Plant extracts are increasingly becoming important additives in food industry due to their antimicrobial and antioxidant abilities that delay the development of off-flavors and improve the color ...stability in ready-to-eat (RTE) meat products. Due to their natural origin, they are excellent candidates to replace synthetic molecules, which are generally considered to have toxicological and carcinogenic effects. The efficient extraction of these antioxidant molecules from their natural sources, along with the determination of their activity in the commercialized products, have been a great challenge for researchers and food chain contributors. The objective of this review is to highlight the application of plant extracts to improve the shelf-life, nutritional and health-related properties of RTE meat products. The sensory effects of these extracts on RTE meat products as well as the possible synergistic effects of a combination of extracts are discussed.
This work aims to evaluate the antimicrobial potential of ethanolic and water extracts of roselle (
, rosemary (
, clove (
), and thyme (
) on some food pathogens and spoilage microorganisms. Agar ...well diffusion method has been used to determine the antimicrobial activities and minimum inhibitory concentrations (MIC) of different plant extracts against Gram-positive bacteria (
), Gram-negative bacteria (
, and
), and one fungus (
). The extracts exhibited both antibacterial and antifungal activities against tested microorganisms. Ethanolic roselle extract showed significant antibacterial activity (
< 0.05) against all tested bacterial strains, while no inhibitory effect on
(CA) was observed. Only the ethanolic extracts of clove and thyme showed antifungal effects against CA with inhibition zones ranging from 25.2 ± 1.4 to 15.8 ± 1.2 mm, respectively.
(BC) appears to be the most sensitive strain to the aqueous extract of clove with a MIC of 0.315%. To enhance our understanding of antimicrobial activity mechanism of plant extracts, the changes in internal pH (pH
), and membrane potential were measured in
(SA) and
(EC) cells after exposure to the plant extracts. The results indicated that the plant extracts significantly affected the cell membrane of Gram-positive and Gram-negative bacteria, as demonstrated by the decline in pH
as well as cell membrane hyperpolarization. In conclusion, plant extracts are of great value as natural antimicrobials and can use safely as food preservatives.
It is still a great challenge to develop soybean protein adhesives with high strength and antimildew properties through a sustainable and facile strategy. Herein, water-soluble dialdehyde chitosan ...(DCS) was obtained by oxidizing chitosan (CS) and used to crosslink soybean meal (SM) to fabricate protein adhesives via the Schiff base reaction. This strategy is simple, all-biomass, and without additional crosslinkers. Owing to the covalent imine bonds and non-covalent hydrogen bonds interactions, the adhesion strength of SM/DCS-4 adhesive reached 1.47 MPa, satisfying the requirement for Type II interior plywood (≥ 0.7 MPa). More importantly, the protein adhesives showed excellent antimildew properties due to the amino and aldehyde groups of DCS and the Schiff base formation. The SM/DCS-4 adhesive exhibited long shelf life (7 d), which is beneficial for industrial applications. This study helps in preparing green and fully bio-based adhesives from agricultural and fishery wastes.
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•Dialdehyde chitosan (DCS) acted as a functional crosslinker.•Highly dense imine bonds and hydrogen bonds strengthened the adhesive network.•DCS can improve the bonding strength and antimildew properties of the adhesive.•The soybean meal (SM)/DCS adhesive exhibited long shelf life (7 d).•The SM/DCS adhesive made full use of agricultural and fishery wastes.
Novel active bionanocomposite films were prepared by incorporating chitosan(CS)/gallic acid (GA) nanoparticles (CGNPs) into a konjac glucomannan (KGM) film. CGNPs with a GA loading efficiency of ...78 ± 2.3% were obtained through ionotropic gelation method, and they presented a spherical morphology with a diameter range of 80–100 nm. The influences of the CGNPs content on the structural, morphological, mechanical, barrier, thermal and antimicrobial properties of KGM/CGNPs films were discussed. The rheological results of film-forming solutions revealed that the CGNPs interacted with KGM through hydrogen bonds in a bionanocomposite matrix, which was coincidence with the fourier transform infrared spectroscopy, X-ray diffraction and thermal analysis results. The microstructure of the films showed that the introduced 5–10% CGNPs appeared to be homogeneously dispersed within the KGM film matrix, thereby reducing the free volume of the composite matrix, and improving the final bionanocomposite films' mechanical, and barrier properties significantly (p < 0.5). In comparison with a pure KGM film, KGM/CGNPs bionanocomposite films showed an excellent antimicrobial activity against food-borne pathogens such as gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli O157:H7) bacteria, because of antimicrobial effectiveness of the CGNPs. Therefore, KGM/CGNPs bionanocomposite films show potential for applications in active food packaging materials.
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•Chitosan/gallic acid nanoparticles (CGNPs)/konjac glucomannan bionanocomposite films were prepared by solvent casting.•The rheology of the film-forming solution was investigated.•CGNPs improved the film’s mechanical and physicochemical properties.•Active films exhibited an antimicrobial effect against food-borne pathogens.•Konjac glucomannan/CGNP films show promising potential as food packaging materials.
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•It’s first time to prepare the natural cellulose-based nonionic antimicrobial biopolymers.•Indole-3-acid-functionalized biopolymers had favorable solubility and antibacterial ...properties.•The minimum inhibitory concentration of soluble nonionic biopolymers was 5 μg disk−1.•Cellulose-based nonionic biopolymers showed good antimicrobial activity, non-leachability, and biocompatibility.
Novel soluble cellulose-based nonionic biopolymers (CIs) with enhanced antimicrobial properties and nonleachability were successfully produced using a sustainable one-pot synthesis method. Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance H-spectrometer (1H NMR), X-ray Photoelectron Spectroscopy (XPS), and Energy Dispersive Spectroscopy (EDS) results demonstrated that the cellulose (MCC) molecules combined with indole-3-acetic acid (IAA) via esterification to produce CIs with abundant terminal indole groups. The degree of substitution of the prepared CI3 reached 1.85 when the molar ratio of IAA to MCC molecules was 4:1. The prepared CI samples were characterized using X-ray diffractometer (XRD), Scanning Electronic Microscopy (SEM), Thermogravimetric Analysis (TGA), and other analysis techniques. Results indicated that after the MCC was grafted with IAA, its crystallinity decreased and solubility increased. After blending CI3 with polycaprolactone (PCL) to form cellulose-based antimicrobial (PCL–CI) films, the films showed good compatibility, preferable biological cell activity, and low water vapor permeability. When the CI3 content was 10%, the tensile strength of the produced PCL–CI10 film reached 9.96 MPa. Moreover, the prepared PCL–CI films exhibited good nonleachability after being immersed in water for 5 d. The disk diffusion assay revealed that the CIs and PCL–CI films had good antimicrobial and bactericidal effects against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The minimal inhibitory concentration was 5 μg disk−1, significantly lower than that of traditional antibiotics and chitosan. The nonionic biopolymers are simple and efficient to prepare and ecofriendly as well as exhibit nontoxicity, good solubility, enhanced antimicrobial properties, and nonleachability, which can provide new ideas for developing natural biomass-based nonionic antimicrobial materials with potential applications in wound dressing, medical devices, and food packaging.
Biodegradable edible films for sour cream packaging were developed based on chitosan (CS), hydroxyethyl cellulose (HEC), Olive leaf extract (OE), and titanium dioxide nanoparticles (TiO2-NPs). The ...prepared CS/HEC/TiO2-OE bionanocomposite films were evaluated for their antimicrobial and antioxidant activities as well as using FT-IR, mechanical, permeability, and contact angle. The effect of developed films on the lipid oxidation, microbiological load, and chemical properties of sour cream was investigated. The fabricated films had an antimicrobial impact against all tested strains. The film containing 8 % OE showed effective protection against fat oxidation, with a peroxide value of 3.21 meq O2/kg, a para-anisidine value 5.40, and free fatty acids of 0.82 mg KOH/kg. The films with OE 4 % and 8 % have a good effect on the microbiological load of sour cream for 90 days. These films did not influence the chemical composition of sour cream and therefore can be used in this sort of dairy product.
The aim of the present research was to investigate the interaction effect of incorporating titanium dioxide (TiO2) (0 %, 0.5 %, and 1 %) nanoparticles and manipulating the proportion of tomato seed ...mucilage (TSM) and gelatin (Ge) (1: 0, 0.33:0.67, 0.67:0.33, and 0:1) on the physical, mechanical, and microbial characteristics of the film. The findings indicated that the incorporation of TiO2 engendered an augmentation in the surface roughness of the film and an elevation in the film's thickness. The mechanical evaluation results revealed that the incorporation of TiO2 into the TSM-Ge films significantly enhanced (p˂0.05) the tensile strength (TS), (up to 300 %), an elevation of Young's modulus, while concurrently leading to a reduction in the elongation at break (EB). The incorporation of TiO2 resulted in a significant enhancement in various properties of the film (p˂0.05), including opacity, contact angle, oxygen permeability (OP), water vapor permeability (WVP), moisture absorption, moisture content, solubility, and swelling. The rise in the proportion of TSM resulted in a concomitant increase in the color differences (ΔE), and yellowness index (YI). Conversely, there was a decrease in the lightness (L*) and the whiteness index (WI). Additionally, an increase was found in opacity, solubility, moisture content, WVP, OP, swelling, and moisture absorption. It was observed that films without TiO2 exhibited no inhibitory effect. However, upon augmenting the concentration of TiO2 to 1 %, notable inhibitory and lethal effects were observed against various microorganisms, including Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida glabrata. The results showed that the TSM-Ge composite film containing TiO2, exhibited potential as a viable choice for food packaging susceptible to microbial spoilage.
•TSM-Ge film containing TiO2, exhibited potential as a viable choice for food packaging•Incorporation of TiO2 into TSM-Ge films exhibited enhancements in the film's physical, permeability, and antimicrobial characteristics.•Incorporation TiO2 and in TSM-Ge films caused the changed film's surface characteristics
To effectively extend the shelf life of fruits meanwhile facilitating consumers to judge their freshness, in this work, a double-layer multifunctional film combining CO2 sensitivity and antibacterial ...properties was successfully prepared by adding methyl red (MR), bromothymol blue (BTB) into gellan gum (GG) as the sensing inner layer, and doping tannic acid (TA) into sodium alginate with sodium carboxymethyl cellulose (CMC) as the antimicrobial outer layer, which was applied to the freshness indication of strawberries. Microscopic morphology and spectral analysis demonstrated that the bi-layer films were fabricated successfully. The mechanical characteristics, thermal stability, water vapor resistance, and antibacterial capabilities of the bilayer films improved as TA concentration rose. They exhibited noticeable color changes at pH = 2–10 and different concentrations of CO2. Application of the prepared films to strawberries revealed that the GG-MB@SC-6%TA film performed most favorably under 4 °C storage conditions, not only monitoring strawberry freshness but also retaining high soluble solids and titratable acidity, resulting in a slight decrease in hardness and weight loss. Therefore, taking into account all of the physical-functional characteristics, the GG-MB@6%TA film has a broad application prospect for intelligent food packaging.
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Essential oils obtained from medicinal and aromatic plants, due to their bioactive principles, represent an important pharmaceutical source for human and animals. The objective of this paperwork was ...to determine the effect of the addition in supplementary feeding of bee colonies of oregano and basil essential oils. The bee colonies fed, during spring, on sugar syrup and essential oils presented a better development, recording a number of bee brood cells that was bigger than in the control variant. At the same time, we observed a significant reduction in the total number of germs within the small intestine in the case of supplementation with these essential oils, correlated with the improvement of health status of bee colonies.
The aquatic environment, independent of their host, is more favorable to pathogenic bacteria than the terrestrial environment. Consequently, pathogenic bacteria can reach very high densities around ...aquatic animals and can cause high mortality. The conventional approach, such as antibiotics, has minimal effectiveness. Additionally, due to the emergence of (multiple) resistance, their use is under intense scientific and public scrutiny. Hence, there is a need for the development of alternative control techniques, with an emphasis on prevention, which is likely to be more cost-effective. In this study, a potential bacterial strain Cytobacillus firmus was isolated from polluted river sediment and characterized using a comprehensive range of techniques including biochemical, 16S rRNA sequencing and antibiogram assay. The pathogenicity of the bacteria was tested in vivo on Labeo rohita fingerlings found as non-pathogenic. Further, the bacteria were found to synthesize silver nanoparticles (AgNPs) using AgNO 3 as a substrate. The obtained AgNPs were characterized by various methods, including UV–vis spectroscopy, FTIR (Fourier-transform infrared spectroscopy), and Transmission Emission Microscopy (TEM). The study found that the AgNPs were 20 nm in size on average. The antimicrobial activity of synthesized AgNPs was examined against the model freshwater pathogenic bacteria, Edwardsiella tarda and both the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were 0.156 μM, while biofilm inhibition activity was also observed at 0.156 μM. The AgNPs showed no haemolytic activity at 0.313 μM. Our findings suggest that C. firmus mediated bacteriogenic AgNPs modulate the activity of common pathogenic bacteria E. tarda . The thoroughness of our research process gives us confidence in the potential of applying AgNPs in aquaculture as a considerable strategy to control the E. tarda infection.
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