Liposomes as Delivery System for Applications in Meat Products

In the meat industry, microbial contamination, and lipid and protein oxidation are important factors for quality deterioration. Although natural preservatives have been widely used in various meat products, their biological activities are often reduced due to their volatility, instability, and easy degradation. Liposomes as an amphiphilic delivery system can be used to encapsulate food active compounds, which can improve their stability, promote antibacterial and antioxidant effects and further extend the shelf life of meat products. In this review, we mainly introduce liposomes and methods of their preparation including conventional and advanced techniques. Meanwhile, the main current applications of liposomes and biopolymer-liposome hybrid systems in meat preservation are presented.

Nutmeg (Myristica fragrans Houtt.) essential oil: A review on its composition, biological, and pharmacological activities

Myristica fragrans (Houtt.) is an evergreen tree native to the Maluku Islands, Indonesia. M. fragrans kernel is extensively used in Indian traditional medicines to treat various diseases. Several studies attempt to compile and interpret the pharmacological potential of Myristica fragrans (Houtt.) aqueous and various chemical extracts. Thus, the pharmacological potential of nutmeg essential oil has not been reviewed phytochemically and pharmacologically. Therefore, the present study aimed to share appropriate literature evidence regarding the plant essential oil chemical composition and therapeutic potential of Myristica fragrans essential oil (MFEO). MFEO of leaf, mace, kernel, and seed were used worldwide as potential Ayurvedic medicine and fragrance. MFEO extracted by various methods and oil yield was 0.7–3.2, 8.1–10.3, 0.3–12.5, and 6.2–7.6% in leaf, mace, seed, and kernel. The primary chemical constituents of MFEO were sabinene, eugenol, myristicin, caryophyllene, β‐myrcene, and α‐pinene. Clinical and experimental investigations have confirmed the antioxidant, antimicrobial, antiinflammatory, anticancer, antimalarial, anticonvulsant, hepatoprotective, antiparasitic, insecticidal, and nematocidal activities of MFEO. It is the first attempt to compile oil yield, composition, and the biological activities of MFEO. In future, several scientific investigations are required to understand the mechanism of action of MFEO and their bioactive constituents.

Phytochemicals: A Promising Weapon in the Arsenal against Antibiotic-Resistant Bacteria

The extensive usage of antibiotics and the rapid emergence of antimicrobial-resistant microbes (AMR) are becoming important global public health issues. Many solutions to these problems have been proposed, including developing alternative compounds with antimicrobial activities, managing existing antimicrobials, and rapidly detecting AMR pathogens. Among all of them, employing alternative compounds such as phytochemicals alone or in combination with other antibacterial agents appears to be both an effective and safe strategy for battling against these pathogens. The present review summarizes the scientific evidence on the biochemical, pharmacological, and clinical aspects of phytochemicals used to treat microbial pathogenesis. A wide range of commercial products are currently available on the market. Their well-documented clinical efficacy suggests that phytomedicines are valuable sources of new types of antimicrobial agents for future use. Innovative approaches and methodologies for identifying plant-derived products effective against AMR are also proposed in this review.

The Essential Oil and Hydrolats from Myristica fragrans Seeds with Magnesium Aluminometasilicate as Excipient: Antioxidant, Antibacterial, and Anti-inflammatory Activity

Nutmeg (Myristica fragrans) essential oil has antimicrobial, antiseptic, antiparasitic, anti-inflammatory, and antioxidant properties. We have recently demonstrated that hydrodistillation of nutmeg essential oil by applying magnesium aluminometasilicate as an excipient significantly increases both the content and amount of bioactive substances in the oil and hydrolats. In this study, we aimed to compare the antioxidant, antimicrobial, and anti-inflammatory activity of hydrolats and essential oil obtained by hydrodistillation in the presence and absence of magnesium aluminometasilicate as an excipient. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method revealed that magnesium aluminometasilicate did not significantly improved antioxidant activity of both essential oil and hydrolat. Antibacterial efficiency was evaluated by monitoring growth of 15 bacterial strains treated by a range of dilutions of the essential oil and the hydrolats. Essential oil with an excipient completely inhibited the growth of E. faecalis, S. mutans (referent), and P. multocida, whereas the pure oil was only efficient against the latter strain. Finally, the anti-inflammatory properties of the substances were assessed in a fibroblast cell culture treated with viral dsRNR mimetic Poly I:C. The essential oil with an excipient protected cells against Poly I:C-induced necrosis more efficiently compared to pure essential oil. Also, both the oil and the hydrolats with aluminometasilicate were more efficient in preventing IL-6 release in the presence of Poly I:C. Our results show that the use of magnesium aluminometasilicate as an excipient might change and in some cases improve the biological activities of nutmeg essential oil and hydrolats.

Antibacterial Effect of Black Pepper Petroleum Ether Extract against Listeria monocytogenes and Salmonella typhimurium

The aim of the present study was to evaluate the antibacterial effect of black pepper petroleum ether extract (BPPE) against Listeria monocytogenes ATCC 19115 and Salmonella typhimurium ATCC 14028. The results showed that the BPPE had a strong antimicrobial activity against L. monocytogenes and S. typhimurium, and 2-methylene-4,8,8-trimethyl-4-vinyl-bicyclo[5.2.0]nonane (9.36%) and caryophyllene oxide (4.85%) were identified as the two primary components of BPPE. The ability of cells to break down hyperoxide was decreased, and the activities of POD and CAT were inhibited. The activities of key metabolic enzymes shed some light on the biochemical mechanism of aglycon cell growth inhibition, indicating that the energetic metabolism of L. monocytogenes and S. typhimurium was markedly influenced by the BPPE. The contents of key organic acids varied significantly, resulting in remarkable abnormalities in the energetic metabolism of L. monocytogenes and S. typhimurium. Thus, the consecution of energetic metabolism was destroyed by the BPPE, which contributed to metabolic dysfunction, the suppression of gene transcription, and cell death.

Plasma-treated poly(ethylene oxide) nanofibers containing tea tree oil/beta-cyclodextrin inclusion complex for antibacterial packaging

This work describes the effect of cold nitrogen plasma to enhance the antibacterial activity of poly(ethylene oxide) (PEO) nanofibers containing antibacterial agent. Beta-cyclodextrin (β-CD) and tea tree oil (TTO) were used as a host-guest to form water-soluble inclusion complex. The encapsulation efficiency of TTO in inclusion complex could reach 73.23% at 60°C. As antibacterial agent, the inclusion complex was encapsulated into PEO matrix by electrospun. After plasma treatment, the release efficiency of antibacterial agent from PEO nanofibers was improved. As a result, the antibacterial activity of PEO nanofibers was enhanced accordingly. The plasma-treated nanofiber membranes achieved the highest antibacterial activity against Escherichia coli O157:H7, which was tested on the beef for 7d, with inhibition efficiently of 99.99% whether at 4°C or 12°C. The plasma-treated PEO nanofiber membranes containing TTO/β-CD inclusion complex (TTO/β-CD-IC) can prolong the shelf-life of beef, suggesting it has potential application in active food packaging.

Antimicrobial effect of black pepper petroleum ether extract for the morphology of Listeria monocytogenes and Salmonella typhimurium

This study aimed to evaluate the effects of black pepper petroleum extract (BPPE) on pathogenic bacteria. The extraction from black pepper showed intense antimicrobial activity against the Gram-positive Listeria monocytogenes ATCC 19115 and the Gram-negative bacteria Salmonella typhimurium ATCC 14028. The minimum inhibitory concentrations of BPPE against L. monocytogenes and S. typhimurium were 0.625 and 1.25 mg/ml, respectively. Detection of Alkaline phosphatase outside the cell revealed that BPPE treatment destroyed the cell wall integrity. BPPE also altered the membrane integrity, thereby causing leaching of 260 and 280 nm UV-absorbing materials into the medium, particularly, nucleic acids and proteins. Propidium iodide infiltration experiments also indicated that BPPE treatment altered the permeability of bacterial cell membrane. Moreover, Na+/K+-ATPase activity was inhibited by BPPE. And the results of scanning electron microscopy showed that BPPE treatment damaged the morphology of the tested bacteria. These results indicated that BPPE could destroy cell wall integrity, alter the permeability of cell membrane, and inhibit the activity of intracellular enzyme, which could kill bacteria.

Liposome containing nutmeg oil as the targeted preservative against Listeria monocytogenes in dumplings

In this study, the antibacterial activities of nutmeg oil and nutmeg oil encapsulated in liposome were evaluated.