Physico-Chemical Study of Curcumin and Its Application in O/W/O Multiple Emulsion

Abstract

Curcuma is a world-renowned herb known for its immense health benefits. In this study, physicochemical analyses were performed on the curcumin standard sample and curcumin multiple emulsions. The emulsions were analysed for thermal and structural stability for 21 days. Confocal laser microscopy (CLSM) was performed in order to observe the emulsion encapsulation. Modulated differential scanning calorimetry (MDSC) and HPLC methods revealed a variety of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin) in the investigated curcumin standard. In addition, the MDSC method was found to be suitable and comparable to HPLC for determining the curcuminoid substances. The analysis of the curcumin release revealed a value of 0.18 w.% after 14 days as the equilibrium value. Furthermore, an increase in the sizes of the emulsions was observed at the end of the 21-day study. The emulsion stability index (ESI) was used to measure the stability of multiple emulsions. The ESI reached 55.8% between 7 and 21 days later. Nano droplets of the oil phase loaded with dispersed curcumin particles captured inside the water-based carboxymethylcellulose micelles were clearly observed by CLSM.

Curcuma particle size evolution by application of bead milling process and curcuminoids content determination

“…Based on curcumin standard calibration range 1–50 μg mL −1 , curcuminoids content in curcuma powder was determined to be 14.16 ± 0.04 mg g −1 , i.e ., 1.42 wt.%. This was in accordance with the fact that curcumin represented the highest amount ratio of all curcuminoids in curcuma powder (Opustilová et al ., 2023), as evident from the difference relative to the DSC curcumin content. However, precision of UV–VIS detection could be reduced due to other colour interfering pigments which can be present in the sample (Kotra et al ., 2019).…”

“…For curcuma powder, two endothermic peaks related to the melting process were observed between 160 and 170 °C. Peak detected around 170 °C (onset temperature T o = 165.9 °C, and peak temperature T p = 169.4 °C with enthalpy of fusion Δ H = 1.69 J g −1 ) could be ascribed to curcumin as the main curcuminoid substance (Jadhav et al ., 2007; Opustilová et al ., 2023). This peak was characterised by the following thermal parameters: T o = 165.9 °C, T p = 169.4 °C and Δ H = 1.69 J g −1 .…”

“…From quantity point of view, there can be a large difference in curcumin content among individual samples (lines) of Curcuma longa . Other major curcuminoids (phenolic secondary metabolites) are demethoxycurcumin, bisdemethoxycurcumin and cyclocurcumin (Tayyem et al ., 2006; Green et al ., 2008; Hayakawa et al ., 2011a, 2011b; Amalraj et al ., 2017; Kotra et al ., 2019; Opustilová et al ., 2023). Among all curcuminoids, curcumin is reported as the most potent compound for its functional and nutraceutical activities (Ali et al ., 2014; Peram et al ., 2017; Mahjoob & Stochaj, 2021).…”

Curcumin: Overview of Extraction Methods, Health Benefits, and Encapsulation and Delivery Using Microemulsions and Nanoemulsions

“…Thermochemical methods were also very recently introduced as an option for curcumin identification. Opustilova et al [104] managed to apply modulated differential scanning calorimetry (MDSC) for the identification of curcumin in its solid state. The characteristic melting point of curcumin crystals was indicated by an endothermic peak with an onset temperature of 168.92 ± 0.11 • C, a peak temperature of 174.83 ± 0.07 • C, and a specific enthalpy of fusion equal to 80.83 ± 0.15 J/g [104].…”

Single-Step Formation of Pickering Double Emulsions by Exploiting Differential Wettability of Particles

“…Double emulsions (DEs), which can be thought of as emulsions within emulsions consist of large droplets which in turn contain one or more smaller nested droplets . The DEs are particularly valuable to a variety of disciplines, including pharmaceuticals, cosmetics, agricultural, and food technology. − The creation of particle-stabilized DEs is advantageous, as it offers long-term protection of the encapsulated species while also allowing the release of these species in response to an external stimulus. However, the lack of straightforward and scalable techniques to create DEs that exhibit excellent stability limits the practical applications of these high interface systems.…”