Characterization, Antioxidant and Antibacterial Activity of Essential Oils and Their Encapsulation into Biodegradable Material Followed by Freeze Drying

Abstract

The study assessed the antimicrobial and antioxidant activities of commonly used and commercially available essential oils as an alternative to synthetic preservatives. The plant sources were as follows: lavender (Lavandula angustifolia), tea tree (Melaleuca alternifolia), bergamot (Citrus bergamia) and peppermint (Mentha piperita). The antioxidant activity of essential oils was tested by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods. The microdilution broth susceptibility assay revealed that lavender and bergamot essential oils were more efficient in inhibiting the bacterial growth than other tested oils, with the minimum inhibitory concentration of 5 μg/mL. This study also reports the successful implementation of an electrostatic extrusion technique for encapsulating essential oils into alginate beads, which enables the essential oils to maintain their free radical scavenging ability over time.

Extending the Shelf-Life of Fresh-Cut Green Bean Pods by Ethanol, Ascorbic Acid, and Essential Oils

“…Our results indicated that PMO had higher radical scavenging activity than the results reported by others [ 25 ] who found that IC50 was recorded at 500 µL mL −1 , which is a very high concentration compared to the concentration used in this study (50 µL mL −1 ). Variations in the antioxidant potential of EOs have been reported, primarily due to the presence of conjugated double bond compounds, which serve as hydrogen/electron donors [ 33 ]. PMO and TTO are also able to scavenge free radicals, which are harmful to the body because of their antioxidant function.…”

Trends in Chitosan as a Primary Biopolymer for Functional Films and Coatings Manufacture for Food and Natural Products

“…Positively, their popularity has recently increased in the food industries and research areas since they are recognized as a green alternative of additives that improve the quality of food and perishable products [ 127 ]. Some studies have demonstrated that essential oils contained in different parts of the plant, such as flowers, leaves, fruits, roots, stems, and seeds [ 128 ], exhibit antimicrobial, analgesic, sedative, anti-inflammatory, spasmolytic, anesthetic, and antioxidant effects [ 129 ]. Nowadays, the tuning of characteristics and properties of edible films and coatings by the addition of essential oils in formulations is continuously evaluated.…”

Polymeric Carriers Designed for Encapsulation of Essential Oils with Biological Activity

“…The alginates are used as matrices for oil encapsulation through technologies based on the external, internal, or inverse gelation mechanisms, due to their high gelling capacity, biocompatibility, low toxicity, and capability of forming three-dimensional networks in the presence of calcium ions [ 59 , 60 , 61 , 62 ]. The review by Martins [ 59 ] presented the oil incorporation techniques using alginate as an encapsulating agent, including the dispersion-crosslinking and dispersion–coacervation techniques.…”