Physicochemical and Antimicrobial Properties of Oleoresin Capsicum Nanoemulsions Formulated with Lecithin and Sucrose Monopalmitate

Abstract

Oleoresin capsicum (OC) is an extract of chili pepper containing the active agent capsaicin. In this study, OC-loaded nanoemulsions were prepared by microfluidization and stabilized with sucrose monopalmitate (SMP) and lecithin. The difference in size and distribution of droplets determined the nanoemulsion behavior mainly due to the interaction of emulsifiers between oil and aqueous phase. The hydrophilic interaction between SMP and aqueous phase and the hydrophobic interaction between lecithin and oil phase were monitored with NMR relaxometry. OC nanoemulsion fabricated with SMP showed the best transparency with smallest droplet size (around 34 nm) and stable with glycerol after 28 days at ambient storage. Lecithin containing nanoemulsions showed improved bioactivity as showing antioxidant (0.82 mg DPPH/L) and antimicrobial (3.40 log for Escherichia coli and 4.37 log for Staphylococcus aureus) activity. Finally, results have important implications to determine the appropriate formulation conditions for OC with food-grade surfactants to be used in pharmaceuticals and food industry.

An overview of nanoemulsion characterization via atomic force microscopy

“…With similar reason, AFM measurement gave a larger droplet size of cinnamaldehyde nanoemulsion with Tween 80 than laser dynamic light scattering (Ji et al 2021). Similarly, Akbas, Soyler, and Oztop (2018) and Akbas, Soyler, and Oztop (2019) found that the droplet size of capsicum nanoemulsions with Tween 80 and glycerol, and sucrose monopalmitate (or lecithin) and glycerol, respectively, measured by AFM, was much larger than that observed under TEM. Together with sample preparation, the weak adsorption of the smallest dispersed droplets to the mica surface and the increase in size of nanoparticles caused by the broadening effect of the tip being in contact with soft or sticky biomaterials, were the reasons for the larger droplet size of lemongrass essential oil nanoemulsions with sodium alginate and Tween 80 observed in AFM images, compared with the value determined by TEM or dynamic light scattering (Salvia-Trujillo et al 2013).…”

The Effect of Polymers on Drug Release Kinetics in Nanoemulsion In Situ Gel Formulation

“…Figure 2. Atomic force microscopy [ 24 ] was used to confirm the size and shape of the particles (Figure 3).…”

Antioxidant potential and factors influencing the content of antioxidant compounds of pepper: A review with current knowledge

“…Another potential novel application of pepper antioxidants is in the food and pharmaceutical industries. For instance, Akbas et al (2019) used food-grade surfactants, such as sucrose monopalmitate or lecithin, to formulate oleoresin capsicum-loaded nanoemulsions and observed that lecithin-containing nanoemulsions exhibited higher antioxidant and antimicrobial activity, whereas the sucrose monopalmitate-containing nanoemulsions were more transparent, had smaller drop size (about 34 nm), and increased stability when stored with glycerol at ambient temperature for 28 days. Similarly, the acetone extract of pepper (C. annuum) with high antioxidant activity, antimicrobial activity, and phenolics and vitamin C contents was also found to be a potential pharmaceutical coloring and preservative additive in multivitamin candy formulations for kids (Al Khalaf et al, 2020).…”