Production of clove oil nanoemulsion with rapid and enhanced antimicrobial activity against gram‐positive and gram‐negative bacteria

Abstract

The clove essential oil is a natural antioxidant and antimicrobial with potential applications in many fields of the industry. Nanoemulsions (NEs) with Dp ~135 nm loaded with clove oil (CO) and crodamol were produced by ultrasound. The presence of crodamol in formulation increased droplet size homogeneity and prevented the diffusional degradation with the consequent increase in the stability. The formulation containing 7 mg/mL of CO presented a high surface area and exhibited the lowest minimum inhibitory concentration against gram‐positive and negative bacteria when compared to the free CO, indicating an increase in the antimicrobial activity with the reduction of the droplet size to the nanometric range. Microbial inhibition kinetics showed a fast action of the NE in the inactivation of microorganisms tested. The antioxidant activity was evaluated and both free and nanoemulsified CO remained with antioxidant potential around 90%. The present work produced CO NE with rapid and increased bioactivity, and strong antioxidant potential, becoming an effective and natural alternative for future applications in food formulations. Practical applications The clove essential oil is very interesting to the food and pharmaceutical industries due to the great antimicrobial and antioxidant properties. However, some limitations are related to its hydrophobic character, which limits the application in food formulations due to the low solubility in aqueous media. The essential oils nanoemulsions can be a great alternative to improve the oil solubility, increase the contact area, and protect the bioactive components that are present in the essential oil. Although some studies have been showing the great potential of the essential oil nanoemulsions, the investigation around the reduction of the emulsion droplet diameter, considering the relation between the nanometric range and the increase in the bioavailability and biological activity, is a critical issue to enable their application in food formulations.

Nanoencapsulation of clove oil and study of physicochemical properties, cytotoxic, hemolytic, and antioxidant activities

“…Clove oil, an essential oil extracted from the spice Syzigum aromaticaum , is known for its therapeutic properties such as antioxidant (Gülçin, Elmastaş, & Aboul‐Enein, 2012), anti‐inflammatory (Chaieb et al, 2007), anti‐aging (Hwang, Lin, Ngo, & Yi, 2018), and activity against pathogenic organisms (Li, Zhang, Bhandari, Xu, & Yang, 2020; de Meneses et al, 2019). These activities are attributed to the presence of unsaturated phenolic compounds mainly eugenol, eugenyl acetate and β‐caryophyllene (Figure 1).…”

“…The anti-bacterial property of clove oil nanoemulsion (Shahavi, Hosseini, Jahanshahi, Meyer, & Darzi, 2016) alone/in combination with cinnamon oil (Zhang, Zhang, Fang, & Liu, 2017), anti-fungal properties of eugenol, clove oil nanoemulsion alone/in combination with other spices have been reported (Acosta et al, 2016;Dehghani, Hosseini, Golmakani, Majdinasab, & Esteghlal, 2018;Ortiz, Salgado, Dufresne, & Mauri, 2018). In addition to this, the antioxidant, insecticidal, and antiviral properties were also extensively studied (Cortés-Rojas, de Souza, & Oliveira, 2014;Kouidhi, Zmantar, & Bakhrouf, 2010). However, scanty reports are available for F I G U R E 1 Chemical structure of clove oil components and surfactants used in the study.…”

<p>Novel Clove Essential Oil Nanoemulgel Tailored by Taguchi’s Model and Scaffold-Based Nanofibers: Phytopharmaceuticals with Promising Potential as Cyclooxygenase-2 Inhibitors in External Inflammation</p>

“…Antibacterial effects of clove essential oil nanoemulsion (CEO-NE) formulations were evaluated in comparison with pure CEO. [7][8][9][10] Moreover, CEO was incorporated into the polyvinylpyrrolidone (PVP)-NFs mats using electrospinning process with the assistance of cyclodextrins (CDs) to prepare a fast-dissolving drug delivery system. Then, antifungal activity against oral fungi and cytotoxicity were evaluated.…”

Effect of the use of ethanol and chia mucilage on the obtainment and techno‐functional properties of chia oil nanoemulsions

“…Thus, the use of alternative technologies such as encapsulation is necessary to slow down the oxidation process while maintaining the stability and nutritional properties of chia seed oil and making it possible to be incorporated into food (Alcântara et al., 2019). Among the encapsulation techniques, the nanoemulsion‐based system stands out for its prospective application in oil encapsulation to avoid oxidative degradation, in addition to the ease of addition to food formulation (Meneses et al., 2019; Sharma et al, 2019). Nanoemulsions have several advantages compared to other encapsulation techniques such as good water dispersibility, better (more translucent) optical properties, better physical stability (against gravitational separation and particle aggregation), and increased bioavailability of the lipophilic bioactive compounds incorporated into them (Firoozi et al, 2020; Karthik et al., 2017).…”