Influence of type of natural emulsifier and microfluidization conditions on Capsicum oleoresin nanoemulsions properties and stability

Abstract

There is a growing interest in the fabrication of colloidal delivery systems for bioactive compounds assembled from natural ingredients, particularly plant-based ones. In this study, Capsicum oleoresin was encapsulated within oil-in-water nanoemulsions by high-pressure microfluidization from natural emulsifiers: whey protein (WP), pea protein (PP), quillaja saponin (QS), and sunflower lecithin (SL). The influence of emulsifier, concentration, and microfluidization conditions (pressure and number of passes), on particle diameter and zeta-potential of nanoemulsions was evaluated. Particle diameter decreased with increasing homogenization pressure and number of passes. All emulsifiers were capable of forming charged droplets with dimensions in the nanometer range at sufficiently high concentrations. The stability of nanoemulsions to environmental stresses (pH, ionic strength, and heating) and storage was studied. The pH and salt stabilities were dependent on the emulsifier type. Overall, natural emulsifiers were effective in producing Capsicum oleoresin-loaded nanoemulsions with small particle size and capsaicin stability. 1 | INTRODUCTION Capsicum peppers are widely used as savory food additives and health-promoting nutritional components, such as vitamin C, pheno

Saponins as Natural Emulsifiers for Nanoemulsions

“…However, on low pH and high salt concentrations, destabilization was observed due to the reduction of the electrostatic repulsion, which is the stability mechanism of quillaja, generated between the highly negatively charged droplets. The range of environmental stability was corroborated several times in other works for this saponin. ,,,, …”

“…The range of environmental stability was corroborated several times in other works for this saponin. 2,15,71,78,79 Regarding regulatory aspects, quillaja extracts have been approved in several commissions. Its use as a food additive was allowed under European Commission regulation number 1129/2011/EC.…”

“… Results for the mean particle diameter varying the percentage of quillaja saponin in 10/90 of oil/water nanoemulsions: (a) Reprinted from Aguiar et al, 78 Copyright (2021), with permission from John Wiley and Sons, (b) Reprinted from Lv et al., 76 Copyright (2018), with permission from the American Chemical Society, (c) Reprinted from Luo et al, 75 Copyright (2017), with permission from Elsevier (WPI corresponding to whey protein isolate), and (d) Reprinted from Yang et al, 74 Copyright (2013), with permission from Elsevier. …”

“…The range of environmental stability was corroborated several times in other works for this saponin. 2 , 15 , 71 , 78 , 79 …”

Astaxanthin-Loaded Pickering Emulsions Stabilized by Nanofibrillated Cellulose: Impact on Emulsion Characteristics, Digestion Behavior, and Bioaccessibility

“…This could be due to the closer packing of the NFC at the interfaces of the emulsion droplets, resulting in stronger electrostatic repulsion between them, which could prevent them from coalescing or aggregating. Consequently, the strong electrostatic repulsion at the droplet interface may also allow the emulsions to stabilize over longer periods of time [ 37 , 38 ]. However, a significant ( p ≤ 0.05) increase in ζ-potential values was observed in all emulsions after 30 days of storage, which may be due to the degradation of AX [ 14 ].…”