In-vitroMycological activity of essential oil fromZingiber zerumbetrhizomes

Natural food preservation with ginger essential oil: Biological properties and delivery systems

Recently, the increasing demand from consumers for preservative-free or naturally preserved foods has forced the food industry to turn to natural herbal and plant-derived preservatives rather than synthetic preservatives to produce safe foods. Essential oils derived from ginger (Zingiber officinale Roscoe) are widely known for their putative health-promoting bioactivities, and this paper covers their extraction methods, chemical composition, and antibacterial and antioxidant activities. Especially, the paper reviews their potential applications in food preservation, including nanoemulsions, emulsions, solid particle encapsulation, and biodegradable food packaging films/coatings. The conclusion drawn is that ginger essential oil can be used not only for direct food preservation but also encapsulated using various delivery forms such as nanoemulsions, Pickering emulsions, and solid particle encapsulation to improve its release control ability. The film of encapsulated ginger essential oil has been proven to be superior to traditional methods in preserving foods such as bread, meat, fish, and fruit.

Healthy Zerumbone: From Natural Sources to Strategies to Improve Its Bioavailability and Oral Administration

Zerumbone is a multifunctional compound with antimicrobial, antitumor, hyperalgesic, antioxidant and anti-inflammatory applications, and constitutes a point molecule for the future synthesis of derivatives with improved efficiency. This monocyclic sesquiterpenoid is found in high content in wild ginger (Zingiber zerumbet Smith), a perennial herb with economic importance as an ornamental as well as a medicinal plant. The presence of zerumbone is a distinctive feature that allows identification and differentiation from other species, not only in Zingiber, but also in Curcuma, Alpinia, Boesenbergia, Ethlingera and Ammomum spp., as well as related families (Costaceaee). To successfully use zerumbone in areas such as medicine, food and agriculture, further research on improving its low solubility and bioavailability, as well as its preservation, is a major current priority. In addition, despite its promising pharmacological activities, preclinical and clinical studies are required to demonstrate and evaluate the in vivo efficacy of zerumbone.

Antifungal Activity of Essential Oil and Plant-Derived Natural Compounds against Aspergillus flavus

Aspergillus flavus is a facultative parasite that contaminates several important food crops at both the pre- and post-harvest stages. Moreover, it is an opportunistic animal and human pathogen that causes aspergillosis diseases. A. flavus also produces the polyketide-derived carcinogenic and mutagenic secondary metabolite aflatoxin, which negatively impacts global food security and threatens human and livestock health. Recently, plant-derived natural compounds and essential oils (EOs) have shown great potential in combatting A. flavus spoilage and aflatoxin contamination. In this review, the in situ antifungal and antiaflatoxigenic properties of EOs are discussed. The mechanisms through which EOs affect A. flavus growth and aflatoxin biosynthesis are then reviewed. Indeed, several involve physical, chemical, or biochemical changes to the cell wall, cell membrane, mitochondria, and related metabolic enzymes and genes. Finally, the future perspectives towards the application of plant-derived natural compounds and EOs in food protection and novel antifungal agent development are discussed. The present review highlights the great potential of plant-derived natural compounds and EOs to protect agricultural commodities and food items from A. flavus spoilage and aflatoxin contamination, along with reducing the threat of aspergillosis diseases.

Comparison of Chemical Composition and Bioactivities of Essential Oils from Fresh and Dry Rhizomes of Zingiber zerumbet (L.) Smith

The chemical constituents and the antioxidant, antimicrobial, and cytotoxic activities of fresh rhizome essential oil (FR-EO) and dry rhizome essential oil (DR-EO) of Zingiber zerumbet (L.) Smith obtained from Southwest China were compared. Zerumbone was the predominant component in both FR-EO and DR-EO (75.0% and 41.9%, respectively). FR-EO, DR-EO, and zerumbone were all demonstrated to have significant antimicrobial capacity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris, with minimum inhibitory concentration (MIC) ranging from 31.25 to 156.25 μg/mL and minimum bactericidal concentration (MBC) ranging from 62.50 to 625.00 μg/mL. Zerumbone showed the strongest antimicrobial potential against all tested microorganisms compared with the fresh and dry rhizome essential oils. FR-EO was found to be more active than DR-EO against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. FR-EO, DR-EO, and zerumbone all showed significant cytotoxic activity against K562, PC-3, and A549 human tumor cell lines in a time- and concentration-dependent manner. Zerumbone exhibited the strongest antiproliferative activity against all tested human tumor cell lines with an IC₅₀ of 4.21–11.09 μg/mL for 72 h incubation, as compared with the fresh and dry rhizome oils. The cytotoxic activity of FR-EO (IC₅₀: 10.48–14.51 μg/mL for 72 h) was found to be significantly higher (p < 0.05) than that of DR-EO (IC₅₀: 13.83–33.24 μg/mL for 72 h). FR-EO, DR-EO, and zerumbone exhibited selective cytotoxic activity to tumor cells, with a significantly low cytotoxicity to normal cells (MRC-5, IC₅₀: 56.98–147.29 μg/mL). However, FR-EO, DR-EO, and zerumbone all exhibited weak free-radical-scavenging activity according to DPPH and ABTS analysis. The findings highlighted in this study show that FR-EO provides appreciably higher content of the bioactive compound, zerumbone, and has higher antimicrobial and cytotoxic properties than DR-EO. Thus, fresh Z. zerumbet rhizome should be preferred in cosmetic, food, and pharmaceutical applications.