GC-MS Profiling of Naturally Extracted Essential Oils: Antimicrobial and Beverage Preservative Actions

Enhancing Antimicrobial Activity of Thyme Essential Oil Through Cellulose Nano Crystals-Stabilized Pickering Emulsions

Essential oils (EOs), such as thyme essential oil (TEO), are widely known for their antimicrobial properties; however, their direct application in food systems is limited due to their poor stability, which affects their efficacy. This study aims to improve the stability and antimicrobial efficacy of TEO by encapsulating it in Pickering emulsions stabilized with cellulose nanocrystals (CNC). Two formulations of Pickering emulsions with 5% and 10% TEO were prepared and compared to traditional surfactant-based emulsions. The stability of the emulsions was assessed over 21 days, and particle size, zeta potential, Raman spectroscopy, and FTIR were used for characterization. The antimicrobial activity was tested against several foodborne pathogens, with minimum inhibitory concentration (MIC) values determined. The 10% TEO Pickering emulsion showed antimicrobial activity, with MIC50 values of 4096 µg/mL against Staphylococcus aureus and Escherichia coli, while the 5% TEO formulation had no effect at MIC50 > 8192 µg/mL. The CNC-stabilized Pickering emulsions exhibited superior stability, showing no phase separation over 21 days. The findings suggest that CNC-stabilized Pickering emulsions are effective at improving the stability and antimicrobial performance of TEO, making them a promising natural preservative for food packaging and safety. Further research is recommended to optimize the formulation and broaden TEO's application in food preservation.

Plants with Antimicrobial Activity against Escherichia coli, a Meta-Analysis for Green Veterinary Pharmacology Applications

Antimicrobial resistance (AMR) poses a critical global health threat, necessitating innovative strategies to combat infectious diseases. Plants and their extracts offer alternatives/support to traditional antibiotics, and their diverse phytocomplexes with antimicrobial properties can be exploited. The Mediterranean hosts a high number of biodiverse plant species known for their bioactive compounds. This study focuses on identifying plant species and phytochemical constituents with antimicrobial activity against Escherichia coli (E. coli). Utilizing a systematic literature review and meta-analysis approach, we screened 3037 entries, yielding 70 studies suitable for MIC (minimum inhibitory concentration) annotation. The results highlighted Lavandula spp., Plectranthus spp. and Lupinus jaimehintoniana as the most effective plants with average MICs of, respectively, 0.144 mg/mL, 0.260 mg/mL, and 0.140 mg/mL. These results might help to fight AMR via the discovery of complementary natural antimicrobial agents to support the development of green veterinary pharmacology. Further exploration of these resources promises valuable insights for future support to antimicrobial strategies.

Activity and safety evaluation of natural preservatives

Synthetic preservatives are widely used in the food industry to control spoilage and growth of pathogenic microorganisms, inhibit lipid oxidation processes and extend the shelf life of food. However, synthetic preservatives have some side effects that can lead to poisoning, cancer and other degenerative diseases. With the improvement of living standards, people are developing safer natural preservatives to replace synthetic preservatives, including plant derived preservatives (polyphenols, essential oils, flavonoids), animal derived preservatives (lysozyme, antimicrobial peptide, chitosan) and microorganism derived preservatives (nisin, natamycin, ε-polylysine, phage). These natural preservatives exert antibacterial effects by disrupting microbial cell wall/membrane structures, interfering with DNA/RNA replication and transcription, and affecting protein synthesis and metabolism. This review summarizes the natural bioactive compounds (polyphenols, flavonoids and terpenoids, etc.) in these preservatives, their antioxidant and antibacterial activities, and safety evaluation in various products.

A Scoping Review of the Clinical Evidence for the Health Benefits of Culinary Doses of Herbs and Spices for the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is a growing global health problem. Evidence suggests that diets rich in phytochemical-containing herbs and spices can contribute to reducing the risk of chronic diseases. This review assesses the scope of evidence supporting the use of herbs and spices in the diet for the prevention or treatment of MetS and its associated health conditions. A search of the PubMed, Scopus and Google Scholar databases was carried out to assess the available clinical evidence for culinary doses of commonly used herbs and spices. Trials that were measuring health factors related to metabolic disorders in healthy individuals, or the health of individuals with MetS or associated diseases, were included. Out of a total of 1738 papers identified, there were 142 relevant studies on black pepper, chilli, cardamom, cinnamon, coriander, cumin, fennel, fenugreek, garlic, ginger, nigella seed, rosemary, sage and turmeric. No relevant research was found for cloves, mint, oregano, parsley or thyme. Cinnamon, fenugreek and ginger were the herbs/spices with the most published trials on them and that showed promise for glycaemic control. Cardamom appears to have potential to reduce inflammatory markers, and cinnamon, ginger and turmeric to reduce blood lipids. Patients with type 2 diabetes were the population most likely to be included in studies, but the preventative benefits of herbs/spices in healthy populations were also investigated, particularly for chilli, ginger and cinnamon. There is evidence for the beneficial effect of culinary doses of many common herbs/spices in the prevention and treatment of MetS and associated disorders.

Harnessing the Power of Plants: A Green Factory for Bioactive Compounds

The plant kingdom has long been revered for its complex biochemical pathways, which give rise to an incredible array of bioactive compounds [...].

Validation of Broth Macrodilution Volatilization Method for Testing of Essential Oils in Liquid and Vapor Phase: Chemical Composition, Cytotoxicity, and Antibacterial Effect of Indian Medicinal Plants against Pneumonia-Causing Pathogens

Essential oils (EOs) have great potential in inhalation therapy for the treatment of respiratory infections. However, innovative methods for evaluation of antimicrobial activity of their vapors are still needed. The current study reports validation of the broth macrodilution volatilization method for assessment of the antibacterial properties of EOs and shows the growth-inhibitory effect of Indian medicinal plants against pneumonia-causing bacteria in liquid and vapor phase. Among all samples tested, Trachyspermum ammi EO exhibits the strongest antibacterial effect against Haemophilus influenzae, with minimum inhibitory concentrations of 128 and 256 µg/mL in the liquid and vapor phases, respectively. Furthermore, Cyperus scariosus EO is found to be nontoxic to normal lung fibroblasts assessed by modified thiazolyl blue tetrazolium bromide assay. Chemical analysis performed using gas chromatography-mass spectrometry identified α-citral, cyperotundone, and thymol as the main constituents of Cymbopogon citratus, C. scariosus, and T. ammi EOs, respectively. In addition, β-cymene is identified as the major compound of T. ammi EO vapors when analyzed using solid-phase microextraction and gas-tight syringe sampling techniques. This study demonstrates the validity of the broth macrodilution volatilization method for antimicrobial screening of volatile compounds in the vapor phase and suggests the therapeutic potential of Indian medicinal plants in inhalation therapy.