was shown by enzyme activity assay, and regulated gene expression of ADK1, AAC, CCIO IV and NADH dehydrogenase was further confirmed by real-time quantitative PCR. Central carbon metabolomics showed that citric acid, cis-Aconitic acid, isocitric acid, alpha-Ketoglutaric acid, succinate, fumarate and malic acid of the tricarboxylic acid cycle metabolites were significantly down-regulated (P < 0.05), and ATP production by oxidative phosphorylation was also significantly reduced (P = 0.02), resulting in insufficient energy production. Thus, ROS levels increased by 141% of the control values and cytochrome C was released, resulting in gradual cell apoptosis. All data indicated that energy metabolism was the target of PLA against R. oryzae. This was the first study to show that energy metabolism could be the target of PLA against R. oryzae, which could provide a theoretical basis to study the mechanism of fungal inhibition.

Lactic Acid Bacteria from African Fermented Cereal-Based Products: Potential Biological Control Agents for Mycotoxins in Kenya.

Cereals play an important role in global food security. Data from the UN Food and Agriculture Organization projects increased consumption of cereals from 2.6 billion tonnes in 2017 to approximately 2.9 billion tonnes by 2027. However, cereals are prone to contamination by toxigenic fungi, which lead to mycotoxicosis. The current methods for mycotoxin control involve the use of chemical preservatives. However, there are concerns about the use of chemicals in food preservation due to their effects on the health, nutritional quality, and organoleptic properties of food. Therefore, alternative methods are needed that are affordable and simple to use. The fermentation technique is based on the use of microorganisms mainly to impart desirable sensory properties and shelf-life extension. The lactic acid bacteria (LAB) are generally regarded as safe (GRAS) due to their long history of application in food fermentation systems and ability to produce antimicrobial compounds (hydroxyl fatty acids, organic acids, phenyllactic acid, hydrogen peroxide, bacteriocins, and carbon dioxide) with a broad range of antifungal activity. Hence, LAB can inhibit the growth of mycotoxin-producing fungi, thereby preventing the production of mycotoxins. Fermentation is also an efficient technique for improving nutrient bioavailability and other functional properties of cereal-based products. This review seeks to provide evidence of the potential of LAB from African fermented cereal-based products as potential biological agents against mycotoxin-producing fungi.

Enhanced Antimicrobial Cellulose/Chitosan/ZnO Biodegradable Composite Membrane.

In this study, chitosan and sugarcane cellulose were used as film-forming materials, while the inorganic agent zinc oxide (ZnO) and natural compound phenyllactic acid (PA) were used as the main bacteriostatic components to fabricate biodegradable antimicrobial composite membranes. The water absorption and antimicrobial properties were investigated by adjusting the concentration of PA. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results demonstrated that the components of the composite membrane were successfully integrated. The addition of ZnO improved the mechanical and antimicrobial properties of the composite membrane, while the addition of PA with high crystallinity significantly reduced the water absorption and swelling. Moreover, the addition of 0.5% PA greatly improved the water absorption of the composite membrane. The results of antimicrobial experiments showed that PA improved the antimicrobial activity of the composite membrane against Staphylococcus aureus, Escherichia coli, Aspergillus niger and Penicillium rubens. Among them, 0.3% PA had the best antimicrobial effect against S. aureus, E. coli and A. niger, while 0.7% PA had the best antimicrobial effect against P. rubens.

Isolation, purification, identification, and discovery of the antibacterial mechanism of ld-phenyllactic acid produced by Lactiplantibacillus plantarum CXG9 isolated from a traditional Chinese fermented vegetable

Phenyllactic acid (PLA) is an antimicrobial compound and has been rarely reported to naturally occur in food sources with the exception of honey, sourdough, and some pickles. In this study, a traditional Chinese fermented vegetable, Stinky xiancaigeng, was found to contain high concentrations of PLA. A high PLA level-producing Lactiplantibacillus plantarum (L. plantarum) CXG9 was subsequently isolated and subjected to genomic analysis. Six L- and two d-lactate dehydrogenase genes were predicted, indicating that PLA produced by L. plantarum CXG9 contained L- and D-isomers. The ratio of L- and D-isomers was 11:1 by chiral high performance liquid chromatography analysis. LD-PLA from L. plantarum CXG9 cultures were then purified by a three-step procedure and identified by mass spectrometry. LD-PLA exhibited strong anti-Listeria monocytogenes activity, with a minimum inhibitory concentration of 2.4 mg/mL. The results of anti-Listeria monocytogenes mechanism demonstrated that LD-PLA damaged cell membrane integrity, increased membrane permeability, induced pore formation, and triggered intracellular material leakage by interacting with cell membrane proteins. These results presented here contribute to the use of PLA in further development and application as an antibacterial agent in the food industry.

Development of a food packaging antibacterial hydrogel based on gelatin, chitosan, and 3-phenyllactic acid for the shelf-life extension of chilled chicken

Food safety caused by microbial contamination is an important problem that is difficult to solve for the food industry. In this study, the effective antibacterial hydrogel from electrospinning nanofibers prepared using gelatin, chitosan, and 3-phenyllactic acid (PLA) after water absorption was used to improve the antibacterial performance and prolong the shelf life of chilled chicken meat. The structure, water-absorbing ability, antibacterial ability, and fresh-keeping ability of this hydrogel were characterized. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that the carboxyl group in PLA reacted with the amino group in chitosan, which formed amide bond under acidic conditions. This bond enhanced the water absorption and stability of the hydrogel. Low-field nuclear magnetic resonance showed that the addition of PLA not only changed the structure of hydrogels but also changed the ratio of different states of water in the hydrogels. The swelling ratio of GCP-1 hydrogel was two times larger than that of GCP-0 hydrogel, and scanning electron micrographs showed that the GCP-1 hydrogel after water absorption had a unique spongy shape. Furthermore, the GCP-1 hydrogel effectively inactivated foodborne pathogens Staphylococcus aureus and Escherichia coli and prolonged the preservation of chilled chicken to 4 days. This study provides an innovative way to apply electrospinning nanofibers in food packaging.

Use of Mustard Extracts Fermented by Lactic Acid Bacteria to Mitigate the Production of Fumonisin B1 and B2 by Fusarium verticillioides in Corn Ears.

Corn (Zea mays) is a worldwide crop subjected to infection by toxigenic fungi such as Fusarium verticillioides during the pre-harvest stage. Fusarium contamination can lead to the synthesis of highly toxic mycotoxins, such as Fumonisin B1 (FB1) and Fumonisin B2 (FB2), which compromises human and animal health. The work aimed to study the antifungal properties of fermented yellow and oriental mustard extracts using nine lactic acid bacteria (LAB) in vitro. Moreover, a chemical characterization of the main phenolic compounds and organic acids were carried out in the extracts. The results highlighted that the yellow mustard, fermented by Lactiplantibacillus plantarum strains, avoided the growth of Fusarium spp. in vitro, showing Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) values, ranging from 7.8 to 15.6 g/L and 15.6 to 31.3 g/L, respectively. Then, the lyophilized yellow mustard fermented extract by L. plantarum TR71 was applied through spray-on corn ears contaminated with F. verticillioides to study the antimycotoxigenic activity. After 14 days of incubation, the control contained 14.71 mg/kg of FB1, while the treatment reduced the content to 1.09 mg/kg (92.6% reduction). Moreover, no FB2 was observed in the treated samples. The chemical characterization showed that lactic acid, 3-phenyllactic acid, and benzoic acid were the antifungal metabolites quantified in higher concentrations in the yellow mustard fermented extract with L. plantarum TR71. The results obtained confirmed the potential application of fermented mustard extracts as a solution to reduce the incidence of mycotoxins in corn ears.

Antifungal Activity of Lactobacillus plantarum ZZUA493 and Its Application to Extend the Shelf Life of Chinese Steamed Buns.

Lactic acid bacteria (LAB) can produce many kinds of antifungal substances, which have been widely proven to have antifungal activity. In this study, 359 strains of LAB were screened for antifungal activity against Aspergillus niger (A. niger) using the 96-well microtiter plate method, and three showed strong activity. Of these, ZZUA493 showed a broad-spectrum antifungal ability against A. niger, Aspergillus oryzae, Trichoderma longibrachiatum, Aspergillus flavus and Fusarium graminearum. ZZUA493 was identified as Lactobacillus plantarum. Protease treatment, the removal of hydrogen peroxide with catalase and heat treatment had no effect on the antifungal activity of the cell-free supernatant (CFS) of ZZUA493; organic acids produced by ZZUA493 appeared to have an important role in fungal growth inhibition. The contents of lactic acid, acetic acid and phenyllactic acid in the CFS tended to be stable at 48 h, and amounted to 28.5, 15.5 and 0.075 mg/mL, respectively. In addition, adding ZZUA493, as an ingredient during their preparation, prolonged the shelf life of Chinese steamed buns. Overall, ZZUA493 appears to have good potential as a fungal inhibitor for food preservation.

Effect of Coix Seed Extracts on Growth and Metabolism of Limosilactobacillus reuteri.

Coix seed (Coix lachryma-jobi L.) is an important nourishing food and traditional Chinese medicine. The role of their bioactive constituents in physiology and pharmacology has received considerable scientific attention. However, very little is known about the role of coix seed bioactive components in the growth of Limosilactobacillus reuteri (L. reuteri). This study aimed to evaluate the effects of coix seed extract (CSE) on the growth, acidifying activity, and metabolism of L. reuteri. The results showed that CSE can increase the growth and acidifying activity of L. reuteri compared with the control group. During the stationary phase, the viable bacteria in the medium supplemented with coix seed oil (CSO, 13.72 Log10 CFU/mL), coix polysaccharide (CPO, 12.24 Log10 CFU/mL), and coix protein (CPR, 11.91 Log10 CFU/mL) were significantly higher (p < 0.05) than the control group (MRS, 9.16 Log10 CFU/mL). CSE also enhanced the biosynthesis of lactic acid and acetic acid of L. reuteri. Untargeted metabolomics results indicated that the carbohydrate metabolism, amino acid metabolism, and nucleotide metabolism activities of L. reuteri were increased after adding CSE. Furthermore, CSE increased the accumulation of bioactive metabolites, such as phenyl lactic acid, vitamins, and biotin. Overall, CSE may have prebiotic potential and can be used to culture L. reuteri with high viable bacteria.