Formulation of Menthol-Loaded Nanostructured Lipid Carriers to Enhance Its Antimicrobial Activity for Food Preservation

Abstract

Purpose: Due to the antimicrobial property, menthol have significant potential for food preservation and foodstuff shelf life improvement. Nevertheless, menthol instability, insolubility, and rapid crystallization in aqueous media make it unsuitable for used in food products. This work was aimed to prepare menthol-loaded nanostructured lipid carriers (NLCs) to enhance its antimicrobial activity. Methods: Morphology, particle size and size distribution, encapsulation efficiency percent (EE%), and physical stability of the optimized formulation, prepared by hot melt homogenization method, were characterized by scanning electron microscopy, particle size analyzing, gas chromatography, and X-ray diffraction (XRD) methods. Minimum inhibitory concentration and minimum bactericidal concentration of menthol-loaded NLCs were evaluated and compared with conventional menthol emulsion against various Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative bacteria (Escherichia coli), as well as one fungus (Candida albicans). Results: Menthol-loaded NLCs were spherically shaped nanosized (115.6 nm) particles with narrow size distribution (PDI = 0.2), suitable menthol EE% (98.73%), and appropriate physical stability after 90 days of storage period. XRD results indicated that menthol was in the amorphous form in the nanoparticles matrix. Antibacterial assay results revealed that the menthol-loaded NLCs exhibited significantly higher in vitro antimicrobial property than conventional menthol emulsion. The results also indicated that menthol-loaded NLCs had better effect on fungi than bacteria, and furthermore, antibacterial efficiency on Gram-positive bacteria was higher than Gram-negative bacteria. Conclusion: In conclusion, NLCs could be a promising carrier for improvement of antimicrobial activity and preservation efficacy of essential oils in foodstuffs.

Essential Oils: Pharmaceutical Applications and Encapsulation Strategies into Lipid-Based Delivery Systems

“…The importance of the incorporation of this EO into DDS has been highlighted, instead, by in vivo studies on infected wound models: the wound-healing rate was accelerated due to the ability of the EO-NLC to decrease the bacterial count, in addition to the intrinsic anti-inflammatory property of the EO, which was also improved by the NLC structure [ 203 ]. The antimicrobial activity of menthol-loaded NLC, with mean size of 115 nm and high EO encapsulation efficiency (98.73%), was investigated by Piran et al [ 204 ]. In particular, menthol-loaded NLC showed higher antibacterial activity against fungi and Gram-positive bacteria compared to the EO emulsion: NLC were able to inhibit the growth of Staphylococcus aureus , Bacillus cereus , Escherichia coli, and C. albicans at concentration of 125, 250, 500, and 78 µg/mL, respectively, while the corresponding MIC values for menthol emulsion were 1000, 2000, 2000, and 156 µg/mL.…”

Nanoscale Drug Delivery Systems: From Medicine to Agriculture

“…In the cosmetic industry, they have been used to encapsulate UV blockers such as 3,4,5-trimethoxybenzoylchitin (TMBC), 2-hydroxy-4-methoxybenzophenone and vitamin E for use as sunscreen (Wissing and Müller, 2001;Song and Liu, 2005). In the food industry, SLNs have been used to encapsulate antioxidant molecules such as ferulic acid and tocopherol (Oehlke et al, 2017), natural antimicrobial compounds (Piran et al, 2017), and hydrophobic flavoring agents (Eltayeb et al, 2013).…”

Towards safe and sustainable innovation in nanotechnology: State-of-play for smart nanomaterials

“…Likewise, nanoencapsulates are used in some of the so called ‘deodorants on request’ to release a fragrance or a bacteria growth inhibitor in response to the changed pH, temperature or moisture of the skin ( Keegan et al, 2012 ; Hofmeister et al, 2014 ). In the food sector nanoencapsulates have been used for different purposes ( Jafari, 2020 ), for instance to prevent nutrients, antioxidant molecules such as ferulic acid and tocopherol ( Oehlke et al, 2017 ), hydrophobic flavouring agents ( Fucinos et al, 2014 ) or natural antimicrobial ingredients ( Piran et al, 2017 ) from breaking down in the body and to allow a slow release at a target specific location or at the presence of a specific molecule. Lowry et al (2019) and Kah et al (2019) have recently reviewed the potential for developing smart nanostructures enabling a targeted (in terms of time, location, dose and form) release and delivery of water, nutrients, agrochemicals and antimicrobials to crops, in order to improve the use efficiency as well as to preserve soil integrity and function.…”

“…In the food sector nanoencapsulates have been used for different purposes ( Jafari, 2020 ), for instance to prevent nutrients, antioxidant molecules such as ferulic acid and tocopherol ( Oehlke et al, 2017 ), hydrophobic flavouring agents ( Fucinos et al, 2014 ) or natural antimicrobial ingredients ( Piran et al, 2017 ) from breaking down in the body and to allow a slow release at a target specific location or at the presence of a specific molecule.…”