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This study aimed to elucidate the molecular mechanism of Lactiplantibacillus plantarum NMGL2 (L. plantarum NMGL2) isolated from traditional Inner Mongolia cheese that how it survived under simultaneous cold and acid conditions, and developed potential protective strategies for bacterial survivability. L. plantarum NMGL2 was previously shown with numerous bioactivities such as antibiofilm, cholesterol-lowering effect, and bile acids binding capacity. In this study, non-directional UPLC-Q-TOF-MS/MS-based metabolomics was performed to investigate the metabolic variations in L. plantarum NMGL2 during refrigerated storage of the fermented milk to comprehend the underlying chemical process of bacterial resistance under the cold and acid conditions. Organic acids, fatty acids, polypeptides, amino acids, and carbohydrates were all among the 122 differently abundant metabolites discovered, which were mostly involved in organic acid, sugar, protein, amino acid, and purine metabolisms, This indicated that the bacteria counteracted the combinational coldness and acidity by increased biosynthesis of several important biomolecules such as glycolipids and glycoproteins for providing cell protection, glutamate for initiating cell deacidification process, and DNA for cell repairing, as well as cell membrane proteins and cell wall peptidoglycan. Western blot analysis confirmed up-regulation of PGRP protein, implicating that the cell wall peptidoglycan played a significant part in bacterial resistance under cold and acid conditions. Further SPME-GC/MS analysis demonstrated different volatile metabolites detected in the fermented milk during the storage, including 7 acids, 4 alcohols, 2 aldehydes, 4 ketones and 3 esters, which provided unique flavor characteristic of fermented milk for favorable consumer acceptance of the product. For the first time, our research elucidates the molecular mechanism by which L. plantarum survives simultaneous cold and acid conditions with development of potential protective strategies under such conditions. [Display omitted] • L. plantarum NMGL2 metabolomics analysis reveals the molecular mechanism involved in bacterial resistance to cold and acid stresses. • Western blot analysis confirmed up-regulation of PGRP protein. • Cell wall peptidoglycan played the major role in the bacterial resistance against the stresses. [ABSTRACT FROM AUTHOR]

As an attractive choice for patients with celiac disease, scaling up production and innovating flavors are significant challenges for the development of traditional Sichuan snack, waxy rice cake. 3D food printing is an emerging technology that enables the production of food with the desired shape and structure. This study introduced two types of Zanthoxylum oil to enhance both the printability and quality of waxy rice cakes, aiming to achieve Sichuan-style taste through the Zanthoxylum oil's effect. The results showed that the waxy rice flour dough with Zanthoxylum oil exhibited shear thinning properties, with viscosity decreasing from 292.59 Pa s to 91.16 Pa s at a shear rate of 1 s⁻1, making it an ideal material for 3D printing. The addition of Zanthoxylum oil significantly enhanced water activity and hydrogen bonds in the dough system. Furthermore, the incorporation of red Zanthoxylum oil accelerated the dough maturation process. 3D printing and TPA results revealed that sticky rice cakes containing 8% and 12% Zanthoxylum oil exhibited optimal printing accuracy, with the 8% sample achieving 96.69% fidelity. After steaming, the waxy rice cake with 8% Zanthoxylum oil retained a height of 18.23 mm and a diameter of 31.74 mm, with a soft, sticky texture. In summary, the product with the addition of 8% red Zanthoxylum oil exhibited superior appearance and texture, making it suitable for 3D printing. This study is expected to realize the customized production of Sichuan-style waxy rice cake. • Zanthoxylum oil enhanced Sichuan-style waxy rice cake quality. • Improved rheological properties led to successful 3D printing. • Enhanced post-steamed appearance of 3D printed rice dough. [ABSTRACT FROM AUTHOR]

Fruits and vegetables are susceptible to Listeria monocytogenes. In this study, the nano emulsion of oregano essential oil (OEO) prepared by ultrasonic (US) nanoemulsion method combined with US has a promising synergistic bactericidal effect on L. monocytogenes , with 255 W/cm2+0.06 μL/mL origano essential oil nanoemulsion (OEONE) completely kill the initial number of bacteria (8.67 ± 0.17 log CFU/mL) after 15 min of treatment. Compared to control, reactive oxygen species (ROS), malondialdehyde (MDA) detection, nucleic acid and protein release tests showed that US + OEONE intensified cell membrane lipid peroxidation and increased cell membrane permeability. Flow cytometry (FCM) once again demonstrated the damage to cell membrane integrity caused by US + OEONE treatment. The results of field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) indicate that US + OEONE treatment alter cell morphology. Also, this study provides evidence to support the use of US + OEONE as a practical preservation method to minimize the presence of L. monocytogenes on the surface of blueberries, and sensory evaluations indicate that US + OEONE-treated blueberries are acceptable. In addition, this method demonstrated the ability to retard microbial proliferation without affecting the color, texture, and antioxidant properties of blueberries during storage. These results indicate that the implementation of US + OEONE is expected to improve the microbial safety of fresh produce. [Display omitted] • Ultrasound (US) and oregano essential oil (OEONE) had a synergistic antibacterial efficacy. • US + OEONE significantly disrupted the permeability and integrity of cell membranes. • US + OEONE obviously altered the morphology and internal microstructure of cells. • US + OEONE caused bacterial oxidative stress and lipid peroxidation. • The treatment method of US + OEONE has promising application effect on blueberry preservation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Survival of L. monocytogenes in minced pork to single or sequential environmental stresses after cold stress was explored. • Thermal and gastric fluid resistance of L. monocytogenes was evaluated after sequential stress. • NaCl adaptation reduced the resistance of L. monocytogenes to LA and Nisin stress, whereas LA induced the opposite trend. • Sequential pressure reduces the effect of a single pressure on the thermal resistance of L. monocytogenes. • Sequential stress of LA 1.25-NaCl 50 renders thermal-treated L. monocytogenes insensitive to simulated gastric fluid. In this study, Listeria monocytogenes from minced pork was evaluated for changes in resistance to thermal treatment and gastric fluid following environmental stresses during food processing. Bacteria were exposed to cold stress, followed by successive exposures to different stressors (lactic acid (LA), NaCl, or Nisin), followed by thermal treatments, and finally, their gastrointestinal tolerance was determined. Adaptation to NaCl stress reduced the tolerance of L. monocytogenes to subsequent LA and Nisin stress. Adaptation to LA stress increased bacterial survival in NaCl and Nisin-stressed environments. Bacteria adapted to Nisin stress showed no change in tolerance to subsequent stress conditions. In addition, treatment with NaCl and LA enhanced the thermal tolerance of L. monocytogenes , but treatment with Nisin decreased the thermal tolerance of the bacteria. Almost all of the sequential stresses reduced the effect of a single stress on bacterial thermal tolerance. The addition of LA and Nisin as a second step of stress reduced the tolerance of L. monocytogenes to gastric fluid, whereas the addition of NaCl enhanced its tolerance. The results of this study are expected to inform processing conditions and sequences for meat preservation and processing and reduce uncertainty in risk assessment of foodborne pathogens due to stress adaptation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Shelf-life enhancement of fruits and vegetables through a novel technique by utilization of microbially driven enzyme glucose oxidase. • Casting a fine layer of hydrogen peroxide on the food item that will protect the fruit from decay. • Produced nanoparticles (ZnO, Ag) ligated with Glucose Oxidize (Gox) purified from Aspergillus niger. • Fruit quality parameters such as TSS, pH, weight loss, DPPH free radical capturing performance. • Enzymes ligated on the surface of nanoparticles (ZnONP) were exceptional for extension of post-harvest shelf life of fruits. This study was designed to extend the shelf life of fruits and vegetables through a novel technique based on utilization of microbially driven enzyme glucose oxidase and casting a fine layer of hydrogen peroxide on the food item that protected the fruit from decay. The produced nanoparticles (ZnO, Ag) were ligated with Glucose Oxidize (GOx) purified from Aspergillus niger. Post ligation studies revealed that ligated enzymes display relatively enhanced activity. Four types of sprays were prepared in order to compare their effectiveness. Glucose oxidase/silver nanoparticles (GOx/AgNPs), glucose oxidase/zinc oxide nanoparticles (GOx/ZnONPs), AgNPs and ZnONPs sprays were applied to guava fruit samples as post-harvest therapeutic agents for a period of 15 days. Fruit quality parameters such as total suspended solids (TSS), pH, weight loss, DPPH free radical capturing performance and firmness confirms that usage of the bioconjugates especially that of GOx/ZnONP was curiously active to maintain the physical appearance of fruit well along with no such deterioration in chemical composition of fruit. Consequently, enzymes ligated on the surface of nanoparticles (ZnONP) are exceptional for extension of post-harvest shelf life of fruits such as guava. [ABSTRACT FROM AUTHOR]